dependencies/assimp/include/assimp/.editorconfig

@@ -0,0 +1,8 @@
+# See <http://EditorConfig.org> for details
+
+[*.{h,hpp,inl}]
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_size = 4
+indent_style = space

dependencies/assimp/include/assimp/BaseImporter.h

@@ -0,0 +1,418 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Definition of the base class for all importer worker classes. */
+#ifndef INCLUDED_AI_BASEIMPORTER_H
+#define INCLUDED_AI_BASEIMPORTER_H
+
+#include "Exceptional.h"
+
+#include <vector>
+#include <set>
+#include <map>
+#include <assimp/types.h>
+#include <assimp/ProgressHandler.hpp>
+#include <assimp/ai_assert.h>
+
+struct aiScene;
+struct aiImporterDesc;
+
+namespace Assimp    {
+
+class Importer;
+class IOSystem;
+class BaseProcess;
+class SharedPostProcessInfo;
+class IOStream;
+
+// utility to do char4 to uint32 in a portable manner
+#define AI_MAKE_MAGIC(string) ((uint32_t)((string[0] << 24) + \
+    (string[1] << 16) + (string[2] << 8) + string[3]))
+
+
+// ---------------------------------------------------------------------------
+/** FOR IMPORTER PLUGINS ONLY: The BaseImporter defines a common interface
+ *  for all importer worker classes.
+ *
+ * The interface defines two functions: CanRead() is used to check if the
+ * importer can handle the format of the given file. If an implementation of
+ * this function returns true, the importer then calls ReadFile() which
+ * imports the given file. ReadFile is not overridable, it just calls
+ * InternReadFile() and catches any ImportErrorException that might occur.
+ */
+class ASSIMP_API BaseImporter {
+    friend class Importer;
+
+private:
+    /* Pushes state into importer for the importer scale */
+    virtual void UpdateImporterScale( Importer* pImp );
+
+public:
+
+    /** Constructor to be privately used by #Importer */
+    BaseImporter() AI_NO_EXCEPT;
+
+    /** Destructor, private as well */
+    virtual ~BaseImporter();
+
+    // -------------------------------------------------------------------
+    /** Returns whether the class can handle the format of the given file.
+     *
+     * The implementation should be as quick as possible. A check for
+     * the file extension is enough. If no suitable loader is found with
+     * this strategy, CanRead() is called again, the 'checkSig' parameter
+     * set to true this time. Now the implementation is expected to
+     * perform a full check of the file structure, possibly searching the
+     * first bytes of the file for magic identifiers or keywords.
+     *
+     * @param pFile Path and file name of the file to be examined.
+     * @param pIOHandler The IO handler to use for accessing any file.
+     * @param checkSig Set to true if this method is called a second time.
+     *   This time, the implementation may take more time to examine the
+     *   contents of the file to be loaded for magic bytes, keywords, etc
+     *   to be able to load files with unknown/not existent file extensions.
+     * @return true if the class can read this file, false if not.
+     */
+    virtual bool CanRead(
+        const std::string& pFile,
+        IOSystem* pIOHandler,
+        bool checkSig
+        ) const = 0;
+
+    // -------------------------------------------------------------------
+    /** Imports the given file and returns the imported data.
+     * If the import succeeds, ownership of the data is transferred to
+     * the caller. If the import fails, NULL is returned. The function
+     * takes care that any partially constructed data is destroyed
+     * beforehand.
+     *
+     * @param pImp #Importer object hosting this loader.
+     * @param pFile Path of the file to be imported.
+     * @param pIOHandler IO-Handler used to open this and possible other files.
+     * @return The imported data or NULL if failed. If it failed a
+     * human-readable error description can be retrieved by calling
+     * GetErrorText()
+     *
+     * @note This function is not intended to be overridden. Implement
+     * InternReadFile() to do the import. If an exception is thrown somewhere
+     * in InternReadFile(), this function will catch it and transform it into
+     *  a suitable response to the caller.
+     */
+    aiScene* ReadFile(
+        Importer* pImp,
+        const std::string& pFile,
+        IOSystem* pIOHandler
+        );
+
+    // -------------------------------------------------------------------
+    /** Returns the error description of the last error that occurred.
+     * @return A description of the last error that occurred. An empty
+     * string if there was no error.
+     */
+    const std::string& GetErrorText() const {
+        return m_ErrorText;
+    }
+
+    // -------------------------------------------------------------------
+    /** Called prior to ReadFile().
+     * The function is a request to the importer to update its configuration
+     * basing on the Importer's configuration property list.
+     * @param pImp Importer instance
+     */
+    virtual void SetupProperties(
+        const Importer* pImp
+        );
+
+    // -------------------------------------------------------------------
+    /** Called by #Importer::GetImporterInfo to get a description of
+     *  some loader features. Importers must provide this information. */
+    virtual const aiImporterDesc* GetInfo() const = 0;
+
+    /**
+     * Will be called only by scale process when scaling is requested.
+     */
+    virtual void SetFileScale(double scale)
+    {
+        fileScale = scale;
+    }
+
+    virtual double GetFileScale() const
+    {
+        return fileScale;
+    }
+
+    enum ImporterUnits {
+        M,
+        MM,
+        CM,
+        INCHES,
+        FEET
+    };
+
+    /**
+     * Assimp Importer
+     * unit conversions available 
+     * if you need another measurment unit add it below.
+     * it's currently defined in assimp that we prefer meters.
+     * */
+    std::map<ImporterUnits, double> importerUnits = {
+        {ImporterUnits::M, 1},
+        {ImporterUnits::CM, 0.01},
+        {ImporterUnits::MM, 0.001},
+        {ImporterUnits::INCHES, 0.0254},
+        {ImporterUnits::FEET, 0.3048}
+    };
+
+    virtual void SetApplicationUnits( const ImporterUnits& unit )
+    {
+        importerScale = importerUnits[unit];
+        applicationUnits = unit;
+    }
+
+    virtual const ImporterUnits& GetApplicationUnits()
+    {
+        return applicationUnits;
+    }
+
+    // -------------------------------------------------------------------
+    /** Called by #Importer::GetExtensionList for each loaded importer.
+     *  Take the extension list contained in the structure returned by
+     *  #GetInfo and insert all file extensions into the given set.
+     *  @param extension set to collect file extensions in*/
+    void GetExtensionList(std::set<std::string>& extensions);
+    
+protected:    
+    ImporterUnits applicationUnits = ImporterUnits::M;
+    double importerScale = 1.0;
+    double fileScale = 1.0;
+
+
+
+    // -------------------------------------------------------------------
+    /** Imports the given file into the given scene structure. The
+     * function is expected to throw an ImportErrorException if there is
+     * an error. If it terminates normally, the data in aiScene is
+     * expected to be correct. Override this function to implement the
+     * actual importing.
+     * <br>
+     *  The output scene must meet the following requirements:<br>
+     * <ul>
+     * <li>At least a root node must be there, even if its only purpose
+     *     is to reference one mesh.</li>
+     * <li>aiMesh::mPrimitiveTypes may be 0. The types of primitives
+     *   in the mesh are determined automatically in this case.</li>
+     * <li>the vertex data is stored in a pseudo-indexed "verbose" format.
+     *   In fact this means that every vertex that is referenced by
+     *   a face is unique. Or the other way round: a vertex index may
+     *   not occur twice in a single aiMesh.</li>
+     * <li>aiAnimation::mDuration may be -1. Assimp determines the length
+     *   of the animation automatically in this case as the length of
+     *   the longest animation channel.</li>
+     * <li>aiMesh::mBitangents may be NULL if tangents and normals are
+     *   given. In this case bitangents are computed as the cross product
+     *   between normal and tangent.</li>
+     * <li>There needn't be a material. If none is there a default material
+     *   is generated. However, it is recommended practice for loaders
+     *   to generate a default material for yourself that matches the
+     *   default material setting for the file format better than Assimp's
+     *   generic default material. Note that default materials *should*
+     *   be named AI_DEFAULT_MATERIAL_NAME if they're just color-shaded
+     *   or AI_DEFAULT_TEXTURED_MATERIAL_NAME if they define a (dummy)
+     *   texture. </li>
+     * </ul>
+     * If the AI_SCENE_FLAGS_INCOMPLETE-Flag is <b>not</b> set:<ul>
+     * <li> at least one mesh must be there</li>
+     * <li> there may be no meshes with 0 vertices or faces</li>
+     * </ul>
+     * This won't be checked (except by the validation step): Assimp will
+     * crash if one of the conditions is not met!
+     *
+     * @param pFile Path of the file to be imported.
+     * @param pScene The scene object to hold the imported data.
+     * NULL is not a valid parameter.
+     * @param pIOHandler The IO handler to use for any file access.
+     * NULL is not a valid parameter. */
+    virtual void InternReadFile(
+        const std::string& pFile,
+        aiScene* pScene,
+        IOSystem* pIOHandler
+        ) = 0;
+
+public: // static utilities
+
+    // -------------------------------------------------------------------
+    /** A utility for CanRead().
+     *
+     *  The function searches the header of a file for a specific token
+     *  and returns true if this token is found. This works for text
+     *  files only. There is a rudimentary handling of UNICODE files.
+     *  The comparison is case independent.
+     *
+     *  @param pIOSystem IO System to work with
+     *  @param file File name of the file
+     *  @param tokens List of tokens to search for
+     *  @param numTokens Size of the token array
+     *  @param searchBytes Number of bytes to be searched for the tokens.
+     */
+    static bool SearchFileHeaderForToken(
+        IOSystem* pIOSystem,
+        const std::string&  file,
+        const char** tokens,
+        unsigned int numTokens,
+        unsigned int searchBytes = 200,
+        bool tokensSol = false,
+        bool noAlphaBeforeTokens = false);
+
+    // -------------------------------------------------------------------
+    /** @brief Check whether a file has a specific file extension
+     *  @param pFile Input file
+     *  @param ext0 Extension to check for. Lowercase characters only, no dot!
+     *  @param ext1 Optional second extension
+     *  @param ext2 Optional third extension
+     *  @note Case-insensitive
+     */
+    static bool SimpleExtensionCheck (
+        const std::string& pFile,
+        const char* ext0,
+        const char* ext1 = NULL,
+        const char* ext2 = NULL);
+
+    // -------------------------------------------------------------------
+    /** @brief Extract file extension from a string
+     *  @param pFile Input file
+     *  @return Extension without trailing dot, all lowercase
+     */
+    static std::string GetExtension (
+        const std::string& pFile);
+
+    // -------------------------------------------------------------------
+    /** @brief Check whether a file starts with one or more magic tokens
+     *  @param pFile Input file
+     *  @param pIOHandler IO system to be used
+     *  @param magic n magic tokens
+     *  @params num Size of magic
+     *  @param offset Offset from file start where tokens are located
+     *  @param Size of one token, in bytes. Maximally 16 bytes.
+     *  @return true if one of the given tokens was found
+     *
+     *  @note For convenience, the check is also performed for the
+     *  byte-swapped variant of all tokens (big endian). Only for
+     *  tokens of size 2,4.
+     */
+    static bool CheckMagicToken(
+        IOSystem* pIOHandler,
+        const std::string& pFile,
+        const void* magic,
+        unsigned int num,
+        unsigned int offset = 0,
+        unsigned int size   = 4);
+
+    // -------------------------------------------------------------------
+    /** An utility for all text file loaders. It converts a file to our
+     *   UTF8 character set. Errors are reported, but ignored.
+     *
+     *  @param data File buffer to be converted to UTF8 data. The buffer
+     *  is resized as appropriate. */
+    static void ConvertToUTF8(
+        std::vector<char>& data);
+
+    // -------------------------------------------------------------------
+    /** An utility for all text file loaders. It converts a file from our
+     *   UTF8 character set back to ISO-8859-1. Errors are reported, but ignored.
+     *
+     *  @param data File buffer to be converted from UTF8 to ISO-8859-1. The buffer
+     *  is resized as appropriate. */
+    static void ConvertUTF8toISO8859_1(
+        std::string& data);
+
+    // -------------------------------------------------------------------
+    /// @brief  Enum to define, if empty files are ok or not.
+    enum TextFileMode { 
+        ALLOW_EMPTY,
+        FORBID_EMPTY 
+    };
+
+    // -------------------------------------------------------------------
+    /** Utility for text file loaders which copies the contents of the
+     *  file into a memory buffer and converts it to our UTF8
+     *  representation.
+     *  @param stream Stream to read from.
+     *  @param data Output buffer to be resized and filled with the
+     *   converted text file data. The buffer is terminated with
+     *   a binary 0.
+     *  @param mode Whether it is OK to load empty text files. */
+    static void TextFileToBuffer(
+        IOStream* stream,
+        std::vector<char>& data,
+        TextFileMode mode = FORBID_EMPTY);
+
+    // -------------------------------------------------------------------
+    /** Utility function to move a std::vector into a aiScene array
+    *  @param vec The vector to be moved
+    *  @param out The output pointer to the allocated array.
+    *  @param numOut The output count of elements copied. */
+    template<typename T>
+    AI_FORCE_INLINE
+    static void CopyVector(
+        std::vector<T>& vec,
+        T*& out,
+        unsigned int& outLength)
+    {
+        outLength = unsigned(vec.size());
+        if (outLength) {
+            out = new T[outLength];
+            std::swap_ranges(vec.begin(), vec.end(), out);
+        }
+    }
+
+protected:
+    /// Error description in case there was one.
+    std::string m_ErrorText;
+    /// Currently set progress handler.
+    ProgressHandler* m_progress;
+};
+
+
+
+} // end of namespace Assimp
+
+#endif // AI_BASEIMPORTER_H_INC

dependencies/assimp/include/assimp/Bitmap.h

@@ -0,0 +1,125 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file Bitmap.h
+ *  @brief Defines bitmap format helper for textures
+ *
+ * Used for file formats which embed their textures into the model file.
+ */
+
+#ifndef AI_BITMAP_H_INC
+#define AI_BITMAP_H_INC
+
+#include "defs.h"
+#include <stdint.h>
+#include <cstddef>
+
+struct aiTexture;
+
+namespace Assimp {
+
+class IOStream;
+
+class ASSIMP_API Bitmap {
+protected:
+
+    struct Header {
+        uint16_t type;
+        uint32_t size;
+        uint16_t reserved1;
+        uint16_t reserved2;
+        uint32_t offset;
+
+        // We define the struct size because sizeof(Header) might return a wrong result because of structure padding.
+        // Moreover, we must use this ugly and error prone syntax because Visual Studio neither support constexpr or sizeof(name_of_field).
+        static const std::size_t header_size =
+            sizeof(uint16_t) + // type
+            sizeof(uint32_t) + // size
+            sizeof(uint16_t) + // reserved1
+            sizeof(uint16_t) + // reserved2
+            sizeof(uint32_t);  // offset
+    };
+
+    struct DIB {
+        uint32_t size;
+        int32_t width;
+        int32_t height;
+        uint16_t planes;
+        uint16_t bits_per_pixel;
+        uint32_t compression;
+        uint32_t image_size;
+        int32_t x_resolution;
+        int32_t y_resolution;
+        uint32_t nb_colors;
+        uint32_t nb_important_colors;
+
+        // We define the struct size because sizeof(DIB) might return a wrong result because of structure padding.
+        // Moreover, we must use this ugly and error prone syntax because Visual Studio neither support constexpr or sizeof(name_of_field).
+        static const std::size_t dib_size =
+            sizeof(uint32_t) + // size
+            sizeof(int32_t) +  // width
+            sizeof(int32_t) +  // height
+            sizeof(uint16_t) + // planes
+            sizeof(uint16_t) + // bits_per_pixel
+            sizeof(uint32_t) + // compression
+            sizeof(uint32_t) + // image_size
+            sizeof(int32_t) +  // x_resolution
+            sizeof(int32_t) +  // y_resolution
+            sizeof(uint32_t) + // nb_colors
+            sizeof(uint32_t);  // nb_important_colors
+    };
+
+    static const std::size_t mBytesPerPixel = 4;
+
+public:
+    static void Save(aiTexture* texture, IOStream* file);
+
+protected:
+    static void WriteHeader(Header& header, IOStream* file);
+    static void WriteDIB(DIB& dib, IOStream* file);
+    static void WriteData(aiTexture* texture, IOStream* file);
+};
+
+}
+
+#endif // AI_BITMAP_H_INC

dependencies/assimp/include/assimp/BlobIOSystem.h

@@ -0,0 +1,338 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file Provides cheat implementations for IOSystem and IOStream to
+ *  redirect exporter output to a blob chain.*/
+
+#ifndef AI_BLOBIOSYSTEM_H_INCLUDED
+#define AI_BLOBIOSYSTEM_H_INCLUDED
+
+#include <assimp/IOStream.hpp>
+#include <assimp/cexport.h>
+#include <assimp/IOSystem.hpp>
+#include <assimp/DefaultLogger.hpp>
+#include <stdint.h>
+#include <set>
+#include <vector>
+
+namespace Assimp    {
+    class BlobIOSystem;
+
+// --------------------------------------------------------------------------------------------
+/** Redirect IOStream to a blob */
+// --------------------------------------------------------------------------------------------
+class BlobIOStream : public IOStream
+{
+public:
+
+    BlobIOStream(BlobIOSystem* creator, const std::string& file, size_t initial = 4096)
+        : buffer()
+        , cur_size()
+        , file_size()
+        , cursor()
+        , initial(initial)
+        , file(file)
+        , creator(creator)
+    {
+    }
+
+
+    virtual ~BlobIOStream();
+
+public:
+
+    // -------------------------------------------------------------------
+    aiExportDataBlob* GetBlob()
+    {
+        aiExportDataBlob* blob = new aiExportDataBlob();
+        blob->size = file_size;
+        blob->data = buffer;
+
+        buffer = NULL;
+
+        return blob;
+    }
+
+
+public:
+
+
+    // -------------------------------------------------------------------
+    virtual size_t Read( void *,
+        size_t,
+        size_t )
+    {
+        return 0;
+    }
+
+    // -------------------------------------------------------------------
+    virtual size_t Write(const void* pvBuffer,
+        size_t pSize,
+        size_t pCount)
+    {
+        pSize *= pCount;
+        if (cursor + pSize > cur_size) {
+            Grow(cursor + pSize);
+        }
+
+        memcpy(buffer+cursor, pvBuffer, pSize);
+        cursor += pSize;
+
+        file_size = std::max(file_size,cursor);
+        return pCount;
+    }
+
+    // -------------------------------------------------------------------
+    virtual aiReturn Seek(size_t pOffset,
+        aiOrigin pOrigin)
+    {
+        switch(pOrigin)
+        {
+        case aiOrigin_CUR:
+            cursor += pOffset;
+            break;
+
+        case aiOrigin_END:
+            cursor = file_size - pOffset;
+            break;
+
+        case aiOrigin_SET:
+            cursor = pOffset;
+            break;
+
+        default:
+            return AI_FAILURE;
+        }
+
+        if (cursor > file_size) {
+            Grow(cursor);
+        }
+
+        file_size = std::max(cursor,file_size);
+        return AI_SUCCESS;
+    }
+
+    // -------------------------------------------------------------------
+    virtual size_t Tell() const
+    {
+        return cursor;
+    }
+
+    // -------------------------------------------------------------------
+    virtual size_t FileSize() const
+    {
+        return file_size;
+    }
+
+    // -------------------------------------------------------------------
+    virtual void Flush()
+    {
+        // ignore
+    }
+
+
+
+private:
+
+    // -------------------------------------------------------------------
+    void Grow(size_t need = 0)
+    {
+        // 1.5 and phi are very heap-friendly growth factors (the first
+        // allows for frequent re-use of heap blocks, the second
+        // forms a fibonacci sequence with similar characteristics -
+        // since this heavily depends on the heap implementation
+        // and other factors as well, i'll just go with 1.5 since
+        // it is quicker to compute).
+        size_t new_size = std::max(initial, std::max( need, cur_size+(cur_size>>1) ));
+
+        const uint8_t* const old = buffer;
+        buffer = new uint8_t[new_size];
+
+        if (old) {
+            memcpy(buffer,old,cur_size);
+            delete[] old;
+        }
+
+        cur_size = new_size;
+    }
+
+private:
+
+    uint8_t* buffer;
+    size_t cur_size,file_size, cursor, initial;
+
+    const std::string file;
+    BlobIOSystem* const creator;
+};
+
+
+#define AI_BLOBIO_MAGIC "$blobfile"
+
+// --------------------------------------------------------------------------------------------
+/** Redirect IOSystem to a blob */
+// --------------------------------------------------------------------------------------------
+class BlobIOSystem : public IOSystem
+{
+
+    friend class BlobIOStream;
+    typedef std::pair<std::string, aiExportDataBlob*> BlobEntry;
+
+public:
+
+    BlobIOSystem()
+    {
+    }
+
+    virtual ~BlobIOSystem()
+    {
+        for(BlobEntry& blobby : blobs) {
+            delete blobby.second;
+        }
+    }
+
+public:
+
+    // -------------------------------------------------------------------
+    const char* GetMagicFileName() const
+    {
+        return AI_BLOBIO_MAGIC;
+    }
+
+
+    // -------------------------------------------------------------------
+    aiExportDataBlob* GetBlobChain()
+    {
+        // one must be the master
+        aiExportDataBlob* master = NULL, *cur;
+        for(const BlobEntry& blobby : blobs) {
+            if (blobby.first == AI_BLOBIO_MAGIC) {
+                master = blobby.second;
+                break;
+            }
+        }
+        if (!master) {
+            ASSIMP_LOG_ERROR("BlobIOSystem: no data written or master file was not closed properly.");
+            return NULL;
+        }
+
+        master->name.Set("");
+
+        cur = master;
+        for(const BlobEntry& blobby : blobs) {
+            if (blobby.second == master) {
+                continue;
+            }
+
+            cur->next = blobby.second;
+            cur = cur->next;
+
+            // extract the file extension from the file written
+            const std::string::size_type s = blobby.first.find_first_of('.');
+            cur->name.Set(s == std::string::npos ? blobby.first : blobby.first.substr(s+1));
+        }
+
+        // give up blob ownership
+        blobs.clear();
+        return master;
+    }
+
+public:
+
+    // -------------------------------------------------------------------
+    virtual bool Exists( const char* pFile) const {
+        return created.find(std::string(pFile)) != created.end();
+    }
+
+
+    // -------------------------------------------------------------------
+    virtual char getOsSeparator() const {
+        return '/';
+    }
+
+
+    // -------------------------------------------------------------------
+    virtual IOStream* Open(const char* pFile,
+        const char* pMode)
+    {
+        if (pMode[0] != 'w') {
+            return NULL;
+        }
+
+        created.insert(std::string(pFile));
+        return new BlobIOStream(this,std::string(pFile));
+    }
+
+    // -------------------------------------------------------------------
+    virtual void Close( IOStream* pFile)
+    {
+        delete pFile;
+    }
+
+private:
+
+    // -------------------------------------------------------------------
+    void OnDestruct(const std::string& filename, BlobIOStream* child)
+    {
+        // we don't know in which the files are closed, so we
+        // can't reliably say that the first must be the master
+        // file ...
+        blobs.push_back( BlobEntry(filename,child->GetBlob()) );
+    }
+
+private:
+    std::set<std::string> created;
+    std::vector< BlobEntry > blobs;
+};
+
+
+// --------------------------------------------------------------------------------------------
+BlobIOStream :: ~BlobIOStream()
+{
+    creator->OnDestruct(file,this);
+    delete[] buffer;
+}
+
+
+} // end Assimp
+
+#endif

dependencies/assimp/include/assimp/ByteSwapper.h

@@ -0,0 +1,287 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Helper class tp perform various byte oder swappings
+   (e.g. little to big endian) */
+#ifndef AI_BYTESWAPPER_H_INC
+#define AI_BYTESWAPPER_H_INC
+
+#include <assimp/ai_assert.h>
+#include <assimp/types.h>
+#include <stdint.h>
+
+#if _MSC_VER >= 1400
+#include <stdlib.h>
+#endif
+
+namespace Assimp    {
+// --------------------------------------------------------------------------------------
+/** Defines some useful byte order swap routines.
+ *
+ * This is required to read big-endian model formats on little-endian machines,
+ * and vice versa. Direct use of this class is DEPRECATED. Use #StreamReader instead. */
+// --------------------------------------------------------------------------------------
+class ByteSwap {
+    ByteSwap() AI_NO_EXCEPT {}
+
+public:
+
+    // ----------------------------------------------------------------------
+    /** Swap two bytes of data
+     *  @param[inout] _szOut A void* to save the reintcasts for the caller. */
+    static inline void Swap2(void* _szOut)
+    {
+        ai_assert(_szOut);
+
+#if _MSC_VER >= 1400
+        uint16_t* const szOut = reinterpret_cast<uint16_t*>(_szOut);
+        *szOut = _byteswap_ushort(*szOut);
+#else
+        uint8_t* const szOut = reinterpret_cast<uint8_t*>(_szOut);
+        std::swap(szOut[0],szOut[1]);
+#endif
+    }
+
+    // ----------------------------------------------------------------------
+    /** Swap four bytes of data
+     *  @param[inout] _szOut A void* to save the reintcasts for the caller. */
+    static inline void Swap4(void* _szOut)
+    {
+        ai_assert(_szOut);
+
+#if _MSC_VER >= 1400
+        uint32_t* const szOut = reinterpret_cast<uint32_t*>(_szOut);
+        *szOut = _byteswap_ulong(*szOut);
+#else
+        uint8_t* const szOut = reinterpret_cast<uint8_t*>(_szOut);
+        std::swap(szOut[0],szOut[3]);
+        std::swap(szOut[1],szOut[2]);
+#endif
+    }
+
+    // ----------------------------------------------------------------------
+    /** Swap eight bytes of data
+     *  @param[inout] _szOut A void* to save the reintcasts for the caller. */
+    static inline void Swap8(void* _szOut)
+    {
+    ai_assert(_szOut);
+
+#if _MSC_VER >= 1400
+        uint64_t* const szOut = reinterpret_cast<uint64_t*>(_szOut);
+        *szOut = _byteswap_uint64(*szOut);
+#else
+        uint8_t* const szOut = reinterpret_cast<uint8_t*>(_szOut);
+        std::swap(szOut[0],szOut[7]);
+        std::swap(szOut[1],szOut[6]);
+        std::swap(szOut[2],szOut[5]);
+        std::swap(szOut[3],szOut[4]);
+#endif
+    }
+
+    // ----------------------------------------------------------------------
+    /** ByteSwap a float. Not a joke.
+     *  @param[inout] fOut ehm. .. */
+    static inline void Swap(float* fOut) {
+        Swap4(fOut);
+    }
+
+    // ----------------------------------------------------------------------
+    /** ByteSwap a double. Not a joke.
+     *  @param[inout] fOut ehm. .. */
+    static inline void Swap(double* fOut) {
+        Swap8(fOut);
+    }
+
+
+    // ----------------------------------------------------------------------
+    /** ByteSwap an int16t. Not a joke.
+     *  @param[inout] fOut ehm. .. */
+    static inline void Swap(int16_t* fOut) {
+        Swap2(fOut);
+    }
+
+    static inline void Swap(uint16_t* fOut) {
+        Swap2(fOut);
+    }
+
+    // ----------------------------------------------------------------------
+    /** ByteSwap an int32t. Not a joke.
+     *  @param[inout] fOut ehm. .. */
+    static inline void Swap(int32_t* fOut){
+        Swap4(fOut);
+    }
+
+    static inline void Swap(uint32_t* fOut){
+        Swap4(fOut);
+    }
+
+    // ----------------------------------------------------------------------
+    /** ByteSwap an int64t. Not a joke.
+     *  @param[inout] fOut ehm. .. */
+    static inline void Swap(int64_t* fOut) {
+        Swap8(fOut);
+    }
+
+    static inline void Swap(uint64_t* fOut) {
+        Swap8(fOut);
+    }
+
+    // ----------------------------------------------------------------------
+    //! Templatized ByteSwap
+    //! \returns param tOut as swapped
+    template<typename Type>
+    static inline Type Swapped(Type tOut)
+    {
+        return _swapper<Type,sizeof(Type)>()(tOut);
+    }
+
+private:
+
+    template <typename T, size_t size> struct _swapper;
+};
+
+template <typename T> struct ByteSwap::_swapper<T,2> {
+    T operator() (T tOut) {
+        Swap2(&tOut);
+        return tOut;
+    }
+};
+
+template <typename T> struct ByteSwap::_swapper<T,4> {
+    T operator() (T tOut) {
+        Swap4(&tOut);
+        return tOut;
+    }
+};
+
+template <typename T> struct ByteSwap::_swapper<T,8> {
+    T operator() (T tOut) {
+        Swap8(&tOut);
+        return tOut;
+    }
+};
+
+
+// --------------------------------------------------------------------------------------
+// ByteSwap macros for BigEndian/LittleEndian support
+// --------------------------------------------------------------------------------------
+#if (defined AI_BUILD_BIG_ENDIAN)
+#   define AI_LE(t) (t)
+#   define AI_BE(t) ByteSwap::Swapped(t)
+#   define AI_LSWAP2(p)
+#   define AI_LSWAP4(p)
+#   define AI_LSWAP8(p)
+#   define AI_LSWAP2P(p)
+#   define AI_LSWAP4P(p)
+#   define AI_LSWAP8P(p)
+#   define LE_NCONST const
+#   define AI_SWAP2(p) ByteSwap::Swap2(&(p))
+#   define AI_SWAP4(p) ByteSwap::Swap4(&(p))
+#   define AI_SWAP8(p) ByteSwap::Swap8(&(p))
+#   define AI_SWAP2P(p) ByteSwap::Swap2((p))
+#   define AI_SWAP4P(p) ByteSwap::Swap4((p))
+#   define AI_SWAP8P(p) ByteSwap::Swap8((p))
+#   define BE_NCONST
+#else
+#   define AI_BE(t) (t)
+#   define AI_LE(t) ByteSwap::Swapped(t)
+#   define AI_SWAP2(p)
+#   define AI_SWAP4(p)
+#   define AI_SWAP8(p)
+#   define AI_SWAP2P(p)
+#   define AI_SWAP4P(p)
+#   define AI_SWAP8P(p)
+#   define BE_NCONST const
+#   define AI_LSWAP2(p)     ByteSwap::Swap2(&(p))
+#   define AI_LSWAP4(p)     ByteSwap::Swap4(&(p))
+#   define AI_LSWAP8(p)     ByteSwap::Swap8(&(p))
+#   define AI_LSWAP2P(p)    ByteSwap::Swap2((p))
+#   define AI_LSWAP4P(p)    ByteSwap::Swap4((p))
+#   define AI_LSWAP8P(p)    ByteSwap::Swap8((p))
+#   define LE_NCONST
+#endif
+
+
+namespace Intern {
+
+// --------------------------------------------------------------------------------------------
+template <typename T, bool doit>
+struct ByteSwapper  {
+    void operator() (T* inout) {
+        ByteSwap::Swap(inout);
+    }
+};
+
+template <typename T>
+struct ByteSwapper<T,false> {
+    void operator() (T*) {
+    }
+};
+
+// --------------------------------------------------------------------------------------------
+template <bool SwapEndianess, typename T, bool RuntimeSwitch>
+struct Getter {
+    void operator() (T* inout, bool le) {
+#ifdef AI_BUILD_BIG_ENDIAN
+        le =  le;
+#else
+        le =  !le;
+#endif
+        if (le) {
+            ByteSwapper<T,(sizeof(T)>1?true:false)> () (inout);
+        }
+        else ByteSwapper<T,false> () (inout);
+    }
+};
+
+template <bool SwapEndianess, typename T>
+struct Getter<SwapEndianess,T,false> {
+
+    void operator() (T* inout, bool /*le*/) {
+        // static branch
+        ByteSwapper<T,(SwapEndianess && sizeof(T)>1)> () (inout);
+    }
+};
+} // end Intern
+} // end Assimp
+
+#endif //!! AI_BYTESWAPPER_H_INC

dependencies/assimp/include/assimp/Compiler/poppack1.h

@@ -0,0 +1,22 @@
+
+// ===============================================================================
+// May be included multiple times - resets structure packing to the defaults 
+// for all supported compilers. Reverts the changes made by #include <pushpack1.h> 
+//
+// Currently this works on the following compilers:
+// MSVC 7,8,9
+// GCC
+// BORLAND (complains about 'pack state changed but not reverted', but works)
+// ===============================================================================
+
+#ifndef AI_PUSHPACK_IS_DEFINED
+#	error pushpack1.h must be included after poppack1.h
+#endif
+
+// reset packing to the original value
+#if defined(_MSC_VER) ||  defined(__BORLANDC__) || defined (__BCPLUSPLUS__)
+#	pragma pack( pop )
+#endif
+#undef PACK_STRUCT
+
+#undef AI_PUSHPACK_IS_DEFINED

dependencies/assimp/include/assimp/Compiler/pstdint.h

@@ -0,0 +1,912 @@
+/*  A portable stdint.h
+ ****************************************************************************
+ *  BSD License:
+ ****************************************************************************
+ *
+ *  Copyright (c) 2005-2016 Paul Hsieh
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************
+ *
+ *  Version 0.1.15.4
+ *
+ *  The ANSI C standard committee, for the C99 standard, specified the
+ *  inclusion of a new standard include file called stdint.h.  This is
+ *  a very useful and long desired include file which contains several
+ *  very precise definitions for integer scalar types that is
+ *  critically important for making portable several classes of
+ *  applications including cryptography, hashing, variable length
+ *  integer libraries and so on.  But for most developers its likely
+ *  useful just for programming sanity.
+ *
+ *  The problem is that some compiler vendors chose to ignore the C99
+ *  standard and some older compilers have no opportunity to be updated.
+ *  Because of this situation, simply including stdint.h in your code
+ *  makes it unportable.
+ *
+ *  So that's what this file is all about.  Its an attempt to build a
+ *  single universal include file that works on as many platforms as
+ *  possible to deliver what stdint.h is supposed to.  Even compilers
+ *  that already come with stdint.h can use this file instead without
+ *  any loss of functionality.  A few things that should be noted about
+ *  this file:
+ *
+ *    1) It is not guaranteed to be portable and/or present an identical
+ *       interface on all platforms.  The extreme variability of the
+ *       ANSI C standard makes this an impossibility right from the
+ *       very get go. Its really only meant to be useful for the vast
+ *       majority of platforms that possess the capability of
+ *       implementing usefully and precisely defined, standard sized
+ *       integer scalars.  Systems which are not intrinsically 2s
+ *       complement may produce invalid constants.
+ *
+ *    2) There is an unavoidable use of non-reserved symbols.
+ *
+ *    3) Other standard include files are invoked.
+ *
+ *    4) This file may come in conflict with future platforms that do
+ *       include stdint.h.  The hope is that one or the other can be
+ *       used with no real difference.
+ *
+ *    5) In the current version, if your platform can't represent
+ *       int32_t, int16_t and int8_t, it just dumps out with a compiler
+ *       error.
+ *
+ *    6) 64 bit integers may or may not be defined.  Test for their
+ *       presence with the test: #ifdef INT64_MAX or #ifdef UINT64_MAX.
+ *       Note that this is different from the C99 specification which
+ *       requires the existence of 64 bit support in the compiler.  If
+ *       this is not defined for your platform, yet it is capable of
+ *       dealing with 64 bits then it is because this file has not yet
+ *       been extended to cover all of your system's capabilities.
+ *
+ *    7) (u)intptr_t may or may not be defined.  Test for its presence
+ *       with the test: #ifdef PTRDIFF_MAX.  If this is not defined
+ *       for your platform, then it is because this file has not yet
+ *       been extended to cover all of your system's capabilities, not
+ *       because its optional.
+ *
+ *    8) The following might not been defined even if your platform is
+ *       capable of defining it:
+ *
+ *       WCHAR_MIN
+ *       WCHAR_MAX
+ *       (u)int64_t
+ *       PTRDIFF_MIN
+ *       PTRDIFF_MAX
+ *       (u)intptr_t
+ *
+ *    9) The following have not been defined:
+ *
+ *       WINT_MIN
+ *       WINT_MAX
+ *
+ *   10) The criteria for defining (u)int_least(*)_t isn't clear,
+ *       except for systems which don't have a type that precisely
+ *       defined 8, 16, or 32 bit types (which this include file does
+ *       not support anyways). Default definitions have been given.
+ *
+ *   11) The criteria for defining (u)int_fast(*)_t isn't something I
+ *       would trust to any particular compiler vendor or the ANSI C
+ *       committee.  It is well known that "compatible systems" are
+ *       commonly created that have very different performance
+ *       characteristics from the systems they are compatible with,
+ *       especially those whose vendors make both the compiler and the
+ *       system.  Default definitions have been given, but its strongly
+ *       recommended that users never use these definitions for any
+ *       reason (they do *NOT* deliver any serious guarantee of
+ *       improved performance -- not in this file, nor any vendor's
+ *       stdint.h).
+ *
+ *   12) The following macros:
+ *
+ *       PRINTF_INTMAX_MODIFIER
+ *       PRINTF_INT64_MODIFIER
+ *       PRINTF_INT32_MODIFIER
+ *       PRINTF_INT16_MODIFIER
+ *       PRINTF_LEAST64_MODIFIER
+ *       PRINTF_LEAST32_MODIFIER
+ *       PRINTF_LEAST16_MODIFIER
+ *       PRINTF_INTPTR_MODIFIER
+ *
+ *       are strings which have been defined as the modifiers required
+ *       for the "d", "u" and "x" printf formats to correctly output
+ *       (u)intmax_t, (u)int64_t, (u)int32_t, (u)int16_t, (u)least64_t,
+ *       (u)least32_t, (u)least16_t and (u)intptr_t types respectively.
+ *       PRINTF_INTPTR_MODIFIER is not defined for some systems which
+ *       provide their own stdint.h.  PRINTF_INT64_MODIFIER is not
+ *       defined if INT64_MAX is not defined.  These are an extension
+ *       beyond what C99 specifies must be in stdint.h.
+ *
+ *       In addition, the following macros are defined:
+ *
+ *       PRINTF_INTMAX_HEX_WIDTH
+ *       PRINTF_INT64_HEX_WIDTH
+ *       PRINTF_INT32_HEX_WIDTH
+ *       PRINTF_INT16_HEX_WIDTH
+ *       PRINTF_INT8_HEX_WIDTH
+ *       PRINTF_INTMAX_DEC_WIDTH
+ *       PRINTF_INT64_DEC_WIDTH
+ *       PRINTF_INT32_DEC_WIDTH
+ *       PRINTF_INT16_DEC_WIDTH
+ *       PRINTF_UINT8_DEC_WIDTH
+ *       PRINTF_UINTMAX_DEC_WIDTH
+ *       PRINTF_UINT64_DEC_WIDTH
+ *       PRINTF_UINT32_DEC_WIDTH
+ *       PRINTF_UINT16_DEC_WIDTH
+ *       PRINTF_UINT8_DEC_WIDTH
+ *
+ *       Which specifies the maximum number of characters required to
+ *       print the number of that type in either hexadecimal or decimal.
+ *       These are an extension beyond what C99 specifies must be in
+ *       stdint.h.
+ *
+ *  Compilers tested (all with 0 warnings at their highest respective
+ *  settings): Borland Turbo C 2.0, WATCOM C/C++ 11.0 (16 bits and 32
+ *  bits), Microsoft Visual C++ 6.0 (32 bit), Microsoft Visual Studio
+ *  .net (VC7), Intel C++ 4.0, GNU gcc v3.3.3
+ *
+ *  This file should be considered a work in progress.  Suggestions for
+ *  improvements, especially those which increase coverage are strongly
+ *  encouraged.
+ *
+ *  Acknowledgements
+ *
+ *  The following people have made significant contributions to the
+ *  development and testing of this file:
+ *
+ *  Chris Howie
+ *  John Steele Scott
+ *  Dave Thorup
+ *  John Dill
+ *  Florian Wobbe
+ *  Christopher Sean Morrison
+ *  Mikkel Fahnoe Jorgensen
+ *
+ */
+
+#include <stddef.h>
+#include <limits.h>
+#include <signal.h>
+
+/*
+ *  For gcc with _STDINT_H, fill in the PRINTF_INT*_MODIFIER macros, and
+ *  do nothing else.  On the Mac OS X version of gcc this is _STDINT_H_.
+ */
+
+#if ((defined(__SUNPRO_C) && __SUNPRO_C >= 0x570) || (defined(_MSC_VER) && _MSC_VER >= 1600) || (defined(__STDC__) && __STDC__ && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || (defined (__WATCOMC__) && (defined (_STDINT_H_INCLUDED) || __WATCOMC__ >= 1250)) || (defined(__GNUC__) && (__GNUC__ > 3 || defined(_STDINT_H) || defined(_STDINT_H_) || defined (__UINT_FAST64_TYPE__)) )) && !defined (_PSTDINT_H_INCLUDED)
+#include <stdint.h>
+#define _PSTDINT_H_INCLUDED
+# if defined(__GNUC__) && (defined(__x86_64__) || defined(__ppc64__)) && !(defined(__APPLE__) && defined(__MACH__))
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "l"
+#  endif
+#  ifndef PRINTF_INT32_MODIFIER
+#   define PRINTF_INT32_MODIFIER ""
+#  endif
+# else
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+#  ifndef PRINTF_INT32_MODIFIER
+#   if (UINT_MAX == UINT32_MAX)
+#    define PRINTF_INT32_MODIFIER ""
+#   else
+#    define PRINTF_INT32_MODIFIER "l"
+#   endif
+#  endif
+# endif
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+# ifndef PRINTF_INTMAX_MODIFIER
+#  define PRINTF_INTMAX_MODIFIER PRINTF_INT64_MODIFIER
+# endif
+# ifndef PRINTF_INT64_HEX_WIDTH
+#  define PRINTF_INT64_HEX_WIDTH "16"
+# endif
+# ifndef PRINTF_UINT64_HEX_WIDTH
+#  define PRINTF_UINT64_HEX_WIDTH "16"
+# endif
+# ifndef PRINTF_INT32_HEX_WIDTH
+#  define PRINTF_INT32_HEX_WIDTH "8"
+# endif
+# ifndef PRINTF_UINT32_HEX_WIDTH
+#  define PRINTF_UINT32_HEX_WIDTH "8"
+# endif
+# ifndef PRINTF_INT16_HEX_WIDTH
+#  define PRINTF_INT16_HEX_WIDTH "4"
+# endif
+# ifndef PRINTF_UINT16_HEX_WIDTH
+#  define PRINTF_UINT16_HEX_WIDTH "4"
+# endif
+# ifndef PRINTF_INT8_HEX_WIDTH
+#  define PRINTF_INT8_HEX_WIDTH "2"
+# endif
+# ifndef PRINTF_UINT8_HEX_WIDTH
+#  define PRINTF_UINT8_HEX_WIDTH "2"
+# endif
+# ifndef PRINTF_INT64_DEC_WIDTH
+#  define PRINTF_INT64_DEC_WIDTH "19"
+# endif
+# ifndef PRINTF_UINT64_DEC_WIDTH
+#  define PRINTF_UINT64_DEC_WIDTH "20"
+# endif
+# ifndef PRINTF_INT32_DEC_WIDTH
+#  define PRINTF_INT32_DEC_WIDTH "10"
+# endif
+# ifndef PRINTF_UINT32_DEC_WIDTH
+#  define PRINTF_UINT32_DEC_WIDTH "10"
+# endif
+# ifndef PRINTF_INT16_DEC_WIDTH
+#  define PRINTF_INT16_DEC_WIDTH "5"
+# endif
+# ifndef PRINTF_UINT16_DEC_WIDTH
+#  define PRINTF_UINT16_DEC_WIDTH "5"
+# endif
+# ifndef PRINTF_INT8_DEC_WIDTH
+#  define PRINTF_INT8_DEC_WIDTH "3"
+# endif
+# ifndef PRINTF_UINT8_DEC_WIDTH
+#  define PRINTF_UINT8_DEC_WIDTH "3"
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_UINT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_UINTMAX_HEX_WIDTH
+#  define PRINTF_UINTMAX_HEX_WIDTH PRINTF_UINT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_UINT64_DEC_WIDTH
+# endif
+# ifndef PRINTF_UINTMAX_DEC_WIDTH
+#  define PRINTF_UINTMAX_DEC_WIDTH PRINTF_UINT64_DEC_WIDTH
+# endif
+
+/*
+ *  Something really weird is going on with Open Watcom.  Just pull some of
+ *  these duplicated definitions from Open Watcom's stdint.h file for now.
+ */
+
+# if defined (__WATCOMC__) && __WATCOMC__ >= 1250
+#  if !defined (INT64_C)
+#   define INT64_C(x)   (x + (INT64_MAX - INT64_MAX))
+#  endif
+#  if !defined (UINT64_C)
+#   define UINT64_C(x)  (x + (UINT64_MAX - UINT64_MAX))
+#  endif
+#  if !defined (INT32_C)
+#   define INT32_C(x)   (x + (INT32_MAX - INT32_MAX))
+#  endif
+#  if !defined (UINT32_C)
+#   define UINT32_C(x)  (x + (UINT32_MAX - UINT32_MAX))
+#  endif
+#  if !defined (INT16_C)
+#   define INT16_C(x)   (x)
+#  endif
+#  if !defined (UINT16_C)
+#   define UINT16_C(x)  (x)
+#  endif
+#  if !defined (INT8_C)
+#   define INT8_C(x)   (x)
+#  endif
+#  if !defined (UINT8_C)
+#   define UINT8_C(x)  (x)
+#  endif
+#  if !defined (UINT64_MAX)
+#   define UINT64_MAX  18446744073709551615ULL
+#  endif
+#  if !defined (INT64_MAX)
+#   define INT64_MAX  9223372036854775807LL
+#  endif
+#  if !defined (UINT32_MAX)
+#   define UINT32_MAX  4294967295UL
+#  endif
+#  if !defined (INT32_MAX)
+#   define INT32_MAX  2147483647L
+#  endif
+#  if !defined (INTMAX_MAX)
+#   define INTMAX_MAX INT64_MAX
+#  endif
+#  if !defined (INTMAX_MIN)
+#   define INTMAX_MIN INT64_MIN
+#  endif
+# endif
+#endif
+
+/*
+ *  I have no idea what is the truly correct thing to do on older Solaris.
+ *  From some online discussions, this seems to be what is being
+ *  recommended.  For people who actually are developing on older Solaris,
+ *  what I would like to know is, does this define all of the relevant
+ *  macros of a complete stdint.h?  Remember, in pstdint.h 64 bit is
+ *  considered optional.
+ */
+
+#if (defined(__SUNPRO_C) && __SUNPRO_C >= 0x420) && !defined(_PSTDINT_H_INCLUDED)
+#include <sys/inttypes.h>
+#define _PSTDINT_H_INCLUDED
+#endif
+
+#ifndef _PSTDINT_H_INCLUDED
+#define _PSTDINT_H_INCLUDED
+
+#ifndef SIZE_MAX
+# define SIZE_MAX (~(size_t)0)
+#endif
+
+/*
+ *  Deduce the type assignments from limits.h under the assumption that
+ *  integer sizes in bits are powers of 2, and follow the ANSI
+ *  definitions.
+ */
+
+#ifndef UINT8_MAX
+# define UINT8_MAX 0xff
+#endif
+#if !defined(uint8_t) && !defined(_UINT8_T) && !defined(vxWorks)
+# if (UCHAR_MAX == UINT8_MAX) || defined (S_SPLINT_S)
+    typedef unsigned char uint8_t;
+#   define UINT8_C(v) ((uint8_t) v)
+# else
+#   error "Platform not supported"
+# endif
+#endif
+
+#ifndef INT8_MAX
+# define INT8_MAX 0x7f
+#endif
+#ifndef INT8_MIN
+# define INT8_MIN INT8_C(0x80)
+#endif
+#if !defined(int8_t) && !defined(_INT8_T) && !defined(vxWorks)
+# if (SCHAR_MAX == INT8_MAX) || defined (S_SPLINT_S)
+    typedef signed char int8_t;
+#   define INT8_C(v) ((int8_t) v)
+# else
+#   error "Platform not supported"
+# endif
+#endif
+
+#ifndef UINT16_MAX
+# define UINT16_MAX 0xffff
+#endif
+#if !defined(uint16_t) && !defined(_UINT16_T) && !defined(vxWorks)
+#if (UINT_MAX == UINT16_MAX) || defined (S_SPLINT_S)
+  typedef unsigned int uint16_t;
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER ""
+# endif
+# define UINT16_C(v) ((uint16_t) (v))
+#elif (USHRT_MAX == UINT16_MAX)
+  typedef unsigned short uint16_t;
+# define UINT16_C(v) ((uint16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef INT16_MAX
+# define INT16_MAX 0x7fff
+#endif
+#ifndef INT16_MIN
+# define INT16_MIN INT16_C(0x8000)
+#endif
+#if !defined(int16_t) && !defined(_INT16_T) && !defined(vxWorks)
+#if (INT_MAX == INT16_MAX) || defined (S_SPLINT_S)
+  typedef signed int int16_t;
+# define INT16_C(v) ((int16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER ""
+# endif
+#elif (SHRT_MAX == INT16_MAX)
+  typedef signed short int16_t;
+# define INT16_C(v) ((int16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef UINT32_MAX
+# define UINT32_MAX (0xffffffffUL)
+#endif
+#if !defined(uint32_t) && !defined(_UINT32_T) && !defined(vxWorks)
+#if (ULONG_MAX == UINT32_MAX) || defined (S_SPLINT_S)
+  typedef unsigned long uint32_t;
+# define UINT32_C(v) v ## UL
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER "l"
+# endif
+#elif (UINT_MAX == UINT32_MAX)
+  typedef unsigned int uint32_t;
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+# define UINT32_C(v) v ## U
+#elif (USHRT_MAX == UINT32_MAX)
+  typedef unsigned short uint32_t;
+# define UINT32_C(v) ((unsigned short) (v))
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef INT32_MAX
+# define INT32_MAX (0x7fffffffL)
+#endif
+#ifndef INT32_MIN
+# define INT32_MIN INT32_C(0x80000000)
+#endif
+#if !defined(int32_t) && !defined(_INT32_T) && !defined(vxWorks)
+#if (LONG_MAX == INT32_MAX) || defined (S_SPLINT_S)
+  typedef signed long int32_t;
+# define INT32_C(v) v ## L
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER "l"
+# endif
+#elif (INT_MAX == INT32_MAX)
+  typedef signed int int32_t;
+# define INT32_C(v) v
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#elif (SHRT_MAX == INT32_MAX)
+  typedef signed short int32_t;
+# define INT32_C(v) ((short) (v))
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+/*
+ *  The macro stdint_int64_defined is temporarily used to record
+ *  whether or not 64 integer support is available.  It must be
+ *  defined for any 64 integer extensions for new platforms that are
+ *  added.
+ */
+
+#undef stdint_int64_defined
+#if (defined(__STDC__) && defined(__STDC_VERSION__)) || defined (S_SPLINT_S)
+# if (__STDC__ && __STDC_VERSION__ >= 199901L) || defined (S_SPLINT_S)
+#  define stdint_int64_defined
+   typedef long long int64_t;
+   typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# endif
+#endif
+
+#if !defined (stdint_int64_defined)
+# if defined(__GNUC__) && !defined(vxWorks)
+#  define stdint_int64_defined
+   __extension__ typedef long long int64_t;
+   __extension__ typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# elif defined(__MWERKS__) || defined (__SUNPRO_C) || defined (__SUNPRO_CC) || defined (__APPLE_CC__) || defined (_LONG_LONG) || defined (_CRAYC) || defined (S_SPLINT_S)
+#  define stdint_int64_defined
+   typedef long long int64_t;
+   typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# elif (defined(__WATCOMC__) && defined(__WATCOM_INT64__)) || (defined(_MSC_VER) && _INTEGRAL_MAX_BITS >= 64) || (defined (__BORLANDC__) && __BORLANDC__ > 0x460) || defined (__alpha) || defined (__DECC)
+#  define stdint_int64_defined
+   typedef __int64 int64_t;
+   typedef unsigned __int64 uint64_t;
+#  define UINT64_C(v) v ## UI64
+#  define  INT64_C(v) v ## I64
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "I64"
+#  endif
+# endif
+#endif
+
+#if !defined (LONG_LONG_MAX) && defined (INT64_C)
+# define LONG_LONG_MAX INT64_C (9223372036854775807)
+#endif
+#ifndef ULONG_LONG_MAX
+# define ULONG_LONG_MAX UINT64_C (18446744073709551615)
+#endif
+
+#if !defined (INT64_MAX) && defined (INT64_C)
+# define INT64_MAX INT64_C (9223372036854775807)
+#endif
+#if !defined (INT64_MIN) && defined (INT64_C)
+# define INT64_MIN INT64_C (-9223372036854775808)
+#endif
+#if !defined (UINT64_MAX) && defined (INT64_C)
+# define UINT64_MAX UINT64_C (18446744073709551615)
+#endif
+
+/*
+ *  Width of hexadecimal for number field.
+ */
+
+#ifndef PRINTF_INT64_HEX_WIDTH
+# define PRINTF_INT64_HEX_WIDTH "16"
+#endif
+#ifndef PRINTF_INT32_HEX_WIDTH
+# define PRINTF_INT32_HEX_WIDTH "8"
+#endif
+#ifndef PRINTF_INT16_HEX_WIDTH
+# define PRINTF_INT16_HEX_WIDTH "4"
+#endif
+#ifndef PRINTF_INT8_HEX_WIDTH
+# define PRINTF_INT8_HEX_WIDTH "2"
+#endif
+#ifndef PRINTF_INT64_DEC_WIDTH
+# define PRINTF_INT64_DEC_WIDTH "19"
+#endif
+#ifndef PRINTF_INT32_DEC_WIDTH
+# define PRINTF_INT32_DEC_WIDTH "10"
+#endif
+#ifndef PRINTF_INT16_DEC_WIDTH
+# define PRINTF_INT16_DEC_WIDTH "5"
+#endif
+#ifndef PRINTF_INT8_DEC_WIDTH
+# define PRINTF_INT8_DEC_WIDTH "3"
+#endif
+#ifndef PRINTF_UINT64_DEC_WIDTH
+# define PRINTF_UINT64_DEC_WIDTH "20"
+#endif
+#ifndef PRINTF_UINT32_DEC_WIDTH
+# define PRINTF_UINT32_DEC_WIDTH "10"
+#endif
+#ifndef PRINTF_UINT16_DEC_WIDTH
+# define PRINTF_UINT16_DEC_WIDTH "5"
+#endif
+#ifndef PRINTF_UINT8_DEC_WIDTH
+# define PRINTF_UINT8_DEC_WIDTH "3"
+#endif
+
+/*
+ *  Ok, lets not worry about 128 bit integers for now.  Moore's law says
+ *  we don't need to worry about that until about 2040 at which point
+ *  we'll have bigger things to worry about.
+ */
+
+#ifdef stdint_int64_defined
+  typedef int64_t intmax_t;
+  typedef uint64_t uintmax_t;
+# define  INTMAX_MAX   INT64_MAX
+# define  INTMAX_MIN   INT64_MIN
+# define UINTMAX_MAX  UINT64_MAX
+# define UINTMAX_C(v) UINT64_C(v)
+# define  INTMAX_C(v)  INT64_C(v)
+# ifndef PRINTF_INTMAX_MODIFIER
+#   define PRINTF_INTMAX_MODIFIER PRINTF_INT64_MODIFIER
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_INT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_INT64_DEC_WIDTH
+# endif
+#else
+  typedef int32_t intmax_t;
+  typedef uint32_t uintmax_t;
+# define  INTMAX_MAX   INT32_MAX
+# define UINTMAX_MAX  UINT32_MAX
+# define UINTMAX_C(v) UINT32_C(v)
+# define  INTMAX_C(v)  INT32_C(v)
+# ifndef PRINTF_INTMAX_MODIFIER
+#   define PRINTF_INTMAX_MODIFIER PRINTF_INT32_MODIFIER
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_INT32_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_INT32_DEC_WIDTH
+# endif
+#endif
+
+/*
+ *  Because this file currently only supports platforms which have
+ *  precise powers of 2 as bit sizes for the default integers, the
+ *  least definitions are all trivial.  Its possible that a future
+ *  version of this file could have different definitions.
+ */
+
+#ifndef stdint_least_defined
+  typedef   int8_t   int_least8_t;
+  typedef  uint8_t  uint_least8_t;
+  typedef  int16_t  int_least16_t;
+  typedef uint16_t uint_least16_t;
+  typedef  int32_t  int_least32_t;
+  typedef uint32_t uint_least32_t;
+# define PRINTF_LEAST32_MODIFIER PRINTF_INT32_MODIFIER
+# define PRINTF_LEAST16_MODIFIER PRINTF_INT16_MODIFIER
+# define  UINT_LEAST8_MAX  UINT8_MAX
+# define   INT_LEAST8_MAX   INT8_MAX
+# define UINT_LEAST16_MAX UINT16_MAX
+# define  INT_LEAST16_MAX  INT16_MAX
+# define UINT_LEAST32_MAX UINT32_MAX
+# define  INT_LEAST32_MAX  INT32_MAX
+# define   INT_LEAST8_MIN   INT8_MIN
+# define  INT_LEAST16_MIN  INT16_MIN
+# define  INT_LEAST32_MIN  INT32_MIN
+# ifdef stdint_int64_defined
+    typedef  int64_t  int_least64_t;
+    typedef uint64_t uint_least64_t;
+#   define PRINTF_LEAST64_MODIFIER PRINTF_INT64_MODIFIER
+#   define UINT_LEAST64_MAX UINT64_MAX
+#   define  INT_LEAST64_MAX  INT64_MAX
+#   define  INT_LEAST64_MIN  INT64_MIN
+# endif
+#endif
+#undef stdint_least_defined
+
+/*
+ *  The ANSI C committee pretending to know or specify anything about
+ *  performance is the epitome of misguided arrogance.  The mandate of
+ *  this file is to *ONLY* ever support that absolute minimum
+ *  definition of the fast integer types, for compatibility purposes.
+ *  No extensions, and no attempt to suggest what may or may not be a
+ *  faster integer type will ever be made in this file.  Developers are
+ *  warned to stay away from these types when using this or any other
+ *  stdint.h.
+ */
+
+typedef   int_least8_t   int_fast8_t;
+typedef  uint_least8_t  uint_fast8_t;
+typedef  int_least16_t  int_fast16_t;
+typedef uint_least16_t uint_fast16_t;
+typedef  int_least32_t  int_fast32_t;
+typedef uint_least32_t uint_fast32_t;
+#define  UINT_FAST8_MAX  UINT_LEAST8_MAX
+#define   INT_FAST8_MAX   INT_LEAST8_MAX
+#define UINT_FAST16_MAX UINT_LEAST16_MAX
+#define  INT_FAST16_MAX  INT_LEAST16_MAX
+#define UINT_FAST32_MAX UINT_LEAST32_MAX
+#define  INT_FAST32_MAX  INT_LEAST32_MAX
+#define   INT_FAST8_MIN   INT_LEAST8_MIN
+#define  INT_FAST16_MIN  INT_LEAST16_MIN
+#define  INT_FAST32_MIN  INT_LEAST32_MIN
+#ifdef stdint_int64_defined
+  typedef  int_least64_t  int_fast64_t;
+  typedef uint_least64_t uint_fast64_t;
+# define UINT_FAST64_MAX UINT_LEAST64_MAX
+# define  INT_FAST64_MAX  INT_LEAST64_MAX
+# define  INT_FAST64_MIN  INT_LEAST64_MIN
+#endif
+
+#undef stdint_int64_defined
+
+/*
+ *  Whatever piecemeal, per compiler thing we can do about the wchar_t
+ *  type limits.
+ */
+
+#if defined(__WATCOMC__) || defined(_MSC_VER) || defined (__GNUC__) && !defined(vxWorks)
+# include <wchar.h>
+# ifndef WCHAR_MIN
+#  define WCHAR_MIN 0
+# endif
+# ifndef WCHAR_MAX
+#  define WCHAR_MAX ((wchar_t)-1)
+# endif
+#endif
+
+/*
+ *  Whatever piecemeal, per compiler/platform thing we can do about the
+ *  (u)intptr_t types and limits.
+ */
+
+#if (defined (_MSC_VER) && defined (_UINTPTR_T_DEFINED)) || defined (_UINTPTR_T)
+# define STDINT_H_UINTPTR_T_DEFINED
+#endif
+
+#ifndef STDINT_H_UINTPTR_T_DEFINED
+# if defined (__alpha__) || defined (__ia64__) || defined (__x86_64__) || defined (_WIN64) || defined (__ppc64__)
+#  define stdint_intptr_bits 64
+# elif defined (__WATCOMC__) || defined (__TURBOC__)
+#  if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__)
+#    define stdint_intptr_bits 16
+#  else
+#    define stdint_intptr_bits 32
+#  endif
+# elif defined (__i386__) || defined (_WIN32) || defined (WIN32) || defined (__ppc64__)
+#  define stdint_intptr_bits 32
+# elif defined (__INTEL_COMPILER)
+/* TODO -- what did Intel do about x86-64? */
+# else
+/* #error "This platform might not be supported yet" */
+# endif
+
+# ifdef stdint_intptr_bits
+#  define stdint_intptr_glue3_i(a,b,c)  a##b##c
+#  define stdint_intptr_glue3(a,b,c)    stdint_intptr_glue3_i(a,b,c)
+#  ifndef PRINTF_INTPTR_MODIFIER
+#    define PRINTF_INTPTR_MODIFIER      stdint_intptr_glue3(PRINTF_INT,stdint_intptr_bits,_MODIFIER)
+#  endif
+#  ifndef PTRDIFF_MAX
+#    define PTRDIFF_MAX                 stdint_intptr_glue3(INT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef PTRDIFF_MIN
+#    define PTRDIFF_MIN                 stdint_intptr_glue3(INT,stdint_intptr_bits,_MIN)
+#  endif
+#  ifndef UINTPTR_MAX
+#    define UINTPTR_MAX                 stdint_intptr_glue3(UINT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef INTPTR_MAX
+#    define INTPTR_MAX                  stdint_intptr_glue3(INT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef INTPTR_MIN
+#    define INTPTR_MIN                  stdint_intptr_glue3(INT,stdint_intptr_bits,_MIN)
+#  endif
+#  ifndef INTPTR_C
+#    define INTPTR_C(x)                 stdint_intptr_glue3(INT,stdint_intptr_bits,_C)(x)
+#  endif
+#  ifndef UINTPTR_C
+#    define UINTPTR_C(x)                stdint_intptr_glue3(UINT,stdint_intptr_bits,_C)(x)
+#  endif
+  typedef stdint_intptr_glue3(uint,stdint_intptr_bits,_t) uintptr_t;
+  typedef stdint_intptr_glue3( int,stdint_intptr_bits,_t)  intptr_t;
+# else
+/* TODO -- This following is likely wrong for some platforms, and does
+   nothing for the definition of uintptr_t. */
+  typedef ptrdiff_t intptr_t;
+# endif
+# define STDINT_H_UINTPTR_T_DEFINED
+#endif
+
+/*
+ *  Assumes sig_atomic_t is signed and we have a 2s complement machine.
+ */
+
+#ifndef SIG_ATOMIC_MAX
+# define SIG_ATOMIC_MAX ((((sig_atomic_t) 1) << (sizeof (sig_atomic_t)*CHAR_BIT-1)) - 1)
+#endif
+
+#endif
+
+#if defined (__TEST_PSTDINT_FOR_CORRECTNESS)
+
+/*
+ *  Please compile with the maximum warning settings to make sure macros are
+ *  not defined more than once.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#define glue3_aux(x,y,z) x ## y ## z
+#define glue3(x,y,z) glue3_aux(x,y,z)
+
+#define DECLU(bits) glue3(uint,bits,_t) glue3(u,bits,) = glue3(UINT,bits,_C) (0);
+#define DECLI(bits) glue3(int,bits,_t) glue3(i,bits,) = glue3(INT,bits,_C) (0);
+
+#define DECL(us,bits) glue3(DECL,us,) (bits)
+
+#define TESTUMAX(bits) glue3(u,bits,) = ~glue3(u,bits,); if (glue3(UINT,bits,_MAX) != glue3(u,bits,)) printf ("Something wrong with UINT%d_MAX\n", bits)
+
+#define REPORTERROR(msg) { err_n++; if (err_first <= 0) err_first = __LINE__; printf msg; }
+
+int main () {
+	int err_n = 0;
+	int err_first = 0;
+	DECL(I,8)
+	DECL(U,8)
+	DECL(I,16)
+	DECL(U,16)
+	DECL(I,32)
+	DECL(U,32)
+#ifdef INT64_MAX
+	DECL(I,64)
+	DECL(U,64)
+#endif
+	intmax_t imax = INTMAX_C(0);
+	uintmax_t umax = UINTMAX_C(0);
+	char str0[256], str1[256];
+
+	sprintf (str0, "%" PRINTF_INT32_MODIFIER "d", INT32_C(2147483647));
+	if (0 != strcmp (str0, "2147483647")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str0));
+	if (atoi(PRINTF_INT32_DEC_WIDTH) != (int) strlen(str0)) REPORTERROR (("Something wrong with PRINTF_INT32_DEC_WIDTH : %s\n", PRINTF_INT32_DEC_WIDTH));
+	sprintf (str0, "%" PRINTF_INT32_MODIFIER "u", UINT32_C(4294967295));
+	if (0 != strcmp (str0, "4294967295")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str0));
+	if (atoi(PRINTF_UINT32_DEC_WIDTH) != (int) strlen(str0)) REPORTERROR (("Something wrong with PRINTF_UINT32_DEC_WIDTH : %s\n", PRINTF_UINT32_DEC_WIDTH));
+#ifdef INT64_MAX
+	sprintf (str1, "%" PRINTF_INT64_MODIFIER "d", INT64_C(9223372036854775807));
+	if (0 != strcmp (str1, "9223372036854775807")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str1));
+	if (atoi(PRINTF_INT64_DEC_WIDTH) != (int) strlen(str1)) REPORTERROR (("Something wrong with PRINTF_INT64_DEC_WIDTH : %s, %d\n", PRINTF_INT64_DEC_WIDTH, (int) strlen(str1)));
+	sprintf (str1, "%" PRINTF_INT64_MODIFIER "u", UINT64_C(18446744073709550591));
+	if (0 != strcmp (str1, "18446744073709550591")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str1));
+	if (atoi(PRINTF_UINT64_DEC_WIDTH) != (int) strlen(str1)) REPORTERROR (("Something wrong with PRINTF_UINT64_DEC_WIDTH : %s, %d\n", PRINTF_UINT64_DEC_WIDTH, (int) strlen(str1)));
+#endif
+
+	sprintf (str0, "%d %x\n", 0, ~0);
+
+	sprintf (str1, "%d %x\n",  i8, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i8 : %s\n", str1));
+	sprintf (str1, "%u %x\n",  u8, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u8 : %s\n", str1));
+	sprintf (str1, "%d %x\n",  i16, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i16 : %s\n", str1));
+	sprintf (str1, "%u %x\n",  u16, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u16 : %s\n", str1));
+	sprintf (str1, "%" PRINTF_INT32_MODIFIER "d %x\n",  i32, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i32 : %s\n", str1));
+	sprintf (str1, "%" PRINTF_INT32_MODIFIER "u %x\n",  u32, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u32 : %s\n", str1));
+#ifdef INT64_MAX
+	sprintf (str1, "%" PRINTF_INT64_MODIFIER "d %x\n",  i64, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i64 : %s\n", str1));
+#endif
+	sprintf (str1, "%" PRINTF_INTMAX_MODIFIER "d %x\n",  imax, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with imax : %s\n", str1));
+	sprintf (str1, "%" PRINTF_INTMAX_MODIFIER "u %x\n",  umax, ~0);
+	if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with umax : %s\n", str1));
+
+	TESTUMAX(8);
+	TESTUMAX(16);
+	TESTUMAX(32);
+#ifdef INT64_MAX
+	TESTUMAX(64);
+#endif
+
+#define STR(v) #v
+#define Q(v) printf ("sizeof " STR(v) " = %u\n", (unsigned) sizeof (v));
+	if (err_n) {
+		printf ("pstdint.h is not correct.  Please use sizes below to correct it:\n");
+	}
+
+	Q(int)
+	Q(unsigned)
+	Q(long int)
+	Q(short int)
+	Q(int8_t)
+	Q(int16_t)
+	Q(int32_t)
+#ifdef INT64_MAX
+	Q(int64_t)
+#endif
+
+	return EXIT_SUCCESS;
+}
+
+#endif

dependencies/assimp/include/assimp/Compiler/pushpack1.h

@@ -0,0 +1,43 @@
+
+
+// ===============================================================================
+// May be included multiple times - sets structure packing to 1 
+// for all supported compilers. #include <poppack1.h> reverts the changes.
+//
+// Currently this works on the following compilers:
+// MSVC 7,8,9
+// GCC
+// BORLAND (complains about 'pack state changed but not reverted', but works)
+// Clang
+//
+//
+// USAGE:
+//
+// struct StructToBePacked {
+// } PACK_STRUCT;
+//
+// ===============================================================================
+
+#ifdef AI_PUSHPACK_IS_DEFINED
+#	error poppack1.h must be included after pushpack1.h
+#endif
+
+#if defined(_MSC_VER) ||  defined(__BORLANDC__) ||	defined (__BCPLUSPLUS__)
+#	pragma pack(push,1)
+#	define PACK_STRUCT
+#elif defined( __GNUC__ ) || defined(__clang__)
+#	if !defined(HOST_MINGW)
+#		define PACK_STRUCT	__attribute__((__packed__))
+#	else
+#		define PACK_STRUCT	__attribute__((gcc_struct, __packed__))
+#	endif
+#else
+#	error Compiler not supported
+#endif
+
+#if defined(_MSC_VER)
+// C4103: Packing was changed after the inclusion of the header, probably missing #pragma pop
+#	pragma warning (disable : 4103) 
+#endif
+
+#define AI_PUSHPACK_IS_DEFINED

dependencies/assimp/include/assimp/CreateAnimMesh.h

@@ -0,0 +1,58 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file CreateAnimMesh.h
+ *  Create AnimMesh from Mesh
+ */
+#ifndef INCLUDED_AI_CREATE_ANIM_MESH_H
+#define INCLUDED_AI_CREATE_ANIM_MESH_H
+
+#include <assimp/mesh.h>
+
+namespace Assimp    {
+
+/** Create aiAnimMesh from aiMesh. */
+ASSIMP_API aiAnimMesh *aiCreateAnimMesh(const aiMesh *mesh);
+
+} // end of namespace Assimp
+#endif // INCLUDED_AI_CREATE_ANIM_MESH_H
+

dependencies/assimp/include/assimp/DefaultIOStream.h

@@ -0,0 +1,140 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Default file I/O using fXXX()-family of functions */
+#ifndef AI_DEFAULTIOSTREAM_H_INC
+#define AI_DEFAULTIOSTREAM_H_INC
+
+#include <stdio.h>
+#include <assimp/IOStream.hpp>
+#include <assimp/importerdesc.h>
+#include <assimp/Defines.h>
+
+namespace Assimp    {
+
+// ----------------------------------------------------------------------------------
+//! @class  DefaultIOStream
+//! @brief  Default IO implementation, use standard IO operations
+//! @note   An instance of this class can exist without a valid file handle
+//!         attached to it. All calls fail, but the instance can nevertheless be
+//!         used with no restrictions.
+class ASSIMP_API DefaultIOStream : public IOStream
+{
+    friend class DefaultIOSystem;
+#if __ANDROID__
+# if __ANDROID_API__ > 9
+#  if defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)
+    friend class AndroidJNIIOSystem;
+#  endif // defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)
+# endif // __ANDROID_API__ > 9
+#endif // __ANDROID__
+
+protected:
+    DefaultIOStream() AI_NO_EXCEPT;
+    DefaultIOStream(FILE* pFile, const std::string &strFilename);
+
+public:
+    /** Destructor public to allow simple deletion to close the file. */
+    ~DefaultIOStream ();
+
+    // -------------------------------------------------------------------
+    /// Read from stream
+    size_t Read(void* pvBuffer,
+        size_t pSize,
+        size_t pCount);
+
+
+    // -------------------------------------------------------------------
+    /// Write to stream
+    size_t Write(const void* pvBuffer,
+        size_t pSize,
+        size_t pCount);
+
+    // -------------------------------------------------------------------
+    /// Seek specific position
+    aiReturn Seek(size_t pOffset,
+        aiOrigin pOrigin);
+
+    // -------------------------------------------------------------------
+    /// Get current seek position
+    size_t Tell() const;
+
+    // -------------------------------------------------------------------
+    /// Get size of file
+    size_t FileSize() const;
+
+    // -------------------------------------------------------------------
+    /// Flush file contents
+    void Flush();
+
+private:
+    //  File data-structure, using clib
+    FILE* mFile;
+    //  Filename
+    std::string mFilename;
+    // Cached file size
+    mutable size_t mCachedSize;
+};
+
+// ----------------------------------------------------------------------------------
+inline
+DefaultIOStream::DefaultIOStream() AI_NO_EXCEPT
+: mFile(nullptr)
+, mFilename("")
+, mCachedSize(SIZE_MAX) {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+inline
+DefaultIOStream::DefaultIOStream (FILE* pFile, const std::string &strFilename)
+: mFile(pFile)
+, mFilename(strFilename)
+, mCachedSize(SIZE_MAX) {
+    // empty
+}
+// ----------------------------------------------------------------------------------
+
+} // ns assimp
+
+#endif //!!AI_DEFAULTIOSTREAM_H_INC
+

dependencies/assimp/include/assimp/DefaultIOSystem.h

@@ -0,0 +1,93 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Default implementation of IOSystem using the standard C file functions */
+#ifndef AI_DEFAULTIOSYSTEM_H_INC
+#define AI_DEFAULTIOSYSTEM_H_INC
+
+#include <assimp/IOSystem.hpp>
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------
+/** Default implementation of IOSystem using the standard C file functions */
+class ASSIMP_API DefaultIOSystem : public IOSystem {
+public:
+    // -------------------------------------------------------------------
+    /** Tests for the existence of a file at the given path. */
+    bool Exists( const char* pFile) const;
+
+    // -------------------------------------------------------------------
+    /** Returns the directory separator. */
+    char getOsSeparator() const;
+
+    // -------------------------------------------------------------------
+    /** Open a new file with a given path. */
+    IOStream* Open( const char* pFile, const char* pMode = "rb");
+
+    // -------------------------------------------------------------------
+    /** Closes the given file and releases all resources associated with it. */
+    void Close( IOStream* pFile);
+
+    // -------------------------------------------------------------------
+    /** Compare two paths */
+    bool ComparePaths (const char* one, const char* second) const;
+
+    /** @brief get the file name of a full filepath
+     * example: /tmp/archive.tar.gz -> archive.tar.gz
+     */
+    static std::string fileName( const std::string &path );
+
+    /** @brief get the complete base name of a full filepath
+     * example: /tmp/archive.tar.gz -> archive.tar
+     */
+    static std::string completeBaseName( const std::string &path);
+
+    /** @brief get the path of a full filepath
+     * example: /tmp/archive.tar.gz -> /tmp/
+     */
+    static std::string absolutePath( const std::string &path);
+};
+
+} //!ns Assimp
+
+#endif //AI_DEFAULTIOSYSTEM_H_INC

dependencies/assimp/include/assimp/DefaultLogger.hpp

@@ -0,0 +1,188 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+/** @file DefaultLogger.hpp
+*/
+
+#ifndef INCLUDED_AI_DEFAULTLOGGER
+#define INCLUDED_AI_DEFAULTLOGGER
+
+#include "Logger.hpp"
+#include "LogStream.hpp"
+#include "NullLogger.hpp"
+#include <vector>
+
+namespace Assimp    {
+// ------------------------------------------------------------------------------------
+class IOStream;
+struct LogStreamInfo;
+
+/** default name of logfile */
+#define ASSIMP_DEFAULT_LOG_NAME "AssimpLog.txt"
+
+// ------------------------------------------------------------------------------------
+/** @brief CPP-API: Primary logging facility of Assimp.
+ *
+ *  The library stores its primary #Logger as a static member of this class.
+ *  #get() returns this primary logger. By default the underlying implementation is
+ *  just a #NullLogger which rejects all log messages. By calling #create(), logging
+ *  is turned on. To capture the log output multiple log streams (#LogStream) can be
+ *  attach to the logger. Some default streams for common streaming locations (such as
+ *  a file, std::cout, OutputDebugString()) are also provided.
+ *
+ *  If you wish to customize the logging at an even deeper level supply your own
+ *  implementation of #Logger to #set().
+ *  @note The whole logging stuff causes a small extra overhead for all imports. */
+class ASSIMP_API DefaultLogger :
+    public Logger   {
+
+public:
+
+    // ----------------------------------------------------------------------
+    /** @brief Creates a logging instance.
+     *  @param name Name for log file. Only valid in combination
+     *    with the aiDefaultLogStream_FILE flag.
+     *  @param severity Log severity, VERBOSE turns on debug messages
+     *  @param defStreams  Default log streams to be attached. Any bitwise
+     *    combination of the aiDefaultLogStream enumerated values.
+     *    If #aiDefaultLogStream_FILE is specified but an empty string is
+     *    passed for 'name', no log file is created at all.
+     *  @param  io IOSystem to be used to open external files (such as the
+     *   log file). Pass NULL to rely on the default implementation.
+     *  This replaces the default #NullLogger with a #DefaultLogger instance. */
+    static Logger *create(const char* name = ASSIMP_DEFAULT_LOG_NAME,
+        LogSeverity severity    = NORMAL,
+        unsigned int defStreams = aiDefaultLogStream_DEBUGGER | aiDefaultLogStream_FILE,
+        IOSystem* io            = NULL);
+
+    // ----------------------------------------------------------------------
+    /** @brief Setup a custom #Logger implementation.
+     *
+     *  Use this if the provided #DefaultLogger class doesn't fit into
+     *  your needs. If the provided message formatting is OK for you,
+     *  it's much easier to use #create() and to attach your own custom
+     *  output streams to it.
+     *  @param logger Pass NULL to setup a default NullLogger*/
+    static void set (Logger *logger);
+
+    // ----------------------------------------------------------------------
+    /** @brief  Getter for singleton instance
+     *   @return Only instance. This is never null, but it could be a
+     *  NullLogger. Use isNullLogger to check this.*/
+    static Logger *get();
+
+    // ----------------------------------------------------------------------
+    /** @brief  Return whether a #NullLogger is currently active
+     *  @return true if the current logger is a #NullLogger.
+     *  Use create() or set() to setup a logger that does actually do
+     *  something else than just rejecting all log messages. */
+    static bool isNullLogger();
+
+    // ----------------------------------------------------------------------
+    /** @brief  Kills the current singleton logger and replaces it with a
+     *  #NullLogger instance. */
+    static void kill();
+
+    // ----------------------------------------------------------------------
+    /** @copydoc Logger::attachStream   */
+    bool attachStream(LogStream *pStream,
+        unsigned int severity);
+
+    // ----------------------------------------------------------------------
+    /** @copydoc Logger::detatchStream */
+    bool detatchStream(LogStream *pStream,
+        unsigned int severity);
+
+private:
+    // ----------------------------------------------------------------------
+    /** @briefPrivate construction for internal use by create().
+     *  @param severity Logging granularity  */
+    explicit DefaultLogger(LogSeverity severity);
+
+    // ----------------------------------------------------------------------
+    /** @briefDestructor    */
+    ~DefaultLogger();
+
+    /** @brief  Logs debug infos, only been written when severity level VERBOSE is set */
+    void OnDebug(const char* message);
+
+    /** @brief  Logs an info message */
+    void OnInfo(const char*  message);
+
+    /** @brief  Logs a warning message */
+    void OnWarn(const char*  message);
+
+    /** @brief  Logs an error message */
+    void OnError(const char* message);
+
+    // ----------------------------------------------------------------------
+    /** @brief Writes a message to all streams */
+    void WriteToStreams(const char* message, ErrorSeverity ErrorSev );
+
+    // ----------------------------------------------------------------------
+    /** @brief Returns the thread id.
+     *  @note This is an OS specific feature, if not supported, a
+     *    zero will be returned.
+     */
+    unsigned int GetThreadID();
+
+private:
+    //  Aliases for stream container
+    typedef std::vector<LogStreamInfo*> StreamArray;
+    typedef std::vector<LogStreamInfo*>::iterator StreamIt;
+    typedef std::vector<LogStreamInfo*>::const_iterator ConstStreamIt;
+
+    //! only logging instance
+    static Logger *m_pLogger;
+    static NullLogger s_pNullLogger;
+
+    //! Attached streams
+    StreamArray m_StreamArray;
+
+    bool noRepeatMsg;
+    char lastMsg[MAX_LOG_MESSAGE_LENGTH*2];
+    size_t lastLen;
+};
+// ------------------------------------------------------------------------------------
+
+} // Namespace Assimp
+
+#endif // !! INCLUDED_AI_DEFAULTLOGGER

dependencies/assimp/include/assimp/Defines.h

@@ -0,0 +1,49 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2012, assimp team
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+// We need those constants, workaround for any platforms where nobody defined them yet
+#if (!defined SIZE_MAX)
+#   define SIZE_MAX (~((size_t)0))
+#endif
+
+#if (!defined UINT_MAX)
+#   define UINT_MAX (~((unsigned int)0))
+#endif
+

dependencies/assimp/include/assimp/Exceptional.h

@@ -0,0 +1,125 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2008, assimp team
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#ifndef INCLUDED_EXCEPTIONAL_H
+#define INCLUDED_EXCEPTIONAL_H
+
+#include <stdexcept>
+#include <assimp/DefaultIOStream.h>
+using std::runtime_error;
+
+#ifdef _MSC_VER
+#   pragma warning(disable : 4275)
+#endif
+
+// ---------------------------------------------------------------------------
+/** FOR IMPORTER PLUGINS ONLY: Simple exception class to be thrown if an
+ *  unrecoverable error occurs while importing. Loading APIs return
+ *  NULL instead of a valid aiScene then.  */
+class DeadlyImportError
+    : public runtime_error
+{
+public:
+    /** Constructor with arguments */
+    explicit DeadlyImportError( const std::string& errorText)
+        : runtime_error(errorText)
+    {
+    }
+
+private:
+};
+
+typedef DeadlyImportError DeadlyExportError;
+
+#ifdef _MSC_VER
+#   pragma warning(default : 4275)
+#endif
+
+// ---------------------------------------------------------------------------
+template <typename T>
+struct ExceptionSwallower   {
+    T operator ()() const {
+        return T();
+    }
+};
+
+// ---------------------------------------------------------------------------
+template <typename T>
+struct ExceptionSwallower<T*>   {
+    T* operator ()() const {
+        return NULL;
+    }
+};
+
+// ---------------------------------------------------------------------------
+template <>
+struct ExceptionSwallower<aiReturn> {
+    aiReturn operator ()() const {
+        try {
+            throw;
+        }
+        catch (std::bad_alloc&) {
+            return aiReturn_OUTOFMEMORY;
+        }
+        catch (...) {
+            return aiReturn_FAILURE;
+        }
+    }
+};
+
+// ---------------------------------------------------------------------------
+template <>
+struct ExceptionSwallower<void> {
+    void operator ()() const {
+        return;
+    }
+};
+
+#define ASSIMP_BEGIN_EXCEPTION_REGION()\
+{\
+    try {
+
+#define ASSIMP_END_EXCEPTION_REGION(type)\
+    } catch(...) {\
+        return ExceptionSwallower<type>()();\
+    }\
+}
+
+#endif // INCLUDED_EXCEPTIONAL_H

dependencies/assimp/include/assimp/Exporter.hpp

@@ -0,0 +1,505 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  Exporter.hpp
+*  @brief Defines the CPP-API for the Assimp export interface
+*/
+#pragma once
+#ifndef AI_EXPORT_HPP_INC
+#define AI_EXPORT_HPP_INC
+
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
+#include "cexport.h"
+#include <map>
+
+namespace Assimp {
+    
+class ExporterPimpl;
+class IOSystem;
+class ProgressHandler;
+
+// ----------------------------------------------------------------------------------
+/** CPP-API: The Exporter class forms an C++ interface to the export functionality
+ * of the Open Asset Import Library. Note that the export interface is available
+ * only if Assimp has been built with ASSIMP_BUILD_NO_EXPORT not defined.
+ *
+ * The interface is modeled after the importer interface and mostly
+ * symmetric. The same rules for threading etc. apply.
+ *
+ * In a nutshell, there are two export interfaces: #Export, which writes the
+ * output file(s) either to the regular file system or to a user-supplied
+ * #IOSystem, and #ExportToBlob which returns a linked list of memory
+ * buffers (blob), each referring to one output file (in most cases
+ * there will be only one output file of course, but this extra complexity is
+ * needed since Assimp aims at supporting a wide range of file formats).
+ *
+ * #ExportToBlob is especially useful if you intend to work
+ * with the data in-memory.
+*/
+class ASSIMP_API ExportProperties;
+
+class ASSIMP_API Exporter {
+public:
+    /** Function pointer type of a Export worker function */
+    typedef void (*fpExportFunc)(const char*, IOSystem*, const aiScene*, const ExportProperties*);
+
+    /** Internal description of an Assimp export format option */
+    struct ExportFormatEntry {
+        /// Public description structure to be returned by aiGetExportFormatDescription()
+        aiExportFormatDesc mDescription;
+
+        // Worker function to do the actual exporting
+        fpExportFunc mExportFunction;
+
+        // Post-processing steps to be executed PRIOR to invoking mExportFunction
+        unsigned int mEnforcePP;
+
+        // Constructor to fill all entries
+        ExportFormatEntry( const char* pId, const char* pDesc, const char* pExtension, fpExportFunc pFunction, unsigned int pEnforcePP = 0u)
+        {
+            mDescription.id = pId;
+            mDescription.description = pDesc;
+            mDescription.fileExtension = pExtension;
+            mExportFunction = pFunction;
+            mEnforcePP = pEnforcePP;
+        }
+
+        ExportFormatEntry() :
+            mExportFunction()
+          , mEnforcePP()
+        {
+            mDescription.id = NULL;
+            mDescription.description = NULL;
+            mDescription.fileExtension = NULL;
+        }
+    };
+
+    /**
+     *  @brief  The class constructor.
+     */
+    Exporter();
+
+    /**
+    *  @brief  The class destructor.
+    */
+    ~Exporter();
+
+    // -------------------------------------------------------------------
+    /** Supplies a custom IO handler to the exporter to use to open and
+     * access files.
+     *
+     * If you need #Export to use custom IO logic to access the files,
+     * you need to supply a custom implementation of IOSystem and
+     * IOFile to the exporter.
+     *
+     * #Exporter takes ownership of the object and will destroy it
+     * afterwards. The previously assigned handler will be deleted.
+     * Pass NULL to take again ownership of your IOSystem and reset Assimp
+     * to use its default implementation, which uses plain file IO.
+     *
+     * @param pIOHandler The IO handler to be used in all file accesses
+     *   of the Importer. */
+    void SetIOHandler( IOSystem* pIOHandler);
+
+    // -------------------------------------------------------------------
+    /** Retrieves the IO handler that is currently set.
+     * You can use #IsDefaultIOHandler() to check whether the returned
+     * interface is the default IO handler provided by ASSIMP. The default
+     * handler is active as long the application doesn't supply its own
+     * custom IO handler via #SetIOHandler().
+     * @return A valid IOSystem interface, never NULL. */
+    IOSystem* GetIOHandler() const;
+
+    // -------------------------------------------------------------------
+    /** Checks whether a default IO handler is active
+     * A default handler is active as long the application doesn't
+     * supply its own custom IO handler via #SetIOHandler().
+     * @return true by default */
+    bool IsDefaultIOHandler() const;
+
+    // -------------------------------------------------------------------
+    /** Supplies a custom progress handler to the exporter. This
+     *  interface exposes an #Update() callback, which is called
+     *  more or less periodically (please don't sue us if it
+     *  isn't as periodically as you'd like it to have ...).
+     *  This can be used to implement progress bars and loading
+     *  timeouts.
+     *  @param pHandler Progress callback interface. Pass nullptr to
+     *    disable progress reporting.
+     *  @note Progress handlers can be used to abort the loading
+     *    at almost any time.*/
+    void SetProgressHandler(ProgressHandler* pHandler);
+
+    // -------------------------------------------------------------------
+    /** Exports the given scene to a chosen file format. Returns the exported
+    * data as a binary blob which you can write into a file or something.
+    * When you're done with the data, simply let the #Exporter instance go
+    * out of scope to have it released automatically.
+    * @param pScene The scene to export. Stays in possession of the caller,
+    *   is not changed by the function.
+    * @param pFormatId ID string to specify to which format you want to
+    *   export to. Use
+    * #GetExportFormatCount / #GetExportFormatDescription to learn which
+    *   export formats are available.
+    * @param pPreprocessing See the documentation for #Export
+    * @return the exported data or NULL in case of error.
+    * @note If the Exporter instance did already hold a blob from
+    *   a previous call to #ExportToBlob, it will be disposed.
+    *   Any IO handlers set via #SetIOHandler are ignored here.
+    * @note Use aiCopyScene() to get a modifiable copy of a previously
+    *   imported scene. */
+    const aiExportDataBlob* ExportToBlob(const aiScene* pScene, const char* pFormatId,
+        unsigned int pPreprocessing = 0u, const ExportProperties* pProperties = nullptr);
+    const aiExportDataBlob* ExportToBlob(  const aiScene* pScene, const std::string& pFormatId,
+        unsigned int pPreprocessing = 0u, const ExportProperties* pProperties = nullptr);
+
+    // -------------------------------------------------------------------
+    /** Convenience function to export directly to a file. Use
+     *  #SetIOSystem to supply a custom IOSystem to gain fine-grained control
+     *  about the output data flow of the export process.
+     * @param pBlob A data blob obtained from a previous call to #aiExportScene. Must not be NULL.
+     * @param pPath Full target file name. Target must be accessible.
+     * @param pPreprocessing Accepts any choice of the #aiPostProcessSteps enumerated
+     *   flags, but in reality only a subset of them makes sense here. Specifying
+     *   'preprocessing' flags is useful if the input scene does not conform to
+     *   Assimp's default conventions as specified in the @link data Data Structures Page @endlink.
+     *   In short, this means the geometry data should use a right-handed coordinate systems, face
+     *   winding should be counter-clockwise and the UV coordinate origin is assumed to be in
+     *   the upper left. The #aiProcess_MakeLeftHanded, #aiProcess_FlipUVs and
+     *   #aiProcess_FlipWindingOrder flags are used in the import side to allow users
+     *   to have those defaults automatically adapted to their conventions. Specifying those flags
+     *   for exporting has the opposite effect, respectively. Some other of the
+     *   #aiPostProcessSteps enumerated values may be useful as well, but you'll need
+     *   to try out what their effect on the exported file is. Many formats impose
+     *   their own restrictions on the structure of the geometry stored therein,
+     *   so some preprocessing may have little or no effect at all, or may be
+     *   redundant as exporters would apply them anyhow. A good example
+     *   is triangulation - whilst you can enforce it by specifying
+     *   the #aiProcess_Triangulate flag, most export formats support only
+     *   triangulate data so they would run the step even if it wasn't requested.
+     *
+     *   If assimp detects that the input scene was directly taken from the importer side of
+     *   the library (i.e. not copied using aiCopyScene and potentially modified afterwards),
+     *   any post-processing steps already applied to the scene will not be applied again, unless
+     *   they show non-idempotent behavior (#aiProcess_MakeLeftHanded, #aiProcess_FlipUVs and
+     *   #aiProcess_FlipWindingOrder).
+     * @return AI_SUCCESS if everything was fine.
+     * @note Use aiCopyScene() to get a modifiable copy of a previously
+     *   imported scene.*/
+    aiReturn Export( const aiScene* pScene, const char* pFormatId, const char* pPath,
+        unsigned int pPreprocessing = 0u, const ExportProperties* pProperties = nullptr);
+    aiReturn Export( const aiScene* pScene, const std::string& pFormatId, const std::string& pPath,
+        unsigned int pPreprocessing = 0u, const ExportProperties* pProperties = nullptr);
+
+    // -------------------------------------------------------------------
+    /** Returns an error description of an error that occurred in #Export
+     *    or #ExportToBlob
+     *
+     * Returns an empty string if no error occurred.
+     * @return A description of the last error, an empty string if no
+     *   error occurred. The string is never NULL.
+     *
+     * @note The returned function remains valid until one of the
+     * following methods is called: #Export, #ExportToBlob, #FreeBlob */
+    const char* GetErrorString() const;
+
+    // -------------------------------------------------------------------
+    /** Return the blob obtained from the last call to #ExportToBlob */
+    const aiExportDataBlob* GetBlob() const;
+
+    // -------------------------------------------------------------------
+    /** Orphan the blob from the last call to #ExportToBlob. This means
+     *  the caller takes ownership and is thus responsible for calling
+     *  the C API function #aiReleaseExportBlob to release it. */
+    const aiExportDataBlob* GetOrphanedBlob() const;
+
+    // -------------------------------------------------------------------
+    /** Frees the current blob.
+     *
+     *  The function does nothing if no blob has previously been
+     *  previously produced via #ExportToBlob. #FreeBlob is called
+     *  automatically by the destructor. The only reason to call
+     *  it manually would be to reclaim as much storage as possible
+     *  without giving up the #Exporter instance yet. */
+    void FreeBlob( );
+
+    // -------------------------------------------------------------------
+    /** Returns the number of export file formats available in the current
+     *  Assimp build. Use #Exporter::GetExportFormatDescription to
+     *  retrieve infos of a specific export format.
+     *
+     *  This includes built-in exporters as well as exporters registered
+     *  using #RegisterExporter.
+     **/
+    size_t GetExportFormatCount() const;
+
+    // -------------------------------------------------------------------
+    /** Returns a description of the nth export file format. Use #
+     *  #Exporter::GetExportFormatCount to learn how many export
+     *  formats are supported.
+     *
+     * The returned pointer is of static storage duration if the
+     * pIndex pertains to a built-in exporter (i.e. one not registered
+     * via #RegistrerExporter). It is restricted to the life-time of the
+     * #Exporter instance otherwise.
+     *
+     * @param pIndex Index of the export format to retrieve information
+     *  for. Valid range is 0 to #Exporter::GetExportFormatCount
+     * @return A description of that specific export format.
+     *  NULL if pIndex is out of range. */
+    const aiExportFormatDesc* GetExportFormatDescription( size_t pIndex ) const;
+
+    // -------------------------------------------------------------------
+    /** Register a custom exporter. Custom export formats are limited to
+     *    to the current #Exporter instance and do not affect the
+     *    library globally. The indexes under which the format's
+     *    export format description can be queried are assigned
+     *    monotonously.
+     *  @param desc Exporter description.
+     *  @return aiReturn_SUCCESS if the export format was successfully
+     *    registered. A common cause that would prevent an exporter
+     *    from being registered is that its format id is already
+     *    occupied by another format. */
+    aiReturn RegisterExporter(const ExportFormatEntry& desc);
+
+    // -------------------------------------------------------------------
+    /** Remove an export format previously registered with #RegisterExporter
+     *  from the #Exporter instance (this can also be used to drop
+     *  built-in exporters because those are implicitly registered
+     *  using #RegisterExporter).
+     *  @param id Format id to be unregistered, this refers to the
+     *    'id' field of #aiExportFormatDesc.
+     *  @note Calling this method on a format description not yet registered
+     *    has no effect.*/
+    void UnregisterExporter(const char* id);
+
+protected:
+    // Just because we don't want you to know how we're hacking around.
+    ExporterPimpl* pimpl;
+};
+
+class ASSIMP_API ExportProperties {
+public:
+    // Data type to store the key hash
+    typedef unsigned int KeyType;
+
+    // typedefs for our four configuration maps.
+    // We don't need more, so there is no need for a generic solution
+    typedef std::map<KeyType, int> IntPropertyMap;
+    typedef std::map<KeyType, ai_real> FloatPropertyMap;
+    typedef std::map<KeyType, std::string> StringPropertyMap;
+    typedef std::map<KeyType, aiMatrix4x4> MatrixPropertyMap;
+
+public:
+    /** Standard constructor
+    * @see ExportProperties()
+    */
+    ExportProperties();
+
+    // -------------------------------------------------------------------
+    /** Copy constructor.
+     *
+     * This copies the configuration properties of another ExportProperties.
+     * @see ExportProperties(const ExportProperties& other)
+     */
+    ExportProperties(const ExportProperties& other);
+
+    // -------------------------------------------------------------------
+    /** Set an integer configuration property.
+     * @param szName Name of the property. All supported properties
+     *   are defined in the aiConfig.g header (all constants share the
+     *   prefix AI_CONFIG_XXX and are simple strings).
+     * @param iValue New value of the property
+     * @return true if the property was set before. The new value replaces
+     *   the previous value in this case.
+     * @note Property of different types (float, int, string ..) are kept
+     *   on different stacks, so calling SetPropertyInteger() for a
+     *   floating-point property has no effect - the loader will call
+     *   GetPropertyFloat() to read the property, but it won't be there.
+     */
+    bool SetPropertyInteger(const char* szName, int iValue);
+
+    // -------------------------------------------------------------------
+    /** Set a boolean configuration property. Boolean properties
+     *  are stored on the integer stack internally so it's possible
+     *  to set them via #SetPropertyBool and query them with
+     *  #GetPropertyBool and vice versa.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyBool(const char* szName, bool value)    {
+        return SetPropertyInteger(szName,value);
+    }
+
+    // -------------------------------------------------------------------
+    /** Set a floating-point configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyFloat(const char* szName, ai_real fValue);
+
+    // -------------------------------------------------------------------
+    /** Set a string configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyString(const char* szName, const std::string& sValue);
+
+    // -------------------------------------------------------------------
+    /** Set a matrix configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyMatrix(const char* szName, const aiMatrix4x4& sValue);
+
+    // -------------------------------------------------------------------
+    /** Get a configuration property.
+     * @param szName Name of the property. All supported properties
+     *   are defined in the aiConfig.g header (all constants share the
+     *   prefix AI_CONFIG_XXX).
+     * @param iErrorReturn Value that is returned if the property
+     *   is not found.
+     * @return Current value of the property
+     * @note Property of different types (float, int, string ..) are kept
+     *   on different lists, so calling SetPropertyInteger() for a
+     *   floating-point property has no effect - the loader will call
+     *   GetPropertyFloat() to read the property, but it won't be there.
+     */
+    int GetPropertyInteger(const char* szName,
+        int iErrorReturn = 0xffffffff) const;
+
+    // -------------------------------------------------------------------
+    /** Get a boolean configuration property. Boolean properties
+     *  are stored on the integer stack internally so it's possible
+     *  to set them via #SetPropertyBool and query them with
+     *  #GetPropertyBool and vice versa.
+     * @see GetPropertyInteger()
+     */
+    bool GetPropertyBool(const char* szName, bool bErrorReturn = false) const {
+        return GetPropertyInteger(szName,bErrorReturn)!=0;
+    }
+
+    // -------------------------------------------------------------------
+    /** Get a floating-point configuration property
+     * @see GetPropertyInteger()
+     */
+    ai_real GetPropertyFloat(const char* szName,
+        ai_real fErrorReturn = 10e10f) const;
+
+    // -------------------------------------------------------------------
+    /** Get a string configuration property
+     *
+     *  The return value remains valid until the property is modified.
+     * @see GetPropertyInteger()
+     */
+    const std::string GetPropertyString(const char* szName,
+        const std::string& sErrorReturn = "") const;
+
+    // -------------------------------------------------------------------
+    /** Get a matrix configuration property
+     *
+     *  The return value remains valid until the property is modified.
+     * @see GetPropertyInteger()
+     */
+    const aiMatrix4x4 GetPropertyMatrix(const char* szName,
+        const aiMatrix4x4& sErrorReturn = aiMatrix4x4()) const;
+
+    // -------------------------------------------------------------------
+    /** Determine a integer configuration property has been set.
+    * @see HasPropertyInteger()
+     */
+    bool HasPropertyInteger(const char* szName) const;
+
+    /** Determine a boolean configuration property has been set.
+    * @see HasPropertyBool()
+     */
+    bool HasPropertyBool(const char* szName) const;
+
+    /** Determine a boolean configuration property has been set.
+    * @see HasPropertyFloat()
+     */
+    bool HasPropertyFloat(const char* szName) const;
+
+    /** Determine a String configuration property has been set.
+    * @see HasPropertyString()
+     */
+    bool HasPropertyString(const char* szName) const;
+
+    /** Determine a Matrix configuration property has been set.
+    * @see HasPropertyMatrix()
+     */
+    bool HasPropertyMatrix(const char* szName) const;
+
+protected:
+
+    /** List of integer properties */
+    IntPropertyMap mIntProperties;
+
+    /** List of floating-point properties */
+    FloatPropertyMap mFloatProperties;
+
+    /** List of string properties */
+    StringPropertyMap mStringProperties;
+
+    /** List of Matrix properties */
+    MatrixPropertyMap mMatrixProperties;
+};
+
+// ----------------------------------------------------------------------------------
+inline 
+const aiExportDataBlob* Exporter::ExportToBlob(  const aiScene* pScene, const std::string& pFormatId,
+                                                 unsigned int pPreprocessing, const ExportProperties* pProperties)
+{
+    return ExportToBlob(pScene,pFormatId.c_str(),pPreprocessing, pProperties);
+}
+
+// ----------------------------------------------------------------------------------
+inline
+aiReturn Exporter :: Export( const aiScene* pScene, const std::string& pFormatId, 
+                                    const std::string& pPath, unsigned int pPreprocessing, 
+                                    const ExportProperties* pProperties)
+{
+    return Export(pScene,pFormatId.c_str(),pPath.c_str(),pPreprocessing, pProperties);
+}
+
+} // namespace Assimp
+
+#endif // ASSIMP_BUILD_NO_EXPORT
+#endif // AI_EXPORT_HPP_INC

dependencies/assimp/include/assimp/GenericProperty.h

@@ -0,0 +1,133 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#ifndef AI_GENERIC_PROPERTY_H_INCLUDED
+#define AI_GENERIC_PROPERTY_H_INCLUDED
+
+#include <assimp/Importer.hpp>
+#include <assimp/ai_assert.h>
+#include "Hash.h"
+
+#include <map>
+
+// ------------------------------------------------------------------------------------------------
+template <class T>
+inline
+bool SetGenericProperty(std::map< unsigned int, T >& list,
+        const char* szName, const T& value) {
+    ai_assert(nullptr != szName);
+    const uint32_t hash = SuperFastHash(szName);
+
+    typename std::map<unsigned int, T>::iterator it = list.find(hash);
+    if (it == list.end())   {
+        list.insert(std::pair<unsigned int, T>( hash, value ));
+        return false;
+    }
+    (*it).second = value;
+
+    return true;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <class T>
+inline
+const T& GetGenericProperty(const std::map< unsigned int, T >& list,
+        const char* szName, const T& errorReturn) {
+    ai_assert(nullptr != szName);
+    const uint32_t hash = SuperFastHash(szName);
+
+    typename std::map<unsigned int, T>::const_iterator it = list.find(hash);
+    if (it == list.end()) {
+        return errorReturn;
+    }
+
+    return (*it).second;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Special version for pointer types - they will be deleted when replaced with another value
+// passing NULL removes the whole property
+template <class T>
+inline
+void SetGenericPropertyPtr(std::map< unsigned int, T* >& list,
+        const char* szName, T* value, bool* bWasExisting = nullptr ) {
+    ai_assert(nullptr != szName);
+    const uint32_t hash = SuperFastHash(szName);
+
+    typename std::map<unsigned int, T*>::iterator it = list.find(hash);
+    if (it == list.end())   {
+        if (bWasExisting) {
+            *bWasExisting = false;
+        }
+
+        list.insert(std::pair<unsigned int,T*>( hash, value ));
+        return;
+    }
+    if ((*it).second != value)  {
+        delete (*it).second;
+        (*it).second = value;
+    }
+    if (!value) {
+        list.erase(it);
+    }
+    if (bWasExisting) {
+        *bWasExisting = true;
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+template <class T>
+inline
+bool HasGenericProperty(const std::map< unsigned int, T >& list,
+        const char* szName) {
+    ai_assert(nullptr != szName);
+    const uint32_t hash = SuperFastHash(szName);
+
+    typename std::map<unsigned int, T>::const_iterator it = list.find(hash);
+    if (it == list.end()) {
+        return false;
+    }
+
+    return true;
+}
+
+#endif // !! AI_GENERIC_PROPERTY_H_INCLUDED

dependencies/assimp/include/assimp/Hash.h

@@ -0,0 +1,118 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#ifndef AI_HASH_H_INCLUDED
+#define AI_HASH_H_INCLUDED
+
+#include <stdint.h>
+#include <string.h>
+
+// ------------------------------------------------------------------------------------------------
+// Hashing function taken from
+// http://www.azillionmonkeys.com/qed/hash.html
+// (incremental version)
+//
+// This code is Copyright 2004-2008 by Paul Hsieh. It is used here in the belief that
+// Assimp's license is considered compatible with Pauls's derivative license as specified
+// on his web page.
+//
+// (stdint.h should have been been included here)
+// ------------------------------------------------------------------------------------------------
+#undef get16bits
+#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
+  || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
+#define get16bits(d) (*((const uint16_t *) (d)))
+#endif
+
+#if !defined (get16bits)
+#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
+                       +(uint32_t)(((const uint8_t *)(d))[0]) )
+#endif
+
+// ------------------------------------------------------------------------------------------------
+inline uint32_t SuperFastHash (const char * data, uint32_t len = 0, uint32_t hash = 0) {
+uint32_t tmp;
+int rem;
+
+    if (!data) return 0;
+    if (!len)len = (uint32_t)::strlen(data);
+
+    rem = len & 3;
+    len >>= 2;
+
+    /* Main loop */
+    for (;len > 0; len--) {
+        hash  += get16bits (data);
+        tmp    = (get16bits (data+2) << 11) ^ hash;
+        hash   = (hash << 16) ^ tmp;
+        data  += 2*sizeof (uint16_t);
+        hash  += hash >> 11;
+    }
+
+    /* Handle end cases */
+    switch (rem) {
+        case 3: hash += get16bits (data);
+                hash ^= hash << 16;
+                hash ^= data[sizeof (uint16_t)] << 18;
+                hash += hash >> 11;
+                break;
+        case 2: hash += get16bits (data);
+                hash ^= hash << 11;
+                hash += hash >> 17;
+                break;
+        case 1: hash += *data;
+                hash ^= hash << 10;
+                hash += hash >> 1;
+    }
+
+    /* Force "avalanching" of final 127 bits */
+    hash ^= hash << 3;
+    hash += hash >> 5;
+    hash ^= hash << 4;
+    hash += hash >> 17;
+    hash ^= hash << 25;
+    hash += hash >> 6;
+
+    return hash;
+}
+
+#endif // !! AI_HASH_H_INCLUDED

dependencies/assimp/include/assimp/IOStream.hpp

@@ -0,0 +1,142 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file IOStream.hpp
+ *  @brief File I/O wrappers for C++.
+ */
+
+#pragma once
+#ifndef AI_IOSTREAM_H_INC
+#define AI_IOSTREAM_H_INC
+
+#include "types.h"
+
+#ifndef __cplusplus
+#   error This header requires C++ to be used. aiFileIO.h is the \
+    corresponding C interface.
+#endif
+
+namespace Assimp    {
+
+// ----------------------------------------------------------------------------------
+/** @brief CPP-API: Class to handle file I/O for C++
+ *
+ *  Derive an own implementation from this interface to provide custom IO handling
+ *  to the Importer. If you implement this interface, be sure to also provide an
+ *  implementation for IOSystem that creates instances of your custom IO class.
+*/
+class ASSIMP_API IOStream
+#ifndef SWIG
+    : public Intern::AllocateFromAssimpHeap
+#endif
+{
+protected:
+    /** Constructor protected, use IOSystem::Open() to create an instance. */
+    IOStream() AI_NO_EXCEPT;
+
+public:
+    // -------------------------------------------------------------------
+    /** @brief Destructor. Deleting the object closes the underlying file,
+     * alternatively you may use IOSystem::Close() to release the file.
+     */
+    virtual ~IOStream();
+
+    // -------------------------------------------------------------------
+    /** @brief Read from the file
+     *
+     * See fread() for more details
+     * This fails for write-only files */
+    virtual size_t Read(void* pvBuffer,
+        size_t pSize,
+        size_t pCount) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Write to the file
+    *
+    * See fwrite() for more details
+    * This fails for read-only files */
+    virtual size_t Write(const void* pvBuffer,
+        size_t pSize,
+        size_t pCount) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Set the read/write cursor of the file
+     *
+     * Note that the offset is _negative_ for aiOrigin_END.
+     * See fseek() for more details */
+    virtual aiReturn Seek(size_t pOffset,
+        aiOrigin pOrigin) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Get the current position of the read/write cursor
+     *
+     * See ftell() for more details */
+    virtual size_t Tell() const = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Returns filesize
+     *  Returns the filesize. */
+    virtual size_t FileSize() const = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Flush the contents of the file buffer (for writers)
+     *  See fflush() for more details.
+     */
+    virtual void Flush() = 0;
+}; //! class IOStream
+
+// ----------------------------------------------------------------------------------
+inline
+IOStream::IOStream() AI_NO_EXCEPT {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+inline
+IOStream::~IOStream() {
+    // empty
+}
+// ----------------------------------------------------------------------------------
+
+} //!namespace Assimp
+
+#endif //!!AI_IOSTREAM_H_INC

dependencies/assimp/include/assimp/IOStreamBuffer.h

@@ -0,0 +1,355 @@
+#pragma once
+
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#include <assimp/types.h>
+#include <assimp/IOStream.hpp>
+
+#include "ParsingUtils.h"
+
+#include <vector>
+
+namespace Assimp {
+
+// ---------------------------------------------------------------------------
+/**
+ *  Implementation of a cached stream buffer.
+ */
+template<class T>
+class IOStreamBuffer {
+public:
+    /// @brief  The class constructor.
+    IOStreamBuffer( size_t cache = 4096 * 4096 );
+
+    /// @brief  The class destructor.
+    ~IOStreamBuffer();
+
+    /// @brief  Will open the cached access for a given stream.
+    /// @param  stream      The stream to cache.
+    /// @return true if successful.
+    bool open( IOStream *stream );
+
+    /// @brief  Will close the cached access.
+    /// @return true if successful.
+    bool close();
+
+    /// @brief  Returns the file-size.
+    /// @return The file-size.
+    size_t size() const;
+    
+    /// @brief  Returns the cache size.
+    /// @return The cache size.
+    size_t cacheSize() const;
+
+    /// @brief  Will read the next block.
+    /// @return true if successful.
+    bool readNextBlock();
+
+    /// @brief  Returns the number of blocks to read.
+    /// @return The number of blocks.
+    size_t getNumBlocks() const;
+
+    /// @brief  Returns the current block index.
+    /// @return The current block index.
+    size_t getCurrentBlockIndex() const;
+
+    /// @brief  Returns the current file pos.
+    /// @return The current file pos.
+    size_t getFilePos() const;
+
+    /// @brief  Will read the next line.
+    /// @param  buffer      The buffer for the next line.
+    /// @return true if successful.
+    bool getNextDataLine( std::vector<T> &buffer, T continuationToken );
+
+    /// @brief  Will read the next line ascii or binary end line char.
+    /// @param  buffer      The buffer for the next line.
+    /// @return true if successful.
+    bool getNextLine(std::vector<T> &buffer);
+
+    /// @brief  Will read the next block.
+    /// @param  buffer      The buffer for the next block.
+    /// @return true if successful.
+    bool getNextBlock( std::vector<T> &buffer );
+
+private:
+    IOStream *m_stream;
+    size_t m_filesize;
+    size_t m_cacheSize;
+    size_t m_numBlocks;
+    size_t m_blockIdx;
+    std::vector<T> m_cache;
+    size_t m_cachePos;
+    size_t m_filePos;
+};
+
+template<class T>
+inline
+IOStreamBuffer<T>::IOStreamBuffer( size_t cache )
+: m_stream( nullptr )
+, m_filesize( 0 )
+, m_cacheSize( cache )
+, m_numBlocks( 0 )
+, m_blockIdx( 0 )
+, m_cachePos( 0 )
+, m_filePos( 0 ) {
+    m_cache.resize( cache );
+    std::fill( m_cache.begin(), m_cache.end(), '\n' );
+}
+
+template<class T>
+inline
+IOStreamBuffer<T>::~IOStreamBuffer() {
+    // empty
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::open( IOStream *stream ) {
+    //  file still opened!
+    if ( nullptr != m_stream ) {
+        return false;
+    }
+
+    //  Invalid stream pointer
+    if ( nullptr == stream ) {
+        return false;
+    }
+
+    m_stream = stream;
+    m_filesize = m_stream->FileSize();
+    if ( m_filesize == 0 ) {
+        return false;
+    }
+    if ( m_filesize < m_cacheSize ) {
+        m_cacheSize = m_filesize;
+    }
+
+    m_numBlocks = m_filesize / m_cacheSize;
+    if ( ( m_filesize % m_cacheSize ) > 0 ) {
+        m_numBlocks++;
+    }
+
+    return true;
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::close() {
+    if ( nullptr == m_stream ) {
+        return false;
+    }
+
+    // init counters and state vars
+    m_stream    = nullptr;
+    m_filesize  = 0;
+    m_numBlocks = 0;
+    m_blockIdx  = 0;
+    m_cachePos  = 0;
+    m_filePos   = 0;
+
+    return true;
+}
+
+template<class T>
+inline
+size_t IOStreamBuffer<T>::size() const {
+    return m_filesize;
+}
+
+template<class T>
+inline
+size_t IOStreamBuffer<T>::cacheSize() const {
+    return m_cacheSize;
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::readNextBlock() {
+    m_stream->Seek( m_filePos, aiOrigin_SET );
+    size_t readLen = m_stream->Read( &m_cache[ 0 ], sizeof( T ), m_cacheSize );
+    if ( readLen == 0 ) {
+        return false;
+    }
+    if ( readLen < m_cacheSize ) {
+        m_cacheSize = readLen;
+    }
+    m_filePos += m_cacheSize;
+    m_cachePos = 0;
+    m_blockIdx++;
+
+    return true;
+}
+
+template<class T>
+inline
+size_t IOStreamBuffer<T>::getNumBlocks() const {
+    return m_numBlocks;
+}
+
+template<class T>
+inline
+size_t IOStreamBuffer<T>::getCurrentBlockIndex() const {
+    return m_blockIdx;
+}
+
+template<class T>
+inline
+size_t IOStreamBuffer<T>::getFilePos() const {
+    return m_filePos;
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::getNextDataLine( std::vector<T> &buffer, T continuationToken ) {
+    buffer.resize( m_cacheSize );
+    if ( m_cachePos >= m_cacheSize || 0 == m_filePos ) {
+        if ( !readNextBlock() ) {
+            return false;
+        }
+    }
+
+    bool continuationFound( false );
+    size_t i = 0;
+    for( ;; ) {
+        if ( continuationToken == m_cache[ m_cachePos ] ) {
+            continuationFound = true;
+            ++m_cachePos;
+        }
+        if ( IsLineEnd( m_cache[ m_cachePos ] ) ) {
+            if ( !continuationFound ) {
+                // the end of the data line
+                break;
+            } else {
+                // skip line end
+                while ( m_cache[m_cachePos] != '\n') {
+                    ++m_cachePos;
+                }
+                ++m_cachePos;
+                continuationFound = false;
+            }
+        }
+
+        buffer[ i ] = m_cache[ m_cachePos ];
+        ++m_cachePos;
+        ++i;
+        if (m_cachePos >= size()) {
+            break;
+        }
+        if ( m_cachePos >= m_cacheSize ) {
+            if ( !readNextBlock() ) {
+                return false;
+            }
+        }
+    }
+    
+    buffer[ i ] = '\n';
+    ++m_cachePos;
+
+    return true;
+}
+
+static inline
+bool isEndOfCache( size_t pos, size_t cacheSize ) {
+    return ( pos == cacheSize );
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::getNextLine(std::vector<T> &buffer) {
+    buffer.resize(m_cacheSize);
+    if ( isEndOfCache( m_cachePos, m_cacheSize ) || 0 == m_filePos) {
+       if (!readNextBlock()) {
+          return false;
+       }
+      }
+
+    if (IsLineEnd(m_cache[m_cachePos])) {
+        // skip line end
+        while (m_cache[m_cachePos] != '\n') {
+            ++m_cachePos;
+        }
+        ++m_cachePos;
+        if ( isEndOfCache( m_cachePos, m_cacheSize ) ) {
+            if ( !readNextBlock() ) {
+                return false;
+            }
+        }
+    }
+
+    size_t i( 0 );
+    while (!IsLineEnd(m_cache[ m_cachePos ])) {
+        buffer[i] = m_cache[ m_cachePos ];
+        ++m_cachePos;
+        ++i;
+        if (m_cachePos >= m_cacheSize) {
+            if (!readNextBlock()) {
+                return false;
+            }
+        }
+    }
+    buffer[i] = '\n';
+    ++m_cachePos;
+
+    return true;
+}
+
+template<class T>
+inline
+bool IOStreamBuffer<T>::getNextBlock( std::vector<T> &buffer) {
+    // Return the last block-value if getNextLine was used before
+    if ( 0 != m_cachePos ) {      
+        buffer = std::vector<T>( m_cache.begin() + m_cachePos, m_cache.end() );
+        m_cachePos = 0;
+    } else {
+        if ( !readNextBlock() ) {
+            return false;
+        }
+
+        buffer = std::vector<T>(m_cache.begin(), m_cache.end());
+    }
+
+    return true;
+}
+
+} // !ns Assimp

dependencies/assimp/include/assimp/IOSystem.hpp

@@ -0,0 +1,357 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file IOSystem.hpp
+ *  @brief File system wrapper for C++. Inherit this class to supply
+ *  custom file handling logic to the Import library.
+*/
+
+#pragma once
+#ifndef AI_IOSYSTEM_H_INC
+#define AI_IOSYSTEM_H_INC
+
+#ifndef __cplusplus
+#   error This header requires C++ to be used. aiFileIO.h is the \
+    corresponding C interface.
+#endif
+
+#include "types.h"
+
+#ifdef _WIN32
+#   include <direct.h>  
+#   include <stdlib.h>  
+#   include <stdio.h>  
+#else
+#   include <sys/stat.h>
+#   include <sys/types.h>
+#   include <unistd.h>
+#endif // _WIN32
+
+#include <vector>
+
+namespace Assimp    {
+
+    class IOStream;
+
+// ---------------------------------------------------------------------------
+/** @brief CPP-API: Interface to the file system.
+ *
+ *  Derive an own implementation from this interface to supply custom file handling
+ *  to the importer library. If you implement this interface, you also want to
+ *  supply a custom implementation for IOStream.
+ *
+ *  @see Importer::SetIOHandler() 
+ */
+class ASSIMP_API IOSystem
+#ifndef SWIG
+    : public Intern::AllocateFromAssimpHeap
+#endif
+{
+public:
+
+    // -------------------------------------------------------------------
+    /** @brief Default constructor.
+     *
+     *  Create an instance of your derived class and assign it to an
+     *  #Assimp::Importer instance by calling Importer::SetIOHandler().
+     */
+    IOSystem() AI_NO_EXCEPT;
+
+    // -------------------------------------------------------------------
+    /** @brief Virtual destructor.
+     *
+     *  It is safe to be called from within DLL Assimp, we're constructed
+     *  on Assimp's heap.
+     */
+    virtual ~IOSystem();
+
+    // -------------------------------------------------------------------
+    /** @brief For backward compatibility
+     *  @see Exists(const char*)
+     */
+    AI_FORCE_INLINE bool Exists( const std::string& pFile) const;
+
+    // -------------------------------------------------------------------
+    /** @brief Tests for the existence of a file at the given path.
+     *
+     * @param pFile Path to the file
+     * @return true if there is a file with this path, else false.
+     */
+    virtual bool Exists( const char* pFile) const = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Returns the system specific directory separator
+     *  @return System specific directory separator
+     */
+    virtual char getOsSeparator() const = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Open a new file with a given path.
+     *
+     *  When the access to the file is finished, call Close() to release
+     *  all associated resources (or the virtual dtor of the IOStream).
+     *
+     *  @param pFile Path to the file
+     *  @param pMode Desired file I/O mode. Required are: "wb", "w", "wt",
+     *         "rb", "r", "rt".
+     *
+     *  @return New IOStream interface allowing the lib to access
+     *         the underlying file.
+     *  @note When implementing this class to provide custom IO handling,
+     *  you probably have to supply an own implementation of IOStream as well.
+     */
+    virtual IOStream* Open(const char* pFile,
+        const char* pMode = "rb") = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief For backward compatibility
+     *  @see Open(const char*, const char*)
+     */
+    inline IOStream* Open(const std::string& pFile,
+        const std::string& pMode = std::string("rb"));
+
+    // -------------------------------------------------------------------
+    /** @brief Closes the given file and releases all resources
+     *    associated with it.
+     *  @param pFile The file instance previously created by Open().
+     */
+    virtual void Close( IOStream* pFile) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Compares two paths and check whether the point to
+     *         identical files.
+     *
+     * The dummy implementation of this virtual member performs a
+     * case-insensitive comparison of the given strings. The default IO
+     * system implementation uses OS mechanisms to convert relative into
+     * absolute paths, so the result can be trusted.
+     * @param one First file
+     * @param second Second file
+     * @return true if the paths point to the same file. The file needn't
+     *   be existing, however.
+     */
+    virtual bool ComparePaths (const char* one,
+        const char* second) const;
+
+    // -------------------------------------------------------------------
+    /** @brief For backward compatibility
+     *  @see ComparePaths(const char*, const char*)
+     */
+    inline bool ComparePaths (const std::string& one,
+        const std::string& second) const;
+
+    // -------------------------------------------------------------------
+    /** @brief Pushes a new directory onto the directory stack.
+     *  @param path Path to push onto the stack.
+     *  @return True, when push was successful, false if path is empty.
+     */
+    virtual bool PushDirectory( const std::string &path );
+
+    // -------------------------------------------------------------------
+    /** @brief Returns the top directory from the stack.
+     *  @return The directory on the top of the stack.
+     *          Returns empty when no directory was pushed to the stack.
+     */
+    virtual const std::string &CurrentDirectory() const;
+
+    // -------------------------------------------------------------------
+    /** @brief Returns the number of directories stored on the stack.
+     *  @return The number of directories of the stack.
+     */
+    virtual size_t StackSize() const;
+
+    // -------------------------------------------------------------------
+    /** @brief Pops the top directory from the stack.
+     *  @return True, when a directory was on the stack. False if no
+     *          directory was on the stack.
+     */
+    virtual bool PopDirectory();
+
+    // -------------------------------------------------------------------
+    /** @brief CReates an new directory at the given path.
+     *  @param  path    [in] The path to create.
+     *  @return True, when a directory was created. False if the directory
+     *           cannot be created.
+     */
+    virtual bool CreateDirectory( const std::string &path );
+
+    // -------------------------------------------------------------------
+    /** @brief Will change the current directory to the given path.
+     *  @param path     [in] The path to change to.
+     *  @return True, when the directory has changed successfully.
+     */
+    virtual bool ChangeDirectory( const std::string &path );
+
+    virtual bool DeleteFile( const std::string &file );
+
+private:
+    std::vector<std::string> m_pathStack;
+};
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+IOSystem::IOSystem() AI_NO_EXCEPT
+: m_pathStack() {
+    // empty
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+IOSystem::~IOSystem() {
+    // empty
+}
+
+// ----------------------------------------------------------------------------
+// For compatibility, the interface of some functions taking a std::string was
+// changed to const char* to avoid crashes between binary incompatible STL
+// versions. This code her is inlined,  so it shouldn't cause any problems.
+// ----------------------------------------------------------------------------
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+IOStream* IOSystem::Open(const std::string& pFile, const std::string& pMode) {
+    // NOTE:
+    // For compatibility, interface was changed to const char* to
+    // avoid crashes between binary incompatible STL versions
+    return Open(pFile.c_str(),pMode.c_str());
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::Exists( const std::string& pFile) const {
+    // NOTE:
+    // For compatibility, interface was changed to const char* to
+    // avoid crashes between binary incompatible STL versions
+    return Exists(pFile.c_str());
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::ComparePaths (const std::string& one, const std::string& second) const {
+    // NOTE:
+    // For compatibility, interface was changed to const char* to
+    // avoid crashes between binary incompatible STL versions
+    return ComparePaths(one.c_str(),second.c_str());
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::PushDirectory( const std::string &path ) {
+    if ( path.empty() ) {
+        return false;
+    }
+
+    m_pathStack.push_back( path );
+
+    return true;
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+const std::string &IOSystem::CurrentDirectory() const {
+    if ( m_pathStack.empty() ) {
+        static const std::string Dummy("");
+        return Dummy;
+    }
+    return m_pathStack[ m_pathStack.size()-1 ];
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+size_t IOSystem::StackSize() const {
+    return m_pathStack.size();
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::PopDirectory() {
+    if ( m_pathStack.empty() ) {
+        return false;
+    }
+
+    m_pathStack.pop_back();
+
+    return true;
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::CreateDirectory( const std::string &path ) {
+    if ( path.empty() ) {
+        return false;
+    }
+
+#ifdef _WIN32
+    return 0 != ::_mkdir( path.c_str() );
+#else
+    return 0 != ::mkdir( path.c_str(), 0777 );
+#endif // _WIN32
+}
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::ChangeDirectory( const std::string &path ) {
+    if ( path.empty() ) {
+        return false;
+    }
+
+#ifdef _WIN32
+    return 0 != ::_chdir( path.c_str() );
+#else
+    return 0 != ::chdir( path.c_str() );
+#endif // _WIN32
+}
+
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE
+bool IOSystem::DeleteFile( const std::string &file ) {
+    if ( file.empty() ) {
+        return false;
+    }
+    const int retCode( ::remove( file.c_str() ) );
+    return ( 0 == retCode );
+}
+} //!ns Assimp
+
+#endif //AI_IOSYSTEM_H_INC

dependencies/assimp/include/assimp/Importer.hpp

@@ -0,0 +1,659 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  Importer.hpp
+ *  @brief Defines the C++-API to the Open Asset Import Library.
+ */
+#pragma once
+#ifndef AI_ASSIMP_HPP_INC
+#define AI_ASSIMP_HPP_INC
+
+#ifndef __cplusplus
+#   error This header requires C++ to be used. Use assimp.h for plain C.
+#endif // __cplusplus
+
+// Public ASSIMP data structures
+#include <assimp/types.h>
+
+namespace Assimp    {
+    // =======================================================================
+    // Public interface to Assimp
+    class Importer;
+    class IOStream;
+    class IOSystem;
+    class ProgressHandler;
+
+    // =======================================================================
+    // Plugin development
+    //
+    // Include the following headers for the declarations:
+    // BaseImporter.h
+    // BaseProcess.h
+    class BaseImporter;
+    class BaseProcess;
+    class SharedPostProcessInfo;
+    class BatchLoader;
+
+    // =======================================================================
+    // Holy stuff, only for members of the high council of the Jedi.
+    class ImporterPimpl;
+} //! namespace Assimp
+
+#define AI_PROPERTY_WAS_NOT_EXISTING 0xffffffff
+
+struct aiScene;
+
+// importerdesc.h
+struct aiImporterDesc;
+
+/** @namespace Assimp Assimp's CPP-API and all internal APIs */
+namespace Assimp    {
+
+// ----------------------------------------------------------------------------------
+/** CPP-API: The Importer class forms an C++ interface to the functionality of the
+*   Open Asset Import Library.
+*
+* Create an object of this class and call ReadFile() to import a file.
+* If the import succeeds, the function returns a pointer to the imported data.
+* The data remains property of the object, it is intended to be accessed
+* read-only. The imported data will be destroyed along with the Importer
+* object. If the import fails, ReadFile() returns a NULL pointer. In this
+* case you can retrieve a human-readable error description be calling
+* GetErrorString(). You can call ReadFile() multiple times with a single Importer
+* instance. Actually, constructing Importer objects involves quite many
+* allocations and may take some time, so it's better to reuse them as often as
+* possible.
+*
+* If you need the Importer to do custom file handling to access the files,
+* implement IOSystem and IOStream and supply an instance of your custom
+* IOSystem implementation by calling SetIOHandler() before calling ReadFile().
+* If you do not assign a custion IO handler, a default handler using the
+* standard C++ IO logic will be used.
+*
+* @note One Importer instance is not thread-safe. If you use multiple
+* threads for loading, each thread should maintain its own Importer instance.
+*/
+class ASSIMP_API Importer   {
+public:
+    /**
+     *  @brief The upper limit for hints.
+     */
+    static const unsigned int MaxLenHint = 200;
+
+public:
+
+    // -------------------------------------------------------------------
+    /** Constructor. Creates an empty importer object.
+     *
+     * Call ReadFile() to start the import process. The configuration
+     * property table is initially empty.
+     */
+    Importer();
+
+    // -------------------------------------------------------------------
+    /** Copy constructor.
+     *
+     * This copies the configuration properties of another Importer.
+     * If this Importer owns a scene it won't be copied.
+     * Call ReadFile() to start the import process.
+     */
+    Importer(const Importer& other)=delete;
+
+    // -------------------------------------------------------------------
+    /** Assignment operator has been deleted
+     */
+    Importer &operator=(const Importer &) = delete;
+
+    // -------------------------------------------------------------------
+    /** Destructor. The object kept ownership of the imported data,
+     * which now will be destroyed along with the object.
+     */
+    ~Importer();
+
+
+    // -------------------------------------------------------------------
+    /** Registers a new loader.
+     *
+     * @param pImp Importer to be added. The Importer instance takes
+     *   ownership of the pointer, so it will be automatically deleted
+     *   with the Importer instance.
+     * @return AI_SUCCESS if the loader has been added. The registration
+     *   fails if there is already a loader for a specific file extension.
+     */
+    aiReturn RegisterLoader(BaseImporter* pImp);
+
+    // -------------------------------------------------------------------
+    /** Unregisters a loader.
+     *
+     * @param pImp Importer to be unregistered.
+     * @return AI_SUCCESS if the loader has been removed. The function
+     *   fails if the loader is currently in use (this could happen
+     *   if the #Importer instance is used by more than one thread) or
+     *   if it has not yet been registered.
+     */
+    aiReturn UnregisterLoader(BaseImporter* pImp);
+
+    // -------------------------------------------------------------------
+    /** Registers a new post-process step.
+     *
+     * At the moment, there's a small limitation: new post processing
+     * steps are added to end of the list, or in other words, executed
+     * last, after all built-in steps.
+     * @param pImp Post-process step to be added. The Importer instance
+     *   takes ownership of the pointer, so it will be automatically
+     *   deleted with the Importer instance.
+     * @return AI_SUCCESS if the step has been added correctly.
+     */
+    aiReturn RegisterPPStep(BaseProcess* pImp);
+
+    // -------------------------------------------------------------------
+    /** Unregisters a post-process step.
+     *
+     * @param pImp Step to be unregistered.
+     * @return AI_SUCCESS if the step has been removed. The function
+     *   fails if the step is currently in use (this could happen
+     *   if the #Importer instance is used by more than one thread) or
+     *   if it has not yet been registered.
+     */
+    aiReturn UnregisterPPStep(BaseProcess* pImp);
+
+    // -------------------------------------------------------------------
+    /** Set an integer configuration property.
+     * @param szName Name of the property. All supported properties
+     *   are defined in the aiConfig.g header (all constants share the
+     *   prefix AI_CONFIG_XXX and are simple strings).
+     * @param iValue New value of the property
+     * @return true if the property was set before. The new value replaces
+     *   the previous value in this case.
+     * @note Property of different types (float, int, string ..) are kept
+     *   on different stacks, so calling SetPropertyInteger() for a
+     *   floating-point property has no effect - the loader will call
+     *   GetPropertyFloat() to read the property, but it won't be there.
+     */
+    bool SetPropertyInteger(const char* szName, int iValue);
+
+    // -------------------------------------------------------------------
+    /** Set a boolean configuration property. Boolean properties
+     *  are stored on the integer stack internally so it's possible
+     *  to set them via #SetPropertyBool and query them with
+     *  #GetPropertyBool and vice versa.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyBool(const char* szName, bool value)    {
+        return SetPropertyInteger(szName,value);
+    }
+
+    // -------------------------------------------------------------------
+    /** Set a floating-point configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyFloat(const char* szName, ai_real fValue);
+
+    // -------------------------------------------------------------------
+    /** Set a string configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyString(const char* szName, const std::string& sValue);
+
+    // -------------------------------------------------------------------
+    /** Set a matrix configuration property.
+     * @see SetPropertyInteger()
+     */
+    bool SetPropertyMatrix(const char* szName, const aiMatrix4x4& sValue);
+
+    // -------------------------------------------------------------------
+    /** Get a configuration property.
+     * @param szName Name of the property. All supported properties
+     *   are defined in the aiConfig.g header (all constants share the
+     *   prefix AI_CONFIG_XXX).
+     * @param iErrorReturn Value that is returned if the property
+     *   is not found.
+     * @return Current value of the property
+     * @note Property of different types (float, int, string ..) are kept
+     *   on different lists, so calling SetPropertyInteger() for a
+     *   floating-point property has no effect - the loader will call
+     *   GetPropertyFloat() to read the property, but it won't be there.
+     */
+    int GetPropertyInteger(const char* szName,
+        int iErrorReturn = 0xffffffff) const;
+
+    // -------------------------------------------------------------------
+    /** Get a boolean configuration property. Boolean properties
+     *  are stored on the integer stack internally so it's possible
+     *  to set them via #SetPropertyBool and query them with
+     *  #GetPropertyBool and vice versa.
+     * @see GetPropertyInteger()
+     */
+    bool GetPropertyBool(const char* szName, bool bErrorReturn = false) const {
+        return GetPropertyInteger(szName,bErrorReturn)!=0;
+    }
+
+    // -------------------------------------------------------------------
+    /** Get a floating-point configuration property
+     * @see GetPropertyInteger()
+     */
+    ai_real GetPropertyFloat(const char* szName,
+        ai_real fErrorReturn = 10e10) const;
+
+    // -------------------------------------------------------------------
+    /** Get a string configuration property
+     *
+     *  The return value remains valid until the property is modified.
+     * @see GetPropertyInteger()
+     */
+    const std::string GetPropertyString(const char* szName,
+        const std::string& sErrorReturn = "") const;
+
+    // -------------------------------------------------------------------
+    /** Get a matrix configuration property
+     *
+     *  The return value remains valid until the property is modified.
+     * @see GetPropertyInteger()
+     */
+    const aiMatrix4x4 GetPropertyMatrix(const char* szName,
+        const aiMatrix4x4& sErrorReturn = aiMatrix4x4()) const;
+
+    // -------------------------------------------------------------------
+    /** Supplies a custom IO handler to the importer to use to open and
+     * access files. If you need the importer to use custom IO logic to
+     * access the files, you need to provide a custom implementation of
+     * IOSystem and IOFile to the importer. Then create an instance of
+     * your custom IOSystem implementation and supply it by this function.
+     *
+     * The Importer takes ownership of the object and will destroy it
+     * afterwards. The previously assigned handler will be deleted.
+     * Pass NULL to take again ownership of your IOSystem and reset Assimp
+     * to use its default implementation.
+     *
+     * @param pIOHandler The IO handler to be used in all file accesses
+     *   of the Importer.
+     */
+    void SetIOHandler( IOSystem* pIOHandler);
+
+    // -------------------------------------------------------------------
+    /** Retrieves the IO handler that is currently set.
+     * You can use #IsDefaultIOHandler() to check whether the returned
+     * interface is the default IO handler provided by ASSIMP. The default
+     * handler is active as long the application doesn't supply its own
+     * custom IO handler via #SetIOHandler().
+     * @return A valid IOSystem interface, never NULL.
+     */
+    IOSystem* GetIOHandler() const;
+
+    // -------------------------------------------------------------------
+    /** Checks whether a default IO handler is active
+     * A default handler is active as long the application doesn't
+     * supply its own custom IO handler via #SetIOHandler().
+     * @return true by default
+     */
+    bool IsDefaultIOHandler() const;
+
+    // -------------------------------------------------------------------
+    /** Supplies a custom progress handler to the importer. This
+     *  interface exposes an #Update() callback, which is called
+     *  more or less periodically (please don't sue us if it
+     *  isn't as periodically as you'd like it to have ...).
+     *  This can be used to implement progress bars and loading
+     *  timeouts.
+     *  @param pHandler Progress callback interface. Pass NULL to
+     *    disable progress reporting.
+     *  @note Progress handlers can be used to abort the loading
+     *    at almost any time.*/
+    void SetProgressHandler ( ProgressHandler* pHandler );
+
+    // -------------------------------------------------------------------
+    /** Retrieves the progress handler that is currently set.
+     * You can use #IsDefaultProgressHandler() to check whether the returned
+     * interface is the default handler provided by ASSIMP. The default
+     * handler is active as long the application doesn't supply its own
+     * custom handler via #SetProgressHandler().
+     * @return A valid ProgressHandler interface, never NULL.
+     */
+    ProgressHandler* GetProgressHandler() const;
+
+    // -------------------------------------------------------------------
+    /** Checks whether a default progress handler is active
+     * A default handler is active as long the application doesn't
+     * supply its own custom progress handler via #SetProgressHandler().
+     * @return true by default
+     */
+    bool IsDefaultProgressHandler() const;
+
+    // -------------------------------------------------------------------
+    /** @brief Check whether a given set of post-processing flags
+     *  is supported.
+     *
+     *  Some flags are mutually exclusive, others are probably
+     *  not available because your excluded them from your
+     *  Assimp builds. Calling this function is recommended if
+     *  you're unsure.
+     *
+     *  @param pFlags Bitwise combination of the aiPostProcess flags.
+     *  @return true if this flag combination is fine.
+     */
+    bool ValidateFlags(unsigned int pFlags) const;
+
+    // -------------------------------------------------------------------
+    /** Reads the given file and returns its contents if successful.
+     *
+     * If the call succeeds, the contents of the file are returned as a
+     * pointer to an aiScene object. The returned data is intended to be
+     * read-only, the importer object keeps ownership of the data and will
+     * destroy it upon destruction. If the import fails, NULL is returned.
+     * A human-readable error description can be retrieved by calling
+     * GetErrorString(). The previous scene will be deleted during this call.
+     * @param pFile Path and filename to the file to be imported.
+     * @param pFlags Optional post processing steps to be executed after
+     *   a successful import. Provide a bitwise combination of the
+     *   #aiPostProcessSteps flags. If you wish to inspect the imported
+     *   scene first in order to fine-tune your post-processing setup,
+     *   consider to use #ApplyPostProcessing().
+     * @return A pointer to the imported data, NULL if the import failed.
+     *   The pointer to the scene remains in possession of the Importer
+     *   instance. Use GetOrphanedScene() to take ownership of it.
+     *
+     * @note Assimp is able to determine the file format of a file
+     * automatically.
+     */
+    const aiScene* ReadFile(
+        const char* pFile,
+        unsigned int pFlags);
+
+    // -------------------------------------------------------------------
+    /** Reads the given file from a memory buffer and returns its
+     *  contents if successful.
+     *
+     * If the call succeeds, the contents of the file are returned as a
+     * pointer to an aiScene object. The returned data is intended to be
+     * read-only, the importer object keeps ownership of the data and will
+     * destroy it upon destruction. If the import fails, NULL is returned.
+     * A human-readable error description can be retrieved by calling
+     * GetErrorString(). The previous scene will be deleted during this call.
+     * Calling this method doesn't affect the active IOSystem.
+     * @param pBuffer Pointer to the file data
+     * @param pLength Length of pBuffer, in bytes
+     * @param pFlags Optional post processing steps to be executed after
+     *   a successful import. Provide a bitwise combination of the
+     *   #aiPostProcessSteps flags. If you wish to inspect the imported
+     *   scene first in order to fine-tune your post-processing setup,
+     *   consider to use #ApplyPostProcessing().
+     * @param pHint An additional hint to the library. If this is a non
+     *   empty string, the library looks for a loader to support
+     *   the file extension specified by pHint and passes the file to
+     *   the first matching loader. If this loader is unable to completely
+     *   the request, the library continues and tries to determine the
+     *   file format on its own, a task that may or may not be successful.
+     *   Check the return value, and you'll know ...
+     * @return A pointer to the imported data, NULL if the import failed.
+     *   The pointer to the scene remains in possession of the Importer
+     *   instance. Use GetOrphanedScene() to take ownership of it.
+     *
+     * @note This is a straightforward way to decode models from memory
+     * buffers, but it doesn't handle model formats that spread their
+     * data across multiple files or even directories. Examples include
+     * OBJ or MD3, which outsource parts of their material info into
+     * external scripts. If you need full functionality, provide
+     * a custom IOSystem to make Assimp find these files and use
+     * the regular ReadFile() API.
+     */
+    const aiScene* ReadFileFromMemory(
+        const void* pBuffer,
+        size_t pLength,
+        unsigned int pFlags,
+        const char* pHint = "");
+
+    // -------------------------------------------------------------------
+    /** Apply post-processing to an already-imported scene.
+     *
+     *  This is strictly equivalent to calling #ReadFile() with the same
+     *  flags. However, you can use this separate function to inspect
+     *  the imported scene first to fine-tune your post-processing setup.
+     *  @param pFlags Provide a bitwise combination of the
+     *   #aiPostProcessSteps flags.
+     *  @return A pointer to the post-processed data. This is still the
+     *   same as the pointer returned by #ReadFile(). However, if
+     *   post-processing fails, the scene could now be NULL.
+     *   That's quite a rare case, post processing steps are not really
+     *   designed to 'fail'. To be exact, the #aiProcess_ValidateDS
+     *   flag is currently the only post processing step which can actually
+     *   cause the scene to be reset to NULL.
+     *
+     *  @note The method does nothing if no scene is currently bound
+     *    to the #Importer instance.  */
+    const aiScene* ApplyPostProcessing(unsigned int pFlags);
+
+    const aiScene* ApplyCustomizedPostProcessing( BaseProcess *rootProcess, bool requestValidation );
+
+    // -------------------------------------------------------------------
+    /** @brief Reads the given file and returns its contents if successful.
+     *
+     * This function is provided for backward compatibility.
+     * See the const char* version for detailed docs.
+     * @see ReadFile(const char*, pFlags)  */
+    const aiScene* ReadFile(
+        const std::string& pFile,
+        unsigned int pFlags);
+
+    // -------------------------------------------------------------------
+    /** Frees the current scene.
+     *
+     *  The function does nothing if no scene has previously been
+     *  read via ReadFile(). FreeScene() is called automatically by the
+     *  destructor and ReadFile() itself.  */
+    void FreeScene( );
+
+    // -------------------------------------------------------------------
+    /** Returns an error description of an error that occurred in ReadFile().
+     *
+     * Returns an empty string if no error occurred.
+     * @return A description of the last error, an empty string if no
+     *   error occurred. The string is never NULL.
+     *
+     * @note The returned function remains valid until one of the
+     * following methods is called: #ReadFile(), #FreeScene(). */
+    const char* GetErrorString() const;
+
+    // -------------------------------------------------------------------
+    /** Returns the scene loaded by the last successful call to ReadFile()
+     *
+     * @return Current scene or NULL if there is currently no scene loaded */
+    const aiScene* GetScene() const;
+
+    // -------------------------------------------------------------------
+    /** Returns the scene loaded by the last successful call to ReadFile()
+     *  and releases the scene from the ownership of the Importer
+     *  instance. The application is now responsible for deleting the
+     *  scene. Any further calls to GetScene() or GetOrphanedScene()
+     *  will return NULL - until a new scene has been loaded via ReadFile().
+     *
+     * @return Current scene or NULL if there is currently no scene loaded
+     * @note Use this method with maximal caution, and only if you have to.
+     *   By design, aiScene's are exclusively maintained, allocated and
+     *   deallocated by Assimp and no one else. The reasoning behind this
+     *   is the golden rule that deallocations should always be done
+     *   by the module that did the original allocation because heaps
+     *   are not necessarily shared. GetOrphanedScene() enforces you
+     *   to delete the returned scene by yourself, but this will only
+     *   be fine if and only if you're using the same heap as assimp.
+     *   On Windows, it's typically fine provided everything is linked
+     *   against the multithreaded-dll version of the runtime library.
+     *   It will work as well for static linkage with Assimp.*/
+    aiScene* GetOrphanedScene();
+
+    // -------------------------------------------------------------------
+    /** Returns whether a given file extension is supported by ASSIMP.
+     *
+     * @param szExtension Extension to be checked.
+     *   Must include a trailing dot '.'. Example: ".3ds", ".md3".
+     *   Cases-insensitive.
+     * @return true if the extension is supported, false otherwise */
+    bool IsExtensionSupported(const char* szExtension) const;
+
+    // -------------------------------------------------------------------
+    /** @brief Returns whether a given file extension is supported by ASSIMP.
+     *
+     * This function is provided for backward compatibility.
+     * See the const char* version for detailed and up-to-date docs.
+     * @see IsExtensionSupported(const char*) */
+    inline bool IsExtensionSupported(const std::string& szExtension) const;
+
+    // -------------------------------------------------------------------
+    /** Get a full list of all file extensions supported by ASSIMP.
+     *
+     * If a file extension is contained in the list this does of course not
+     * mean that ASSIMP is able to load all files with this extension ---
+     * it simply means there is an importer loaded which claims to handle
+     * files with this file extension.
+     * @param szOut String to receive the extension list.
+     *   Format of the list: "*.3ds;*.obj;*.dae". This is useful for
+     *   use with the WinAPI call GetOpenFileName(Ex). */
+    void GetExtensionList(aiString& szOut) const;
+
+    // -------------------------------------------------------------------
+    /** @brief Get a full list of all file extensions supported by ASSIMP.
+     *
+     * This function is provided for backward compatibility.
+     * See the aiString version for detailed and up-to-date docs.
+     * @see GetExtensionList(aiString&)*/
+    inline void GetExtensionList(std::string& szOut) const;
+
+    // -------------------------------------------------------------------
+    /** Get the number of importers currently registered with Assimp. */
+    size_t GetImporterCount() const;
+
+    // -------------------------------------------------------------------
+    /** Get meta data for the importer corresponding to a specific index..
+    *
+    *  For the declaration of #aiImporterDesc, include <assimp/importerdesc.h>.
+    *  @param index Index to query, must be within [0,GetImporterCount())
+    *  @return Importer meta data structure, NULL if the index does not
+    *     exist or if the importer doesn't offer meta information (
+    *     importers may do this at the cost of being hated by their peers).*/
+    const aiImporterDesc* GetImporterInfo(size_t index) const;
+
+    // -------------------------------------------------------------------
+    /** Find the importer corresponding to a specific index.
+    *
+    *  @param index Index to query, must be within [0,GetImporterCount())
+    *  @return Importer instance. NULL if the index does not
+    *     exist. */
+    BaseImporter* GetImporter(size_t index) const;
+
+    // -------------------------------------------------------------------
+    /** Find the importer corresponding to a specific file extension.
+    *
+    *  This is quite similar to #IsExtensionSupported except a
+    *  BaseImporter instance is returned.
+    *  @param szExtension Extension to check for. The following formats
+    *    are recognized (BAH being the file extension): "BAH" (comparison
+    *    is case-insensitive), ".bah", "*.bah" (wild card and dot
+    *    characters at the beginning of the extension are skipped).
+    *  @return NULL if no importer is found*/
+    BaseImporter* GetImporter (const char* szExtension) const;
+
+    // -------------------------------------------------------------------
+    /** Find the importer index corresponding to a specific file extension.
+    *
+    *  @param szExtension Extension to check for. The following formats
+    *    are recognized (BAH being the file extension): "BAH" (comparison
+    *    is case-insensitive), ".bah", "*.bah" (wild card and dot
+    *    characters at the beginning of the extension are skipped).
+    *  @return (size_t)-1 if no importer is found */
+    size_t GetImporterIndex (const char* szExtension) const;
+
+    // -------------------------------------------------------------------
+    /** Returns the storage allocated by ASSIMP to hold the scene data
+     * in memory.
+     *
+     * This refers to the currently loaded file, see #ReadFile().
+     * @param in Data structure to be filled.
+     * @note The returned memory statistics refer to the actual
+     *   size of the use data of the aiScene. Heap-related overhead
+     *   is (naturally) not included.*/
+    void GetMemoryRequirements(aiMemoryInfo& in) const;
+
+    // -------------------------------------------------------------------
+    /** Enables "extra verbose" mode.
+     *
+     * 'Extra verbose' means the data structure is validated after *every*
+     * single post processing step to make sure everyone modifies the data
+     * structure in a well-defined manner. This is a debug feature and not
+     * intended for use in production environments. */
+    void SetExtraVerbose(bool bDo);
+
+    // -------------------------------------------------------------------
+    /** Private, do not use. */
+    ImporterPimpl* Pimpl() { return pimpl; }
+    const ImporterPimpl* Pimpl() const { return pimpl; }
+
+protected:
+
+    // Just because we don't want you to know how we're hacking around.
+    ImporterPimpl* pimpl;
+}; //! class Importer
+
+
+// ----------------------------------------------------------------------------
+// For compatibility, the interface of some functions taking a std::string was
+// changed to const char* to avoid crashes between binary incompatible STL
+// versions. This code her is inlined,  so it shouldn't cause any problems.
+// ----------------------------------------------------------------------------
+
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE const aiScene* Importer::ReadFile( const std::string& pFile,unsigned int pFlags){
+    return ReadFile(pFile.c_str(),pFlags);
+}
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE void Importer::GetExtensionList(std::string& szOut) const   {
+    aiString s;
+    GetExtensionList(s);
+    szOut = s.data;
+}
+// ----------------------------------------------------------------------------
+AI_FORCE_INLINE bool Importer::IsExtensionSupported(const std::string& szExtension) const   {
+    return IsExtensionSupported(szExtension.c_str());
+}
+
+} // !namespace Assimp
+
+#endif // AI_ASSIMP_HPP_INC

dependencies/assimp/include/assimp/LineSplitter.h

@@ -0,0 +1,285 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  LineSplitter.h
+ *  @brief LineSplitter, a helper class to iterate through all lines
+ *    of a file easily. Works with StreamReader.
+ */
+#pragma once
+#ifndef INCLUDED_LINE_SPLITTER_H
+#define INCLUDED_LINE_SPLITTER_H
+
+#include <stdexcept>
+#include "StreamReader.h"
+#include "ParsingUtils.h"
+
+namespace Assimp {
+
+// ------------------------------------------------------------------------------------------------
+/** Usage:
+@code
+for(LineSplitter splitter(stream);splitter;++splitter) {
+
+    if (*splitter == "hi!") {
+       ...
+    }
+    else if (splitter->substr(0,5) == "hello") {
+       ...
+       // access the third token in the line (tokens are space-separated)
+       if (strtol(splitter[2]) > 5) { .. }
+    }
+
+    std::cout << "Current line is: " << splitter.get_index() << std::endl;
+}
+@endcode
+*/
+// ------------------------------------------------------------------------------------------------
+class LineSplitter {
+public:
+    typedef size_t line_idx;
+
+    // -----------------------------------------
+    /** construct from existing stream reader
+    note: trim is *always* assumed true if skyp_empty_lines==true
+    */
+    LineSplitter(StreamReaderLE& stream, bool skip_empty_lines = true, bool trim = true);
+
+    ~LineSplitter();
+
+    // -----------------------------------------
+    /** pseudo-iterator increment */
+    LineSplitter& operator++();
+
+    // -----------------------------------------
+    LineSplitter& operator++(int);
+
+    // -----------------------------------------
+    /** get a pointer to the beginning of a particular token */
+    const char* operator[] (size_t idx) const;
+
+    // -----------------------------------------
+    /** extract the start positions of N tokens from the current line*/
+    template <size_t N>
+    void get_tokens(const char* (&tokens)[N]) const;
+
+    // -----------------------------------------
+    /** member access */
+    const std::string* operator -> () const;
+
+    std::string operator* () const;
+
+    // -----------------------------------------
+    /** boolean context */
+    operator bool() const;
+
+    // -----------------------------------------
+    /** line indices are zero-based, empty lines are included */
+    operator line_idx() const;
+
+    line_idx get_index() const;
+
+    // -----------------------------------------
+    /** access the underlying stream object */
+    StreamReaderLE& get_stream();
+
+    // -----------------------------------------
+    /** !strcmp((*this)->substr(0,strlen(check)),check) */
+    bool match_start(const char* check);
+
+    // -----------------------------------------
+    /** swallow the next call to ++, return the previous value. */
+    void swallow_next_increment();
+
+    LineSplitter( const LineSplitter & ) = delete;
+    LineSplitter(LineSplitter &&) = delete;
+    LineSplitter &operator = ( const LineSplitter & ) = delete;
+
+private:
+    line_idx mIdx;
+    std::string mCur;
+    StreamReaderLE& mStream;
+    bool mSwallow, mSkip_empty_lines, mTrim;
+};
+
+inline
+LineSplitter::LineSplitter(StreamReaderLE& stream, bool skip_empty_lines, bool trim )
+: mIdx(0)
+, mCur()
+, mStream(stream)
+, mSwallow()
+, mSkip_empty_lines(skip_empty_lines)
+, mTrim(trim) {
+    mCur.reserve(1024);
+    operator++();
+    mIdx = 0;
+}
+
+inline
+LineSplitter::~LineSplitter() {
+    // empty
+}
+
+inline
+LineSplitter& LineSplitter::operator++() {
+    if (mSwallow) {
+        mSwallow = false;
+        return *this;
+    }
+
+    if (!*this) {
+        throw std::logic_error("End of file, no more lines to be retrieved.");
+    }
+
+    char s;
+    mCur.clear();
+    while (mStream.GetRemainingSize() && (s = mStream.GetI1(), 1)) {
+        if (s == '\n' || s == '\r') {
+            if (mSkip_empty_lines) {
+                while (mStream.GetRemainingSize() && ((s = mStream.GetI1()) == ' ' || s == '\r' || s == '\n'));
+                if (mStream.GetRemainingSize()) {
+                    mStream.IncPtr(-1);
+                }
+            } else {
+                // skip both potential line terminators but don't read past this line.
+                if (mStream.GetRemainingSize() && (s == '\r' && mStream.GetI1() != '\n')) {
+                    mStream.IncPtr(-1);
+                }
+                if (mTrim) {
+                    while (mStream.GetRemainingSize() && ((s = mStream.GetI1()) == ' ' || s == '\t'));
+                    if (mStream.GetRemainingSize()) {
+                        mStream.IncPtr(-1);
+                    }
+                }
+            }
+            break;
+        }
+        mCur += s;
+    }
+    ++mIdx;
+
+    return *this;
+}
+
+inline
+LineSplitter &LineSplitter::operator++(int) {
+    return ++(*this);
+}
+
+inline
+const char *LineSplitter::operator[] (size_t idx) const {
+    const char* s = operator->()->c_str();
+
+    SkipSpaces(&s);
+    for (size_t i = 0; i < idx; ++i) {
+
+        for (; !IsSpace(*s); ++s) {
+            if (IsLineEnd(*s)) {
+                throw std::range_error("Token index out of range, EOL reached");
+            }
+        }
+        SkipSpaces(&s);
+    }
+    return s;
+}
+
+template <size_t N>
+inline
+void LineSplitter::get_tokens(const char* (&tokens)[N]) const {
+    const char* s = operator->()->c_str();
+
+    SkipSpaces(&s);
+    for (size_t i = 0; i < N; ++i) {
+        if (IsLineEnd(*s)) {
+            throw std::range_error("Token count out of range, EOL reached");
+        }
+        tokens[i] = s;
+
+        for (; *s && !IsSpace(*s); ++s);
+        SkipSpaces(&s);
+    }
+}
+
+inline
+const std::string* LineSplitter::operator -> () const {
+    return &mCur;
+}
+
+inline
+std::string LineSplitter::operator* () const {
+    return mCur;
+}
+
+inline
+LineSplitter::operator bool() const {
+    return mStream.GetRemainingSize() > 0;
+}
+
+inline
+LineSplitter::operator line_idx() const {
+    return mIdx;
+}
+
+inline
+LineSplitter::line_idx LineSplitter::get_index() const {
+    return mIdx;
+}
+
+inline
+StreamReaderLE &LineSplitter::get_stream() {
+    return mStream;
+}
+
+inline
+bool LineSplitter::match_start(const char* check) {
+    const size_t len = ::strlen(check);
+
+    return len <= mCur.length() && std::equal(check, check + len, mCur.begin());
+}
+
+inline
+void LineSplitter::swallow_next_increment() {
+    mSwallow = true;
+}
+
+} // Namespace Assimp
+
+#endif // INCLUDED_LINE_SPLITTER_H

dependencies/assimp/include/assimp/LogAux.h

@@ -0,0 +1,131 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  LogAux.h
+ *  @brief Common logging usage patterns for importer implementations
+ */
+#ifndef INCLUDED_AI_LOGAUX_H
+#define INCLUDED_AI_LOGAUX_H
+
+#include <assimp/TinyFormatter.h>
+#include <assimp/Exceptional.h>
+#include <assimp/DefaultLogger.hpp>
+
+namespace Assimp {
+
+template<class TDeriving>
+class LogFunctions {
+public:
+    // ------------------------------------------------------------------------------------------------
+    static void ThrowException(const std::string& msg)
+    {
+        throw DeadlyImportError(Prefix()+msg);
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogWarn(const Formatter::format& message)   {
+        if (!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_WARN(Prefix()+(std::string)message);
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogError(const Formatter::format& message)  {
+        if (!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_ERROR(Prefix()+(std::string)message);
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogInfo(const Formatter::format& message)   {
+        if (!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_INFO(Prefix()+(std::string)message);
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogDebug(const Formatter::format& message)  {
+        if (!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_DEBUG(Prefix()+(std::string)message);
+        }
+    }
+
+    // https://sourceforge.net/tracker/?func=detail&atid=1067632&aid=3358562&group_id=226462
+#if !defined(__GNUC__) || !defined(__APPLE__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogWarn  (const char* message) {
+        if (!DefaultLogger::isNullLogger()) {
+            LogWarn(Formatter::format(message));
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogError  (const char* message) {
+        if (!DefaultLogger::isNullLogger()) {
+            LogError(Formatter::format(message));
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogInfo  (const char* message) {
+        if (!DefaultLogger::isNullLogger()) {
+            LogInfo(Formatter::format(message));
+        }
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    static void LogDebug  (const char* message) {
+        if (!DefaultLogger::isNullLogger()) {
+            LogDebug(Formatter::format(message));
+        }
+    }
+
+#endif
+
+private:
+    static const char* Prefix();
+
+};
+} // ! Assimp
+
+#endif

dependencies/assimp/include/assimp/LogStream.hpp

@@ -0,0 +1,111 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file LogStream.hpp
+ *  @brief Abstract base class 'LogStream', representing an output log stream.
+ */
+#ifndef INCLUDED_AI_LOGSTREAM_H
+#define INCLUDED_AI_LOGSTREAM_H
+
+#include "types.h"
+
+namespace Assimp    {
+
+class IOSystem;
+
+// ------------------------------------------------------------------------------------
+/** @brief CPP-API: Abstract interface for log stream implementations.
+ *
+ *  Several default implementations are provided, see #aiDefaultLogStream for more
+ *  details. Writing your own implementation of LogStream is just necessary if these
+ *  are not enough for your purpose. */
+class ASSIMP_API LogStream
+#ifndef SWIG
+    : public Intern::AllocateFromAssimpHeap
+#endif
+{
+protected:
+    /** @brief  Default constructor */
+    LogStream() AI_NO_EXCEPT;
+
+public:
+    /** @brief  Virtual destructor  */
+    virtual ~LogStream();
+
+    // -------------------------------------------------------------------
+    /** @brief  Overwrite this for your own output methods
+     *
+     *  Log messages *may* consist of multiple lines and you shouldn't
+     *  expect a consistent formatting. If you want custom formatting
+     *  (e.g. generate HTML), supply a custom instance of Logger to
+     *  #DefaultLogger:set(). Usually you can *expect* that a log message
+     *  is exactly one line and terminated with a single \n character.
+     *  @param message Message to be written */
+    virtual void write(const char* message) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Creates a default log stream
+     *  @param streams Type of the default stream
+     *  @param name For aiDefaultLogStream_FILE: name of the output file
+     *  @param io For aiDefaultLogStream_FILE: IOSystem to be used to open the output
+     *   file. Pass NULL for the default implementation.
+     *  @return New LogStream instance.  */
+    static LogStream* createDefaultStream(aiDefaultLogStream stream,
+        const char* name = "AssimpLog.txt",
+        IOSystem* io = nullptr );
+
+}; // !class LogStream
+
+inline
+LogStream::LogStream() AI_NO_EXCEPT {
+    // empty
+}
+
+inline
+LogStream::~LogStream() {
+    // empty
+}
+
+// ------------------------------------------------------------------------------------
+} // Namespace Assimp
+
+#endif

dependencies/assimp/include/assimp/Logger.hpp

@@ -0,0 +1,305 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Logger.hpp
+ *  @brief Abstract base class 'Logger', base of the logging system.
+ */
+#ifndef INCLUDED_AI_LOGGER_H
+#define INCLUDED_AI_LOGGER_H
+
+#include <assimp/types.h>
+#include <assimp/TinyFormatter.h>
+
+namespace Assimp {
+
+class LogStream;
+
+// Maximum length of a log message. Longer messages are rejected.
+#define MAX_LOG_MESSAGE_LENGTH 1024u
+
+// ----------------------------------------------------------------------------------
+/** @brief CPP-API: Abstract interface for logger implementations.
+ *  Assimp provides a default implementation and uses it for almost all
+ *  logging stuff ('DefaultLogger'). This class defines just basic logging
+ *  behavior and is not of interest for you. Instead, take a look at #DefaultLogger. */
+class ASSIMP_API Logger
+#ifndef SWIG
+    : public Intern::AllocateFromAssimpHeap
+#endif
+{
+public:
+
+    // ----------------------------------------------------------------------
+    /** @enum   LogSeverity
+     *  @brief  Log severity to describe the granularity of logging.
+     */
+    enum LogSeverity {
+        NORMAL,     //!< Normal granularity of logging
+        VERBOSE     //!< Debug infos will be logged, too
+    };
+
+    // ----------------------------------------------------------------------
+    /** @enum   ErrorSeverity
+     *  @brief  Description for severity of a log message.
+     *
+     *  Every LogStream has a bitwise combination of these flags.
+     *  A LogStream doesn't receive any messages of a specific type
+     *  if it doesn't specify the corresponding ErrorSeverity flag.
+     */
+    enum ErrorSeverity {
+        Debugging   = 1,    //!< Debug log message
+        Info        = 2,    //!< Info log message
+        Warn        = 4,    //!< Warn log message
+        Err         = 8     //!< Error log message
+    };
+
+public:
+
+    /** @brief  Virtual destructor */
+    virtual ~Logger();
+
+    // ----------------------------------------------------------------------
+    /** @brief  Writes a debug message
+     *   @param message Debug message*/
+    void debug(const char* message);
+    void debug(const std::string &message);
+
+    // ----------------------------------------------------------------------
+    /** @brief  Writes a info message
+     *  @param  message Info message*/
+    void info(const char* message);
+    void info(const std::string &message);
+
+    // ----------------------------------------------------------------------
+    /** @brief  Writes a warning message
+     *  @param  message Warn message*/
+    void warn(const char* message);
+    void warn(const std::string &message);
+
+    // ----------------------------------------------------------------------
+    /** @brief  Writes an error message
+     *  @param  message Error message*/
+    void error(const char* message);
+    void error(const std::string &message);
+
+    // ----------------------------------------------------------------------
+    /** @brief  Set a new log severity.
+     *  @param  log_severity New severity for logging*/
+    void setLogSeverity(LogSeverity log_severity);
+
+    // ----------------------------------------------------------------------
+    /** @brief Get the current log severity*/
+    LogSeverity getLogSeverity() const;
+
+    // ----------------------------------------------------------------------
+    /** @brief  Attach a new log-stream
+     *
+     *  The logger takes ownership of the stream and is responsible
+     *  for its destruction (which is done using ::delete when the logger
+     *  itself is destroyed). Call detachStream to detach a stream and to
+     *  gain ownership of it again.
+     *   @param pStream  Log-stream to attach
+     *  @param severity  Message filter, specified which types of log
+     *    messages are dispatched to the stream. Provide a bitwise
+     *    combination of the ErrorSeverity flags.
+     *  @return true if the stream has been attached, false otherwise.*/
+    virtual bool attachStream(LogStream *pStream,
+        unsigned int severity = Debugging | Err | Warn | Info) = 0;
+
+    // ----------------------------------------------------------------------
+    /** @brief  Detach a still attached stream from the logger (or
+     *          modify the filter flags bits)
+     *   @param pStream Log-stream instance for detaching
+     *  @param severity Provide a bitwise combination of the ErrorSeverity
+     *    flags. This value is &~ed with the current flags of the stream,
+     *    if the result is 0 the stream is detached from the Logger and
+     *    the caller retakes the possession of the stream.
+     *  @return true if the stream has been detached, false otherwise.*/
+    virtual bool detatchStream(LogStream *pStream,
+        unsigned int severity = Debugging | Err | Warn | Info) = 0;
+
+protected:
+    /**
+     *  Default constructor
+     */
+    Logger() AI_NO_EXCEPT;
+
+    /**
+     *  Construction with a given log severity
+     */
+    explicit Logger(LogSeverity severity);
+
+    // ----------------------------------------------------------------------
+    /**
+     *  @brief Called as a request to write a specific debug message
+     *  @param  message Debug message. Never longer than
+     *    MAX_LOG_MESSAGE_LENGTH characters (excluding the '0').
+     *  @note  The message string is only valid until the scope of
+     *    the function is left.
+     */
+    virtual void OnDebug(const char* message)= 0;
+
+    // ----------------------------------------------------------------------
+    /**
+     *  @brief Called as a request to write a specific info message
+     *  @param  message Info message. Never longer than
+     *    MAX_LOG_MESSAGE_LENGTH characters (ecxluding the '0').
+     *  @note  The message string is only valid until the scope of
+     *    the function is left.
+     */
+    virtual void OnInfo(const char* message) = 0;
+
+    // ----------------------------------------------------------------------
+    /**
+     *  @brief Called as a request to write a specific warn message
+     *  @param  message Warn message. Never longer than
+     *    MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
+     *  @note  The message string is only valid until the scope of
+     *    the function is left.
+     */
+    virtual void OnWarn(const char* essage) = 0;
+
+    // ----------------------------------------------------------------------
+    /**
+     *  @brief Called as a request to write a specific error message
+     *  @param  message Error message. Never longer than
+     *    MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
+     *  @note  The message string is only valid until the scope of
+     *    the function is left.
+     */
+    virtual void OnError(const char* message) = 0;
+
+protected:
+    LogSeverity m_Severity;
+};
+
+// ----------------------------------------------------------------------------------
+//  Default constructor
+inline
+Logger::Logger() AI_NO_EXCEPT
+: m_Severity(NORMAL) {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+//  Virtual destructor
+inline
+Logger::~Logger() {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+// Construction with given logging severity
+inline
+Logger::Logger(LogSeverity severity)
+: m_Severity(severity) {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+// Log severity setter
+inline
+void Logger::setLogSeverity(LogSeverity log_severity){
+    m_Severity = log_severity;
+}
+
+// ----------------------------------------------------------------------------------
+// Log severity getter
+inline
+Logger::LogSeverity Logger::getLogSeverity() const {
+    return m_Severity;
+}
+
+// ----------------------------------------------------------------------------------
+inline
+void Logger::debug(const std::string &message) {
+    return debug(message.c_str());
+}
+
+// ----------------------------------------------------------------------------------
+inline
+void Logger::error(const std::string &message) {
+    return error(message.c_str());
+}
+
+// ----------------------------------------------------------------------------------
+inline
+void Logger::warn(const std::string &message) {
+    return warn(message.c_str());
+}
+
+// ----------------------------------------------------------------------------------
+inline
+void Logger::info(const std::string &message) {
+    return info(message.c_str());
+}
+
+// ------------------------------------------------------------------------------------------------
+#define ASSIMP_LOG_WARN_F(string,...)\
+    DefaultLogger::get()->warn((Formatter::format(string),__VA_ARGS__))
+
+#define ASSIMP_LOG_ERROR_F(string,...)\
+    DefaultLogger::get()->error((Formatter::format(string),__VA_ARGS__))
+
+#define ASSIMP_LOG_DEBUG_F(string,...)\
+    DefaultLogger::get()->debug((Formatter::format(string),__VA_ARGS__))
+
+#define ASSIMP_LOG_INFO_F(string,...)\
+    DefaultLogger::get()->info((Formatter::format(string),__VA_ARGS__))
+
+
+#define ASSIMP_LOG_WARN(string)\
+    DefaultLogger::get()->warn(string)
+
+#define ASSIMP_LOG_ERROR(string)\
+    DefaultLogger::get()->error(string)
+
+#define ASSIMP_LOG_DEBUG(string)\
+    DefaultLogger::get()->debug(string)
+
+#define ASSIMP_LOG_INFO(string)\
+    DefaultLogger::get()->info(string)
+
+
+} // Namespace Assimp
+
+#endif // !! INCLUDED_AI_LOGGER_H

dependencies/assimp/include/assimp/Macros.h

@@ -0,0 +1,49 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/* Helper macro to set a pointer to NULL in debug builds
+ */
+#if (defined ASSIMP_BUILD_DEBUG)
+#   define AI_DEBUG_INVALIDATE_PTR(x) x = NULL;
+#else
+#   define AI_DEBUG_INVALIDATE_PTR(x)
+#endif
+

dependencies/assimp/include/assimp/MathFunctions.h

@@ -0,0 +1,86 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2016, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+#pragma once
+
+/** @file  MathFunctions.h
+*  @brief Implementation of math utility functions.
+ *
+*/
+
+#include <limits>
+
+namespace Assimp {
+namespace Math {
+
+// TODO: use binary GCD for unsigned integers ....
+template < typename IntegerType >
+inline
+IntegerType gcd( IntegerType a, IntegerType b ) {
+	const IntegerType zero = (IntegerType)0;
+	while ( true ) {
+		if ( a == zero )
+			return b;
+		b %= a;
+
+		if ( b == zero )
+			return a;
+		a %= b;
+	}
+}
+
+template < typename IntegerType >
+inline
+IntegerType lcm( IntegerType a, IntegerType b ) {
+	const IntegerType t = gcd (a,b);
+	if (!t)
+        return t;
+	return a / t * b;
+}
+
+template<class T>
+inline
+T getEpsilon() {
+    return std::numeric_limits<T>::epsilon();
+}
+
+}
+}

dependencies/assimp/include/assimp/MemoryIOWrapper.h

@@ -0,0 +1,244 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file MemoryIOWrapper.h
+ *  Handy IOStream/IOSystem implemetation to read directly from a memory buffer */
+#ifndef AI_MEMORYIOSTREAM_H_INC
+#define AI_MEMORYIOSTREAM_H_INC
+
+#include <assimp/IOStream.hpp>
+#include <assimp/IOSystem.hpp>
+#include <assimp/ai_assert.h>
+#include <stdint.h>
+
+namespace Assimp    {
+    
+#define AI_MEMORYIO_MAGIC_FILENAME "$$$___magic___$$$"
+#define AI_MEMORYIO_MAGIC_FILENAME_LENGTH 17
+
+// ----------------------------------------------------------------------------------
+/** Implementation of IOStream to read directly from a memory buffer */
+// ----------------------------------------------------------------------------------
+class MemoryIOStream : public IOStream {
+public:
+    MemoryIOStream (const uint8_t* buff, size_t len, bool own = false)
+    : buffer (buff)
+    , length(len)
+    , pos((size_t)0)
+    , own(own) {
+        // empty
+    }
+
+    ~MemoryIOStream ()  {
+        if(own) {
+            delete[] buffer;
+        }
+    }
+
+    // -------------------------------------------------------------------
+    // Read from stream
+    size_t Read(void* pvBuffer, size_t pSize, size_t pCount)    {
+        ai_assert(nullptr != pvBuffer);
+        ai_assert(0 != pSize);
+        
+        const size_t cnt = std::min( pCount, (length-pos) / pSize);
+        const size_t ofs = pSize * cnt;
+
+        ::memcpy(pvBuffer,buffer+pos,ofs);
+        pos += ofs;
+
+        return cnt;
+    }
+
+    // -------------------------------------------------------------------
+    // Write to stream
+    size_t Write(const void* /*pvBuffer*/, size_t /*pSize*/,size_t /*pCount*/)  {
+        ai_assert(false); // won't be needed
+        return 0;
+    }
+
+    // -------------------------------------------------------------------
+    // Seek specific position
+    aiReturn Seek(size_t pOffset, aiOrigin pOrigin) {
+        if (aiOrigin_SET == pOrigin) {
+            if (pOffset > length) {
+                return AI_FAILURE;
+            }
+            pos = pOffset;
+        } else if (aiOrigin_END == pOrigin) {
+            if (pOffset > length) {
+                return AI_FAILURE;
+            }
+            pos = length-pOffset;
+        } else {
+            if (pOffset+pos > length) {
+                return AI_FAILURE;
+            }
+            pos += pOffset;
+        }
+        return AI_SUCCESS;
+    }
+
+    // -------------------------------------------------------------------
+    // Get current seek position
+    size_t Tell() const {
+        return pos;
+    }
+
+    // -------------------------------------------------------------------
+    // Get size of file
+    size_t FileSize() const {
+        return length;
+    }
+
+    // -------------------------------------------------------------------
+    // Flush file contents
+    void Flush() {
+        ai_assert(false); // won't be needed
+    }
+
+private:
+    const uint8_t* buffer;
+    size_t length,pos;
+    bool own;
+};
+
+// ---------------------------------------------------------------------------
+/** Dummy IO system to read from a memory buffer */
+class MemoryIOSystem : public IOSystem {
+public:
+    /** Constructor. */
+    MemoryIOSystem(const uint8_t* buff, size_t len, IOSystem* io)
+    : buffer(buff)
+    , length(len)
+    , existing_io(io)
+    , created_streams() {
+        // empty
+    }
+
+    /** Destructor. */
+    ~MemoryIOSystem() {
+    }
+
+    // -------------------------------------------------------------------
+    /** Tests for the existence of a file at the given path. */
+    bool Exists(const char* pFile) const override {
+        if (0 == strncmp( pFile, AI_MEMORYIO_MAGIC_FILENAME, AI_MEMORYIO_MAGIC_FILENAME_LENGTH ) ) {
+            return true;
+        }
+        return existing_io ? existing_io->Exists(pFile) : false;
+    }
+
+    // -------------------------------------------------------------------
+    /** Returns the directory separator. */
+    char getOsSeparator() const override {
+        return existing_io ? existing_io->getOsSeparator()
+                           : '/';  // why not? it doesn't care
+    }
+
+    // -------------------------------------------------------------------
+    /** Open a new file with a given path. */
+    IOStream* Open(const char* pFile, const char* pMode = "rb") override {
+        if ( 0 == strncmp( pFile, AI_MEMORYIO_MAGIC_FILENAME, AI_MEMORYIO_MAGIC_FILENAME_LENGTH ) ) {
+            created_streams.emplace_back(new MemoryIOStream(buffer, length));
+            return created_streams.back();
+        }
+        return existing_io ? existing_io->Open(pFile, pMode) : NULL;
+    }
+
+    // -------------------------------------------------------------------
+    /** Closes the given file and releases all resources associated with it. */
+    void Close( IOStream* pFile) override {
+        auto it = std::find(created_streams.begin(), created_streams.end(), pFile);
+        if (it != created_streams.end()) {
+            delete pFile;
+            created_streams.erase(it);
+        } else if (existing_io) {
+            existing_io->Close(pFile);
+        }
+    }
+
+    // -------------------------------------------------------------------
+    /** Compare two paths */
+    bool ComparePaths(const char* one, const char* second) const override {
+        return existing_io ? existing_io->ComparePaths(one, second) : false;
+    }
+
+    bool PushDirectory( const std::string &path ) override { 
+        return existing_io ? existing_io->PushDirectory(path) : false;
+    }
+
+    const std::string &CurrentDirectory() const override {
+        static std::string empty;
+        return existing_io ? existing_io->CurrentDirectory() : empty;
+    }
+
+    size_t StackSize() const override {
+        return existing_io ? existing_io->StackSize() : 0;
+    }
+
+    bool PopDirectory() override {
+        return existing_io ? existing_io->PopDirectory() : false;
+    }
+
+    bool CreateDirectory( const std::string &path ) override {
+        return existing_io ? existing_io->CreateDirectory(path) : false;
+    }
+
+    bool ChangeDirectory( const std::string &path ) override {
+        return existing_io ? existing_io->ChangeDirectory(path) : false;
+    }
+
+    bool DeleteFile( const std::string &file ) override {
+        return existing_io ? existing_io->DeleteFile(file) : false;
+    }
+
+private:
+    const uint8_t* buffer;
+    size_t length;
+    IOSystem* existing_io;
+    std::vector<IOStream*> created_streams;
+};
+
+} // end namespace Assimp
+
+#endif

dependencies/assimp/include/assimp/NullLogger.hpp

@@ -0,0 +1,99 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  NullLogger.hpp
+ *  @brief Dummy logger
+*/
+
+#ifndef INCLUDED_AI_NULLLOGGER_H
+#define INCLUDED_AI_NULLLOGGER_H
+
+#include "Logger.hpp"
+
+namespace Assimp {
+
+// ---------------------------------------------------------------------------
+/** @brief CPP-API: Empty logging implementation.
+ *
+ * Does nothing! Used by default if the application hasn't requested a
+ * custom logger via #DefaultLogger::set() or #DefaultLogger::create(); */
+class ASSIMP_API NullLogger
+    : public Logger {
+
+public:
+
+    /** @brief  Logs a debug message */
+    void OnDebug(const char* message) {
+        (void)message; //this avoids compiler warnings
+    }
+
+    /** @brief  Logs an info message */
+    void OnInfo(const char* message) {
+        (void)message; //this avoids compiler warnings
+    }
+
+    /** @brief  Logs a warning message */
+    void OnWarn(const char* message) {
+        (void)message; //this avoids compiler warnings
+    }
+
+    /** @brief  Logs an error message */
+    void OnError(const char* message) {
+        (void)message; //this avoids compiler warnings
+    }
+
+    /** @brief  Detach a still attached stream from logger */
+    bool attachStream(LogStream *pStream, unsigned int severity) {
+        (void)pStream; (void)severity; //this avoids compiler warnings
+        return false;
+    }
+
+    /** @brief  Detach a still attached stream from logger */
+    bool detatchStream(LogStream *pStream, unsigned int severity) {
+        (void)pStream; (void)severity; //this avoids compiler warnings
+        return false;
+    }
+
+private:
+};
+}
+#endif // !! AI_NULLLOGGER_H_INCLUDED

dependencies/assimp/include/assimp/ParsingUtils.h

@@ -0,0 +1,259 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+
+/** @file ParsingUtils.h
+ *  @brief Defines helper functions for text parsing
+ */
+#ifndef AI_PARSING_UTILS_H_INC
+#define AI_PARSING_UTILS_H_INC
+
+#include "StringComparison.h"
+#include "StringUtils.h"
+#include <assimp/defs.h>
+
+namespace Assimp {
+
+// NOTE: the functions below are mostly intended as replacement for
+// std::upper, std::lower, std::isupper, std::islower, std::isspace.
+// we don't bother of locales. We don't want them. We want reliable
+// (i.e. identical) results across all locales.
+
+// The functions below accept any character type, but know only
+// about ASCII. However, UTF-32 is the only safe ASCII superset to
+// use since it doesn't have multi-byte sequences.
+
+static const unsigned int BufferSize = 4096;
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+char_t ToLower( char_t in ) {
+    return (in >= (char_t)'A' && in <= (char_t)'Z') ? (char_t)(in+0x20) : in;
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+char_t ToUpper( char_t in) {
+    return (in >= (char_t)'a' && in <= (char_t)'z') ? (char_t)(in-0x20) : in;
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool IsUpper( char_t in) {
+    return (in >= (char_t)'A' && in <= (char_t)'Z');
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool IsLower( char_t in) {
+    return (in >= (char_t)'a' && in <= (char_t)'z');
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool IsSpace( char_t in) {
+    return (in == (char_t)' ' || in == (char_t)'\t');
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool IsLineEnd( char_t in) {
+    return (in==(char_t)'\r'||in==(char_t)'\n'||in==(char_t)'\0'||in==(char_t)'\f');
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool IsSpaceOrNewLine( char_t in) {
+    return IsSpace<char_t>(in) || IsLineEnd<char_t>(in);
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipSpaces( const char_t* in, const char_t** out) {
+    while( *in == ( char_t )' ' || *in == ( char_t )'\t' ) {
+        ++in;
+    }
+    *out = in;
+    return !IsLineEnd<char_t>(*in);
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipSpaces( const char_t** inout) {
+    return SkipSpaces<char_t>(*inout,inout);
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipLine( const char_t* in, const char_t** out) {
+    while( *in != ( char_t )'\r' && *in != ( char_t )'\n' && *in != ( char_t )'\0' ) {
+        ++in;
+    }
+
+    // files are opened in binary mode. Ergo there are both NL and CR
+    while( *in == ( char_t )'\r' || *in == ( char_t )'\n' ) {
+        ++in;
+    }
+    *out = in;
+    return *in != (char_t)'\0';
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipLine( const char_t** inout) {
+    return SkipLine<char_t>(*inout,inout);
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipSpacesAndLineEnd( const char_t* in, const char_t** out) {
+    while( *in == ( char_t )' ' || *in == ( char_t )'\t' || *in == ( char_t )'\r' || *in == ( char_t )'\n' ) {
+        ++in;
+    }
+    *out = in;
+    return *in != '\0';
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool SkipSpacesAndLineEnd( const char_t** inout) {
+    return SkipSpacesAndLineEnd<char_t>(*inout,inout);
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool GetNextLine( const char_t*& buffer, char_t out[ BufferSize ] ) {
+    if( ( char_t )'\0' == *buffer ) {
+        return false;
+    }
+
+    char* _out = out;
+    char* const end = _out + BufferSize;
+    while( !IsLineEnd( *buffer ) && _out < end ) {
+        *_out++ = *buffer++;
+    }
+    *_out = (char_t)'\0';
+
+    while( IsLineEnd( *buffer ) && '\0' != *buffer ) {
+        ++buffer;
+    }
+
+    return true;
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE bool IsNumeric( char_t in) {
+    return ( in >= '0' && in <= '9' ) || '-' == in || '+' == in;
+}
+
+// ---------------------------------------------------------------------------------
+template <class char_t>
+AI_FORCE_INLINE
+bool TokenMatch(char_t*& in, const char* token, unsigned int len)
+{
+    if (!::strncmp(token,in,len) && IsSpaceOrNewLine(in[len])) {
+        if (in[len] != '\0') {
+            in += len+1;
+        } else {
+            // If EOF after the token make sure we don't go past end of buffer
+            in += len;
+        }
+        return true;
+    }
+
+    return false;
+}
+// ---------------------------------------------------------------------------------
+/** @brief Case-ignoring version of TokenMatch
+ *  @param in Input
+ *  @param token Token to check for
+ *  @param len Number of characters to check
+ */
+AI_FORCE_INLINE
+bool TokenMatchI(const char*& in, const char* token, unsigned int len) {
+    if (!ASSIMP_strincmp(token,in,len) && IsSpaceOrNewLine(in[len])) {
+        in += len+1;
+        return true;
+    }
+    return false;
+}
+
+// ---------------------------------------------------------------------------------
+AI_FORCE_INLINE
+void SkipToken(const char*& in) {
+    SkipSpaces(&in);
+    while ( !IsSpaceOrNewLine( *in ) ) {
+        ++in;
+    }
+}
+
+// ---------------------------------------------------------------------------------
+AI_FORCE_INLINE
+std::string GetNextToken(const char*& in) {
+    SkipSpacesAndLineEnd(&in);
+    const char* cur = in;
+    while ( !IsSpaceOrNewLine( *in ) ) {
+        ++in;
+    }
+    return std::string(cur,(size_t)(in-cur));
+}
+
+// ---------------------------------------------------------------------------------
+
+} // ! namespace Assimp
+
+#endif // ! AI_PARSING_UTILS_H_INC

dependencies/assimp/include/assimp/Profiler.h

@@ -0,0 +1,99 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Profiler.h
+ *  @brief Utility to measure the respective runtime of each import step
+ */
+#ifndef INCLUDED_PROFILER_H
+#define INCLUDED_PROFILER_H
+
+#include <chrono>
+#include <assimp/DefaultLogger.hpp>
+#include "TinyFormatter.h"
+
+#include <map>
+
+namespace Assimp {
+namespace Profiling {
+
+using namespace Formatter;
+
+// ------------------------------------------------------------------------------------------------
+/** Simple wrapper around boost::timer to simplify reporting. Timings are automatically
+ *  dumped to the log file.
+ */
+class Profiler {
+public:
+    Profiler() {
+        // empty
+    }
+
+public:
+
+    /** Start a named timer */
+    void BeginRegion(const std::string& region) {
+        regions[region] = std::chrono::system_clock::now();
+        ASSIMP_LOG_DEBUG((format("START `"),region,"`"));
+    }
+
+
+    /** End a specific named timer and write its end time to the log */
+    void EndRegion(const std::string& region) {
+        RegionMap::const_iterator it = regions.find(region);
+        if (it == regions.end()) {
+            return;
+        }
+
+        std::chrono::duration<double> elapsedSeconds = std::chrono::system_clock::now() - regions[region];
+        ASSIMP_LOG_DEBUG((format("END   `"),region,"`, dt= ", elapsedSeconds.count()," s"));
+    }
+
+private:
+    typedef std::map<std::string,std::chrono::time_point<std::chrono::system_clock>> RegionMap;
+    RegionMap regions;
+};
+
+}
+}
+
+#endif
+

dependencies/assimp/include/assimp/ProgressHandler.hpp

@@ -0,0 +1,145 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file ProgressHandler.hpp
+ *  @brief Abstract base class 'ProgressHandler'.
+ */
+#pragma once
+#ifndef AI_PROGRESSHANDLER_H_INC
+#define AI_PROGRESSHANDLER_H_INC
+
+#include "types.h"
+
+namespace Assimp    {
+
+// ------------------------------------------------------------------------------------
+/** @brief CPP-API: Abstract interface for custom progress report receivers.
+ *
+ *  Each #Importer instance maintains its own #ProgressHandler. The default
+ *  implementation provided by Assimp doesn't do anything at all. */
+class ASSIMP_API ProgressHandler
+#ifndef SWIG
+    : public Intern::AllocateFromAssimpHeap
+#endif
+{
+protected:
+    /// @brief  Default constructor
+    ProgressHandler () AI_NO_EXCEPT {
+        // empty
+    }
+
+public:
+    /// @brief  Virtual destructor.
+    virtual ~ProgressHandler () {
+    }
+
+    // -------------------------------------------------------------------
+    /** @brief Progress callback.
+     *  @param percentage An estimate of the current loading progress,
+     *    in percent. Or -1.f if such an estimate is not available.
+     *
+     *  There are restriction on what you may do from within your
+     *  implementation of this method: no exceptions may be thrown and no
+     *  non-const #Importer methods may be called. It is
+     *  not generally possible to predict the number of callbacks
+     *  fired during a single import.
+     *
+     *  @return Return false to abort loading at the next possible
+     *   occasion (loaders and Assimp are generally allowed to perform
+     *   all needed cleanup tasks prior to returning control to the
+     *   caller). If the loading is aborted, #Importer::ReadFile()
+     *   returns always NULL.
+     *   */
+    virtual bool Update(float percentage = -1.f) = 0;
+
+    // -------------------------------------------------------------------
+    /** @brief Progress callback for file loading steps
+     *  @param numberOfSteps The number of total post-processing
+     *   steps
+     *  @param currentStep The index of the current post-processing
+     *   step that will run, or equal to numberOfSteps if all of
+     *   them has finished. This number is always strictly monotone
+     *   increasing, although not necessarily linearly.
+     *
+     *  @note This is currently only used at the start and the end
+     *   of the file parsing.
+     *   */
+    virtual void UpdateFileRead(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
+        float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
+        Update( f * 0.5f );
+    }
+
+    // -------------------------------------------------------------------
+    /** @brief Progress callback for post-processing steps
+     *  @param numberOfSteps The number of total post-processing
+     *   steps
+     *  @param currentStep The index of the current post-processing
+     *   step that will run, or equal to numberOfSteps if all of
+     *   them has finished. This number is always strictly monotone
+     *   increasing, although not necessarily linearly.
+     *   */
+    virtual void UpdatePostProcess(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
+        float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
+        Update( f * 0.5f + 0.5f );
+    }
+
+
+    // -------------------------------------------------------------------
+    /** @brief Progress callback for export steps.
+     *  @param numberOfSteps The number of total processing
+     *   steps
+     *  @param currentStep The index of the current post-processing
+     *   step that will run, or equal to numberOfSteps if all of
+     *   them has finished. This number is always strictly monotone
+     *   increasing, although not necessarily linearly.
+     *   */
+    virtual void UpdateFileWrite(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
+        float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
+        Update(f * 0.5f);
+    }
+}; // !class ProgressHandler
+
+// ------------------------------------------------------------------------------------
+
+} // Namespace Assimp
+
+#endif // AI_PROGRESSHANDLER_H_INC

dependencies/assimp/include/assimp/RemoveComments.h

@@ -0,0 +1,91 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Declares a helper class, "CommentRemover", which can be
+ *  used to remove comments (single and multi line) from a text file.
+ */
+#ifndef AI_REMOVE_COMMENTS_H_INC
+#define AI_REMOVE_COMMENTS_H_INC
+
+
+#include <assimp/defs.h>
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------
+/** \brief Helper class to remove single and multi line comments from a file
+ *
+ *  Some mesh formats like MD5 have comments that are quite similar
+ *  to those in C or C++ so this code has been moved to a separate
+ *  module.
+ */
+class ASSIMP_API CommentRemover
+{
+    // class cannot be instanced
+    CommentRemover() {}
+
+public:
+
+    //! Remove single-line comments. The end of a line is
+    //! expected to be either NL or CR or NLCR.
+    //! \param szComment The start sequence of the comment, e.g. "//"
+    //! \param szBuffer Buffer to work with
+    //! \param chReplacement Character to be used as replacement
+    //! for commented lines. By default this is ' '
+    static void RemoveLineComments(const char* szComment,
+        char* szBuffer, char chReplacement = ' ');
+
+    //! Remove multi-line comments. The end of a line is
+    //! expected to be either NL or CR or NLCR. Multi-line comments
+    //! may not be nested (as in C).
+    //! \param szCommentStart The start sequence of the comment, e.g. "/*"
+    //! \param szCommentEnd The end sequence of the comment, e.g. "*/"
+    //! \param szBuffer Buffer to work with
+    //! \param chReplacement Character to be used as replacement
+    //! for commented lines. By default this is ' '
+    static void RemoveMultiLineComments(const char* szCommentStart,
+        const char* szCommentEnd,char* szBuffer,
+        char chReplacement = ' ');
+};
+} // ! Assimp
+
+#endif // !! AI_REMOVE_COMMENTS_H_INC

dependencies/assimp/include/assimp/SGSpatialSort.h

@@ -0,0 +1,150 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** Small helper classes to optimize finding vertices close to a given location
+ */
+#ifndef AI_D3DSSPATIALSORT_H_INC
+#define AI_D3DSSPATIALSORT_H_INC
+
+#include <assimp/types.h>
+#include <vector>
+#include <stdint.h>
+
+namespace Assimp    {
+
+// ----------------------------------------------------------------------------------
+/** Specialized version of SpatialSort to support smoothing groups
+ *  This is used in by the 3DS, ASE and LWO loaders. 3DS and ASE share their
+ *  normal computation code in SmoothingGroups.inl, the LWO loader has its own
+ *  implementation to handle all details of its file format correctly.
+ */
+// ----------------------------------------------------------------------------------
+class ASSIMP_API SGSpatialSort
+{
+public:
+
+    SGSpatialSort();
+
+    // -------------------------------------------------------------------
+    /** Construction from a given face array, handling smoothing groups
+     *  properly
+     */
+    explicit SGSpatialSort(const std::vector<aiVector3D>& vPositions);
+
+    // -------------------------------------------------------------------
+    /** Add a vertex to the spatial sort
+     * @param vPosition Vertex position to be added
+     * @param index Index of the vrtex
+     * @param smoothingGroup SmoothingGroup for this vertex
+     */
+    void Add(const aiVector3D& vPosition, unsigned int index,
+        unsigned int smoothingGroup);
+
+    // -------------------------------------------------------------------
+    /** Prepare the spatial sorter for use. This step runs in O(logn)
+     */
+    void Prepare();
+
+    /** Destructor */
+    ~SGSpatialSort();
+
+    // -------------------------------------------------------------------
+    /** Returns an iterator for all positions close to the given position.
+     * @param pPosition The position to look for vertices.
+     * @param pSG Only included vertices with at least one shared smooth group
+     * @param pRadius Maximal distance from the position a vertex may have
+     *   to be counted in.
+     * @param poResults The container to store the indices of the found
+     *   positions. Will be emptied by the call so it may contain anything.
+     * @param exactMatch Specifies whether smoothing groups are bit masks
+     *   (false) or integral values (true). In the latter case, a vertex
+     *   cannot belong to more than one smoothing group.
+     * @return An iterator to iterate over all vertices in the given area.
+     */
+    // -------------------------------------------------------------------
+    void FindPositions( const aiVector3D& pPosition, uint32_t pSG,
+        float pRadius, std::vector<unsigned int>& poResults,
+        bool exactMatch = false) const;
+
+protected:
+    /** Normal of the sorting plane, normalized. The center is always at (0, 0, 0) */
+    aiVector3D mPlaneNormal;
+
+    // -------------------------------------------------------------------
+    /** An entry in a spatially sorted position array. Consists of a
+     *  vertex index, its position and its pre-calculated distance from
+     *  the reference plane */
+    // -------------------------------------------------------------------
+    struct Entry {
+        unsigned int mIndex;    ///< The vertex referred by this entry
+        aiVector3D mPosition;   ///< Position
+        uint32_t mSmoothGroups;
+        float mDistance;        ///< Distance of this vertex to the sorting plane
+
+        Entry() AI_NO_EXCEPT
+        : mIndex(0)
+        , mPosition()
+        , mSmoothGroups(0)
+        , mDistance(0.0f) {
+            // empty
+        }
+
+        Entry( unsigned int pIndex, const aiVector3D& pPosition, float pDistance,uint32_t pSG)
+        : mIndex( pIndex)
+        , mPosition( pPosition)
+        , mSmoothGroups(pSG)
+        , mDistance( pDistance) {
+            // empty
+        }
+
+        bool operator < (const Entry& e) const {
+            return mDistance < e.mDistance;
+        }
+    };
+
+    // all positions, sorted by distance to the sorting plane
+    std::vector<Entry> mPositions;
+};
+
+} // end of namespace Assimp
+
+#endif // AI_SPATIALSORT_H_INC

dependencies/assimp/include/assimp/SceneCombiner.h

@@ -0,0 +1,403 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Declares a helper class, "SceneCombiner" providing various
+ *  utilities to merge scenes.
+ */
+#ifndef AI_SCENE_COMBINER_H_INC
+#define AI_SCENE_COMBINER_H_INC
+
+#include <assimp/ai_assert.h>
+#include <assimp/types.h>
+#include <assimp/Defines.h>
+#include <stddef.h>
+#include <set>
+#include <list>
+#include <stdint.h>
+
+#include <vector>
+
+struct aiScene;
+struct aiNode;
+struct aiMaterial;
+struct aiTexture;
+struct aiCamera;
+struct aiLight;
+struct aiMetadata;
+struct aiBone;
+struct aiMesh;
+struct aiAnimMesh;
+struct aiAnimation;
+struct aiNodeAnim;
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------
+/** \brief Helper data structure for SceneCombiner.
+ *
+ *  Describes to which node a scene must be attached to.
+ */
+struct AttachmentInfo
+{
+    AttachmentInfo()
+        :   scene           (NULL)
+        ,   attachToNode    (NULL)
+    {}
+
+    AttachmentInfo(aiScene* _scene, aiNode* _attachToNode)
+        :   scene           (_scene)
+        ,   attachToNode    (_attachToNode)
+    {}
+
+    aiScene* scene;
+    aiNode*  attachToNode;
+};
+
+// ---------------------------------------------------------------------------
+struct NodeAttachmentInfo
+{
+    NodeAttachmentInfo()
+        :   node            (NULL)
+        ,   attachToNode    (NULL)
+        ,   resolved        (false)
+        ,   src_idx         (SIZE_MAX)
+    {}
+
+    NodeAttachmentInfo(aiNode* _scene, aiNode* _attachToNode,size_t idx)
+        :   node            (_scene)
+        ,   attachToNode    (_attachToNode)
+        ,   resolved        (false)
+        ,   src_idx         (idx)
+    {}
+
+    aiNode*  node;
+    aiNode*  attachToNode;
+    bool     resolved;
+    size_t   src_idx;
+};
+
+// ---------------------------------------------------------------------------
+/** @def AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES
+ *  Generate unique names for all named scene items
+ */
+#define AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES      0x1
+
+/** @def AI_INT_MERGE_SCENE_GEN_UNIQUE_MATNAMES
+ *  Generate unique names for materials, too.
+ *  This is not absolutely required to pass the validation.
+ */
+#define AI_INT_MERGE_SCENE_GEN_UNIQUE_MATNAMES   0x2
+
+/** @def AI_INT_MERGE_SCENE_DUPLICATES_DEEP_CPY
+ * Use deep copies of duplicate scenes
+ */
+#define AI_INT_MERGE_SCENE_DUPLICATES_DEEP_CPY   0x4
+
+/** @def AI_INT_MERGE_SCENE_RESOLVE_CROSS_ATTACHMENTS
+ * If attachment nodes are not found in the given master scene,
+ * search the other imported scenes for them in an any order.
+ */
+#define AI_INT_MERGE_SCENE_RESOLVE_CROSS_ATTACHMENTS 0x8
+
+/** @def AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES_IF_NECESSARY
+ * Can be combined with AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES.
+ * Unique names are generated, but only if this is absolutely
+ * required to avoid name conflicts.
+ */
+#define AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES_IF_NECESSARY 0x10
+
+typedef std::pair<aiBone*,unsigned int> BoneSrcIndex;
+
+// ---------------------------------------------------------------------------
+/** @brief Helper data structure for SceneCombiner::MergeBones.
+ */
+struct BoneWithHash : public std::pair<uint32_t,aiString*>  {
+    std::vector<BoneSrcIndex> pSrcBones;
+};
+
+// ---------------------------------------------------------------------------
+/** @brief Utility for SceneCombiner
+ */
+struct SceneHelper
+{
+    SceneHelper ()
+        : scene     (NULL)
+        , idlen     (0)
+    {
+        id[0] = 0;
+    }
+
+    explicit SceneHelper (aiScene* _scene)
+        : scene     (_scene)
+        , idlen     (0)
+    {
+        id[0] = 0;
+    }
+
+    AI_FORCE_INLINE aiScene* operator-> () const
+    {
+        return scene;
+    }
+
+    // scene we're working on
+    aiScene* scene;
+
+    // prefix to be added to all identifiers in the scene ...
+    char id [32];
+
+    // and its strlen()
+    unsigned int idlen;
+
+    // hash table to quickly check whether a name is contained in the scene
+    std::set<unsigned int> hashes;
+};
+
+// ---------------------------------------------------------------------------
+/** \brief Static helper class providing various utilities to merge two
+ *    scenes. It is intended as internal utility and NOT for use by
+ *    applications.
+ *
+ * The class is currently being used by various postprocessing steps
+ * and loaders (ie. LWS).
+ */
+class ASSIMP_API SceneCombiner {
+    // class cannot be instanced
+    SceneCombiner() {
+        // empty
+    }
+
+    ~SceneCombiner() {
+        // empty
+    }
+
+public:
+    // -------------------------------------------------------------------
+    /** Merges two or more scenes.
+     *
+     *  @param dest  Receives a pointer to the destination scene. If the
+     *    pointer doesn't point to NULL when the function is called, the
+     *    existing scene is cleared and refilled.
+     *  @param src Non-empty list of scenes to be merged. The function
+     *    deletes the input scenes afterwards. There may be duplicate scenes.
+     *  @param flags Combination of the AI_INT_MERGE_SCENE flags defined above
+     */
+    static void MergeScenes(aiScene** dest,std::vector<aiScene*>& src,
+        unsigned int flags = 0);
+
+    // -------------------------------------------------------------------
+    /** Merges two or more scenes and attaches all scenes to a specific
+     *  position in the node graph of the master scene.
+     *
+     *  @param dest Receives a pointer to the destination scene. If the
+     *    pointer doesn't point to NULL when the function is called, the
+     *    existing scene is cleared and refilled.
+     *  @param master Master scene. It will be deleted afterwards. All
+     *    other scenes will be inserted in its node graph.
+     *  @param src Non-empty list of scenes to be merged along with their
+     *    corresponding attachment points in the master scene. The function
+     *    deletes the input scenes afterwards. There may be duplicate scenes.
+     *  @param flags Combination of the AI_INT_MERGE_SCENE flags defined above
+     */
+    static void MergeScenes(aiScene** dest, aiScene* master,
+        std::vector<AttachmentInfo>& src,
+        unsigned int flags = 0);
+
+    // -------------------------------------------------------------------
+    /** Merges two or more meshes
+     *
+     *  The meshes should have equal vertex formats. Only components
+     *  that are provided by ALL meshes will be present in the output mesh.
+     *  An exception is made for VColors - they are set to black. The
+     *  meshes should have the same material indices, too. The output
+     *  material index is always the material index of the first mesh.
+     *
+     *  @param dest Destination mesh. Must be empty.
+     *  @param flags Currently no parameters
+     *  @param begin First mesh to be processed
+     *  @param end Points to the mesh after the last mesh to be processed
+     */
+    static void MergeMeshes(aiMesh** dest,unsigned int flags,
+        std::vector<aiMesh*>::const_iterator begin,
+        std::vector<aiMesh*>::const_iterator end);
+
+    // -------------------------------------------------------------------
+    /** Merges two or more bones
+     *
+     *  @param out Mesh to receive the output bone list
+     *  @param flags Currently no parameters
+     *  @param begin First mesh to be processed
+     *  @param end Points to the mesh after the last mesh to be processed
+     */
+    static void MergeBones(aiMesh* out,std::vector<aiMesh*>::const_iterator it,
+        std::vector<aiMesh*>::const_iterator end);
+
+    // -------------------------------------------------------------------
+    /** Merges two or more materials
+     *
+     *  The materials should be complementary as much as possible. In case
+     *  of a property present in different materials, the first occurrence
+     *  is used.
+     *
+     *  @param dest Destination material. Must be empty.
+     *  @param begin First material to be processed
+     *  @param end Points to the material after the last material to be processed
+     */
+    static void MergeMaterials(aiMaterial** dest,
+        std::vector<aiMaterial*>::const_iterator begin,
+        std::vector<aiMaterial*>::const_iterator end);
+
+    // -------------------------------------------------------------------
+    /** Builds a list of uniquely named bones in a mesh list
+     *
+     *  @param asBones Receives the output list
+     *  @param it First mesh to be processed
+     *  @param end Last mesh to be processed
+     */
+    static void BuildUniqueBoneList(std::list<BoneWithHash>& asBones,
+        std::vector<aiMesh*>::const_iterator it,
+        std::vector<aiMesh*>::const_iterator end);
+
+    // -------------------------------------------------------------------
+    /** Add a name prefix to all nodes in a scene.
+     *
+     *  @param Current node. This function is called recursively.
+     *  @param prefix Prefix to be added to all nodes
+     *  @param len STring length
+     */
+    static void AddNodePrefixes(aiNode* node, const char* prefix,
+        unsigned int len);
+
+    // -------------------------------------------------------------------
+    /** Add an offset to all mesh indices in a node graph
+     *
+     *  @param Current node. This function is called recursively.
+     *  @param offset Offset to be added to all mesh indices
+     */
+    static void OffsetNodeMeshIndices (aiNode* node, unsigned int offset);
+
+    // -------------------------------------------------------------------
+    /** Attach a list of node graphs to well-defined nodes in a master
+     *  graph. This is a helper for MergeScenes()
+     *
+     *  @param master Master scene
+     *  @param srcList List of source scenes along with their attachment
+     *    points. If an attachment point is NULL (or does not exist in
+     *    the master graph), a scene is attached to the root of the master
+     *    graph (as an additional child node)
+     *  @duplicates List of duplicates. If elem[n] == n the scene is not
+     *    a duplicate. Otherwise elem[n] links scene n to its first occurrence.
+     */
+    static void AttachToGraph ( aiScene* master,
+        std::vector<NodeAttachmentInfo>& srcList);
+
+    static void AttachToGraph (aiNode* attach,
+        std::vector<NodeAttachmentInfo>& srcList);
+
+
+    // -------------------------------------------------------------------
+    /** Get a deep copy of a scene
+     *
+     *  @param dest Receives a pointer to the destination scene
+     *  @param src Source scene - remains unmodified.
+     */
+    static void CopyScene(aiScene** dest,const aiScene* source,bool allocate = true);
+
+
+    // -------------------------------------------------------------------
+    /** Get a flat copy of a scene
+     *
+     *  Only the first hierarchy layer is copied. All pointer members of
+     *  aiScene are shared by source and destination scene.  If the
+     *    pointer doesn't point to NULL when the function is called, the
+     *    existing scene is cleared and refilled.
+     *  @param dest Receives a pointer to the destination scene
+     *  @param src Source scene - remains unmodified.
+     */
+    static void CopySceneFlat(aiScene** dest,const aiScene* source);
+
+
+    // -------------------------------------------------------------------
+    /** Get a deep copy of a mesh
+     *
+     *  @param dest Receives a pointer to the destination mesh
+     *  @param src Source mesh - remains unmodified.
+     */
+    static void Copy     (aiMesh** dest, const aiMesh* src);
+
+    // similar to Copy():
+    static void Copy  (aiAnimMesh** dest, const aiAnimMesh* src);
+    static void Copy  (aiMaterial** dest, const aiMaterial* src);
+    static void Copy  (aiTexture** dest, const aiTexture* src);
+    static void Copy  (aiAnimation** dest, const aiAnimation* src);
+    static void Copy  (aiCamera** dest, const aiCamera* src);
+    static void Copy  (aiBone** dest, const aiBone* src);
+    static void Copy  (aiLight** dest, const aiLight* src);
+    static void Copy  (aiNodeAnim** dest, const aiNodeAnim* src);
+    static void Copy  (aiMetadata** dest, const aiMetadata* src);
+
+    // recursive, of course
+    static void Copy     (aiNode** dest, const aiNode* src);
+
+
+private:
+
+    // -------------------------------------------------------------------
+    // Same as AddNodePrefixes, but with an additional check
+    static void AddNodePrefixesChecked(aiNode* node, const char* prefix,
+        unsigned int len,
+        std::vector<SceneHelper>& input,
+        unsigned int cur);
+
+    // -------------------------------------------------------------------
+    // Add node identifiers to a hashing set
+    static void AddNodeHashes(aiNode* node, std::set<unsigned int>& hashes);
+
+
+    // -------------------------------------------------------------------
+    // Search for duplicate names
+    static bool FindNameMatch(const aiString& name,
+        std::vector<SceneHelper>& input, unsigned int cur);
+};
+
+}
+
+#endif // !! AI_SCENE_COMBINER_H_INC

dependencies/assimp/include/assimp/SkeletonMeshBuilder.h

@@ -0,0 +1,125 @@
+/** Helper class to construct a dummy mesh for file formats containing only motion data */
+
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file SkeletonMeshBuilder.h
+ *  Declares SkeletonMeshBuilder, a tiny utility to build dummy meshes
+ *  for animation skeletons.
+ */
+
+#ifndef AI_SKELETONMESHBUILDER_H_INC
+#define AI_SKELETONMESHBUILDER_H_INC
+
+#include <vector>
+#include <assimp/mesh.h>
+
+struct aiMaterial;
+struct aiScene;
+struct aiNode;
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------
+/**
+ * This little helper class constructs a dummy mesh for a given scene
+ * the resembles the node hierarchy. This is useful for file formats
+ * that don't carry any mesh data but only animation data.
+ */
+class ASSIMP_API SkeletonMeshBuilder
+{
+public:
+
+    // -------------------------------------------------------------------
+    /** The constructor processes the given scene and adds a mesh there.
+     *
+     * Does nothing if the scene already has mesh data.
+     * @param pScene The scene for which a skeleton mesh should be constructed.
+     * @param root The node to start with. NULL is the scene root
+     * @param bKnobsOnly Set this to true if you don't want the connectors
+     *   between the knobs representing the nodes.
+     */
+    SkeletonMeshBuilder( aiScene* pScene, aiNode* root = NULL,
+        bool bKnobsOnly = false);
+
+protected:
+
+    // -------------------------------------------------------------------
+    /** Recursively builds a simple mesh representation for the given node
+     * and also creates a joint for the node that affects this part of
+     * the mesh.
+     * @param pNode The node to build geometry for.
+     */
+    void CreateGeometry( const aiNode* pNode);
+
+    // -------------------------------------------------------------------
+    /** Creates the mesh from the internally accumulated stuff and returns it.
+     */
+    aiMesh* CreateMesh();
+
+    // -------------------------------------------------------------------
+    /** Creates a dummy material and returns it. */
+    aiMaterial* CreateMaterial();
+
+protected:
+    /** space to assemble the mesh data: points */
+    std::vector<aiVector3D> mVertices;
+
+    /** faces */
+    struct Face
+    {
+        unsigned int mIndices[3];
+        Face();
+        Face( unsigned int p0, unsigned int p1, unsigned int p2)
+        { mIndices[0] = p0; mIndices[1] = p1; mIndices[2] = p2; }
+    };
+    std::vector<Face> mFaces;
+
+    /** bones */
+    std::vector<aiBone*> mBones;
+
+    bool mKnobsOnly;
+};
+
+} // end of namespace Assimp
+
+#endif // AI_SKELETONMESHBUILDER_H_INC

dependencies/assimp/include/assimp/SmoothingGroups.h

@@ -0,0 +1,108 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Defines the helper data structures for importing 3DS files.
+http://www.jalix.org/ressources/graphics/3DS/_unofficials/3ds-unofficial.txt */
+
+#ifndef AI_SMOOTHINGGROUPS_H_INC
+#define AI_SMOOTHINGGROUPS_H_INC
+
+#include <assimp/vector3.h>
+#include <stdint.h>
+#include <vector>
+
+// ---------------------------------------------------------------------------
+/** Helper structure representing a face with smoothing groups assigned */
+struct FaceWithSmoothingGroup {
+    FaceWithSmoothingGroup() AI_NO_EXCEPT
+    : mIndices()
+    , iSmoothGroup(0) {
+        // in debug builds set all indices to a common magic value
+#ifdef ASSIMP_BUILD_DEBUG
+        this->mIndices[0] = 0xffffffff;
+        this->mIndices[1] = 0xffffffff;
+        this->mIndices[2] = 0xffffffff;
+#endif
+    }
+
+
+    //! Indices. .3ds is using uint16. However, after
+    //! an unique vertex set has been generated,
+    //! individual index values might exceed 2^16
+    uint32_t mIndices[3];
+
+    //! specifies to which smoothing group the face belongs to
+    uint32_t iSmoothGroup;
+};
+
+// ---------------------------------------------------------------------------
+/** Helper structure representing a mesh whose faces have smoothing
+    groups assigned. This allows us to reuse the code for normal computations
+    from smoothings groups for several loaders (3DS, ASE). All of them
+    use face structures which inherit from #FaceWithSmoothingGroup,
+    but as they add extra members and need to be copied by value we
+    need to use a template here.
+    */
+template <class T>
+struct MeshWithSmoothingGroups
+{
+    //! Vertex positions
+    std::vector<aiVector3D> mPositions;
+
+    //! Face lists
+    std::vector<T> mFaces;
+
+    //! List of normal vectors
+    std::vector<aiVector3D> mNormals;
+};
+
+// ---------------------------------------------------------------------------
+/** Computes normal vectors for the mesh
+ */
+template <class T>
+void ComputeNormalsWithSmoothingsGroups(MeshWithSmoothingGroups<T>& sMesh);
+
+
+// include implementations
+#include "SmoothingGroups.inl"
+
+#endif // !! AI_SMOOTHINGGROUPS_H_INC

dependencies/assimp/include/assimp/SmoothingGroups.inl

@@ -0,0 +1,138 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2012, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms, 
+with or without modification, are permitted provided that the following 
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file Generation of normal vectors basing on smoothing groups */
+
+#ifndef AI_SMOOTHINGGROUPS_INL_INCLUDED
+#define AI_SMOOTHINGGROUPS_INL_INCLUDED
+
+// internal headers
+#include <assimp/SGSpatialSort.h>
+
+// CRT header
+#include <algorithm>
+
+using namespace Assimp;
+
+// ------------------------------------------------------------------------------------------------
+template <class T>
+void ComputeNormalsWithSmoothingsGroups(MeshWithSmoothingGroups<T>& sMesh)
+{
+    // First generate face normals
+    sMesh.mNormals.resize(sMesh.mPositions.size(),aiVector3D());
+    for( unsigned int a = 0; a < sMesh.mFaces.size(); a++)
+    {
+        T& face = sMesh.mFaces[a];
+
+        aiVector3D* pV1 = &sMesh.mPositions[face.mIndices[0]];
+        aiVector3D* pV2 = &sMesh.mPositions[face.mIndices[1]];
+        aiVector3D* pV3 = &sMesh.mPositions[face.mIndices[2]];
+
+        aiVector3D pDelta1 = *pV2 - *pV1;
+        aiVector3D pDelta2 = *pV3 - *pV1;
+        aiVector3D vNor = pDelta1 ^ pDelta2;
+
+        for (unsigned int c = 0; c < 3;++c)
+            sMesh.mNormals[face.mIndices[c]] = vNor;
+    }
+
+    // calculate the position bounds so we have a reliable epsilon to check position differences against 
+    aiVector3D minVec( 1e10f, 1e10f, 1e10f), maxVec( -1e10f, -1e10f, -1e10f);
+    for( unsigned int a = 0; a < sMesh.mPositions.size(); a++)
+    {
+        minVec.x = std::min( minVec.x, sMesh.mPositions[a].x);
+        minVec.y = std::min( minVec.y, sMesh.mPositions[a].y);
+        minVec.z = std::min( minVec.z, sMesh.mPositions[a].z);
+        maxVec.x = std::max( maxVec.x, sMesh.mPositions[a].x);
+        maxVec.y = std::max( maxVec.y, sMesh.mPositions[a].y);
+        maxVec.z = std::max( maxVec.z, sMesh.mPositions[a].z);
+    }
+    const float posEpsilon = (maxVec - minVec).Length() * 1e-5f;
+    std::vector<aiVector3D> avNormals;
+    avNormals.resize(sMesh.mNormals.size());
+    
+    // now generate the spatial sort tree
+    SGSpatialSort sSort;
+    for( typename std::vector<T>::iterator i =  sMesh.mFaces.begin();
+        i != sMesh.mFaces.end();++i)
+    {
+        for (unsigned int c = 0; c < 3;++c)
+            sSort.Add(sMesh.mPositions[(*i).mIndices[c]],(*i).mIndices[c],(*i).iSmoothGroup);
+    }
+    sSort.Prepare();
+
+    std::vector<bool> vertexDone(sMesh.mPositions.size(),false);
+    for( typename std::vector<T>::iterator i =  sMesh.mFaces.begin();
+        i != sMesh.mFaces.end();++i)
+    {
+        std::vector<unsigned int> poResult;
+        for (unsigned int c = 0; c < 3;++c)
+        {
+            unsigned int idx = (*i).mIndices[c];
+            if (vertexDone[idx])continue;
+
+            sSort.FindPositions(sMesh.mPositions[idx],(*i).iSmoothGroup,
+                posEpsilon,poResult);
+
+            aiVector3D vNormals;
+            for (std::vector<unsigned int>::const_iterator
+                a =  poResult.begin();
+                a != poResult.end();++a)
+            {
+                vNormals += sMesh.mNormals[(*a)];
+            }
+            vNormals.NormalizeSafe();
+
+            // write back into all affected normals
+            for (std::vector<unsigned int>::const_iterator
+                a =  poResult.begin();
+                a != poResult.end();++a)
+            {
+                idx = *a;
+                avNormals [idx] = vNormals;
+                vertexDone[idx] = true;
+            }
+        }
+    }
+    sMesh.mNormals = avNormals;
+}
+
+#endif // !! AI_SMOOTHINGGROUPS_INL_INCLUDED

dependencies/assimp/include/assimp/SpatialSort.h

@@ -0,0 +1,174 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** Small helper classes to optimise finding vertizes close to a given location */
+#ifndef AI_SPATIALSORT_H_INC
+#define AI_SPATIALSORT_H_INC
+
+#include <vector>
+#include <assimp/types.h>
+
+namespace Assimp {
+
+// ------------------------------------------------------------------------------------------------
+/** A little helper class to quickly find all vertices in the epsilon environment of a given
+ * position. Construct an instance with an array of positions. The class stores the given positions
+ * by their indices and sorts them by their distance to an arbitrary chosen plane.
+ * You can then query the instance for all vertices close to a given position in an average O(log n)
+ * time, with O(n) worst case complexity when all vertices lay on the plane. The plane is chosen
+ * so that it avoids common planes in usual data sets. */
+// ------------------------------------------------------------------------------------------------
+class ASSIMP_API SpatialSort
+{
+public:
+
+    SpatialSort();
+
+    // ------------------------------------------------------------------------------------
+    /** Constructs a spatially sorted representation from the given position array.
+     * Supply the positions in its layout in memory, the class will only refer to them
+     * by index.
+     * @param pPositions Pointer to the first position vector of the array.
+     * @param pNumPositions Number of vectors to expect in that array.
+     * @param pElementOffset Offset in bytes from the beginning of one vector in memory
+     *   to the beginning of the next vector. */
+    SpatialSort( const aiVector3D* pPositions, unsigned int pNumPositions,
+        unsigned int pElementOffset);
+
+    /** Destructor */
+    ~SpatialSort();
+
+public:
+
+    // ------------------------------------------------------------------------------------
+    /** Sets the input data for the SpatialSort. This replaces existing data, if any.
+     *  The new data receives new indices in ascending order.
+     *
+     * @param pPositions Pointer to the first position vector of the array.
+     * @param pNumPositions Number of vectors to expect in that array.
+     * @param pElementOffset Offset in bytes from the beginning of one vector in memory
+     *   to the beginning of the next vector.
+     * @param pFinalize Specifies whether the SpatialSort's internal representation
+     *   is finalized after the new data has been added. Finalization is
+     *   required in order to use #FindPosition() or #GenerateMappingTable().
+     *   If you don't finalize yet, you can use #Append() to add data from
+     *   other sources.*/
+    void Fill( const aiVector3D* pPositions, unsigned int pNumPositions,
+        unsigned int pElementOffset,
+        bool pFinalize = true);
+
+
+    // ------------------------------------------------------------------------------------
+    /** Same as #Fill(), except the method appends to existing data in the #SpatialSort. */
+    void Append( const aiVector3D* pPositions, unsigned int pNumPositions,
+        unsigned int pElementOffset,
+        bool pFinalize = true);
+
+
+    // ------------------------------------------------------------------------------------
+    /** Finalize the spatial hash data structure. This can be useful after
+     *  multiple calls to #Append() with the pFinalize parameter set to false.
+     *  This is finally required before one of #FindPositions() and #GenerateMappingTable()
+     *  can be called to query the spatial sort.*/
+    void Finalize();
+
+    // ------------------------------------------------------------------------------------
+    /** Returns an iterator for all positions close to the given position.
+     * @param pPosition The position to look for vertices.
+     * @param pRadius Maximal distance from the position a vertex may have to be counted in.
+     * @param poResults The container to store the indices of the found positions.
+     *   Will be emptied by the call so it may contain anything.
+     * @return An iterator to iterate over all vertices in the given area.*/
+    void FindPositions( const aiVector3D& pPosition, ai_real pRadius,
+        std::vector<unsigned int>& poResults) const;
+
+    // ------------------------------------------------------------------------------------
+    /** Fills an array with indices of all positions identical to the given position. In
+     *  opposite to FindPositions(), not an epsilon is used but a (very low) tolerance of
+     *  four floating-point units.
+     * @param pPosition The position to look for vertices.
+     * @param poResults The container to store the indices of the found positions.
+     *   Will be emptied by the call so it may contain anything.*/
+    void FindIdenticalPositions( const aiVector3D& pPosition,
+        std::vector<unsigned int>& poResults) const;
+
+    // ------------------------------------------------------------------------------------
+    /** Compute a table that maps each vertex ID referring to a spatially close
+     *  enough position to the same output ID. Output IDs are assigned in ascending order
+     *  from 0...n.
+     * @param fill Will be filled with numPositions entries.
+     * @param pRadius Maximal distance from the position a vertex may have to
+     *   be counted in.
+     *  @return Number of unique vertices (n).  */
+    unsigned int GenerateMappingTable(std::vector<unsigned int>& fill,
+        ai_real pRadius) const;
+
+protected:
+    /** Normal of the sorting plane, normalized. The center is always at (0, 0, 0) */
+    aiVector3D mPlaneNormal;
+
+    /** An entry in a spatially sorted position array. Consists of a vertex index,
+     * its position and its pre-calculated distance from the reference plane */
+    struct Entry {
+        unsigned int mIndex; ///< The vertex referred by this entry
+        aiVector3D mPosition; ///< Position
+        ai_real mDistance; ///< Distance of this vertex to the sorting plane
+
+        Entry() AI_NO_EXCEPT
+        : mIndex( 999999999 ), mPosition(), mDistance( 99999. ) {
+            // empty        
+        }
+        Entry( unsigned int pIndex, const aiVector3D& pPosition, ai_real pDistance)
+        : mIndex( pIndex), mPosition( pPosition), mDistance( pDistance) {
+            // empty
+        }
+
+        bool operator < (const Entry& e) const { return mDistance < e.mDistance; }
+    };
+
+    // all positions, sorted by distance to the sorting plane
+    std::vector<Entry> mPositions;
+};
+
+} // end of namespace Assimp
+
+#endif // AI_SPATIALSORT_H_INC

dependencies/assimp/include/assimp/StandardShapes.h

@@ -0,0 +1,200 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Declares a helper class, "StandardShapes" which generates
+ *  vertices for standard shapes, such as cylnders, cones, spheres ..
+ */
+#ifndef AI_STANDARD_SHAPES_H_INC
+#define AI_STANDARD_SHAPES_H_INC
+
+#include <assimp/vector3.h>
+#include <vector>
+
+struct aiMesh;
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------
+/** \brief Helper class to generate vertex buffers for standard geometric
+ *  shapes, such as cylinders, cones, boxes, spheres, elipsoids ... .
+ */
+class ASSIMP_API StandardShapes
+{
+    // class cannot be instanced
+    StandardShapes() {}
+
+public:
+
+
+    // ----------------------------------------------------------------
+    /** Generates a mesh from an array of vertex positions.
+     *
+     *  @param positions List of vertex positions
+     *  @param numIndices Number of indices per primitive
+     *  @return Output mesh
+     */
+    static aiMesh* MakeMesh(const std::vector<aiVector3D>& positions,
+        unsigned int numIndices);
+
+
+    static aiMesh* MakeMesh ( unsigned int (*GenerateFunc)
+        (std::vector<aiVector3D>&));
+
+    static aiMesh* MakeMesh ( unsigned int (*GenerateFunc)
+        (std::vector<aiVector3D>&, bool));
+
+    static aiMesh* MakeMesh ( unsigned int n,  void (*GenerateFunc)
+        (unsigned int,std::vector<aiVector3D>&));
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a hexahedron (cube)
+     *
+     *  Hexahedrons can be scaled on all axes.
+     *  @param positions Receives output triangles.
+     *  @param polygons If you pass true here quads will be returned
+     *  @return Number of vertices per face
+     */
+    static unsigned int MakeHexahedron(
+        std::vector<aiVector3D>& positions,
+        bool polygons = false);
+
+    // ----------------------------------------------------------------
+    /** @brief Generates an icosahedron
+     *
+     *  @param positions Receives output triangles.
+     *  @return Number of vertices per face
+     */
+    static unsigned int MakeIcosahedron(
+        std::vector<aiVector3D>& positions);
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a dodecahedron
+     *
+     *  @param positions Receives output triangles
+     *  @param polygons If you pass true here pentagons will be returned
+     *  @return Number of vertices per face
+     */
+    static unsigned int MakeDodecahedron(
+        std::vector<aiVector3D>& positions,
+        bool polygons = false);
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates an octahedron
+     *
+     *  @param positions Receives output triangles.
+     *  @return Number of vertices per face
+     */
+    static unsigned int MakeOctahedron(
+        std::vector<aiVector3D>& positions);
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a tetrahedron
+     *
+     *  @param positions Receives output triangles.
+     *  @return Number of vertices per face
+     */
+    static unsigned int MakeTetrahedron(
+        std::vector<aiVector3D>& positions);
+
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a sphere
+     *
+     *  @param tess Number of subdivions - 0 generates a octahedron
+     *  @param positions Receives output triangles.
+     */
+    static void MakeSphere(unsigned int tess,
+        std::vector<aiVector3D>& positions);
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a cone or a cylinder, either open or closed.
+     *
+     *  @code
+     *
+     *       |-----|       <- radius 1
+     *
+     *        __x__        <- ]               ^
+     *       /     \          | height        |
+     *      /       \         |               Y
+     *     /         \        |
+     *    /           \       |
+     *   /______x______\   <- ] <- end cap
+     *
+     *   |-------------|   <- radius 2
+     *
+     *  @endcode
+     *
+     *  @param height Height of the cone
+     *  @param radius1 First radius
+     *  @param radius2 Second radius
+     *  @param tess Number of triangles.
+     *  @param bOpened true for an open cone/cylinder. An open shape has
+     *    no 'end caps'
+     *  @param positions Receives output triangles
+     */
+    static void MakeCone(ai_real height,ai_real radius1,
+        ai_real radius2,unsigned int tess,
+        std::vector<aiVector3D>& positions,bool bOpen= false);
+
+
+    // ----------------------------------------------------------------
+    /** @brief Generates a flat circle
+     *
+     *  The circle is constructed in the planned formed by the x,z
+     *  axes of the cartesian coordinate system.
+     *
+     *  @param radius Radius of the circle
+     *  @param tess Number of segments.
+     *  @param positions Receives output triangles.
+     */
+    static void MakeCircle(ai_real radius, unsigned int tess,
+        std::vector<aiVector3D>& positions);
+
+};
+} // ! Assimp
+
+#endif // !! AI_STANDARD_SHAPES_H_INC

dependencies/assimp/include/assimp/StreamReader.h

@@ -0,0 +1,343 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file Defines the StreamReader class which reads data from
+ *  a binary stream with a well-defined endianness.
+ */
+
+#ifndef AI_STREAMREADER_H_INCLUDED
+#define AI_STREAMREADER_H_INCLUDED
+
+#include <assimp/IOStream.hpp>
+#include <assimp/Defines.h>
+
+#include "ByteSwapper.h"
+#include "Exceptional.h"
+#include <memory>
+
+namespace Assimp {
+
+// --------------------------------------------------------------------------------------------
+/** Wrapper class around IOStream to allow for consistent reading of binary data in both
+ *  little and big endian format. Don't attempt to instance the template directly. Use
+ *  StreamReaderLE to read from a little-endian stream and StreamReaderBE to read from a
+ *  BE stream. The class expects that the endianness of any input data is known at
+ *  compile-time, which should usually be true (#BaseImporter::ConvertToUTF8 implements
+ *  runtime endianness conversions for text files).
+ *
+ *  XXX switch from unsigned int for size types to size_t? or ptrdiff_t?*/
+// --------------------------------------------------------------------------------------------
+template <bool SwapEndianess = false, bool RuntimeSwitch = false>
+class StreamReader {
+public:
+    // FIXME: use these data types throughout the whole library,
+    // then change them to 64 bit values :-)
+    using diff = int;
+    using pos  = unsigned int;
+
+    // ---------------------------------------------------------------------
+    /** Construction from a given stream with a well-defined endianness.
+     *
+     *  The StreamReader holds a permanent strong reference to the
+     *  stream, which is released upon destruction.
+     *  @param stream Input stream. The stream is not restarted if
+     *    its file pointer is not at 0. Instead, the stream reader
+     *    reads from the current position to the end of the stream.
+     *  @param le If @c RuntimeSwitch is true: specifies whether the
+     *    stream is in little endian byte order. Otherwise the
+     *    endianness information is contained in the @c SwapEndianess
+     *    template parameter and this parameter is meaningless.  */
+    StreamReader(std::shared_ptr<IOStream> stream, bool le = false)
+        : stream(stream)
+        , le(le)
+    {
+        ai_assert(stream);
+        InternBegin();
+    }
+
+    // ---------------------------------------------------------------------
+    StreamReader(IOStream* stream, bool le = false)
+        : stream(std::shared_ptr<IOStream>(stream))
+        , le(le)
+    {
+        ai_assert(stream);
+        InternBegin();
+    }
+
+    // ---------------------------------------------------------------------
+    ~StreamReader() {
+        delete[] buffer;
+    }
+
+    // deprecated, use overloaded operator>> instead
+
+    // ---------------------------------------------------------------------
+    /** Read a float from the stream  */
+    float GetF4()
+    {
+        return Get<float>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a double from the stream  */
+    double GetF8()  {
+        return Get<double>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a signed 16 bit integer from the stream */
+    int16_t GetI2() {
+        return Get<int16_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a signed 8 bit integer from the stream */
+    int8_t GetI1()  {
+        return Get<int8_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read an signed 32 bit integer from the stream */
+    int32_t GetI4() {
+        return Get<int32_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a signed 64 bit integer from the stream */
+    int64_t GetI8() {
+        return Get<int64_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a unsigned 16 bit integer from the stream */
+    uint16_t GetU2()    {
+        return Get<uint16_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a unsigned 8 bit integer from the stream */
+    uint8_t GetU1() {
+        return Get<uint8_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read an unsigned 32 bit integer from the stream */
+    uint32_t GetU4()    {
+        return Get<uint32_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Read a unsigned 64 bit integer from the stream */
+    uint64_t GetU8()    {
+        return Get<uint64_t>();
+    }
+
+    // ---------------------------------------------------------------------
+    /** Get the remaining stream size (to the end of the stream) */
+    unsigned int GetRemainingSize() const {
+        return (unsigned int)(end - current);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Get the remaining stream size (to the current read limit). The
+     *  return value is the remaining size of the stream if no custom
+     *  read limit has been set. */
+    unsigned int GetRemainingSizeToLimit() const {
+        return (unsigned int)(limit - current);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Increase the file pointer (relative seeking)  */
+    void IncPtr(intptr_t plus)    {
+        current += plus;
+        if (current > limit) {
+            throw DeadlyImportError("End of file or read limit was reached");
+        }
+    }
+
+    // ---------------------------------------------------------------------
+    /** Get the current file pointer */
+    int8_t* GetPtr() const  {
+        return current;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Set current file pointer (Get it from #GetPtr). This is if you
+     *  prefer to do pointer arithmetics on your own or want to copy
+     *  large chunks of data at once.
+     *  @param p The new pointer, which is validated against the size
+     *    limit and buffer boundaries. */
+    void SetPtr(int8_t* p)  {
+        current = p;
+        if (current > limit || current < buffer) {
+            throw DeadlyImportError("End of file or read limit was reached");
+        }
+    }
+
+    // ---------------------------------------------------------------------
+    /** Copy n bytes to an external buffer
+     *  @param out Destination for copying
+     *  @param bytes Number of bytes to copy */
+    void CopyAndAdvance(void* out, size_t bytes)    {
+        int8_t* ur = GetPtr();
+        SetPtr(ur+bytes); // fire exception if eof
+
+        ::memcpy(out,ur,bytes);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Get the current offset from the beginning of the file */
+    int GetCurrentPos() const   {
+        return (unsigned int)(current - buffer);
+    }
+
+    void SetCurrentPos(size_t pos) {
+        SetPtr(buffer + pos);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Setup a temporary read limit
+     *
+     *  @param limit Maximum number of bytes to be read from
+     *    the beginning of the file. Specifying UINT_MAX
+     *    resets the limit to the original end of the stream.
+     *  Returns the previously set limit. */
+    unsigned int SetReadLimit(unsigned int _limit)  {
+        unsigned int prev = GetReadLimit();
+        if (UINT_MAX == _limit) {
+            limit = end;
+            return prev;
+        }
+
+        limit = buffer + _limit;
+        if (limit > end) {
+            throw DeadlyImportError("StreamReader: Invalid read limit");
+        }
+        return prev;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Get the current read limit in bytes. Reading over this limit
+     *  accidentally raises an exception.  */
+    unsigned int GetReadLimit() const    {
+        return (unsigned int)(limit - buffer);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Skip to the read limit in bytes. Reading over this limit
+     *  accidentally raises an exception. */
+    void SkipToReadLimit()  {
+        current = limit;
+    }
+
+    // ---------------------------------------------------------------------
+    /** overload operator>> and allow chaining of >> ops. */
+    template <typename T>
+    StreamReader& operator >> (T& f) {
+        f = Get<T>();
+        return *this;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Generic read method. ByteSwap::Swap(T*) *must* be defined */
+    template <typename T>
+    T Get() {
+        if ( current + sizeof(T) > limit) {
+            throw DeadlyImportError("End of file or stream limit was reached");
+        }
+
+        T f;
+        ::memcpy (&f, current, sizeof(T));
+        Intern::Getter<SwapEndianess,T,RuntimeSwitch>() (&f,le);
+        current += sizeof(T);
+
+        return f;
+    }
+
+private:
+    // ---------------------------------------------------------------------
+    void InternBegin() {
+        if (!stream) {
+            // in case someone wonders: StreamReader is frequently invoked with
+            // no prior validation whether the input stream is valid. Since
+            // no one bothers changing the error message, this message here
+            // is passed down to the caller and 'unable to open file'
+            // simply describes best what happened.
+            throw DeadlyImportError("StreamReader: Unable to open file");
+        }
+
+        const size_t s = stream->FileSize() - stream->Tell();
+        if (!s) {
+            throw DeadlyImportError("StreamReader: File is empty or EOF is already reached");
+        }
+
+        current = buffer = new int8_t[s];
+        const size_t read = stream->Read(current,1,s);
+        // (read < s) can only happen if the stream was opened in text mode, in which case FileSize() is not reliable
+        ai_assert(read <= s);
+        end = limit = &buffer[read-1] + 1;
+    }
+
+private:
+    std::shared_ptr<IOStream> stream;
+    int8_t *buffer, *current, *end, *limit;
+    bool le;
+};
+
+// --------------------------------------------------------------------------------------------
+// `static` StreamReaders. Their byte order is fixed and they might be a little bit faster.
+#ifdef AI_BUILD_BIG_ENDIAN
+    typedef StreamReader<true>  StreamReaderLE;
+    typedef StreamReader<false> StreamReaderBE;
+#else
+    typedef StreamReader<true>  StreamReaderBE;
+    typedef StreamReader<false> StreamReaderLE;
+#endif
+
+// `dynamic` StreamReader. The byte order of the input data is specified in the
+// c'tor. This involves runtime branching and might be a little bit slower.
+typedef StreamReader<true,true> StreamReaderAny;
+
+} // end namespace Assimp
+
+#endif // !! AI_STREAMREADER_H_INCLUDED

dependencies/assimp/include/assimp/StreamWriter.h

@@ -0,0 +1,303 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file Defines the StreamWriter class which writes data to
+ *  a binary stream with a well-defined endianness. */
+
+#ifndef AI_STREAMWRITER_H_INCLUDED
+#define AI_STREAMWRITER_H_INCLUDED
+
+#include "ByteSwapper.h"
+#include <assimp/IOStream.hpp>
+
+#include <memory>
+#include <vector>
+
+namespace Assimp {
+
+// --------------------------------------------------------------------------------------------
+/** Wrapper class around IOStream to allow for consistent writing of binary data in both
+ *  little and big endian format. Don't attempt to instance the template directly. Use
+ *  StreamWriterLE to write to a little-endian stream and StreamWriterBE to write to a
+ *  BE stream. Alternatively, there is StreamWriterAny if the endianness of the output
+ *  stream is to be determined at runtime.
+ */
+// --------------------------------------------------------------------------------------------
+template <bool SwapEndianess = false, bool RuntimeSwitch = false>
+class StreamWriter
+{
+    enum {
+        INITIAL_CAPACITY = 1024
+    };
+
+public:
+
+    // ---------------------------------------------------------------------
+    /** Construction from a given stream with a well-defined endianness.
+     *
+     *  The StreamReader holds a permanent strong reference to the
+     *  stream, which is released upon destruction.
+     *  @param stream Input stream. The stream is not re-seeked and writing
+          continues at the current position of the stream cursor.
+     *  @param le If @c RuntimeSwitch is true: specifies whether the
+     *    stream is in little endian byte order. Otherwise the
+     *    endianness information is defined by the @c SwapEndianess
+     *    template parameter and this parameter is meaningless.  */
+    StreamWriter(std::shared_ptr<IOStream> stream, bool le = false)
+        : stream(stream)
+        , le(le)
+        , cursor()
+    {
+        ai_assert(stream);
+        buffer.reserve(INITIAL_CAPACITY);
+    }
+
+    // ---------------------------------------------------------------------
+    StreamWriter(IOStream* stream, bool le = false)
+        : stream(std::shared_ptr<IOStream>(stream))
+        , le(le)
+        , cursor()
+    {
+        ai_assert(stream);
+        buffer.reserve(INITIAL_CAPACITY);
+    }
+
+    // ---------------------------------------------------------------------
+    ~StreamWriter() {
+        stream->Write(buffer.data(), 1, buffer.size());
+        stream->Flush();
+    }
+
+public:
+
+    // ---------------------------------------------------------------------
+    /** Flush the contents of the internal buffer, and the output IOStream */
+    void Flush()
+    {
+        stream->Write(buffer.data(), 1, buffer.size());
+        stream->Flush();
+        buffer.clear();
+        cursor = 0;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Seek to the given offset / origin in the output IOStream.
+     *
+     *  Flushes the internal buffer and the output IOStream prior to seeking. */
+    aiReturn Seek(size_t pOffset, aiOrigin pOrigin=aiOrigin_SET)
+    {
+        Flush();
+        return stream->Seek(pOffset, pOrigin);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Tell the current position in the output IOStream.
+     *
+     *  First flushes the internal buffer and the output IOStream. */
+    size_t Tell()
+    {
+        Flush();
+        return stream->Tell();
+    }
+
+public:
+
+    // ---------------------------------------------------------------------
+    /** Write a float to the stream  */
+    void PutF4(float f)
+    {
+        Put(f);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a double to the stream  */
+    void PutF8(double d)    {
+        Put(d);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a signed 16 bit integer to the stream */
+    void PutI2(int16_t n)   {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a signed 8 bit integer to the stream */
+    void PutI1(int8_t n)    {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write an signed 32 bit integer to the stream */
+    void PutI4(int32_t n)   {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a signed 64 bit integer to the stream */
+    void PutI8(int64_t n)   {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a unsigned 16 bit integer to the stream */
+    void PutU2(uint16_t n)  {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a unsigned 8 bit integer to the stream */
+    void PutU1(uint8_t n)   {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write an unsigned 32 bit integer to the stream */
+    void PutU4(uint32_t n)  {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a unsigned 64 bit integer to the stream */
+    void PutU8(uint64_t n)  {
+        Put(n);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a single character to the stream */
+    void PutChar(char c)    {
+        Put(c);
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write an aiString to the stream */
+    void PutString(const aiString& s)
+    {
+        // as Put(T f) below
+        if (cursor + s.length >= buffer.size()) {
+            buffer.resize(cursor + s.length);
+        }
+        void* dest = &buffer[cursor];
+        ::memcpy(dest, s.C_Str(), s.length);
+        cursor += s.length;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Write a std::string to the stream */
+    void PutString(const std::string& s)
+    {
+        // as Put(T f) below
+        if (cursor + s.size() >= buffer.size()) {
+            buffer.resize(cursor + s.size());
+        }
+        void* dest = &buffer[cursor];
+        ::memcpy(dest, s.c_str(), s.size());
+        cursor += s.size();
+    }
+
+public:
+
+    // ---------------------------------------------------------------------
+    /** overload operator<< and allow chaining of MM ops. */
+    template <typename T>
+    StreamWriter& operator << (T f) {
+        Put(f);
+        return *this;
+    }
+
+    // ---------------------------------------------------------------------
+    std::size_t GetCurrentPos() const {
+        return cursor;
+    }
+
+    // ---------------------------------------------------------------------
+    void SetCurrentPos(std::size_t new_cursor) {
+        cursor = new_cursor;
+    }
+
+    // ---------------------------------------------------------------------
+    /** Generic write method. ByteSwap::Swap(T*) *must* be defined */
+    template <typename T>
+    void Put(T f)   {
+        Intern :: Getter<SwapEndianess,T,RuntimeSwitch>() (&f, le);
+
+        if (cursor + sizeof(T) >= buffer.size()) {
+            buffer.resize(cursor + sizeof(T));
+        }
+
+        void* dest = &buffer[cursor];
+
+        // reinterpret_cast + assignment breaks strict aliasing rules
+        // and generally causes trouble on platforms such as ARM that
+        // do not silently ignore alignment faults.
+        ::memcpy(dest, &f, sizeof(T));
+        cursor += sizeof(T);
+    }
+
+private:
+
+    std::shared_ptr<IOStream> stream;
+    bool le;
+
+    std::vector<uint8_t> buffer;
+    std::size_t cursor;
+};
+
+
+// --------------------------------------------------------------------------------------------
+// `static` StreamWriter. Their byte order is fixed and they might be a little bit faster.
+#ifdef AI_BUILD_BIG_ENDIAN
+    typedef StreamWriter<true>  StreamWriterLE;
+    typedef StreamWriter<false> StreamWriterBE;
+#else
+    typedef StreamWriter<true>  StreamWriterBE;
+    typedef StreamWriter<false> StreamWriterLE;
+#endif
+
+// `dynamic` StreamWriter. The byte order of the input data is specified in the
+// c'tor. This involves runtime branching and might be a little bit slower.
+typedef StreamWriter<true,true> StreamWriterAny;
+
+} // end namespace Assimp
+
+#endif // !! AI_STREAMWriter_H_INCLUDED

dependencies/assimp/include/assimp/StringComparison.h

@@ -0,0 +1,233 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Definition of platform independent string workers:
+
+   ASSIMP_itoa10
+   ASSIMP_stricmp
+   ASSIMP_strincmp
+
+   These functions are not consistently available on all platforms,
+   or the provided implementations behave too differently.
+*/
+#ifndef INCLUDED_AI_STRING_WORKERS_H
+#define INCLUDED_AI_STRING_WORKERS_H
+
+#include <assimp/ai_assert.h>
+#include <assimp/defs.h>
+#include "StringComparison.h"
+
+#include <string.h>
+#include <stdint.h>
+#include <string>
+
+namespace Assimp    {
+
+// -------------------------------------------------------------------------------
+/** @brief itoa with a fixed base 10
+ * 'itoa' is not consistently available on all platforms so it is quite useful
+ * to have a small replacement function here. No need to use a full sprintf()
+ * if we just want to print a number ...
+ * @param out Output buffer
+ * @param max Maximum number of characters to be written, including '\0'.
+ *   This parameter may not be 0.
+ * @param number Number to be written
+ * @return Length of the output string, excluding the '\0'
+ */
+AI_FORCE_INLINE
+unsigned int ASSIMP_itoa10( char* out, unsigned int max, int32_t number) {
+    ai_assert(NULL != out);
+
+    // write the unary minus to indicate we have a negative number
+    unsigned int written = 1u;
+    if (number < 0 && written < max)    {
+        *out++ = '-';
+        ++written;
+        number = -number;
+    }
+
+    // We begin with the largest number that is not zero.
+    int32_t cur = 1000000000; // 2147483648
+    bool mustPrint = false;
+    while (written < max)   {
+
+        const unsigned int digit = number / cur;
+        if (mustPrint || digit > 0 || 1 == cur) {
+            // print all future zeroe's from now
+            mustPrint = true;
+
+            *out++ = '0'+static_cast<char>(digit);
+
+            ++written;
+            number -= digit*cur;
+            if (1 == cur) {
+                break;
+            }
+        }
+        cur /= 10;
+    }
+
+    // append a terminal zero
+    *out++ = '\0';
+    return written-1;
+}
+
+// -------------------------------------------------------------------------------
+/** @brief itoa with a fixed base 10 (Secure template overload)
+ *  The compiler should choose this function if he or she is able to determine the
+ *  size of the array automatically.
+ */
+template <size_t length>
+AI_FORCE_INLINE
+unsigned int ASSIMP_itoa10( char(& out)[length], int32_t number) {
+    return ASSIMP_itoa10(out,length,number);
+}
+
+// -------------------------------------------------------------------------------
+/** @brief Helper function to do platform independent string comparison.
+ *
+ *  This is required since stricmp() is not consistently available on
+ *  all platforms. Some platforms use the '_' prefix, others don't even
+ *  have such a function.
+ *
+ *  @param s1 First input string
+ *  @param s2 Second input string
+ *  @return 0 if the given strings are identical
+ */
+AI_FORCE_INLINE
+int ASSIMP_stricmp(const char *s1, const char *s2) {
+    ai_assert( NULL != s1 );
+    ai_assert( NULL != s2 );
+
+#if (defined _MSC_VER)
+
+    return ::_stricmp(s1,s2);
+#elif defined( __GNUC__ )
+
+    return ::strcasecmp(s1,s2);
+#else
+
+    char c1, c2;
+    do  {
+        c1 = tolower(*s1++);
+        c2 = tolower(*s2++);
+    }
+    while ( c1 && (c1 == c2) );
+    return c1 - c2;
+#endif
+}
+
+// -------------------------------------------------------------------------------
+/** @brief Case independent comparison of two std::strings
+ *
+ *  @param a First  string
+ *  @param b Second string
+ *  @return 0 if a == b
+ */
+AI_FORCE_INLINE
+int ASSIMP_stricmp(const std::string& a, const std::string& b) {
+    int i = (int)b.length()-(int)a.length();
+    return (i ? i : ASSIMP_stricmp(a.c_str(),b.c_str()));
+}
+
+// -------------------------------------------------------------------------------
+/** @brief Helper function to do platform independent string comparison.
+ *
+ *  This is required since strincmp() is not consistently available on
+ *  all platforms. Some platforms use the '_' prefix, others don't even
+ *  have such a function.
+ *
+ *  @param s1 First input string
+ *  @param s2 Second input string
+ *  @param n Macimum number of characters to compare
+ *  @return 0 if the given strings are identical
+ */
+AI_FORCE_INLINE
+int ASSIMP_strincmp(const char *s1, const char *s2, unsigned int n) {
+    ai_assert( NULL != s1 );
+    ai_assert( NULL != s2 );
+    if ( !n ) {
+        return 0;
+    }
+
+#if (defined _MSC_VER)
+
+    return ::_strnicmp(s1,s2,n);
+
+#elif defined( __GNUC__ )
+
+    return ::strncasecmp(s1,s2, n);
+
+#else
+    char c1, c2;
+    unsigned int p = 0;
+    do
+    {
+        if (p++ >= n)return 0;
+        c1 = tolower(*s1++);
+        c2 = tolower(*s2++);
+    }
+    while ( c1 && (c1 == c2) );
+
+    return c1 - c2;
+#endif
+}
+
+
+// -------------------------------------------------------------------------------
+/** @brief Evaluates an integer power
+ *
+ * todo: move somewhere where it fits better in than here
+ */
+AI_FORCE_INLINE
+unsigned int integer_pow( unsigned int base, unsigned int power ) {
+    unsigned int res = 1;
+    for ( unsigned int i = 0; i < power; ++i ) {
+        res *= base;
+    }
+
+    return res;
+}
+
+} // end of namespace
+
+#endif // !  AI_STRINGCOMPARISON_H_INC

dependencies/assimp/include/assimp/StringUtils.h

@@ -0,0 +1,143 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+#ifndef INCLUDED_AI_STRINGUTILS_H
+#define INCLUDED_AI_STRINGUTILS_H
+
+#include <assimp/defs.h>
+
+#include <sstream>
+#include <stdarg.h>
+#include <cstdlib>
+
+///	@fn		ai_snprintf
+///	@brief	The portable version of the function snprintf ( C99 standard ), which works on visual studio compilers 2013 and earlier.
+///	@param	outBuf		The buffer to write in
+///	@param	size		The buffer size
+///	@param	format		The format string
+///	@param	ap			The additional arguments.
+///	@return	The number of written characters if the buffer size was big enough. If an encoding error occurs, a negative number is returned.
+#if defined(_MSC_VER) && _MSC_VER < 1900
+
+    AI_FORCE_INLINE
+    int c99_ai_vsnprintf(char *outBuf, size_t size, const char *format, va_list ap) {
+		int count(-1);
+		if (0 != size) {
+			count = _vsnprintf_s(outBuf, size, _TRUNCATE, format, ap);
+		}
+		if (count == -1) {
+			count = _vscprintf(format, ap);
+		}
+
+		return count;
+	}
+
+    AI_FORCE_INLINE
+    int ai_snprintf(char *outBuf, size_t size, const char *format, ...) {
+		int count;
+		va_list ap;
+
+		va_start(ap, format);
+		count = c99_ai_vsnprintf(outBuf, size, format, ap);
+		va_end(ap);
+
+		return count;
+	}
+
+#else
+#   define ai_snprintf snprintf
+#endif
+
+///	@fn		to_string
+///	@brief	The portable version of to_string ( some gcc-versions on embedded devices are not supporting this).
+///	@param	value   The value to write into the std::string.
+///	@return	The value as a std::string
+template <typename T>
+AI_FORCE_INLINE
+std::string to_string( T value ) {
+    std::ostringstream os;
+    os << value;
+
+    return os.str();
+}
+
+///	@fn		ai_strtof
+///	@brief	The portable version of strtof.
+///	@param	begin   The first character of the string.
+/// @param  end     The last character
+///	@return	The float value, 0.0f in cas of an error.
+AI_FORCE_INLINE
+float ai_strtof( const char *begin, const char *end ) {
+    if ( nullptr == begin ) {
+        return 0.0f;
+    }
+    float val( 0.0f );
+    if ( nullptr == end ) {
+        val = static_cast< float >( ::atof( begin ) );
+    } else {
+        std::string::size_type len( end - begin );
+        std::string token( begin, len );
+        val = static_cast< float >( ::atof( token.c_str() ) );
+    }
+
+    return val;
+}
+
+///	@fn		DecimalToHexa
+///	@brief	The portable to convert a decimal value into a hexadecimal string.
+///	@param	toConvert   Value to convert
+///	@return	The hexadecimal string, is empty in case of an error.
+template<class T>
+AI_FORCE_INLINE
+std::string DecimalToHexa( T toConvert ) {
+    std::string result;
+    std::stringstream ss;
+    ss << std::hex << toConvert;
+    ss >> result;
+
+    for ( size_t i = 0; i < result.size(); ++i ) {
+        result[ i ] = toupper( result[ i ] );
+    }
+
+    return result;
+}
+
+#endif // INCLUDED_AI_STRINGUTILS_H

dependencies/assimp/include/assimp/Subdivision.h

@@ -0,0 +1,131 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Defines a helper class to evaluate subdivision surfaces.*/
+#pragma once
+#ifndef AI_SUBDISIVION_H_INC
+#define AI_SUBDISIVION_H_INC
+
+#include <cstddef>
+#include <assimp/types.h>
+
+struct aiMesh;
+
+namespace Assimp    {
+
+// ------------------------------------------------------------------------------
+/** Helper class to evaluate subdivision surfaces. Different algorithms
+ *  are provided for choice. */
+// ------------------------------------------------------------------------------
+class ASSIMP_API Subdivider {
+public:
+
+    /** Enumerates all supported subvidision algorithms */
+    enum Algorithm  {
+        CATMULL_CLARKE = 0x1
+    };
+
+    virtual ~Subdivider();
+
+    // ---------------------------------------------------------------
+    /** Create a subdivider of a specific type
+     *
+     *  @param algo Algorithm to be used for subdivision
+     *  @return Subdivider instance. */
+    static Subdivider* Create (Algorithm algo);
+
+    // ---------------------------------------------------------------
+    /** Subdivide a mesh using the selected algorithm
+     *
+     *  @param mesh First mesh to be subdivided. Must be in verbose
+     *    format.
+     *  @param out Receives the output mesh, allocated by me.
+     *  @param num Number of subdivisions to perform.
+     *  @param discard_input If true is passed, the input mesh is
+     *    deleted after the subdivision is complete. This can
+     *    improve performance because it allows the optimization
+     *    to reuse the existing mesh for intermediate results.
+     *  @pre out!=mesh*/
+    virtual void Subdivide ( aiMesh* mesh,
+        aiMesh*& out, unsigned int num,
+        bool discard_input = false) = 0;
+
+    // ---------------------------------------------------------------
+    /** Subdivide multiple meshes using the selected algorithm. This
+     *  avoids erroneous smoothing on objects consisting of multiple
+     *  per-material meshes. Usually, most 3d modellers smooth on a
+     *  per-object base, regardless the materials assigned to the
+     *  meshes.
+     *
+     *  @param smesh Array of meshes to be subdivided. Must be in
+     *    verbose format.
+     *  @param nmesh Number of meshes in smesh.
+     *  @param out Receives the output meshes. The array must be
+     *    sufficiently large (at least @c nmesh elements) and may not
+     *    overlap the input array. Output meshes map one-to-one to
+     *    their corresponding input meshes. The meshes are allocated
+     *    by the function.
+     *  @param discard_input If true is passed, input meshes are
+     *    deleted after the subdivision is complete. This can
+     *    improve performance because it allows the optimization
+     *    of reusing existing meshes for intermediate results.
+     *  @param num Number of subdivisions to perform.
+     *  @pre nmesh != 0, smesh and out may not overlap*/
+    virtual void Subdivide (
+        aiMesh** smesh,
+        size_t nmesh,
+        aiMesh** out,
+        unsigned int num,
+        bool discard_input = false) = 0;
+
+};
+
+inline
+Subdivider::~Subdivider() {
+    // empty
+}
+
+} // end namespace Assimp
+
+
+#endif // !!  AI_SUBDISIVION_H_INC
+

dependencies/assimp/include/assimp/TinyFormatter.h

@@ -0,0 +1,166 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  TinyFormatter.h
+ *  @brief Utility to format log messages more easily. Introduced
+ *    to get rid of the boost::format dependency. Much slinker,
+ *    basically just extends stringstream.
+ */
+#ifndef INCLUDED_TINY_FORMATTER_H
+#define INCLUDED_TINY_FORMATTER_H
+
+#include <sstream>
+
+namespace Assimp {
+namespace Formatter {
+
+// ------------------------------------------------------------------------------------------------
+/** stringstream utility. Usage:
+ *  @code
+ *  void writelog(const std::string&s);
+ *  void writelog(const std::wstring&s);
+ *  ...
+ *  writelog(format()<< "hi! this is a number: " << 4);
+ *  writelog(wformat()<< L"hi! this is a number: " << 4);
+ *
+ *  @endcode */
+template < typename T,
+    typename CharTraits = std::char_traits<T>,
+    typename Allocator  = std::allocator<T>
+>
+class basic_formatter
+{
+
+public:
+
+    typedef class std::basic_string<
+        T,CharTraits,Allocator
+    > string;
+
+    typedef class std::basic_ostringstream<
+        T,CharTraits,Allocator
+    > stringstream;
+
+public:
+
+    basic_formatter() {}
+
+    /* Allow basic_formatter<T>'s to be used almost interchangeably
+     * with std::(w)string or const (w)char* arguments because the
+     * conversion c'tor is called implicitly. */
+    template <typename TT>
+    basic_formatter(const TT& sin)  {
+        underlying << sin;
+    }
+
+
+    // The problem described here:
+    // https://sourceforge.net/tracker/?func=detail&atid=1067632&aid=3358562&group_id=226462
+    // can also cause trouble here. Apparently, older gcc versions sometimes copy temporaries
+    // being bound to const ref& function parameters. Copying streams is not permitted, though.
+    // This workaround avoids this by manually specifying a copy ctor.
+#if !defined(__GNUC__) || !defined(__APPLE__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+    explicit basic_formatter(const basic_formatter& other) {
+        underlying << (string)other;
+    }
+#endif
+
+
+public:
+
+    operator string () const {
+        return underlying.str();
+    }
+
+
+    /* note - this is declared const because binding temporaries does only
+     * work for const references, so many function prototypes will
+     * include const basic_formatter<T>& s but might still want to
+     * modify the formatted string without the need for a full copy.*/
+    template <typename TToken>
+    const basic_formatter& operator << (const TToken& s) const {
+        underlying << s;
+        return *this;
+    }
+
+    template <typename TToken>
+    basic_formatter& operator << (const TToken& s) {
+        underlying << s;
+        return *this;
+    }
+
+
+    // comma operator overloaded as well, choose your preferred way.
+    template <typename TToken>
+    const basic_formatter& operator, (const TToken& s) const {
+        underlying << s;
+        return *this;
+    }
+
+    template <typename TToken>
+    basic_formatter& operator, (const TToken& s) {
+        underlying << s;
+        return *this;
+    }
+
+    // Fix for MSVC8
+    // See https://sourceforge.net/projects/assimp/forums/forum/817654/topic/4372824
+    template <typename TToken>
+    basic_formatter& operator, (TToken& s) {
+        underlying << s;
+        return *this;
+    }
+
+
+private:
+    mutable stringstream underlying;
+};
+
+
+typedef basic_formatter< char > format;
+typedef basic_formatter< wchar_t > wformat;
+
+} // ! namespace Formatter
+
+} // ! namespace Assimp
+
+#endif

dependencies/assimp/include/assimp/Vertex.h

@@ -0,0 +1,348 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+/** @file Defines a helper class to represent an interleaved vertex
+  along with arithmetic operations to support vertex operations
+  such as subdivision, smoothing etc.
+
+  While the code is kept as general as possible, arithmetic operations
+  that are not currently well-defined (and would cause compile errors
+  due to missing operators in the math library), are commented.
+  */
+#ifndef AI_VERTEX_H_INC
+#define AI_VERTEX_H_INC
+
+#include <assimp/vector3.h>
+#include <assimp/mesh.h>
+#include <assimp/ai_assert.h>
+#include <functional>
+
+namespace Assimp    {
+
+    ///////////////////////////////////////////////////////////////////////////
+    // std::plus-family operates on operands with identical types - we need to
+    // support all the (vectype op float) combinations in vector maths.
+    // Providing T(float) would open the way to endless implicit conversions.
+    ///////////////////////////////////////////////////////////////////////////
+    namespace Intern {
+        template <typename T0, typename T1, typename TRES = T0> struct plus {
+            TRES operator() (const T0& t0, const T1& t1) const {
+                return t0+t1;
+            }
+        };
+        template <typename T0, typename T1, typename TRES = T0> struct minus {
+            TRES operator() (const T0& t0, const T1& t1) const {
+                return t0-t1;
+            }
+        };
+        template <typename T0, typename T1, typename TRES = T0> struct multiplies {
+            TRES operator() (const T0& t0, const T1& t1) const {
+                return t0*t1;
+            }
+        };
+        template <typename T0, typename T1, typename TRES = T0> struct divides {
+            TRES operator() (const T0& t0, const T1& t1) const {
+                return t0/t1;
+            }
+        };
+    }
+
+// ------------------------------------------------------------------------------------------------
+/** Intermediate description a vertex with all possible components. Defines a full set of
+ *  operators, so you may use such a 'Vertex' in basic arithmetics. All operators are applied
+ *  to *all* vertex components equally. This is useful for stuff like interpolation
+ *  or subdivision, but won't work if special handling is required for some vertex components. */
+// ------------------------------------------------------------------------------------------------
+class Vertex
+{
+    friend Vertex operator + (const Vertex&,const Vertex&);
+    friend Vertex operator - (const Vertex&,const Vertex&);
+
+//  friend Vertex operator + (const Vertex&,ai_real);
+//  friend Vertex operator - (const Vertex&,ai_real);
+    friend Vertex operator * (const Vertex&,ai_real);
+    friend Vertex operator / (const Vertex&,ai_real);
+
+//  friend Vertex operator + (ai_real, const Vertex&);
+//  friend Vertex operator - (ai_real, const Vertex&);
+    friend Vertex operator * (ai_real, const Vertex&);
+//  friend Vertex operator / (ai_real, const Vertex&);
+
+public:
+
+    Vertex() {}
+
+    // ----------------------------------------------------------------------------
+    /** Extract a particular vertex from a mesh and interleave all components */
+    explicit Vertex(const aiMesh* msh, unsigned int idx) {
+        ai_assert(idx < msh->mNumVertices);
+        position = msh->mVertices[idx];
+
+        if (msh->HasNormals()) {
+            normal = msh->mNormals[idx];
+        }
+
+        if (msh->HasTangentsAndBitangents()) {
+            tangent = msh->mTangents[idx];
+            bitangent = msh->mBitangents[idx];
+        }
+
+        for (unsigned int i = 0; msh->HasTextureCoords(i); ++i) {
+            texcoords[i] = msh->mTextureCoords[i][idx];
+        }
+
+        for (unsigned int i = 0; msh->HasVertexColors(i); ++i) {
+            colors[i] = msh->mColors[i][idx];
+        }
+    }
+
+    // ----------------------------------------------------------------------------
+    /** Extract a particular vertex from a anim mesh and interleave all components */
+    explicit Vertex(const aiAnimMesh* msh, unsigned int idx) {
+        ai_assert(idx < msh->mNumVertices);
+        position = msh->mVertices[idx];
+
+        if (msh->HasNormals()) {
+            normal = msh->mNormals[idx];
+        }
+
+        if (msh->HasTangentsAndBitangents()) {
+            tangent = msh->mTangents[idx];
+            bitangent = msh->mBitangents[idx];
+        }
+
+        for (unsigned int i = 0; msh->HasTextureCoords(i); ++i) {
+            texcoords[i] = msh->mTextureCoords[i][idx];
+        }
+
+        for (unsigned int i = 0; msh->HasVertexColors(i); ++i) {
+           colors[i] = msh->mColors[i][idx];
+        }
+    }
+
+public:
+
+    Vertex& operator += (const Vertex& v) {
+        *this = *this+v;
+        return *this;
+    }
+
+    Vertex& operator -= (const Vertex& v) {
+        *this = *this-v;
+        return *this;
+    }
+
+
+/*
+    Vertex& operator += (ai_real v) {
+        *this = *this+v;
+        return *this;
+    }
+
+    Vertex& operator -= (ai_real v) {
+        *this = *this-v;
+        return *this;
+    }
+*/
+    Vertex& operator *= (ai_real v) {
+        *this = *this*v;
+        return *this;
+    }
+
+    Vertex& operator /= (ai_real v) {
+        *this = *this/v;
+        return *this;
+    }
+
+public:
+
+    // ----------------------------------------------------------------------------
+    /** Convert back to non-interleaved storage */
+    void SortBack(aiMesh* out, unsigned int idx) const {
+
+        ai_assert(idx<out->mNumVertices);
+        out->mVertices[idx] = position;
+
+        if (out->HasNormals()) {
+            out->mNormals[idx] = normal;
+        }
+
+        if (out->HasTangentsAndBitangents()) {
+            out->mTangents[idx] = tangent;
+            out->mBitangents[idx] = bitangent;
+        }
+
+        for(unsigned int i = 0; out->HasTextureCoords(i); ++i) {
+            out->mTextureCoords[i][idx] = texcoords[i];
+        }
+
+        for(unsigned int i = 0; out->HasVertexColors(i); ++i) {
+            out->mColors[i][idx] = colors[i];
+        }
+    }
+
+private:
+
+    // ----------------------------------------------------------------------------
+    /** Construct from two operands and a binary operation to combine them */
+    template <template <typename t> class op> static Vertex BinaryOp(const Vertex& v0, const Vertex& v1) {
+        // this is a heavy task for the compiler to optimize ... *pray*
+
+        Vertex res;
+        res.position  = op<aiVector3D>()(v0.position,v1.position);
+        res.normal    = op<aiVector3D>()(v0.normal,v1.normal);
+        res.tangent   = op<aiVector3D>()(v0.tangent,v1.tangent);
+        res.bitangent = op<aiVector3D>()(v0.bitangent,v1.bitangent);
+
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+            res.texcoords[i] = op<aiVector3D>()(v0.texcoords[i],v1.texcoords[i]);
+        }
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
+            res.colors[i] = op<aiColor4D>()(v0.colors[i],v1.colors[i]);
+        }
+        return res;
+    }
+
+    // ----------------------------------------------------------------------------
+    /** This time binary arithmetics of v0 with a floating-point number */
+    template <template <typename, typename, typename> class op> static Vertex BinaryOp(const Vertex& v0, ai_real f) {
+        // this is a heavy task for the compiler to optimize ... *pray*
+
+        Vertex res;
+        res.position  = op<aiVector3D,ai_real,aiVector3D>()(v0.position,f);
+        res.normal    = op<aiVector3D,ai_real,aiVector3D>()(v0.normal,f);
+        res.tangent   = op<aiVector3D,ai_real,aiVector3D>()(v0.tangent,f);
+        res.bitangent = op<aiVector3D,ai_real,aiVector3D>()(v0.bitangent,f);
+
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+            res.texcoords[i] = op<aiVector3D,ai_real,aiVector3D>()(v0.texcoords[i],f);
+        }
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
+            res.colors[i] = op<aiColor4D,ai_real,aiColor4D>()(v0.colors[i],f);
+        }
+        return res;
+    }
+
+    // ----------------------------------------------------------------------------
+    /** This time binary arithmetics of v0 with a floating-point number */
+    template <template <typename, typename, typename> class op> static Vertex BinaryOp(ai_real f, const Vertex& v0) {
+        // this is a heavy task for the compiler to optimize ... *pray*
+
+        Vertex res;
+        res.position  = op<ai_real,aiVector3D,aiVector3D>()(f,v0.position);
+        res.normal    = op<ai_real,aiVector3D,aiVector3D>()(f,v0.normal);
+        res.tangent   = op<ai_real,aiVector3D,aiVector3D>()(f,v0.tangent);
+        res.bitangent = op<ai_real,aiVector3D,aiVector3D>()(f,v0.bitangent);
+
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+            res.texcoords[i] = op<ai_real,aiVector3D,aiVector3D>()(f,v0.texcoords[i]);
+        }
+        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
+            res.colors[i] = op<ai_real,aiColor4D,aiColor4D>()(f,v0.colors[i]);
+        }
+        return res;
+    }
+
+public:
+
+    aiVector3D position;
+    aiVector3D normal;
+    aiVector3D tangent, bitangent;
+
+    aiVector3D texcoords[AI_MAX_NUMBER_OF_TEXTURECOORDS];
+    aiColor4D colors[AI_MAX_NUMBER_OF_COLOR_SETS];
+};
+
+
+
+// ------------------------------------------------------------------------------------------------
+AI_FORCE_INLINE Vertex operator + (const Vertex& v0,const Vertex& v1) {
+    return Vertex::BinaryOp<std::plus>(v0,v1);
+}
+
+AI_FORCE_INLINE Vertex operator - (const Vertex& v0,const Vertex& v1) {
+    return Vertex::BinaryOp<std::minus>(v0,v1);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+/*
+AI_FORCE_INLINE Vertex operator + (const Vertex& v0,ai_real f) {
+    return Vertex::BinaryOp<Intern::plus>(v0,f);
+}
+
+AI_FORCE_INLINE Vertex operator - (const Vertex& v0,ai_real f) {
+    return Vertex::BinaryOp<Intern::minus>(v0,f);
+}
+
+*/
+
+AI_FORCE_INLINE Vertex operator * (const Vertex& v0,ai_real f) {
+    return Vertex::BinaryOp<Intern::multiplies>(v0,f);
+}
+
+AI_FORCE_INLINE Vertex operator / (const Vertex& v0,ai_real f) {
+    return Vertex::BinaryOp<Intern::multiplies>(v0,1.f/f);
+}
+
+// ------------------------------------------------------------------------------------------------
+/*
+AI_FORCE_INLINE Vertex operator + (ai_real f,const Vertex& v0) {
+    return Vertex::BinaryOp<Intern::plus>(f,v0);
+}
+
+AI_FORCE_INLINE Vertex operator - (ai_real f,const Vertex& v0) {
+    return Vertex::BinaryOp<Intern::minus>(f,v0);
+}
+*/
+
+AI_FORCE_INLINE Vertex operator * (ai_real f,const Vertex& v0) {
+    return Vertex::BinaryOp<Intern::multiplies>(f,v0);
+}
+
+/*
+AI_FORCE_INLINE Vertex operator / (ai_real f,const Vertex& v0) {
+    return Vertex::BinaryOp<Intern::divides>(f,v0);
+}
+*/
+
+}
+#endif

dependencies/assimp/include/assimp/XMLTools.h

@@ -0,0 +1,83 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#ifndef INCLUDED_ASSIMP_XML_TOOLS_H
+#define INCLUDED_ASSIMP_XML_TOOLS_H
+
+#include <string>
+
+namespace Assimp {
+    // XML escape the 5 XML special characters (",',<,> and &) in |data|
+    // Based on http://stackoverflow.com/questions/5665231
+    std::string XMLEscape(const std::string& data) {
+        std::string buffer;
+
+        const size_t size = data.size();
+        buffer.reserve(size + size / 8);
+        for(size_t i = 0; i < size; ++i) {
+            const char c = data[i];
+            switch(c) {
+                case '&' :
+                    buffer.append("&amp;");
+                    break;
+                case '\"':
+                    buffer.append("&quot;");
+                    break;
+                case '\'':
+                    buffer.append("&apos;");
+                    break;
+                case '<' :
+                    buffer.append("&lt;");
+                    break;
+                case '>' :
+                    buffer.append("&gt;");
+                    break;
+                default:
+                    buffer.append(&c, 1);
+                    break;
+            }
+        }
+        return buffer;
+    }
+}
+
+#endif // INCLUDED_ASSIMP_XML_TOOLS_H

dependencies/assimp/include/assimp/ZipArchiveIOSystem.h

@@ -0,0 +1,87 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file ZipArchiveIOSystem.h
+ *  @brief Implementation of IOSystem to read a ZIP file from another IOSystem
+*/
+
+#ifndef AI_ZIPARCHIVEIOSYSTEM_H_INC
+#define AI_ZIPARCHIVEIOSYSTEM_H_INC
+
+#include <assimp/IOStream.hpp>
+#include <assimp/IOSystem.hpp>
+
+namespace Assimp {
+    class ZipArchiveIOSystem : public IOSystem {
+    public:
+        //! Open a Zip using the proffered IOSystem
+        ZipArchiveIOSystem(IOSystem* pIOHandler, const char *pFilename, const char* pMode = "r");
+        ZipArchiveIOSystem(IOSystem* pIOHandler, const std::string& rFilename, const char* pMode = "r");
+        virtual ~ZipArchiveIOSystem();
+        bool Exists(const char* pFilename) const override;
+        char getOsSeparator() const override;
+        IOStream* Open(const char* pFilename, const char* pMode = "rb") override;
+        void Close(IOStream* pFile) override;
+
+        // Specific to ZIP
+        //! The file was opened and is a ZIP
+        bool isOpen() const;
+
+        //! Get the list of all files with their simplified paths
+        //! Intended for use within Assimp library boundaries
+        void getFileList(std::vector<std::string>& rFileList) const;
+
+        //! Get the list of all files with extension (must be lowercase)
+        //! Intended for use within Assimp library boundaries
+        void getFileListExtension(std::vector<std::string>& rFileList, const std::string& extension) const;
+
+        static bool isZipArchive(IOSystem* pIOHandler, const char *pFilename);
+        static bool isZipArchive(IOSystem* pIOHandler, const std::string& rFilename);
+
+    private:
+        class Implement;
+        Implement *pImpl = nullptr;
+    };
+} // Namespace Assimp
+
+#endif // AI_ZIPARCHIVEIOSYSTEM_H_INC

dependencies/assimp/include/assimp/aabb.h

@@ -0,0 +1,76 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+#pragma once
+#ifndef AI_AABB_H_INC
+#define AI_AABB_H_INC
+
+#include <assimp/vector3.h>
+
+struct aiAABB {
+    C_STRUCT aiVector3D mMin;
+    C_STRUCT aiVector3D mMax;
+
+#ifdef __cplusplus
+
+    aiAABB()
+    : mMin()
+    , mMax() {
+        // empty
+    }
+
+    aiAABB(const aiVector3D &min, const aiVector3D &max )
+    : mMin(min)
+    , mMax(max) {
+        // empty
+    }
+
+    ~aiAABB() {
+        // empty
+    }
+
+#endif 
+};
+
+
+#endif

dependencies/assimp/include/assimp/ai_assert.h

@@ -0,0 +1,57 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+#pragma once
+#ifndef AI_ASSERT_H_INC
+#define AI_ASSERT_H_INC
+
+#ifdef ASSIMP_BUILD_DEBUG
+#   include <assert.h>
+#   define ai_assert(expression) assert( expression )
+#   define ai_assert_entry()     assert( false )
+#else
+#   define  ai_assert(expression)
+#   define  ai_assert_entry() 
+#endif // ASSIMP_BUILD_DEBUG
+
+#endif // AI_ASSERT_H_INC
+

dependencies/assimp/include/assimp/anim.h

@@ -0,0 +1,577 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** 
+  * @file   anim.h
+  * @brief  Defines the data structures in which the imported animations
+  *         are returned.
+  */
+#pragma once
+#ifndef AI_ANIM_H_INC
+#define AI_ANIM_H_INC
+
+#include <assimp/types.h>
+#include <assimp/quaternion.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ---------------------------------------------------------------------------
+/** A time-value pair specifying a certain 3D vector for the given time. */
+struct aiVectorKey
+{
+    /** The time of this key */
+    double mTime;
+
+    /** The value of this key */
+    C_STRUCT aiVector3D mValue;
+
+#ifdef __cplusplus
+
+    /// @brief  The default constructor.
+    aiVectorKey() AI_NO_EXCEPT
+    : mTime( 0.0 )
+    , mValue() {
+        // empty
+    }
+
+    /// @brief  Construction from a given time and key value.
+
+    aiVectorKey(double time, const aiVector3D& value)
+    : mTime( time )
+    , mValue( value ) {
+        // empty
+    }
+
+    typedef aiVector3D elem_type;
+
+    // Comparison operators. For use with std::find();
+    bool operator == (const aiVectorKey& rhs) const {
+        return rhs.mValue == this->mValue;
+    }
+    bool operator != (const aiVectorKey& rhs ) const {
+        return rhs.mValue != this->mValue;
+    }
+
+    // Relational operators. For use with std::sort();
+    bool operator < (const aiVectorKey& rhs ) const {
+        return mTime < rhs.mTime;
+    }
+    bool operator > (const aiVectorKey& rhs ) const {
+        return mTime > rhs.mTime;
+    }
+#endif // __cplusplus
+};
+
+// ---------------------------------------------------------------------------
+/** A time-value pair specifying a rotation for the given time.
+ *  Rotations are expressed with quaternions. */
+struct aiQuatKey
+{
+    /** The time of this key */
+    double mTime;
+
+    /** The value of this key */
+    C_STRUCT aiQuaternion mValue;
+
+#ifdef __cplusplus
+    aiQuatKey() AI_NO_EXCEPT
+    : mTime( 0.0 )
+    , mValue() {
+        // empty
+    }
+
+    /** Construction from a given time and key value */
+    aiQuatKey(double time, const aiQuaternion& value)
+        :   mTime   (time)
+        ,   mValue  (value)
+    {}
+
+    typedef aiQuaternion elem_type;
+
+    // Comparison operators. For use with std::find();
+    bool operator == (const aiQuatKey& rhs ) const {
+        return rhs.mValue == this->mValue;
+    }
+    bool operator != (const aiQuatKey& rhs ) const {
+        return rhs.mValue != this->mValue;
+    }
+
+    // Relational operators. For use with std::sort();
+    bool operator < (const aiQuatKey& rhs ) const {
+        return mTime < rhs.mTime;
+    }
+    bool operator > (const aiQuatKey& rhs ) const {
+        return mTime > rhs.mTime;
+    }
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Binds a anim-mesh to a specific point in time. */
+struct aiMeshKey
+{
+    /** The time of this key */
+    double mTime;
+
+    /** Index into the aiMesh::mAnimMeshes array of the
+     *  mesh corresponding to the #aiMeshAnim hosting this
+     *  key frame. The referenced anim mesh is evaluated
+     *  according to the rules defined in the docs for #aiAnimMesh.*/
+    unsigned int mValue;
+
+#ifdef __cplusplus
+
+    aiMeshKey() AI_NO_EXCEPT
+    : mTime(0.0)
+    , mValue(0)
+    {
+    }
+
+    /** Construction from a given time and key value */
+    aiMeshKey(double time, const unsigned int value)
+        :   mTime   (time)
+        ,   mValue  (value)
+    {}
+
+    typedef unsigned int elem_type;
+
+    // Comparison operators. For use with std::find();
+    bool operator == (const aiMeshKey& o) const {
+        return o.mValue == this->mValue;
+    }
+    bool operator != (const aiMeshKey& o) const {
+        return o.mValue != this->mValue;
+    }
+
+    // Relational operators. For use with std::sort();
+    bool operator < (const aiMeshKey& o) const {
+        return mTime < o.mTime;
+    }
+    bool operator > (const aiMeshKey& o) const {
+        return mTime > o.mTime;
+    }
+
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Binds a morph anim mesh to a specific point in time. */
+struct aiMeshMorphKey
+{
+    /** The time of this key */
+    double mTime;
+
+    /** The values and weights at the time of this key */
+    unsigned int *mValues;
+    double *mWeights;
+
+    /** The number of values and weights */
+    unsigned int mNumValuesAndWeights;
+#ifdef __cplusplus
+	aiMeshMorphKey() AI_NO_EXCEPT
+		: mTime(0.0)
+		, mValues(nullptr)
+		, mWeights(nullptr)
+		, mNumValuesAndWeights(0)
+	{
+
+	}
+
+    ~aiMeshMorphKey()
+    {
+        if (mNumValuesAndWeights && mValues && mWeights) {
+            delete [] mValues;
+            delete [] mWeights;
+        }
+    }
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Defines how an animation channel behaves outside the defined time
+ *  range. This corresponds to aiNodeAnim::mPreState and
+ *  aiNodeAnim::mPostState.*/
+enum aiAnimBehaviour
+{
+    /** The value from the default node transformation is taken*/
+    aiAnimBehaviour_DEFAULT  = 0x0,
+
+    /** The nearest key value is used without interpolation */
+    aiAnimBehaviour_CONSTANT = 0x1,
+
+    /** The value of the nearest two keys is linearly
+     *  extrapolated for the current time value.*/
+    aiAnimBehaviour_LINEAR   = 0x2,
+
+    /** The animation is repeated.
+     *
+     *  If the animation key go from n to m and the current
+     *  time is t, use the value at (t-n) % (|m-n|).*/
+    aiAnimBehaviour_REPEAT   = 0x3,
+
+    /** This value is not used, it is just here to force the
+     *  the compiler to map this enum to a 32 Bit integer  */
+#ifndef SWIG
+    _aiAnimBehaviour_Force32Bit = INT_MAX
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Describes the animation of a single node. The name specifies the
+ *  bone/node which is affected by this animation channel. The keyframes
+ *  are given in three separate series of values, one each for position,
+ *  rotation and scaling. The transformation matrix computed from these
+ *  values replaces the node's original transformation matrix at a
+ *  specific time.
+ *  This means all keys are absolute and not relative to the bone default pose.
+ *  The order in which the transformations are applied is
+ *  - as usual - scaling, rotation, translation.
+ *
+ *  @note All keys are returned in their correct, chronological order.
+ *  Duplicate keys don't pass the validation step. Most likely there
+ *  will be no negative time values, but they are not forbidden also ( so
+ *  implementations need to cope with them! ) */
+struct aiNodeAnim {
+    /** The name of the node affected by this animation. The node
+     *  must exist and it must be unique.*/
+    C_STRUCT aiString mNodeName;
+
+    /** The number of position keys */
+    unsigned int mNumPositionKeys;
+
+    /** The position keys of this animation channel. Positions are
+     * specified as 3D vector. The array is mNumPositionKeys in size.
+     *
+     * If there are position keys, there will also be at least one
+     * scaling and one rotation key.*/
+    C_STRUCT aiVectorKey* mPositionKeys;
+
+    /** The number of rotation keys */
+    unsigned int mNumRotationKeys;
+
+    /** The rotation keys of this animation channel. Rotations are
+     *  given as quaternions,  which are 4D vectors. The array is
+     *  mNumRotationKeys in size.
+     *
+     * If there are rotation keys, there will also be at least one
+     * scaling and one position key. */
+    C_STRUCT aiQuatKey* mRotationKeys;
+
+    /** The number of scaling keys */
+    unsigned int mNumScalingKeys;
+
+    /** The scaling keys of this animation channel. Scalings are
+     *  specified as 3D vector. The array is mNumScalingKeys in size.
+     *
+     * If there are scaling keys, there will also be at least one
+     * position and one rotation key.*/
+    C_STRUCT aiVectorKey* mScalingKeys;
+
+    /** Defines how the animation behaves before the first
+     *  key is encountered.
+     *
+     *  The default value is aiAnimBehaviour_DEFAULT (the original
+     *  transformation matrix of the affected node is used).*/
+    C_ENUM aiAnimBehaviour mPreState;
+
+    /** Defines how the animation behaves after the last
+     *  key was processed.
+     *
+     *  The default value is aiAnimBehaviour_DEFAULT (the original
+     *  transformation matrix of the affected node is taken).*/
+    C_ENUM aiAnimBehaviour mPostState;
+
+#ifdef __cplusplus
+    aiNodeAnim() AI_NO_EXCEPT
+    : mNumPositionKeys( 0 )
+    , mPositionKeys( nullptr )
+    , mNumRotationKeys( 0 )
+    , mRotationKeys( nullptr )
+    , mNumScalingKeys( 0 )
+    , mScalingKeys( nullptr )
+    , mPreState( aiAnimBehaviour_DEFAULT )
+    , mPostState( aiAnimBehaviour_DEFAULT ) {
+         // empty
+    }
+
+    ~aiNodeAnim() {
+        delete [] mPositionKeys;
+        delete [] mRotationKeys;
+        delete [] mScalingKeys;
+    }
+#endif // __cplusplus
+};
+
+// ---------------------------------------------------------------------------
+/** Describes vertex-based animations for a single mesh or a group of
+ *  meshes. Meshes carry the animation data for each frame in their
+ *  aiMesh::mAnimMeshes array. The purpose of aiMeshAnim is to
+ *  define keyframes linking each mesh attachment to a particular
+ *  point in time. */
+struct aiMeshAnim
+{
+    /** Name of the mesh to be animated. An empty string is not allowed,
+     *  animated meshes need to be named (not necessarily uniquely,
+     *  the name can basically serve as wild-card to select a group
+     *  of meshes with similar animation setup)*/
+    C_STRUCT aiString mName;
+
+    /** Size of the #mKeys array. Must be 1, at least. */
+    unsigned int mNumKeys;
+
+    /** Key frames of the animation. May not be NULL. */
+    C_STRUCT aiMeshKey* mKeys;
+
+#ifdef __cplusplus
+
+    aiMeshAnim() AI_NO_EXCEPT
+        : mNumKeys()
+        , mKeys()
+    {}
+
+    ~aiMeshAnim()
+    {
+        delete[] mKeys;
+    }
+
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Describes a morphing animation of a given mesh. */
+struct aiMeshMorphAnim
+{
+    /** Name of the mesh to be animated. An empty string is not allowed,
+     *  animated meshes need to be named (not necessarily uniquely,
+     *  the name can basically serve as wildcard to select a group
+     *  of meshes with similar animation setup)*/
+    C_STRUCT aiString mName;
+
+    /** Size of the #mKeys array. Must be 1, at least. */
+    unsigned int mNumKeys;
+
+    /** Key frames of the animation. May not be NULL. */
+    C_STRUCT aiMeshMorphKey* mKeys;
+
+#ifdef __cplusplus
+
+    aiMeshMorphAnim() AI_NO_EXCEPT
+        : mNumKeys()
+        , mKeys()
+    {}
+
+    ~aiMeshMorphAnim()
+    {
+        delete[] mKeys;
+    }
+
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** An animation consists of key-frame data for a number of nodes. For
+ *  each node affected by the animation a separate series of data is given.*/
+struct aiAnimation {
+    /** The name of the animation. If the modeling package this data was
+     *  exported from does support only a single animation channel, this
+     *  name is usually empty (length is zero). */
+    C_STRUCT aiString mName;
+
+    /** Duration of the animation in ticks.  */
+    double mDuration;
+
+    /** Ticks per second. 0 if not specified in the imported file */
+    double mTicksPerSecond;
+
+    /** The number of bone animation channels. Each channel affects
+     *  a single node. */
+    unsigned int mNumChannels;
+
+    /** The node animation channels. Each channel affects a single node.
+     *  The array is mNumChannels in size. */
+    C_STRUCT aiNodeAnim** mChannels;
+
+
+    /** The number of mesh animation channels. Each channel affects
+     *  a single mesh and defines vertex-based animation. */
+    unsigned int mNumMeshChannels;
+
+    /** The mesh animation channels. Each channel affects a single mesh.
+     *  The array is mNumMeshChannels in size. */
+    C_STRUCT aiMeshAnim** mMeshChannels;
+
+    /** The number of mesh animation channels. Each channel affects
+     *  a single mesh and defines morphing animation. */
+    unsigned int mNumMorphMeshChannels;
+
+    /** The morph mesh animation channels. Each channel affects a single mesh.
+     *  The array is mNumMorphMeshChannels in size. */
+    C_STRUCT aiMeshMorphAnim **mMorphMeshChannels;
+
+#ifdef __cplusplus
+    aiAnimation() AI_NO_EXCEPT
+    : mDuration(-1.)
+    , mTicksPerSecond(0.)
+    , mNumChannels(0)
+    , mChannels(nullptr)
+    , mNumMeshChannels(0)
+    , mMeshChannels(nullptr)
+    , mNumMorphMeshChannels(0)
+    , mMorphMeshChannels(nullptr) {
+        // empty
+    }
+
+    ~aiAnimation() {
+        // DO NOT REMOVE THIS ADDITIONAL CHECK
+        if ( mNumChannels && mChannels )  {
+            for( unsigned int a = 0; a < mNumChannels; a++) {
+                delete mChannels[ a ];
+            }
+
+            delete [] mChannels;
+        }
+        if (mNumMeshChannels && mMeshChannels)  {
+            for( unsigned int a = 0; a < mNumMeshChannels; a++) {
+                delete mMeshChannels[a];
+            }
+
+            delete [] mMeshChannels;
+        }
+        if (mNumMorphMeshChannels && mMorphMeshChannels) {
+                for( unsigned int a = 0; a < mNumMorphMeshChannels; a++) {
+                        delete mMorphMeshChannels[a];
+                }
+            
+            delete [] mMorphMeshChannels;
+        }
+    }
+#endif // __cplusplus
+};
+
+#ifdef __cplusplus
+
+}
+
+/// @brief  Some C++ utilities for inter- and extrapolation
+namespace Assimp {
+
+// ---------------------------------------------------------------------------
+/** 
+  * @brief CPP-API: Utility class to simplify interpolations of various data types.
+  *
+  *  The type of interpolation is chosen automatically depending on the
+  *  types of the arguments. 
+  */
+template <typename T>
+struct Interpolator
+{
+    // ------------------------------------------------------------------
+    /** @brief Get the result of the interpolation between a,b.
+     *
+     *  The interpolation algorithm depends on the type of the operands.
+     *  aiQuaternion's and aiQuatKey's SLERP, the rest does a simple
+     *  linear interpolation. */
+    void operator () (T& out,const T& a, const T& b, ai_real d) const {
+        out = a + (b-a)*d;
+    }
+}; // ! Interpolator <T>
+
+//! @cond Never
+
+template <>
+struct Interpolator <aiQuaternion>  {
+    void operator () (aiQuaternion& out,const aiQuaternion& a,
+        const aiQuaternion& b, ai_real d) const
+    {
+        aiQuaternion::Interpolate(out,a,b,d);
+    }
+}; // ! Interpolator <aiQuaternion>
+
+template <>
+struct Interpolator <unsigned int>  {
+    void operator () (unsigned int& out,unsigned int a,
+        unsigned int b, ai_real d) const
+    {
+        out = d>0.5f ? b : a;
+    }
+}; // ! Interpolator <aiQuaternion>
+
+template <>
+struct Interpolator<aiVectorKey>  {
+    void operator () (aiVector3D& out,const aiVectorKey& a,
+        const aiVectorKey& b, ai_real d) const
+    {
+        Interpolator<aiVector3D> ipl;
+        ipl(out,a.mValue,b.mValue,d);
+    }
+}; // ! Interpolator <aiVectorKey>
+
+template <>
+struct Interpolator<aiQuatKey>  {
+    void operator () (aiQuaternion& out, const aiQuatKey& a,
+        const aiQuatKey& b, ai_real d) const
+    {
+        Interpolator<aiQuaternion> ipl;
+        ipl(out,a.mValue,b.mValue,d);
+    }
+}; // ! Interpolator <aiQuatKey>
+
+template <>
+struct Interpolator<aiMeshKey>     {
+    void operator () (unsigned int& out, const aiMeshKey& a,
+        const aiMeshKey& b, ai_real d) const
+    {
+        Interpolator<unsigned int> ipl;
+        ipl(out,a.mValue,b.mValue,d);
+    }
+}; // ! Interpolator <aiQuatKey>
+
+//! @endcond
+
+} //  ! end namespace Assimp
+
+#endif // __cplusplus
+
+#endif // AI_ANIM_H_INC

dependencies/assimp/include/assimp/camera.h

@@ -0,0 +1,221 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file camera.h
+ *  @brief Defines the aiCamera data structure
+ */
+
+#pragma once
+#ifndef AI_CAMERA_H_INC
+#define AI_CAMERA_H_INC
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ---------------------------------------------------------------------------
+/** Helper structure to describe a virtual camera.
+ *
+ * Cameras have a representation in the node graph and can be animated.
+ * An important aspect is that the camera itself is also part of the
+ * scene-graph. This means, any values such as the look-at vector are not
+ * *absolute*, they're <b>relative</b> to the coordinate system defined
+ * by the node which corresponds to the camera. This allows for camera
+ * animations. For static cameras parameters like the 'look-at' or 'up' vectors
+ * are usually specified directly in aiCamera, but beware, they could also
+ * be encoded in the node transformation. The following (pseudo)code sample
+ * shows how to do it: <br><br>
+ * @code
+ * // Get the camera matrix for a camera at a specific time
+ * // if the node hierarchy for the camera does not contain
+ * // at least one animated node this is a static computation
+ * get-camera-matrix (node sceneRoot, camera cam) : matrix
+ * {
+ *    node   cnd = find-node-for-camera(cam)
+ *    matrix cmt = identity()
+ *
+ *    // as usual - get the absolute camera transformation for this frame
+ *    for each node nd in hierarchy from sceneRoot to cnd
+ *      matrix cur
+ *      if (is-animated(nd))
+ *         cur = eval-animation(nd)
+ *      else cur = nd->mTransformation;
+ *      cmt = mult-matrices( cmt, cur )
+ *    end for
+ *
+ *    // now multiply with the camera's own local transform
+ *    cam = mult-matrices (cam, get-camera-matrix(cmt) )
+ * }
+ * @endcode
+ *
+ * @note some file formats (such as 3DS, ASE) export a "target point" -
+ * the point the camera is looking at (it can even be animated). Assimp
+ * writes the target point as a subnode of the camera's main node,
+ * called "<camName>.Target". However this is just additional information
+ * then the transformation tracks of the camera main node make the
+ * camera already look in the right direction.
+ *
+*/
+struct aiCamera
+{
+    /** The name of the camera.
+     *
+     *  There must be a node in the scenegraph with the same name.
+     *  This node specifies the position of the camera in the scene
+     *  hierarchy and can be animated.
+     */
+    C_STRUCT aiString mName;
+
+    /** Position of the camera relative to the coordinate space
+     *  defined by the corresponding node.
+     *
+     *  The default value is 0|0|0.
+     */
+    C_STRUCT aiVector3D mPosition;
+
+    /** 'Up' - vector of the camera coordinate system relative to
+     *  the coordinate space defined by the corresponding node.
+     *
+     *  The 'right' vector of the camera coordinate system is
+     *  the cross product of  the up and lookAt vectors.
+     *  The default value is 0|1|0. The vector
+     *  may be normalized, but it needn't.
+     */
+    C_STRUCT aiVector3D mUp;
+
+
+    /** 'LookAt' - vector of the camera coordinate system relative to
+     *  the coordinate space defined by the corresponding node.
+     *
+     *  This is the viewing direction of the user.
+     *  The default value is 0|0|1. The vector
+     *  may be normalized, but it needn't.
+     */
+    C_STRUCT aiVector3D mLookAt;
+
+    /** Half horizontal field of view angle, in radians.
+     *
+     *  The field of view angle is the angle between the center
+     *  line of the screen and the left or right border.
+     *  The default value is 1/4PI.
+     */
+    float mHorizontalFOV;
+
+    /** Distance of the near clipping plane from the camera.
+     *
+     * The value may not be 0.f (for arithmetic reasons to prevent
+     * a division through zero). The default value is 0.1f.
+     */
+    float mClipPlaneNear;
+
+    /** Distance of the far clipping plane from the camera.
+     *
+     * The far clipping plane must, of course, be further away than the
+     * near clipping plane. The default value is 1000.f. The ratio
+     * between the near and the far plane should not be too
+     * large (between 1000-10000 should be ok) to avoid floating-point
+     * inaccuracies which could lead to z-fighting.
+     */
+    float mClipPlaneFar;
+
+    /** Screen aspect ratio.
+     *
+     * This is the ration between the width and the height of the
+     * screen. Typical values are 4/3, 1/2 or 1/1. This value is
+     * 0 if the aspect ratio is not defined in the source file.
+     * 0 is also the default value.
+     */
+    float mAspect;
+
+#ifdef __cplusplus
+
+    aiCamera() AI_NO_EXCEPT
+        : mUp               (0.f,1.f,0.f)
+        , mLookAt           (0.f,0.f,1.f)
+        , mHorizontalFOV    (0.25f * (float)AI_MATH_PI)
+        , mClipPlaneNear    (0.1f)
+        , mClipPlaneFar     (1000.f)
+        , mAspect           (0.f)
+    {}
+
+    /** @brief Get a *right-handed* camera matrix from me
+     *  @param out Camera matrix to be filled
+     */
+    void GetCameraMatrix (aiMatrix4x4& out) const
+    {
+        /** todo: test ... should work, but i'm not absolutely sure */
+
+        /** We don't know whether these vectors are already normalized ...*/
+        aiVector3D zaxis = mLookAt;     zaxis.Normalize();
+        aiVector3D yaxis = mUp;         yaxis.Normalize();
+        aiVector3D xaxis = mUp^mLookAt; xaxis.Normalize();
+
+        out.a4 = -(xaxis * mPosition);
+        out.b4 = -(yaxis * mPosition);
+        out.c4 = -(zaxis * mPosition);
+
+        out.a1 = xaxis.x;
+        out.a2 = xaxis.y;
+        out.a3 = xaxis.z;
+
+        out.b1 = yaxis.x;
+        out.b2 = yaxis.y;
+        out.b3 = yaxis.z;
+
+        out.c1 = zaxis.x;
+        out.c2 = zaxis.y;
+        out.c3 = zaxis.z;
+
+        out.d1 = out.d2 = out.d3 = 0.f;
+        out.d4 = 1.f;
+    }
+
+#endif
+};
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // AI_CAMERA_H_INC

dependencies/assimp/include/assimp/cexport.h

@@ -0,0 +1,261 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2011, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  cexport.h
+*  @brief Defines the C-API for the Assimp export interface
+*/
+#pragma once
+#ifndef AI_EXPORT_H_INC
+#define AI_EXPORT_H_INC
+
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
+// Public ASSIMP data structures
+#include <assimp/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct aiScene;  // aiScene.h
+struct aiFileIO; // aiFileIO.h
+
+// --------------------------------------------------------------------------------
+/** Describes an file format which Assimp can export to. Use #aiGetExportFormatCount() to
+* learn how many export formats the current Assimp build supports and #aiGetExportFormatDescription()
+* to retrieve a description of an export format option.
+*/
+struct aiExportFormatDesc
+{
+    /// a short string ID to uniquely identify the export format. Use this ID string to
+    /// specify which file format you want to export to when calling #aiExportScene().
+    /// Example: "dae" or "obj"
+    const char* id;
+
+    /// A short description of the file format to present to users. Useful if you want
+    /// to allow the user to select an export format.
+    const char* description;
+
+    /// Recommended file extension for the exported file in lower case.
+    const char* fileExtension;
+};
+
+
+// --------------------------------------------------------------------------------
+/** Returns the number of export file formats available in the current Assimp build.
+ * Use aiGetExportFormatDescription() to retrieve infos of a specific export format.
+ */
+ASSIMP_API size_t aiGetExportFormatCount(void);
+
+// --------------------------------------------------------------------------------
+/** Returns a description of the nth export file format. Use #aiGetExportFormatCount()
+ * to learn how many export formats are supported. The description must be released by
+ * calling aiReleaseExportFormatDescription afterwards.
+ * @param pIndex Index of the export format to retrieve information for. Valid range is
+ *    0 to #aiGetExportFormatCount()
+ * @return A description of that specific export format. NULL if pIndex is out of range.
+ */
+ASSIMP_API const C_STRUCT aiExportFormatDesc* aiGetExportFormatDescription( size_t pIndex);
+
+// --------------------------------------------------------------------------------
+/** Release a description of the nth export file format. Must be returned by
+* aiGetExportFormatDescription
+* @param desc Pointer to the description
+*/
+ASSIMP_API void aiReleaseExportFormatDescription( const C_STRUCT aiExportFormatDesc *desc );
+
+// --------------------------------------------------------------------------------
+/** Create a modifiable copy of a scene.
+ *  This is useful to import files via Assimp, change their topology and
+ *  export them again. Since the scene returned by the various importer functions
+ *  is const, a modifiable copy is needed.
+ *  @param pIn Valid scene to be copied
+ *  @param pOut Receives a modifyable copy of the scene. Use aiFreeScene() to
+ *    delete it again.
+ */
+ASSIMP_API void aiCopyScene(const C_STRUCT aiScene* pIn,
+    C_STRUCT aiScene** pOut);
+
+
+// --------------------------------------------------------------------------------
+/** Frees a scene copy created using aiCopyScene() */
+ASSIMP_API void aiFreeScene(const C_STRUCT aiScene* pIn);
+
+// --------------------------------------------------------------------------------
+/** Exports the given scene to a chosen file format and writes the result file(s) to disk.
+* @param pScene The scene to export. Stays in possession of the caller, is not changed by the function.
+*   The scene is expected to conform to Assimp's Importer output format as specified
+*   in the @link data Data Structures Page @endlink. In short, this means the model data
+*   should use a right-handed coordinate systems, face winding should be counter-clockwise
+*   and the UV coordinate origin is assumed to be in the upper left. If your input data
+*   uses different conventions, have a look at the last parameter.
+* @param pFormatId ID string to specify to which format you want to export to. Use
+* aiGetExportFormatCount() / aiGetExportFormatDescription() to learn which export formats are available.
+* @param pFileName Output file to write
+* @param pPreprocessing Accepts any choice of the #aiPostProcessSteps enumerated
+*   flags, but in reality only a subset of them makes sense here. Specifying
+*   'preprocessing' flags is useful if the input scene does not conform to
+*   Assimp's default conventions as specified in the @link data Data Structures Page @endlink.
+*   In short, this means the geometry data should use a right-handed coordinate systems, face
+*   winding should be counter-clockwise and the UV coordinate origin is assumed to be in
+*   the upper left. The #aiProcess_MakeLeftHanded, #aiProcess_FlipUVs and
+*   #aiProcess_FlipWindingOrder flags are used in the import side to allow users
+*   to have those defaults automatically adapted to their conventions. Specifying those flags
+*   for exporting has the opposite effect, respectively. Some other of the
+*   #aiPostProcessSteps enumerated values may be useful as well, but you'll need
+*   to try out what their effect on the exported file is. Many formats impose
+*   their own restrictions on the structure of the geometry stored therein,
+*   so some preprocessing may have little or no effect at all, or may be
+*   redundant as exporters would apply them anyhow. A good example
+*   is triangulation - whilst you can enforce it by specifying
+*   the #aiProcess_Triangulate flag, most export formats support only
+*   triangulate data so they would run the step anyway.
+*
+*   If assimp detects that the input scene was directly taken from the importer side of
+*   the library (i.e. not copied using aiCopyScene and potetially modified afterwards),
+*   any postprocessing steps already applied to the scene will not be applied again, unless
+*   they show non-idempotent behaviour (#aiProcess_MakeLeftHanded, #aiProcess_FlipUVs and
+*   #aiProcess_FlipWindingOrder).
+* @return a status code indicating the result of the export
+* @note Use aiCopyScene() to get a modifiable copy of a previously
+*   imported scene.
+*/
+ASSIMP_API aiReturn aiExportScene( const C_STRUCT aiScene* pScene,
+    const char* pFormatId,
+    const char* pFileName,
+    unsigned int pPreprocessing);
+
+
+// --------------------------------------------------------------------------------
+/** Exports the given scene to a chosen file format using custom IO logic supplied by you.
+* @param pScene The scene to export. Stays in possession of the caller, is not changed by the function.
+* @param pFormatId ID string to specify to which format you want to export to. Use
+* aiGetExportFormatCount() / aiGetExportFormatDescription() to learn which export formats are available.
+* @param pFileName Output file to write
+* @param pIO custom IO implementation to be used. Use this if you use your own storage methods.
+*   If none is supplied, a default implementation using standard file IO is used. Note that
+*   #aiExportSceneToBlob is provided as convenience function to export to memory buffers.
+* @param pPreprocessing Please see the documentation for #aiExportScene
+* @return a status code indicating the result of the export
+* @note Include <aiFileIO.h> for the definition of #aiFileIO.
+* @note Use aiCopyScene() to get a modifiable copy of a previously
+*   imported scene.
+*/
+ASSIMP_API aiReturn aiExportSceneEx( const C_STRUCT aiScene* pScene,
+    const char* pFormatId,
+    const char* pFileName,
+    C_STRUCT aiFileIO* pIO,
+    unsigned int pPreprocessing );
+
+// --------------------------------------------------------------------------------
+/** Describes a blob of exported scene data. Use #aiExportSceneToBlob() to create a blob containing an
+* exported scene. The memory referred by this structure is owned by Assimp.
+* to free its resources. Don't try to free the memory on your side - it will crash for most build configurations
+* due to conflicting heaps.
+*
+* Blobs can be nested - each blob may reference another blob, which may in turn reference another blob and so on.
+* This is used when exporters write more than one output file for a given #aiScene. See the remarks for
+* #aiExportDataBlob::name for more information.
+*/
+struct aiExportDataBlob
+{
+    /// Size of the data in bytes
+    size_t size;
+
+    /// The data.
+    void* data;
+
+    /** Name of the blob. An empty string always
+        indicates the first (and primary) blob,
+        which contains the actual file data.
+        Any other blobs are auxiliary files produced
+        by exporters (i.e. material files). Existence
+        of such files depends on the file format. Most
+        formats don't split assets across multiple files.
+
+        If used, blob names usually contain the file
+        extension that should be used when writing
+        the data to disc.
+     */
+    C_STRUCT aiString name;
+
+    /** Pointer to the next blob in the chain or NULL if there is none. */
+    C_STRUCT aiExportDataBlob * next;
+
+#ifdef __cplusplus
+    /// Default constructor
+    aiExportDataBlob() { size = 0; data = next = NULL; }
+    /// Releases the data
+    ~aiExportDataBlob() { delete [] static_cast<unsigned char*>( data ); delete next; }
+
+private:
+    // no copying
+    aiExportDataBlob(const aiExportDataBlob& );
+    aiExportDataBlob& operator= (const aiExportDataBlob& );
+#endif // __cplusplus
+};
+
+// --------------------------------------------------------------------------------
+/** Exports the given scene to a chosen file format. Returns the exported data as a binary blob which
+* you can write into a file or something. When you're done with the data, use #aiReleaseExportBlob()
+* to free the resources associated with the export.
+* @param pScene The scene to export. Stays in possession of the caller, is not changed by the function.
+* @param pFormatId ID string to specify to which format you want to export to. Use
+* #aiGetExportFormatCount() / #aiGetExportFormatDescription() to learn which export formats are available.
+* @param pPreprocessing Please see the documentation for #aiExportScene
+* @return the exported data or NULL in case of error
+*/
+ASSIMP_API const C_STRUCT aiExportDataBlob* aiExportSceneToBlob( const C_STRUCT aiScene* pScene, const char* pFormatId,
+    unsigned int pPreprocessing );
+
+// --------------------------------------------------------------------------------
+/** Releases the memory associated with the given exported data. Use this function to free a data blob
+* returned by aiExportScene().
+* @param pData the data blob returned by #aiExportSceneToBlob
+*/
+ASSIMP_API void aiReleaseExportBlob( const C_STRUCT aiExportDataBlob* pData );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // ASSIMP_BUILD_NO_EXPORT
+#endif // AI_EXPORT_H_INC

dependencies/assimp/include/assimp/cfileio.h

@@ -0,0 +1,138 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file cfileio.h
+ *  @brief Defines generic C routines to access memory-mapped files
+ */
+#pragma once
+#ifndef AI_FILEIO_H_INC
+#define AI_FILEIO_H_INC
+
+#include <assimp/types.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+struct aiFileIO;
+struct aiFile;
+
+// aiFile callbacks
+typedef size_t          (*aiFileWriteProc) (C_STRUCT aiFile*,   const char*, size_t, size_t);
+typedef size_t          (*aiFileReadProc)  (C_STRUCT aiFile*,   char*, size_t,size_t);
+typedef size_t          (*aiFileTellProc)  (C_STRUCT aiFile*);
+typedef void            (*aiFileFlushProc) (C_STRUCT aiFile*);
+typedef C_ENUM aiReturn (*aiFileSeek)      (C_STRUCT aiFile*, size_t, C_ENUM aiOrigin);
+
+// aiFileIO callbacks
+typedef C_STRUCT aiFile* (*aiFileOpenProc)  (C_STRUCT aiFileIO*, const char*, const char*);
+typedef void             (*aiFileCloseProc) (C_STRUCT aiFileIO*, C_STRUCT aiFile*);
+
+// Represents user-defined data
+typedef char* aiUserData;
+
+// ----------------------------------------------------------------------------------
+/** @brief C-API: File system callbacks
+ *
+ *  Provided are functions to open and close files. Supply a custom structure to
+ *  the import function. If you don't, a default implementation is used. Use custom
+ *  file systems to enable reading from other sources, such as ZIPs
+ *  or memory locations. */
+struct aiFileIO
+{
+    /** Function used to open a new file
+     */
+    aiFileOpenProc OpenProc;
+
+    /** Function used to close an existing file
+     */
+    aiFileCloseProc CloseProc;
+
+    /** User-defined, opaque data */
+    aiUserData UserData;
+};
+
+// ----------------------------------------------------------------------------------
+/** @brief C-API: File callbacks
+ *
+ *  Actually, it's a data structure to wrap a set of fXXXX (e.g fopen)
+ *  replacement functions.
+ *
+ *  The default implementation of the functions utilizes the fXXX functions from
+ *  the CRT. However, you can supply a custom implementation to Assimp by
+ *  delivering a custom aiFileIO. Use this to enable reading from other sources,
+ *  such as ZIP archives or memory locations. */
+struct aiFile
+{
+    /** Callback to read from a file */
+    aiFileReadProc ReadProc;
+
+    /** Callback to write to a file */
+    aiFileWriteProc WriteProc;
+
+    /** Callback to retrieve the current position of
+     *  the file cursor (ftell())
+     */
+    aiFileTellProc TellProc;
+
+    /** Callback to retrieve the size of the file,
+     *  in bytes
+     */
+    aiFileTellProc FileSizeProc;
+
+    /** Callback to set the current position
+     * of the file cursor (fseek())
+     */
+    aiFileSeek SeekProc;
+
+    /** Callback to flush the file contents
+     */
+    aiFileFlushProc FlushProc;
+
+    /** User-defined, opaque data
+     */
+    aiUserData UserData;
+};
+
+#ifdef __cplusplus
+}
+#endif
+#endif // AI_FILEIO_H_INC

dependencies/assimp/include/assimp/cimport.h

@@ -0,0 +1,565 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  cimport.h
+ *  @brief Defines the C-API to the Open Asset Import Library.
+ */
+#pragma once
+#ifndef AI_ASSIMP_H_INC
+#define AI_ASSIMP_H_INC
+
+#include <assimp/types.h>
+#include "importerdesc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct aiScene;  // aiScene.h
+struct aiFileIO; // aiFileIO.h
+typedef void (*aiLogStreamCallback)(const char* /* message */, char* /* user */);
+
+// --------------------------------------------------------------------------------
+/** C-API: Represents a log stream. A log stream receives all log messages and
+ *  streams them _somewhere_.
+ *  @see aiGetPredefinedLogStream
+ *  @see aiAttachLogStream
+ *  @see aiDetachLogStream */
+// --------------------------------------------------------------------------------
+struct aiLogStream
+{
+    /** callback to be called */
+    aiLogStreamCallback callback;
+
+    /** user data to be passed to the callback */
+    char* user;
+};
+
+
+// --------------------------------------------------------------------------------
+/** C-API: Represents an opaque set of settings to be used during importing.
+ *  @see aiCreatePropertyStore
+ *  @see aiReleasePropertyStore
+ *  @see aiImportFileExWithProperties
+ *  @see aiSetPropertyInteger
+ *  @see aiSetPropertyFloat
+ *  @see aiSetPropertyString
+ *  @see aiSetPropertyMatrix
+ */
+// --------------------------------------------------------------------------------
+struct aiPropertyStore { char sentinel; };
+
+/** Our own C boolean type */
+typedef int aiBool;
+
+#define AI_FALSE 0
+#define AI_TRUE 1
+
+// --------------------------------------------------------------------------------
+/** Reads the given file and returns its content.
+ *
+ * If the call succeeds, the imported data is returned in an aiScene structure.
+ * The data is intended to be read-only, it stays property of the ASSIMP
+ * library and will be stable until aiReleaseImport() is called. After you're
+ * done with it, call aiReleaseImport() to free the resources associated with
+ * this file. If the import fails, NULL is returned instead. Call
+ * aiGetErrorString() to retrieve a human-readable error text.
+ * @param pFile Path and filename of the file to be imported,
+ *   expected to be a null-terminated c-string. NULL is not a valid value.
+ * @param pFlags Optional post processing steps to be executed after
+ *   a successful import. Provide a bitwise combination of the
+ *   #aiPostProcessSteps flags.
+ * @return Pointer to the imported data or NULL if the import failed.
+ */
+ASSIMP_API const C_STRUCT aiScene* aiImportFile(
+    const char* pFile,
+    unsigned int pFlags);
+
+// --------------------------------------------------------------------------------
+/** Reads the given file using user-defined I/O functions and returns
+ *   its content.
+ *
+ * If the call succeeds, the imported data is returned in an aiScene structure.
+ * The data is intended to be read-only, it stays property of the ASSIMP
+ * library and will be stable until aiReleaseImport() is called. After you're
+ * done with it, call aiReleaseImport() to free the resources associated with
+ * this file. If the import fails, NULL is returned instead. Call
+ * aiGetErrorString() to retrieve a human-readable error text.
+ * @param pFile Path and filename of the file to be imported,
+ *   expected to be a null-terminated c-string. NULL is not a valid value.
+ * @param pFlags Optional post processing steps to be executed after
+ *   a successful import. Provide a bitwise combination of the
+ *   #aiPostProcessSteps flags.
+ * @param pFS aiFileIO structure. Will be used to open the model file itself
+ *   and any other files the loader needs to open.  Pass NULL to use the default
+ *   implementation.
+ * @return Pointer to the imported data or NULL if the import failed.
+ * @note Include <aiFileIO.h> for the definition of #aiFileIO.
+ */
+ASSIMP_API const C_STRUCT aiScene* aiImportFileEx(
+    const char* pFile,
+    unsigned int pFlags,
+    C_STRUCT aiFileIO* pFS);
+
+// --------------------------------------------------------------------------------
+/** Same as #aiImportFileEx, but adds an extra parameter containing importer settings.
+ *
+ * @param pFile Path and filename of the file to be imported,
+ *   expected to be a null-terminated c-string. NULL is not a valid value.
+ * @param pFlags Optional post processing steps to be executed after
+ *   a successful import. Provide a bitwise combination of the
+ *   #aiPostProcessSteps flags.
+ * @param pFS aiFileIO structure. Will be used to open the model file itself
+ *   and any other files the loader needs to open.  Pass NULL to use the default
+ *   implementation.
+ * @param pProps #aiPropertyStore instance containing import settings.
+ * @return Pointer to the imported data or NULL if the import failed.
+ * @note Include <aiFileIO.h> for the definition of #aiFileIO.
+ * @see aiImportFileEx
+ */
+ASSIMP_API const C_STRUCT aiScene* aiImportFileExWithProperties(
+    const char* pFile,
+    unsigned int pFlags,
+    C_STRUCT aiFileIO* pFS,
+    const C_STRUCT aiPropertyStore* pProps);
+
+// --------------------------------------------------------------------------------
+/** Reads the given file from a given memory buffer,
+ *
+ * If the call succeeds, the contents of the file are returned as a pointer to an
+ * aiScene object. The returned data is intended to be read-only, the importer keeps
+ * ownership of the data and will destroy it upon destruction. If the import fails,
+ * NULL is returned.
+ * A human-readable error description can be retrieved by calling aiGetErrorString().
+ * @param pBuffer Pointer to the file data
+ * @param pLength Length of pBuffer, in bytes
+ * @param pFlags Optional post processing steps to be executed after
+ *   a successful import. Provide a bitwise combination of the
+ *   #aiPostProcessSteps flags. If you wish to inspect the imported
+ *   scene first in order to fine-tune your post-processing setup,
+ *   consider to use #aiApplyPostProcessing().
+ * @param pHint An additional hint to the library. If this is a non empty string,
+ *   the library looks for a loader to support the file extension specified by pHint
+ *   and passes the file to the first matching loader. If this loader is unable to
+ *   completely the request, the library continues and tries to determine the file
+ *   format on its own, a task that may or may not be successful.
+ *   Check the return value, and you'll know ...
+ * @return A pointer to the imported data, NULL if the import failed.
+ *
+ * @note This is a straightforward way to decode models from memory
+ * buffers, but it doesn't handle model formats that spread their
+ * data across multiple files or even directories. Examples include
+ * OBJ or MD3, which outsource parts of their material info into
+ * external scripts. If you need full functionality, provide
+ * a custom IOSystem to make Assimp find these files and use
+ * the regular aiImportFileEx()/aiImportFileExWithProperties() API.
+ */
+ASSIMP_API const C_STRUCT aiScene* aiImportFileFromMemory(
+    const char* pBuffer,
+    unsigned int pLength,
+    unsigned int pFlags,
+    const char* pHint);
+
+// --------------------------------------------------------------------------------
+/** Same as #aiImportFileFromMemory, but adds an extra parameter containing importer settings.
+ *
+ * @param pBuffer Pointer to the file data
+ * @param pLength Length of pBuffer, in bytes
+ * @param pFlags Optional post processing steps to be executed after
+ *   a successful import. Provide a bitwise combination of the
+ *   #aiPostProcessSteps flags. If you wish to inspect the imported
+ *   scene first in order to fine-tune your post-processing setup,
+ *   consider to use #aiApplyPostProcessing().
+ * @param pHint An additional hint to the library. If this is a non empty string,
+ *   the library looks for a loader to support the file extension specified by pHint
+ *   and passes the file to the first matching loader. If this loader is unable to
+ *   completely the request, the library continues and tries to determine the file
+ *   format on its own, a task that may or may not be successful.
+ *   Check the return value, and you'll know ...
+ * @param pProps #aiPropertyStore instance containing import settings.
+ * @return A pointer to the imported data, NULL if the import failed.
+ *
+ * @note This is a straightforward way to decode models from memory
+ * buffers, but it doesn't handle model formats that spread their
+ * data across multiple files or even directories. Examples include
+ * OBJ or MD3, which outsource parts of their material info into
+ * external scripts. If you need full functionality, provide
+ * a custom IOSystem to make Assimp find these files and use
+ * the regular aiImportFileEx()/aiImportFileExWithProperties() API.
+ * @see aiImportFileFromMemory
+ */
+ASSIMP_API const C_STRUCT aiScene* aiImportFileFromMemoryWithProperties(
+    const char* pBuffer,
+    unsigned int pLength,
+    unsigned int pFlags,
+    const char* pHint,
+    const C_STRUCT aiPropertyStore* pProps);
+
+// --------------------------------------------------------------------------------
+/** Apply post-processing to an already-imported scene.
+ *
+ * This is strictly equivalent to calling #aiImportFile()/#aiImportFileEx with the
+ * same flags. However, you can use this separate function to inspect the imported
+ * scene first to fine-tune your post-processing setup.
+ * @param pScene Scene to work on.
+ * @param pFlags Provide a bitwise combination of the #aiPostProcessSteps flags.
+ * @return A pointer to the post-processed data. Post processing is done in-place,
+ *   meaning this is still the same #aiScene which you passed for pScene. However,
+ *   _if_ post-processing failed, the scene could now be NULL. That's quite a rare
+ *   case, post processing steps are not really designed to 'fail'. To be exact,
+ *   the #aiProcess_ValidateDataStructure flag is currently the only post processing step
+ *   which can actually cause the scene to be reset to NULL.
+ */
+ASSIMP_API const C_STRUCT aiScene* aiApplyPostProcessing(
+    const C_STRUCT aiScene* pScene,
+    unsigned int pFlags);
+
+// --------------------------------------------------------------------------------
+/** Get one of the predefine log streams. This is the quick'n'easy solution to
+ *  access Assimp's log system. Attaching a log stream can slightly reduce Assimp's
+ *  overall import performance.
+ *
+ *  Usage is rather simple (this will stream the log to a file, named log.txt, and
+ *  the stdout stream of the process:
+ *  @code
+ *    struct aiLogStream c;
+ *    c = aiGetPredefinedLogStream(aiDefaultLogStream_FILE,"log.txt");
+ *    aiAttachLogStream(&c);
+ *    c = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT,NULL);
+ *    aiAttachLogStream(&c);
+ *  @endcode
+ *
+ *  @param pStreams One of the #aiDefaultLogStream enumerated values.
+ *  @param file Solely for the #aiDefaultLogStream_FILE flag: specifies the file to write to.
+ *    Pass NULL for all other flags.
+ *  @return The log stream. callback is set to NULL if something went wrong.
+ */
+ASSIMP_API C_STRUCT aiLogStream aiGetPredefinedLogStream(
+    C_ENUM aiDefaultLogStream pStreams,
+    const char* file);
+
+// --------------------------------------------------------------------------------
+/** Attach a custom log stream to the libraries' logging system.
+ *
+ *  Attaching a log stream can slightly reduce Assimp's overall import
+ *  performance. Multiple log-streams can be attached.
+ *  @param stream Describes the new log stream.
+ *  @note To ensure proper destruction of the logging system, you need to manually
+ *    call aiDetachLogStream() on every single log stream you attach.
+ *    Alternatively (for the lazy folks) #aiDetachAllLogStreams is provided.
+ */
+ASSIMP_API void aiAttachLogStream(
+    const C_STRUCT aiLogStream* stream);
+
+// --------------------------------------------------------------------------------
+/** Enable verbose logging. Verbose logging includes debug-related stuff and
+ *  detailed import statistics. This can have severe impact on import performance
+ *  and memory consumption. However, it might be useful to find out why a file
+ *  didn't read correctly.
+ *  @param d AI_TRUE or AI_FALSE, your decision.
+ */
+ASSIMP_API void aiEnableVerboseLogging(aiBool d);
+
+// --------------------------------------------------------------------------------
+/** Detach a custom log stream from the libraries' logging system.
+ *
+ *  This is the counterpart of #aiAttachLogStream. If you attached a stream,
+ *  don't forget to detach it again.
+ *  @param stream The log stream to be detached.
+ *  @return AI_SUCCESS if the log stream has been detached successfully.
+ *  @see aiDetachAllLogStreams
+ */
+ASSIMP_API C_ENUM aiReturn aiDetachLogStream(
+    const C_STRUCT aiLogStream* stream);
+
+// --------------------------------------------------------------------------------
+/** Detach all active log streams from the libraries' logging system.
+ *  This ensures that the logging system is terminated properly and all
+ *  resources allocated by it are actually freed. If you attached a stream,
+ *  don't forget to detach it again.
+ *  @see aiAttachLogStream
+ *  @see aiDetachLogStream
+ */
+ASSIMP_API void aiDetachAllLogStreams(void);
+
+// --------------------------------------------------------------------------------
+/** Releases all resources associated with the given import process.
+ *
+ * Call this function after you're done with the imported data.
+ * @param pScene The imported data to release. NULL is a valid value.
+ */
+ASSIMP_API void aiReleaseImport(
+    const C_STRUCT aiScene* pScene);
+
+// --------------------------------------------------------------------------------
+/** Returns the error text of the last failed import process.
+ *
+ * @return A textual description of the error that occurred at the last
+ * import process. NULL if there was no error. There can't be an error if you
+ * got a non-NULL #aiScene from #aiImportFile/#aiImportFileEx/#aiApplyPostProcessing.
+ */
+ASSIMP_API const char* aiGetErrorString(void);
+
+// --------------------------------------------------------------------------------
+/** Returns whether a given file extension is supported by ASSIMP
+ *
+ * @param szExtension Extension for which the function queries support for.
+ * Must include a leading dot '.'. Example: ".3ds", ".md3"
+ * @return AI_TRUE if the file extension is supported.
+ */
+ASSIMP_API aiBool aiIsExtensionSupported(
+    const char* szExtension);
+
+// --------------------------------------------------------------------------------
+/** Get a list of all file extensions supported by ASSIMP.
+ *
+ * If a file extension is contained in the list this does, of course, not
+ * mean that ASSIMP is able to load all files with this extension.
+ * @param szOut String to receive the extension list.
+ * Format of the list: "*.3ds;*.obj;*.dae". NULL is not a valid parameter.
+ */
+ASSIMP_API void aiGetExtensionList(
+    C_STRUCT aiString* szOut);
+
+// --------------------------------------------------------------------------------
+/** Get the approximated storage required by an imported asset
+ * @param pIn Input asset.
+ * @param in Data structure to be filled.
+ */
+ASSIMP_API void aiGetMemoryRequirements(
+    const C_STRUCT aiScene* pIn,
+    C_STRUCT aiMemoryInfo* in);
+
+
+
+// --------------------------------------------------------------------------------
+/** Create an empty property store. Property stores are used to collect import
+ *  settings.
+ * @return New property store. Property stores need to be manually destroyed using
+ *   the #aiReleasePropertyStore API function.
+ */
+ASSIMP_API C_STRUCT aiPropertyStore* aiCreatePropertyStore(void);
+
+// --------------------------------------------------------------------------------
+/** Delete a property store.
+ * @param p Property store to be deleted.
+ */
+ASSIMP_API void aiReleasePropertyStore(C_STRUCT aiPropertyStore* p);
+
+// --------------------------------------------------------------------------------
+/** Set an integer property.
+ *
+ *  This is the C-version of #Assimp::Importer::SetPropertyInteger(). In the C
+ *  interface, properties are always shared by all imports. It is not possible to
+ *  specify them per import.
+ *
+ * @param store Store to modify. Use #aiCreatePropertyStore to obtain a store.
+ * @param szName Name of the configuration property to be set. All supported
+ *   public properties are defined in the config.h header file (AI_CONFIG_XXX).
+ * @param value New value for the property
+ */
+ASSIMP_API void aiSetImportPropertyInteger(
+    C_STRUCT aiPropertyStore* store,
+    const char* szName,
+    int value);
+
+// --------------------------------------------------------------------------------
+/** Set a floating-point property.
+ *
+ *  This is the C-version of #Assimp::Importer::SetPropertyFloat(). In the C
+ *  interface, properties are always shared by all imports. It is not possible to
+ *  specify them per import.
+ *
+ * @param store Store to modify. Use #aiCreatePropertyStore to obtain a store.
+ * @param szName Name of the configuration property to be set. All supported
+ *   public properties are defined in the config.h header file (AI_CONFIG_XXX).
+ * @param value New value for the property
+ */
+ASSIMP_API void aiSetImportPropertyFloat(
+    C_STRUCT aiPropertyStore* store,
+    const char* szName,
+    ai_real value);
+
+// --------------------------------------------------------------------------------
+/** Set a string property.
+ *
+ *  This is the C-version of #Assimp::Importer::SetPropertyString(). In the C
+ *  interface, properties are always shared by all imports. It is not possible to
+ *  specify them per import.
+ *
+ * @param store Store to modify. Use #aiCreatePropertyStore to obtain a store.
+ * @param szName Name of the configuration property to be set. All supported
+ *   public properties are defined in the config.h header file (AI_CONFIG_XXX).
+ * @param st New value for the property
+ */
+ASSIMP_API void aiSetImportPropertyString(
+    C_STRUCT aiPropertyStore* store,
+    const char* szName,
+    const C_STRUCT aiString* st);
+
+// --------------------------------------------------------------------------------
+/** Set a matrix property.
+ *
+ *  This is the C-version of #Assimp::Importer::SetPropertyMatrix(). In the C
+ *  interface, properties are always shared by all imports. It is not possible to
+ *  specify them per import.
+ *
+ * @param store Store to modify. Use #aiCreatePropertyStore to obtain a store.
+ * @param szName Name of the configuration property to be set. All supported
+ *   public properties are defined in the config.h header file (AI_CONFIG_XXX).
+ * @param mat New value for the property
+ */
+ASSIMP_API void aiSetImportPropertyMatrix(
+    C_STRUCT aiPropertyStore* store,
+    const char* szName,
+    const C_STRUCT aiMatrix4x4* mat);
+
+// --------------------------------------------------------------------------------
+/** Construct a quaternion from a 3x3 rotation matrix.
+ *  @param quat Receives the output quaternion.
+ *  @param mat Matrix to 'quaternionize'.
+ *  @see aiQuaternion(const aiMatrix3x3& pRotMatrix)
+ */
+ASSIMP_API void aiCreateQuaternionFromMatrix(
+    C_STRUCT aiQuaternion* quat,
+    const C_STRUCT aiMatrix3x3* mat);
+
+// --------------------------------------------------------------------------------
+/** Decompose a transformation matrix into its rotational, translational and
+ *  scaling components.
+ *
+ * @param mat Matrix to decompose
+ * @param scaling Receives the scaling component
+ * @param rotation Receives the rotational component
+ * @param position Receives the translational component.
+ * @see aiMatrix4x4::Decompose (aiVector3D&, aiQuaternion&, aiVector3D&) const;
+ */
+ASSIMP_API void aiDecomposeMatrix(
+    const C_STRUCT aiMatrix4x4* mat,
+    C_STRUCT aiVector3D* scaling,
+    C_STRUCT aiQuaternion* rotation,
+    C_STRUCT aiVector3D* position);
+
+// --------------------------------------------------------------------------------
+/** Transpose a 4x4 matrix.
+ *  @param mat Pointer to the matrix to be transposed
+ */
+ASSIMP_API void aiTransposeMatrix4(
+    C_STRUCT aiMatrix4x4* mat);
+
+// --------------------------------------------------------------------------------
+/** Transpose a 3x3 matrix.
+ *  @param mat Pointer to the matrix to be transposed
+ */
+ASSIMP_API void aiTransposeMatrix3(
+    C_STRUCT aiMatrix3x3* mat);
+
+// --------------------------------------------------------------------------------
+/** Transform a vector by a 3x3 matrix
+ *  @param vec Vector to be transformed.
+ *  @param mat Matrix to transform the vector with.
+ */
+ASSIMP_API void aiTransformVecByMatrix3(
+    C_STRUCT aiVector3D* vec,
+    const C_STRUCT aiMatrix3x3* mat);
+
+// --------------------------------------------------------------------------------
+/** Transform a vector by a 4x4 matrix
+ *  @param vec Vector to be transformed.
+ *  @param mat Matrix to transform the vector with.
+ */
+ASSIMP_API void aiTransformVecByMatrix4(
+    C_STRUCT aiVector3D* vec,
+    const C_STRUCT aiMatrix4x4* mat);
+
+// --------------------------------------------------------------------------------
+/** Multiply two 4x4 matrices.
+ *  @param dst First factor, receives result.
+ *  @param src Matrix to be multiplied with 'dst'.
+ */
+ASSIMP_API void aiMultiplyMatrix4(
+    C_STRUCT aiMatrix4x4* dst,
+    const C_STRUCT aiMatrix4x4* src);
+
+// --------------------------------------------------------------------------------
+/** Multiply two 3x3 matrices.
+ *  @param dst First factor, receives result.
+ *  @param src Matrix to be multiplied with 'dst'.
+ */
+ASSIMP_API void aiMultiplyMatrix3(
+    C_STRUCT aiMatrix3x3* dst,
+    const C_STRUCT aiMatrix3x3* src);
+
+// --------------------------------------------------------------------------------
+/** Get a 3x3 identity matrix.
+ *  @param mat Matrix to receive its personal identity
+ */
+ASSIMP_API void aiIdentityMatrix3(
+    C_STRUCT aiMatrix3x3* mat);
+
+// --------------------------------------------------------------------------------
+/** Get a 4x4 identity matrix.
+ *  @param mat Matrix to receive its personal identity
+ */
+ASSIMP_API void aiIdentityMatrix4(
+    C_STRUCT aiMatrix4x4* mat);
+
+// --------------------------------------------------------------------------------
+/** Returns the number of import file formats available in the current Assimp build.
+ * Use aiGetImportFormatDescription() to retrieve infos of a specific import format.
+ */
+ASSIMP_API size_t aiGetImportFormatCount(void);
+
+// --------------------------------------------------------------------------------
+/** Returns a description of the nth import file format. Use #aiGetImportFormatCount()
+ * to learn how many import formats are supported.
+ * @param pIndex Index of the import format to retrieve information for. Valid range is
+ *    0 to #aiGetImportFormatCount()
+ * @return A description of that specific import format. NULL if pIndex is out of range.
+ */
+ASSIMP_API const C_STRUCT aiImporterDesc* aiGetImportFormatDescription( size_t pIndex);
+#ifdef __cplusplus
+}
+#endif
+
+#endif // AI_ASSIMP_H_INC

dependencies/assimp/include/assimp/color4.h

@@ -0,0 +1,104 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file color4.h
+ *  @brief RGBA color structure, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_COLOR4D_H_INC
+#define AI_COLOR4D_H_INC
+
+#include "defs.h"
+
+#ifdef __cplusplus
+
+// ----------------------------------------------------------------------------------
+/** Represents a color in Red-Green-Blue space including an
+*   alpha component. Color values range from 0 to 1. */
+// ----------------------------------------------------------------------------------
+template <typename TReal>
+class aiColor4t
+{
+public:
+    aiColor4t() AI_NO_EXCEPT : r(), g(), b(), a() {}
+    aiColor4t (TReal _r, TReal _g, TReal _b, TReal _a)
+        : r(_r), g(_g), b(_b), a(_a) {}
+    explicit aiColor4t (TReal _r) : r(_r), g(_r), b(_r), a(_r) {}
+    aiColor4t (const aiColor4t& o) = default;
+
+public:
+    // combined operators
+    const aiColor4t& operator += (const aiColor4t& o);
+    const aiColor4t& operator -= (const aiColor4t& o);
+    const aiColor4t& operator *= (TReal f);
+    const aiColor4t& operator /= (TReal f);
+
+public:
+    // comparison
+    bool operator == (const aiColor4t& other) const;
+    bool operator != (const aiColor4t& other) const;
+    bool operator <  (const aiColor4t& other) const;
+
+    // color tuple access, rgba order
+    inline TReal operator[](unsigned int i) const;
+    inline TReal& operator[](unsigned int i);
+
+    /** check whether a color is (close to) black */
+    inline bool IsBlack() const;
+
+public:
+
+    // Red, green, blue and alpha color values
+    TReal r, g, b, a;
+};  // !struct aiColor4D
+
+typedef aiColor4t<ai_real> aiColor4D;
+
+#else
+
+struct aiColor4D {
+    ai_real r, g, b, a;
+};
+
+#endif // __cplusplus
+
+#endif // AI_COLOR4D_H_INC

dependencies/assimp/include/assimp/color4.inl

@@ -0,0 +1,209 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  color4.inl
+ *  @brief Inline implementation of aiColor4t<TReal> operators
+ */
+#pragma once
+#ifndef AI_COLOR4D_INL_INC
+#define AI_COLOR4D_INL_INC
+
+#ifdef __cplusplus
+#include "color4.h"
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE const aiColor4t<TReal>& aiColor4t<TReal>::operator += (const aiColor4t<TReal>& o) {
+    r += o.r; g += o.g; b += o.b; a += o.a;
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE const aiColor4t<TReal>& aiColor4t<TReal>::operator -= (const aiColor4t<TReal>& o) {
+    r -= o.r; g -= o.g; b -= o.b; a -= o.a;
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE const aiColor4t<TReal>& aiColor4t<TReal>::operator *= (TReal f) {
+    r *= f; g *= f; b *= f; a *= f;
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE const aiColor4t<TReal>& aiColor4t<TReal>::operator /= (TReal f) {
+    r /= f; g /= f; b /= f; a /= f;
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE TReal aiColor4t<TReal>::operator[](unsigned int i) const {
+    switch ( i ) {
+        case 0:
+            return r;
+        case 1:
+            return g;
+        case 2:
+            return b;
+        case 3:
+            return a;
+        default:
+            break;
+    }
+    return r;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE TReal& aiColor4t<TReal>::operator[](unsigned int i) {
+    switch ( i ) {
+        case 0:
+            return r;
+        case 1:
+            return g;
+        case 2:
+            return b;
+        case 3:
+            return a;
+        default:
+            break;
+    }
+    return r;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE bool aiColor4t<TReal>::operator== (const aiColor4t<TReal>& other) const {
+    return r == other.r && g == other.g && b == other.b && a == other.a;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE bool aiColor4t<TReal>::operator!= (const aiColor4t<TReal>& other) const {
+    return r != other.r || g != other.g || b != other.b || a != other.a;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE bool aiColor4t<TReal>::operator< (const aiColor4t<TReal>& other) const {
+    return r < other.r || (
+        r == other.r && (
+            g < other.g || (
+                g == other.g && (
+                    b < other.b || (
+                        b == other.b && (
+                            a < other.a
+                        )
+                    )
+                )
+            )
+        )
+    );
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE aiColor4t<TReal> operator + (const aiColor4t<TReal>& v1, const aiColor4t<TReal>& v2)    {
+    return aiColor4t<TReal>( v1.r + v2.r, v1.g + v2.g, v1.b + v2.b, v1.a + v2.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE aiColor4t<TReal> operator - (const aiColor4t<TReal>& v1, const aiColor4t<TReal>& v2)    {
+    return aiColor4t<TReal>( v1.r - v2.r, v1.g - v2.g, v1.b - v2.b, v1.a - v2.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE aiColor4t<TReal> operator * (const aiColor4t<TReal>& v1, const aiColor4t<TReal>& v2)    {
+    return aiColor4t<TReal>( v1.r * v2.r, v1.g * v2.g, v1.b * v2.b, v1.a * v2.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE aiColor4t<TReal> operator / (const aiColor4t<TReal>& v1, const aiColor4t<TReal>& v2)    {
+    return aiColor4t<TReal>( v1.r / v2.r, v1.g / v2.g, v1.b / v2.b, v1.a / v2.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE aiColor4t<TReal> operator * ( TReal f, const aiColor4t<TReal>& v)   {
+    return aiColor4t<TReal>( f*v.r, f*v.g, f*v.b, f*v.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator * ( const aiColor4t<TReal>& v, TReal f)  {
+    return aiColor4t<TReal>( f*v.r, f*v.g, f*v.b, f*v.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator / ( const aiColor4t<TReal>& v, TReal f)  {
+    return v * (1/f);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator / ( TReal f,const aiColor4t<TReal>& v)   {
+    return aiColor4t<TReal>(f,f,f,f)/v;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator + ( const aiColor4t<TReal>& v, TReal f)  {
+    return aiColor4t<TReal>( f+v.r, f+v.g, f+v.b, f+v.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator - ( const aiColor4t<TReal>& v, TReal f)  {
+    return aiColor4t<TReal>( v.r-f, v.g-f, v.b-f, v.a-f);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator + ( TReal f, const aiColor4t<TReal>& v)  {
+    return aiColor4t<TReal>( f+v.r, f+v.g, f+v.b, f+v.a);
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE  aiColor4t<TReal> operator - ( TReal f, const aiColor4t<TReal>& v)  {
+    return aiColor4t<TReal>( f-v.r, f-v.g, f-v.b, f-v.a);
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiColor4t<TReal> :: IsBlack() const {
+    // The alpha component doesn't care here. black is black.
+    static const TReal epsilon = 10e-3f;
+    return std::fabs( r ) < epsilon && std::fabs( g ) < epsilon && std::fabs( b ) < epsilon;
+}
+
+#endif // __cplusplus
+#endif // AI_VECTOR3D_INL_INC

dependencies/assimp/include/assimp/defs.h

@@ -0,0 +1,310 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file defs.h
+ *  @brief Assimp build configuration setup. See the notes in the comment
+ *  blocks to find out how to customize _your_ Assimp build.
+ */
+
+#pragma once
+#ifndef AI_DEFINES_H_INC
+#define AI_DEFINES_H_INC
+
+#include <assimp/config.h>
+
+//////////////////////////////////////////////////////////////////////////
+/* Define ASSIMP_BUILD_NO_XX_IMPORTER to disable a specific
+ * file format loader. The loader is be excluded from the
+ * build in this case. 'XX' stands for the most common file
+ * extension of the file format. E.g.:
+ * ASSIMP_BUILD_NO_X_IMPORTER disables the X loader.
+ *
+ * If you're unsure about that, take a look at the implementation of the
+ * import plugin you wish to disable. You'll find the right define in the
+ * first lines of the corresponding unit.
+ *
+ * Other (mixed) configuration switches are listed here:
+ *    ASSIMP_BUILD_NO_COMPRESSED_X
+ *      - Disable support for compressed X files (zip)
+ *    ASSIMP_BUILD_NO_COMPRESSED_BLEND
+ *      - Disable support for compressed Blender files (zip)
+ *    ASSIMP_BUILD_NO_COMPRESSED_IFC
+ *      - Disable support for IFCZIP files (unzip)
+ */
+//////////////////////////////////////////////////////////////////////////
+
+#ifndef ASSIMP_BUILD_NO_COMPRESSED_X
+#   define ASSIMP_BUILD_NEED_Z_INFLATE
+#endif
+
+#ifndef ASSIMP_BUILD_NO_COMPRESSED_BLEND
+#   define ASSIMP_BUILD_NEED_Z_INFLATE
+#endif
+
+#ifndef ASSIMP_BUILD_NO_COMPRESSED_IFC
+#   define ASSIMP_BUILD_NEED_Z_INFLATE
+#   define ASSIMP_BUILD_NEED_UNZIP
+#endif
+
+#ifndef ASSIMP_BUILD_NO_Q3BSP_IMPORTER
+#   define ASSIMP_BUILD_NEED_Z_INFLATE
+#   define ASSIMP_BUILD_NEED_UNZIP
+#endif
+
+//////////////////////////////////////////////////////////////////////////
+/* Define ASSIMP_BUILD_NO_XX_PROCESS to disable a specific
+ * post processing step. This is the current list of process names ('XX'):
+ * CALCTANGENTS
+ * JOINVERTICES
+ * TRIANGULATE
+ * DROPFACENORMALS
+ * GENFACENORMALS
+ * GENVERTEXNORMALS
+ * REMOVEVC
+ * SPLITLARGEMESHES
+ * PRETRANSFORMVERTICES
+ * LIMITBONEWEIGHTS
+ * VALIDATEDS
+ * IMPROVECACHELOCALITY
+ * FIXINFACINGNORMALS
+ * REMOVE_REDUNDANTMATERIALS
+ * OPTIMIZEGRAPH
+ * SORTBYPTYPE
+ * FINDINVALIDDATA
+ * TRANSFORMTEXCOORDS
+ * GENUVCOORDS
+ * ENTITYMESHBUILDER
+ * EMBEDTEXTURES
+ * MAKELEFTHANDED
+ * FLIPUVS
+ * FLIPWINDINGORDER
+ * OPTIMIZEMESHES
+ * OPTIMIZEANIMS
+ * OPTIMIZEGRAPH
+ * GENENTITYMESHES
+ * FIXTEXTUREPATHS
+ * GENBOUNDINGBOXES */
+//////////////////////////////////////////////////////////////////////////
+
+#ifdef _MSC_VER
+#   undef ASSIMP_API
+
+    //////////////////////////////////////////////////////////////////////////
+    /* Define 'ASSIMP_BUILD_DLL_EXPORT' to build a DLL of the library */
+    //////////////////////////////////////////////////////////////////////////
+#   ifdef ASSIMP_BUILD_DLL_EXPORT
+#       define ASSIMP_API __declspec(dllexport)
+#       define ASSIMP_API_WINONLY __declspec(dllexport)
+#       pragma warning (disable : 4251)
+
+    //////////////////////////////////////////////////////////////////////////
+    /* Define 'ASSIMP_DLL' before including Assimp to link to ASSIMP in
+     * an external DLL under Windows. Default is static linkage. */
+    //////////////////////////////////////////////////////////////////////////
+#   elif (defined ASSIMP_DLL)
+#       define ASSIMP_API __declspec(dllimport)
+#       define ASSIMP_API_WINONLY __declspec(dllimport)
+#   else
+#       define ASSIMP_API
+#       define ASSIMP_API_WINONLY
+#   endif
+
+    /* Force the compiler to inline a function, if possible
+     */
+#   define AI_FORCE_INLINE __forceinline
+
+    /* Tells the compiler that a function never returns. Used in code analysis
+     * to skip dead paths (e.g. after an assertion evaluated to false). */
+#   define AI_WONT_RETURN __declspec(noreturn)
+
+#elif defined(SWIG)
+
+    /* Do nothing, the relevant defines are all in AssimpSwigPort.i */
+
+#else
+
+#   define AI_WONT_RETURN
+
+#   define ASSIMP_API __attribute__ ((visibility("default")))
+#   define ASSIMP_API_WINONLY
+#   define AI_FORCE_INLINE inline
+#endif // (defined _MSC_VER)
+
+#ifdef __GNUC__
+#   define AI_WONT_RETURN_SUFFIX  __attribute__((noreturn))
+#else
+#   define AI_WONT_RETURN_SUFFIX
+#endif // (defined __clang__)
+
+#ifdef __cplusplus
+    /* No explicit 'struct' and 'enum' tags for C++, this keeps showing up
+     * in doxydocs.
+     */
+#   define C_STRUCT
+#   define C_ENUM
+#else
+    //////////////////////////////////////////////////////////////////////////
+    /* To build the documentation, make sure ASSIMP_DOXYGEN_BUILD
+     * is defined by Doxygen's preprocessor. The corresponding
+     * entries in the DOXYFILE are: */
+    //////////////////////////////////////////////////////////////////////////
+#if 0
+    ENABLE_PREPROCESSING   = YES
+    MACRO_EXPANSION        = YES
+    EXPAND_ONLY_PREDEF     = YES
+    SEARCH_INCLUDES        = YES
+    INCLUDE_PATH           =
+    INCLUDE_FILE_PATTERNS  =
+    PREDEFINED             = ASSIMP_DOXYGEN_BUILD=1
+    EXPAND_AS_DEFINED      = C_STRUCT C_ENUM
+    SKIP_FUNCTION_MACROS   = YES
+#endif
+    //////////////////////////////////////////////////////////////////////////
+    /* Doxygen gets confused if we use c-struct typedefs to avoid
+     * the explicit 'struct' notation. This trick here has the same
+     * effect as the TYPEDEF_HIDES_STRUCT option, but we don't need
+     * to typedef all structs/enums. */
+     //////////////////////////////////////////////////////////////////////////
+#   if (defined ASSIMP_DOXYGEN_BUILD)
+#       define C_STRUCT
+#       define C_ENUM
+#   else
+#       define C_STRUCT struct
+#       define C_ENUM   enum
+#   endif
+#endif
+
+#if (defined(__BORLANDC__) || defined (__BCPLUSPLUS__))
+#   error Currently, Borland is unsupported. Feel free to port Assimp.
+#endif
+
+
+    //////////////////////////////////////////////////////////////////////////
+    /* Define ASSIMP_BUILD_SINGLETHREADED to compile assimp
+     * without threading support. The library doesn't utilize
+     * threads then and is itself not threadsafe. */
+    //////////////////////////////////////////////////////////////////////////
+#ifndef ASSIMP_BUILD_SINGLETHREADED
+#   define ASSIMP_BUILD_SINGLETHREADED
+#endif
+
+#if defined(_DEBUG) || ! defined(NDEBUG)
+#   define ASSIMP_BUILD_DEBUG
+#endif
+
+    //////////////////////////////////////////////////////////////////////////
+    /* Define ASSIMP_DOUBLE_PRECISION to compile assimp
+     * with double precision support (64-bit). */
+    //////////////////////////////////////////////////////////////////////////
+
+#ifdef ASSIMP_DOUBLE_PRECISION
+    typedef double ai_real;
+    typedef signed long long int ai_int;
+    typedef unsigned long long int ai_uint;
+#ifndef ASSIMP_AI_REAL_TEXT_PRECISION
+#define ASSIMP_AI_REAL_TEXT_PRECISION 16
+#endif // ASSIMP_AI_REAL_TEXT_PRECISION
+#else // ASSIMP_DOUBLE_PRECISION
+    typedef float ai_real;
+    typedef signed int ai_int;
+    typedef unsigned int ai_uint;
+#ifndef ASSIMP_AI_REAL_TEXT_PRECISION
+#define ASSIMP_AI_REAL_TEXT_PRECISION 8
+#endif // ASSIMP_AI_REAL_TEXT_PRECISION
+#endif // ASSIMP_DOUBLE_PRECISION
+
+    //////////////////////////////////////////////////////////////////////////
+    /* Useful constants */
+    //////////////////////////////////////////////////////////////////////////
+
+/* This is PI. Hi PI. */
+#define AI_MATH_PI          (3.141592653589793238462643383279 )
+#define AI_MATH_TWO_PI      (AI_MATH_PI * 2.0)
+#define AI_MATH_HALF_PI     (AI_MATH_PI * 0.5)
+
+/* And this is to avoid endless casts to float */
+#define AI_MATH_PI_F        (3.1415926538f)
+#define AI_MATH_TWO_PI_F    (AI_MATH_PI_F * 2.0f)
+#define AI_MATH_HALF_PI_F   (AI_MATH_PI_F * 0.5f)
+
+/* Tiny macro to convert from radians to degrees and back */
+#define AI_DEG_TO_RAD(x) ((x)*(ai_real)0.0174532925)
+#define AI_RAD_TO_DEG(x) ((x)*(ai_real)57.2957795)
+
+/* Numerical limits */
+static const ai_real ai_epsilon = (ai_real) 0.00001;
+
+/* Support for big-endian builds */
+#if defined(__BYTE_ORDER__)
+#   if (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#       if !defined(__BIG_ENDIAN__)
+#           define __BIG_ENDIAN__
+#       endif
+#   else /* little endian */
+#       if defined (__BIG_ENDIAN__)
+#           undef __BIG_ENDIAN__
+#       endif
+#   endif
+#endif
+#if defined(__BIG_ENDIAN__)
+#   define AI_BUILD_BIG_ENDIAN
+#endif
+
+
+/* To avoid running out of memory
+ * This can be adjusted for specific use cases
+ * It's NOT a total limit, just a limit for individual allocations
+ */
+#define AI_MAX_ALLOC(type) ((256U * 1024 * 1024) / sizeof(type))
+
+#ifndef _MSC_VER
+#  define AI_NO_EXCEPT noexcept
+#else
+#  if (_MSC_VER >= 1915 )
+#    define AI_NO_EXCEPT noexcept
+#  else
+#    define AI_NO_EXCEPT
+#  endif
+#endif // _MSC_VER
+
+#endif // !! AI_DEFINES_H_INC

dependencies/assimp/include/assimp/fast_atof.h

@@ -0,0 +1,373 @@
+#pragma once
+
+// Copyright (C) 2002-2007 Nikolaus Gebhardt
+// This file is part of the "Irrlicht Engine" and the "irrXML" project.
+// For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
+
+// ------------------------------------------------------------------------------------
+// Original description: (Schrompf)
+// Adapted to the ASSIMP library because the builtin atof indeed takes AGES to parse a
+// float inside a large string. Before parsing, it does a strlen on the given point.
+// Changes:
+//  22nd October 08 (Aramis_acg): Added temporary cast to double, added strtoul10_64
+//     to ensure long numbers are handled correctly
+// ------------------------------------------------------------------------------------
+
+
+#ifndef FAST_A_TO_F_H_INCLUDED
+#define FAST_A_TO_F_H_INCLUDED
+
+#include <cmath>
+#include <limits>
+#include <stdint.h>
+#include <stdexcept>
+#include <assimp/defs.h>
+
+#include "StringComparison.h"
+#include <assimp/DefaultLogger.hpp>
+
+#ifdef _MSC_VER
+#  include <stdint.h>
+#else
+#  include <assimp/Compiler/pstdint.h>
+#endif
+
+namespace Assimp {
+
+const double fast_atof_table[16] =  {  // we write [16] here instead of [] to work around a swig bug
+    0.0,
+    0.1,
+    0.01,
+    0.001,
+    0.0001,
+    0.00001,
+    0.000001,
+    0.0000001,
+    0.00000001,
+    0.000000001,
+    0.0000000001,
+    0.00000000001,
+    0.000000000001,
+    0.0000000000001,
+    0.00000000000001,
+    0.000000000000001
+};
+
+
+// ------------------------------------------------------------------------------------
+// Convert a string in decimal format to a number
+// ------------------------------------------------------------------------------------
+inline
+unsigned int strtoul10( const char* in, const char** out=0) {
+    unsigned int value = 0;
+
+    for ( ;; ) {
+        if ( *in < '0' || *in > '9' ) {
+            break;
+        }
+
+        value = ( value * 10 ) + ( *in - '0' );
+        ++in;
+    }
+    if ( out ) {
+        *out = in;
+    }
+    return value;
+}
+
+// ------------------------------------------------------------------------------------
+// Convert a string in octal format to a number
+// ------------------------------------------------------------------------------------
+inline
+unsigned int strtoul8( const char* in, const char** out=0) {
+    unsigned int value( 0 );
+    for ( ;; ) {
+        if ( *in < '0' || *in > '7' ) {
+            break;
+        }
+
+        value = ( value << 3 ) + ( *in - '0' );
+        ++in;
+    }
+    if ( out ) {
+        *out = in;
+    }
+    return value;
+}
+
+// ------------------------------------------------------------------------------------
+// Convert a string in hex format to a number
+// ------------------------------------------------------------------------------------
+inline
+unsigned int strtoul16( const char* in, const char** out=0) {
+    unsigned int value( 0 );
+    for ( ;; ) {
+        if ( *in >= '0' && *in <= '9' ) {
+            value = ( value << 4u ) + ( *in - '0' );
+        } else if (*in >= 'A' && *in <= 'F') {
+            value = ( value << 4u ) + ( *in - 'A' ) + 10;
+        } else if (*in >= 'a' && *in <= 'f') {
+            value = ( value << 4u ) + ( *in - 'a' ) + 10;
+        } else {
+            break;
+        }
+        ++in;
+    }
+    if ( out ) {
+        *out = in;
+    }
+    return value;
+}
+
+// ------------------------------------------------------------------------------------
+// Convert just one hex digit
+// Return value is UINT_MAX if the input character is not a hex digit.
+// ------------------------------------------------------------------------------------
+inline
+unsigned int HexDigitToDecimal(char in) {
+    unsigned int out( UINT_MAX );
+    if ( in >= '0' && in <= '9' ) {
+        out = in - '0';
+    } else if ( in >= 'a' && in <= 'f' ) {
+        out = 10u + in - 'a';
+    } else if ( in >= 'A' && in <= 'F' ) {
+        out = 10u + in - 'A';
+    }
+
+    // return value is UINT_MAX if the input is not a hex digit
+    return out;
+}
+
+// ------------------------------------------------------------------------------------
+// Convert a hex-encoded octet (2 characters, i.e. df or 1a).
+// ------------------------------------------------------------------------------------
+inline
+uint8_t HexOctetToDecimal(const char* in) {
+    return ((uint8_t)HexDigitToDecimal(in[0])<<4)+(uint8_t)HexDigitToDecimal(in[1]);
+}
+
+// ------------------------------------------------------------------------------------
+// signed variant of strtoul10
+// ------------------------------------------------------------------------------------
+inline
+int strtol10( const char* in, const char** out=0) {
+    bool inv = (*in=='-');
+    if ( inv || *in == '+' ) {
+        ++in;
+    }
+
+    int value = strtoul10(in,out);
+    if (inv) {
+        value = -value;
+    }
+    return value;
+}
+
+// ------------------------------------------------------------------------------------
+// Parse a C++-like integer literal - hex and oct prefixes.
+// 0xNNNN - hex
+// 0NNN   - oct
+// NNN    - dec
+// ------------------------------------------------------------------------------------
+inline
+unsigned int strtoul_cppstyle( const char* in, const char** out=0) {
+    if ('0' == in[0]) {
+        return 'x' == in[1] ? strtoul16(in+2,out) : strtoul8(in+1,out);
+    }
+    return strtoul10(in, out);
+}
+
+// ------------------------------------------------------------------------------------
+// Special version of the function, providing higher accuracy and safety
+// It is mainly used by fast_atof to prevent ugly and unwanted integer overflows.
+// ------------------------------------------------------------------------------------
+inline
+uint64_t strtoul10_64( const char* in, const char** out=0, unsigned int* max_inout=0) {
+    unsigned int cur = 0;
+    uint64_t value = 0;
+
+    if ( *in < '0' || *in > '9' ) {
+        throw std::invalid_argument( std::string( "The string \"" ) + in + "\" cannot be converted into a value." );
+    }
+
+    for ( ;; ) {
+        if ( *in < '0' || *in > '9' ) {
+            break;
+        }
+
+        const uint64_t new_value = ( value * (uint64_t) 10 ) + ( (uint64_t) ( *in - '0' ) );
+
+        // numeric overflow, we rely on you
+        if ( new_value < value ) {
+            ASSIMP_LOG_WARN_F( "Converting the string \"", in, "\" into a value resulted in overflow." );
+            return 0;
+        }
+
+        value = new_value;
+
+        ++in;
+        ++cur;
+
+        if (max_inout && *max_inout == cur) {
+            if (out) { /* skip to end */
+                while ( *in >= '0' && *in <= '9' ) {
+                    ++in;
+                }
+                *out = in;
+            }
+
+            return value;
+        }
+    }
+    if ( out ) {
+        *out = in;
+    }
+
+    if ( max_inout ) {
+        *max_inout = cur;
+    }
+
+    return value;
+}
+
+// ------------------------------------------------------------------------------------
+// signed variant of strtoul10_64
+// ------------------------------------------------------------------------------------
+inline
+int64_t strtol10_64(const char* in, const char** out = 0, unsigned int* max_inout = 0) {
+    bool inv = (*in == '-');
+    if ( inv || *in == '+' ) {
+        ++in;
+    }
+
+    int64_t value = strtoul10_64(in, out, max_inout);
+    if (inv) {
+        value = -value;
+    }
+    return value;
+}
+
+// Number of relevant decimals for floating-point parsing.
+#define AI_FAST_ATOF_RELAVANT_DECIMALS 15
+
+// ------------------------------------------------------------------------------------
+//! Provides a fast function for converting a string into a float,
+//! about 6 times faster than atof in win32.
+// If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
+// ------------------------------------------------------------------------------------
+template<typename Real>
+inline
+const char* fast_atoreal_move(const char* c, Real& out, bool check_comma = true) {
+    Real f = 0;
+
+    bool inv = (*c == '-');
+    if (inv || *c == '+') {
+        ++c;
+    }
+
+    if ((c[0] == 'N' || c[0] == 'n') && ASSIMP_strincmp(c, "nan", 3) == 0) {
+        out = std::numeric_limits<Real>::quiet_NaN();
+        c += 3;
+        return c;
+    }
+
+    if ((c[0] == 'I' || c[0] == 'i') && ASSIMP_strincmp(c, "inf", 3) == 0) {
+        out = std::numeric_limits<Real>::infinity();
+        if (inv) {
+            out = -out;
+        }
+        c += 3;
+        if ((c[0] == 'I' || c[0] == 'i') && ASSIMP_strincmp(c, "inity", 5) == 0) {
+            c += 5;
+        }
+        return c;
+     }
+
+    if (!(c[0] >= '0' && c[0] <= '9') &&
+            !((c[0] == '.' || (check_comma && c[0] == ',')) && c[1] >= '0' && c[1] <= '9')) {
+        throw std::invalid_argument("Cannot parse string "
+                                    "as real number: does not start with digit "
+                                    "or decimal point followed by digit.");
+    }
+
+    if (*c != '.' && (! check_comma || c[0] != ',')) {
+        f = static_cast<Real>( strtoul10_64 ( c, &c) );
+    }
+
+    if ((*c == '.' || (check_comma && c[0] == ',')) && c[1] >= '0' && c[1] <= '9') {
+        ++c;
+
+        // NOTE: The original implementation is highly inaccurate here. The precision of a single
+        // IEEE 754 float is not high enough, everything behind the 6th digit tends to be more
+        // inaccurate than it would need to be. Casting to double seems to solve the problem.
+        // strtol_64 is used to prevent integer overflow.
+
+        // Another fix: this tends to become 0 for long numbers if we don't limit the maximum
+        // number of digits to be read. AI_FAST_ATOF_RELAVANT_DECIMALS can be a value between
+        // 1 and 15.
+        unsigned int diff = AI_FAST_ATOF_RELAVANT_DECIMALS;
+        double pl = static_cast<double>( strtoul10_64 ( c, &c, &diff ));
+
+        pl *= fast_atof_table[diff];
+        f += static_cast<Real>( pl );
+    }
+    // For backwards compatibility: eat trailing dots, but not trailing commas.
+    else if (*c == '.') {
+        ++c;
+    }
+
+    // A major 'E' must be allowed. Necessary for proper reading of some DXF files.
+    // Thanks to Zhao Lei to point out that this if() must be outside the if (*c == '.' ..)
+    if (*c == 'e' || *c == 'E') {
+        ++c;
+        const bool einv = (*c=='-');
+        if (einv || *c=='+') {
+            ++c;
+        }
+
+        // The reason float constants are used here is that we've seen cases where compilers
+        // would perform such casts on compile-time constants at runtime, which would be
+        // bad considering how frequently fast_atoreal_move<float> is called in Assimp.
+        Real exp = static_cast<Real>( strtoul10_64(c, &c) );
+        if (einv) {
+            exp = -exp;
+        }
+        f *= std::pow(static_cast<Real>(10.0), exp);
+    }
+
+    if (inv) {
+        f = -f;
+    }
+    out = f;
+    return c;
+}
+
+// ------------------------------------------------------------------------------------
+// The same but more human.
+inline
+ai_real fast_atof(const char* c) {
+    ai_real ret(0.0);
+    fast_atoreal_move<ai_real>(c, ret);
+
+    return ret;
+}
+
+inline
+ai_real fast_atof( const char* c, const char** cout) {
+    ai_real ret(0.0);
+    *cout = fast_atoreal_move<ai_real>(c, ret);
+
+    return ret;
+}
+
+inline
+ai_real fast_atof( const char** inout) {
+    ai_real ret(0.0);
+    *inout = fast_atoreal_move<ai_real>(*inout, ret);
+
+    return ret;
+}
+
+} //! namespace Assimp
+
+#endif // FAST_A_TO_F_H_INCLUDED

dependencies/assimp/include/assimp/importerdesc.h

@@ -0,0 +1,146 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file importerdesc.h
+ *  @brief #aiImporterFlags, aiImporterDesc implementation.
+ */
+#pragma once
+#ifndef AI_IMPORTER_DESC_H_INC
+#define AI_IMPORTER_DESC_H_INC
+
+
+/** Mixed set of flags for #aiImporterDesc, indicating some features
+  *  common to many importers*/
+enum aiImporterFlags
+{
+    /** Indicates that there is a textual encoding of the
+     *  file format; and that it is supported.*/
+    aiImporterFlags_SupportTextFlavour = 0x1,
+
+    /** Indicates that there is a binary encoding of the
+     *  file format; and that it is supported.*/
+    aiImporterFlags_SupportBinaryFlavour = 0x2,
+
+    /** Indicates that there is a compressed encoding of the
+     *  file format; and that it is supported.*/
+    aiImporterFlags_SupportCompressedFlavour = 0x4,
+
+    /** Indicates that the importer reads only a very particular
+      * subset of the file format. This happens commonly for
+      * declarative or procedural formats which cannot easily
+      * be mapped to #aiScene */
+    aiImporterFlags_LimitedSupport = 0x8,
+
+    /** Indicates that the importer is highly experimental and
+      * should be used with care. This only happens for trunk
+      * (i.e. SVN) versions, experimental code is not included
+      * in releases. */
+    aiImporterFlags_Experimental = 0x10
+};
+
+
+/** Meta information about a particular importer. Importers need to fill
+ *  this structure, but they can freely decide how talkative they are.
+ *  A common use case for loader meta info is a user interface
+ *  in which the user can choose between various import/export file
+ *  formats. Building such an UI by hand means a lot of maintenance
+ *  as importers/exporters are added to Assimp, so it might be useful
+ *  to have a common mechanism to query some rough importer
+ *  characteristics. */
+struct aiImporterDesc
+{
+    /** Full name of the importer (i.e. Blender3D importer)*/
+    const char* mName;
+
+    /** Original author (left blank if unknown or whole assimp team) */
+    const char* mAuthor;
+
+    /** Current maintainer, left blank if the author maintains */
+    const char* mMaintainer;
+
+    /** Implementation comments, i.e. unimplemented features*/
+    const char* mComments;
+
+    /** These flags indicate some characteristics common to many
+        importers. */
+    unsigned int mFlags;
+
+    /** Minimum format version that can be loaded im major.minor format,
+        both are set to 0 if there is either no version scheme
+        or if the loader doesn't care. */
+    unsigned int mMinMajor;
+    unsigned int mMinMinor;
+
+    /** Maximum format version that can be loaded im major.minor format,
+        both are set to 0 if there is either no version scheme
+        or if the loader doesn't care. Loaders that expect to be
+        forward-compatible to potential future format versions should
+        indicate  zero, otherwise they should specify the current
+        maximum version.*/
+    unsigned int mMaxMajor;
+    unsigned int mMaxMinor;
+
+    /** List of file extensions this importer can handle.
+        List entries are separated by space characters.
+        All entries are lower case without a leading dot (i.e.
+        "xml dae" would be a valid value. Note that multiple
+        importers may respond to the same file extension -
+        assimp calls all importers in the order in which they
+        are registered and each importer gets the opportunity
+        to load the file until one importer "claims" the file. Apart
+        from file extension checks, importers typically use
+        other methods to quickly reject files (i.e. magic
+        words) so this does not mean that common or generic
+        file extensions such as XML would be tediously slow. */
+    const char* mFileExtensions;
+};
+
+/** \brief  Returns the Importer description for a given extension.
+
+Will return a NULL-pointer if no assigned importer desc. was found for the given extension
+    \param  extension   [in] The extension to look for
+    \return A pointer showing to the ImporterDesc, \see aiImporterDesc.
+*/
+ASSIMP_API const C_STRUCT aiImporterDesc* aiGetImporterDesc( const char *extension );
+
+#endif // AI_IMPORTER_DESC_H_INC

dependencies/assimp/include/assimp/irrXMLWrapper.h

@@ -0,0 +1,149 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+#ifndef INCLUDED_AI_IRRXML_WRAPPER
+#define INCLUDED_AI_IRRXML_WRAPPER
+
+// some long includes ....
+#ifdef ASSIMP_USE_HUNTER
+#  include <irrXML/irrXML.h>
+#else
+#  include <irrXML.h>
+#endif
+#include "IOStream.hpp"
+#include "BaseImporter.h"
+#include <vector>
+
+namespace Assimp    {
+
+// ---------------------------------------------------------------------------------
+/** @brief Utility class to make IrrXML work together with our custom IO system
+ *  See the IrrXML docs for more details.
+ *
+ *  Construct IrrXML-Reader in BaseImporter::InternReadFile():
+ *  @code
+ * // open the file
+ * std::unique_ptr<IOStream> file( pIOHandler->Open( pFile));
+ * if( file.get() == NULL) {
+ *    throw DeadlyImportError( "Failed to open file " + pFile + ".");
+ * }
+ *
+ * // generate a XML reader for it
+ * std::unique_ptr<CIrrXML_IOStreamReader> mIOWrapper( new CIrrXML_IOStreamReader( file.get()));
+ * mReader = irr::io::createIrrXMLReader( mIOWrapper.get());
+ * if( !mReader) {
+ *    ThrowException( "xxxx: Unable to open file.");
+ * }
+ * @endcode
+ **/
+class CIrrXML_IOStreamReader : public irr::io::IFileReadCallBack {
+public:
+
+    // ----------------------------------------------------------------------------------
+    //! Construction from an existing IOStream
+    explicit CIrrXML_IOStreamReader(IOStream* _stream)
+        : stream (_stream)
+        , t (0)
+    {
+
+        // Map the buffer into memory and convert it to UTF8. IrrXML provides its
+        // own conversion, which is merely a cast from uintNN_t to uint8_t. Thus,
+        // it is not suitable for our purposes and we have to do it BEFORE IrrXML
+        // gets the buffer. Sadly, this forces us to map the whole file into
+        // memory.
+
+        data.resize(stream->FileSize());
+        stream->Read(&data[0],data.size(),1);
+
+        // Remove null characters from the input sequence otherwise the parsing will utterly fail
+        // std::find is usually much faster than manually iterating
+        // It is very unlikely that there will be any null characters
+        auto null_char_iter = std::find(data.begin(), data.end(), '\0');
+
+        while (null_char_iter != data.end())
+        {
+            null_char_iter = data.erase(null_char_iter);
+            null_char_iter = std::find(null_char_iter, data.end(), '\0');
+        }
+
+        BaseImporter::ConvertToUTF8(data);
+    }
+
+    // ----------------------------------------------------------------------------------
+    //! Virtual destructor
+    virtual ~CIrrXML_IOStreamReader() {}
+
+    // ----------------------------------------------------------------------------------
+    //!   Reads an amount of bytes from the file.
+    /**  @param buffer:       Pointer to output buffer.
+     *   @param sizeToRead:   Amount of bytes to read
+     *   @return              Returns how much bytes were read.  */
+    virtual int read(void* buffer, int sizeToRead)  {
+        if(sizeToRead<0) {
+            return 0;
+        }
+        if(t+sizeToRead>data.size()) {
+            sizeToRead = static_cast<int>(data.size()-t);
+        }
+
+        memcpy(buffer,&data.front()+t,sizeToRead);
+
+        t += sizeToRead;
+        return sizeToRead;
+    }
+
+    // ----------------------------------------------------------------------------------
+    //! Returns size of file in bytes
+    virtual int getSize()   {
+        return (int)data.size();
+    }
+
+private:
+    IOStream* stream;
+    std::vector<char> data;
+    size_t t;
+
+}; // ! class CIrrXML_IOStreamReader
+
+} // ! Assimp
+
+#endif // !! INCLUDED_AI_IRRXML_WRAPPER

dependencies/assimp/include/assimp/light.h

@@ -0,0 +1,259 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file light.h
+ *  @brief Defines the aiLight data structure
+ */
+
+#pragma once
+#ifndef AI_LIGHT_H_INC
+#define AI_LIGHT_H_INC
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ---------------------------------------------------------------------------
+/** Enumerates all supported types of light sources.
+ */
+enum aiLightSourceType
+{
+    aiLightSource_UNDEFINED     = 0x0,
+
+    //! A directional light source has a well-defined direction
+    //! but is infinitely far away. That's quite a good
+    //! approximation for sun light.
+    aiLightSource_DIRECTIONAL   = 0x1,
+
+    //! A point light source has a well-defined position
+    //! in space but no direction - it emits light in all
+    //! directions. A normal bulb is a point light.
+    aiLightSource_POINT         = 0x2,
+
+    //! A spot light source emits light in a specific
+    //! angle. It has a position and a direction it is pointing to.
+    //! A good example for a spot light is a light spot in
+    //! sport arenas.
+    aiLightSource_SPOT          = 0x3,
+
+    //! The generic light level of the world, including the bounces
+    //! of all other light sources.
+    //! Typically, there's at most one ambient light in a scene.
+    //! This light type doesn't have a valid position, direction, or
+    //! other properties, just a color.
+    aiLightSource_AMBIENT       = 0x4,
+
+    //! An area light is a rectangle with predefined size that uniformly
+    //! emits light from one of its sides. The position is center of the
+    //! rectangle and direction is its normal vector.
+    aiLightSource_AREA          = 0x5,
+
+    /** This value is not used. It is just there to force the
+     *  compiler to map this enum to a 32 Bit integer.
+     */
+#ifndef SWIG
+    _aiLightSource_Force32Bit = INT_MAX
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** Helper structure to describe a light source.
+ *
+ *  Assimp supports multiple sorts of light sources, including
+ *  directional, point and spot lights. All of them are defined with just
+ *  a single structure and distinguished by their parameters.
+ *  Note - some file formats (such as 3DS, ASE) export a "target point" -
+ *  the point a spot light is looking at (it can even be animated). Assimp
+ *  writes the target point as a subnode of a spotlights's main node,
+ *  called "<spotName>.Target". However, this is just additional information
+ *  then, the transformation tracks of the main node make the
+ *  spot light already point in the right direction.
+*/
+struct aiLight
+{
+    /** The name of the light source.
+     *
+     *  There must be a node in the scenegraph with the same name.
+     *  This node specifies the position of the light in the scene
+     *  hierarchy and can be animated.
+     */
+    C_STRUCT aiString mName;
+
+    /** The type of the light source.
+     *
+     * aiLightSource_UNDEFINED is not a valid value for this member.
+     */
+    C_ENUM aiLightSourceType mType;
+
+    /** Position of the light source in space. Relative to the
+     *  transformation of the node corresponding to the light.
+     *
+     *  The position is undefined for directional lights.
+     */
+    C_STRUCT aiVector3D mPosition;
+
+    /** Direction of the light source in space. Relative to the
+     *  transformation of the node corresponding to the light.
+     *
+     *  The direction is undefined for point lights. The vector
+     *  may be normalized, but it needn't.
+     */
+    C_STRUCT aiVector3D mDirection;
+
+    /** Up direction of the light source in space. Relative to the
+     *  transformation of the node corresponding to the light.
+     *
+     *  The direction is undefined for point lights. The vector
+     *  may be normalized, but it needn't.
+     */
+    C_STRUCT aiVector3D mUp;
+
+    /** Constant light attenuation factor.
+     *
+     *  The intensity of the light source at a given distance 'd' from
+     *  the light's position is
+     *  @code
+     *  Atten = 1/( att0 + att1 * d + att2 * d*d)
+     *  @endcode
+     *  This member corresponds to the att0 variable in the equation.
+     *  Naturally undefined for directional lights.
+     */
+    float mAttenuationConstant;
+
+    /** Linear light attenuation factor.
+     *
+     *  The intensity of the light source at a given distance 'd' from
+     *  the light's position is
+     *  @code
+     *  Atten = 1/( att0 + att1 * d + att2 * d*d)
+     *  @endcode
+     *  This member corresponds to the att1 variable in the equation.
+     *  Naturally undefined for directional lights.
+     */
+    float mAttenuationLinear;
+
+    /** Quadratic light attenuation factor.
+     *
+     *  The intensity of the light source at a given distance 'd' from
+     *  the light's position is
+     *  @code
+     *  Atten = 1/( att0 + att1 * d + att2 * d*d)
+     *  @endcode
+     *  This member corresponds to the att2 variable in the equation.
+     *  Naturally undefined for directional lights.
+     */
+    float mAttenuationQuadratic;
+
+    /** Diffuse color of the light source
+     *
+     *  The diffuse light color is multiplied with the diffuse
+     *  material color to obtain the final color that contributes
+     *  to the diffuse shading term.
+     */
+    C_STRUCT aiColor3D mColorDiffuse;
+
+    /** Specular color of the light source
+     *
+     *  The specular light color is multiplied with the specular
+     *  material color to obtain the final color that contributes
+     *  to the specular shading term.
+     */
+    C_STRUCT aiColor3D mColorSpecular;
+
+    /** Ambient color of the light source
+     *
+     *  The ambient light color is multiplied with the ambient
+     *  material color to obtain the final color that contributes
+     *  to the ambient shading term. Most renderers will ignore
+     *  this value it, is just a remaining of the fixed-function pipeline
+     *  that is still supported by quite many file formats.
+     */
+    C_STRUCT aiColor3D mColorAmbient;
+
+    /** Inner angle of a spot light's light cone.
+     *
+     *  The spot light has maximum influence on objects inside this
+     *  angle. The angle is given in radians. It is 2PI for point
+     *  lights and undefined for directional lights.
+     */
+    float mAngleInnerCone;
+
+    /** Outer angle of a spot light's light cone.
+     *
+     *  The spot light does not affect objects outside this angle.
+     *  The angle is given in radians. It is 2PI for point lights and
+     *  undefined for directional lights. The outer angle must be
+     *  greater than or equal to the inner angle.
+     *  It is assumed that the application uses a smooth
+     *  interpolation between the inner and the outer cone of the
+     *  spot light.
+     */
+    float mAngleOuterCone;
+
+    /** Size of area light source. */
+    C_STRUCT aiVector2D mSize;
+
+#ifdef __cplusplus
+
+    aiLight() AI_NO_EXCEPT
+        :   mType                 (aiLightSource_UNDEFINED)
+        ,   mAttenuationConstant  (0.f)
+        ,   mAttenuationLinear    (1.f)
+        ,   mAttenuationQuadratic (0.f)
+        ,   mAngleInnerCone       ((float)AI_MATH_TWO_PI)
+        ,   mAngleOuterCone       ((float)AI_MATH_TWO_PI)
+        ,   mSize                 (0.f, 0.f)
+    {
+    }
+
+#endif
+};
+
+#ifdef __cplusplus
+}
+#endif 
+
+
+#endif // !! AI_LIGHT_H_INC

dependencies/assimp/include/assimp/material.inl

@@ -0,0 +1,390 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file material.inl
+ *  @brief Defines the C++ getters for the material system
+ */
+
+#pragma once
+#ifndef AI_MATERIAL_INL_INC
+#define AI_MATERIAL_INL_INC
+
+// ---------------------------------------------------------------------------
+inline aiPropertyTypeInfo ai_real_to_property_type_info(float)
+{
+	return aiPTI_Float;
+}
+
+inline aiPropertyTypeInfo ai_real_to_property_type_info(double)
+{
+	return aiPTI_Double;
+}
+// ---------------------------------------------------------------------------
+
+//! @cond never
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::GetTexture( aiTextureType type,
+   unsigned int  index,
+   C_STRUCT aiString* path,
+   aiTextureMapping* mapping    /*= NULL*/,
+   unsigned int* uvindex        /*= NULL*/,
+   ai_real* blend               /*= NULL*/,
+   aiTextureOp* op              /*= NULL*/,
+   aiTextureMapMode* mapmode    /*= NULL*/) const
+{
+    return ::aiGetMaterialTexture(this,type,index,path,mapping,uvindex,blend,op,mapmode);
+}
+
+// ---------------------------------------------------------------------------
+inline unsigned int aiMaterial::GetTextureCount(aiTextureType type) const
+{
+    return ::aiGetMaterialTextureCount(this,type);
+}
+
+// ---------------------------------------------------------------------------
+template <typename Type>
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx, Type* pOut,
+    unsigned int* pMax) const
+{
+    unsigned int iNum = pMax ? *pMax : 1;
+
+    const aiMaterialProperty* prop;
+    const aiReturn ret = ::aiGetMaterialProperty(this,pKey,type,idx,
+        (const aiMaterialProperty**)&prop);
+    if ( AI_SUCCESS == ret )    {
+
+        if (prop->mDataLength < sizeof(Type)*iNum) {
+            return AI_FAILURE;
+        }
+
+        if (prop->mType != aiPTI_Buffer) {
+            return AI_FAILURE;
+        }
+
+        iNum = std::min((size_t)iNum,prop->mDataLength / sizeof(Type));
+        ::memcpy(pOut,prop->mData,iNum * sizeof(Type));
+        if (pMax) {
+            *pMax = iNum;
+        }
+    }
+    return ret;
+}
+
+// ---------------------------------------------------------------------------
+template <typename Type>
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,Type& pOut) const
+{
+    const aiMaterialProperty* prop;
+    const aiReturn ret = ::aiGetMaterialProperty(this,pKey,type,idx,
+        (const aiMaterialProperty**)&prop);
+    if ( AI_SUCCESS == ret ) {
+
+        if (prop->mDataLength < sizeof(Type)) {
+            return AI_FAILURE;
+        }
+
+        if (prop->mType != aiPTI_Buffer) {
+            return AI_FAILURE;
+        }
+
+        ::memcpy( &pOut, prop->mData, sizeof( Type ) );
+    }
+    return ret;
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,ai_real* pOut,
+    unsigned int* pMax) const
+{
+    return ::aiGetMaterialFloatArray(this,pKey,type,idx,pOut,pMax);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,int* pOut,
+    unsigned int* pMax) const
+{
+    return ::aiGetMaterialIntegerArray(this,pKey,type,idx,pOut,pMax);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,ai_real& pOut) const
+{
+    return aiGetMaterialFloat(this,pKey,type,idx,&pOut);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,int& pOut) const
+{
+    return aiGetMaterialInteger(this,pKey,type,idx,&pOut);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,aiColor4D& pOut) const
+{
+    return aiGetMaterialColor(this,pKey,type,idx,&pOut);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,aiColor3D& pOut) const
+{
+    aiColor4D c;
+    const aiReturn ret = aiGetMaterialColor(this,pKey,type,idx,&c);
+    pOut = aiColor3D(c.r,c.g,c.b);
+    return ret;
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,aiString& pOut) const
+{
+    return aiGetMaterialString(this,pKey,type,idx,&pOut);
+}
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::Get(const char* pKey,unsigned int type,
+    unsigned int idx,aiUVTransform& pOut) const
+{
+    return aiGetMaterialUVTransform(this,pKey,type,idx,&pOut);
+}
+
+
+// ---------------------------------------------------------------------------
+template<class TYPE>
+aiReturn aiMaterial::AddProperty (const TYPE* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(TYPE),
+        pKey,type,index,aiPTI_Buffer);
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const float* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(float),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const double* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(double),
+        pKey,type,index,aiPTI_Double);
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const aiUVTransform* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiUVTransform),
+        pKey,type,index,ai_real_to_property_type_info(pInput->mRotation));
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const aiColor4D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiColor4D),
+        pKey,type,index,ai_real_to_property_type_info(pInput->a));
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const aiColor3D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiColor3D),
+        pKey,type,index,ai_real_to_property_type_info(pInput->b));
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const aiVector3D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiVector3D),
+        pKey,type,index,ai_real_to_property_type_info(pInput->x));
+}
+
+// ---------------------------------------------------------------------------
+inline aiReturn aiMaterial::AddProperty(const int* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(int),
+        pKey,type,index,aiPTI_Integer);
+}
+
+
+// ---------------------------------------------------------------------------
+// The template specializations below are for backwards compatibility.
+// The recommended way to add material properties is using the non-template
+// overloads.
+// ---------------------------------------------------------------------------
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<float>(const float* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(float),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<double>(const double* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(double),
+        pKey,type,index,aiPTI_Double);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<aiUVTransform>(const aiUVTransform* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiUVTransform),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<aiColor4D>(const aiColor4D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiColor4D),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<aiColor3D>(const aiColor3D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiColor3D),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<aiVector3D>(const aiVector3D* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(aiVector3D),
+        pKey,type,index,aiPTI_Float);
+}
+
+// ---------------------------------------------------------------------------
+template<>
+inline aiReturn aiMaterial::AddProperty<int>(const int* pInput,
+    const unsigned int pNumValues,
+    const char* pKey,
+    unsigned int type,
+    unsigned int index)
+{
+    return AddBinaryProperty((const void*)pInput,
+        pNumValues * sizeof(int),
+        pKey,type,index,aiPTI_Integer);
+}
+
+//! @endcond
+
+#endif //! AI_MATERIAL_INL_INC

dependencies/assimp/include/assimp/matrix3x3.h

@@ -0,0 +1,183 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file matrix3x3.h
+ *  @brief Definition of a 3x3 matrix, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_MATRIX3X3_H_INC
+#define AI_MATRIX3X3_H_INC
+
+#include "defs.h"
+
+#ifdef __cplusplus
+
+template <typename T> class aiMatrix4x4t;
+template <typename T> class aiVector2t;
+
+// ---------------------------------------------------------------------------
+/** @brief Represents a row-major 3x3 matrix
+ *
+ *  There's much confusion about matrix layouts (column vs. row order).
+ *  This is *always* a row-major matrix. Not even with the
+ *  #aiProcess_ConvertToLeftHanded flag, which absolutely does not affect
+ *  matrix order - it just affects the handedness of the coordinate system
+ *  defined thereby.
+ */
+template <typename TReal>
+class aiMatrix3x3t
+{
+public:
+
+    aiMatrix3x3t() AI_NO_EXCEPT :
+        a1(static_cast<TReal>(1.0f)), a2(), a3(),
+        b1(), b2(static_cast<TReal>(1.0f)), b3(),
+        c1(), c2(), c3(static_cast<TReal>(1.0f)) {}
+
+    aiMatrix3x3t (  TReal _a1, TReal _a2, TReal _a3,
+                    TReal _b1, TReal _b2, TReal _b3,
+                    TReal _c1, TReal _c2, TReal _c3) :
+        a1(_a1), a2(_a2), a3(_a3),
+        b1(_b1), b2(_b2), b3(_b3),
+        c1(_c1), c2(_c2), c3(_c3)
+    {}
+
+public:
+
+    // matrix multiplication.
+    aiMatrix3x3t& operator *= (const aiMatrix3x3t& m);
+    aiMatrix3x3t  operator  * (const aiMatrix3x3t& m) const;
+
+    // array access operators
+    TReal* operator[]       (unsigned int p_iIndex);
+    const TReal* operator[] (unsigned int p_iIndex) const;
+
+    // comparison operators
+    bool operator== (const aiMatrix4x4t<TReal>& m) const;
+    bool operator!= (const aiMatrix4x4t<TReal>& m) const;
+
+    bool Equal(const aiMatrix4x4t<TReal>& m, TReal epsilon = 1e-6) const;
+
+    template <typename TOther>
+    operator aiMatrix3x3t<TOther> () const;
+
+public:
+
+    // -------------------------------------------------------------------
+    /** @brief Construction from a 4x4 matrix. The remaining parts
+     *  of the matrix are ignored.
+     */
+    explicit aiMatrix3x3t( const aiMatrix4x4t<TReal>& pMatrix);
+
+    // -------------------------------------------------------------------
+    /** @brief Transpose the matrix
+     */
+    aiMatrix3x3t& Transpose();
+
+    // -------------------------------------------------------------------
+    /** @brief Invert the matrix.
+     *  If the matrix is not invertible all elements are set to qnan.
+     *  Beware, use (f != f) to check whether a TReal f is qnan.
+     */
+    aiMatrix3x3t& Inverse();
+    TReal Determinant() const;
+
+public:
+    // -------------------------------------------------------------------
+    /** @brief Returns a rotation matrix for a rotation around z
+     *  @param a Rotation angle, in radians
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix3x3t& RotationZ(TReal a, aiMatrix3x3t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a rotation matrix for a rotation around
+     *    an arbitrary axis.
+     *
+     *  @param a Rotation angle, in radians
+     *  @param axis Axis to rotate around
+     *  @param out To be filled
+     */
+    static aiMatrix3x3t& Rotation( TReal a,
+        const aiVector3t<TReal>& axis, aiMatrix3x3t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a translation matrix
+     *  @param v Translation vector
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix3x3t& Translation( const aiVector2t<TReal>& v, aiMatrix3x3t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief A function for creating a rotation matrix that rotates a
+     *  vector called "from" into another vector called "to".
+     * Input : from[3], to[3] which both must be *normalized* non-zero vectors
+     * Output: mtx[3][3] -- a 3x3 matrix in column-major form
+     * Authors: Tomas Möller, John Hughes
+     *          "Efficiently Building a Matrix to Rotate One Vector to Another"
+     *          Journal of Graphics Tools, 4(4):1-4, 1999
+     */
+    static aiMatrix3x3t& FromToMatrix(const aiVector3t<TReal>& from,
+        const aiVector3t<TReal>& to, aiMatrix3x3t& out);
+
+public:
+    TReal a1, a2, a3;
+    TReal b1, b2, b3;
+    TReal c1, c2, c3;
+};
+
+typedef aiMatrix3x3t<ai_real> aiMatrix3x3;
+
+#else
+
+struct aiMatrix3x3 {
+    ai_real a1, a2, a3;
+    ai_real b1, b2, b3;
+    ai_real c1, c2, c3;
+};
+
+#endif // __cplusplus
+
+#endif // AI_MATRIX3X3_H_INC

dependencies/assimp/include/assimp/matrix3x3.inl

@@ -0,0 +1,357 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file matrix3x3.inl
+ *  @brief Inline implementation of the 3x3 matrix operators
+ */
+#pragma once
+#ifndef AI_MATRIX3X3_INL_INC
+#define AI_MATRIX3X3_INL_INC
+
+#ifdef __cplusplus
+#include "matrix3x3.h"
+
+#include "matrix4x4.h"
+#include <algorithm>
+#include <cmath>
+#include <limits>
+
+// ------------------------------------------------------------------------------------------------
+// Construction from a 4x4 matrix. The remaining parts of the matrix are ignored.
+template <typename TReal>
+inline aiMatrix3x3t<TReal>::aiMatrix3x3t( const aiMatrix4x4t<TReal>& pMatrix)
+{
+    a1 = pMatrix.a1; a2 = pMatrix.a2; a3 = pMatrix.a3;
+    b1 = pMatrix.b1; b2 = pMatrix.b2; b3 = pMatrix.b3;
+    c1 = pMatrix.c1; c2 = pMatrix.c2; c3 = pMatrix.c3;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::operator *= (const aiMatrix3x3t<TReal>& m)
+{
+    *this = aiMatrix3x3t<TReal>(m.a1 * a1 + m.b1 * a2 + m.c1 * a3,
+        m.a2 * a1 + m.b2 * a2 + m.c2 * a3,
+        m.a3 * a1 + m.b3 * a2 + m.c3 * a3,
+        m.a1 * b1 + m.b1 * b2 + m.c1 * b3,
+        m.a2 * b1 + m.b2 * b2 + m.c2 * b3,
+        m.a3 * b1 + m.b3 * b2 + m.c3 * b3,
+        m.a1 * c1 + m.b1 * c2 + m.c1 * c3,
+        m.a2 * c1 + m.b2 * c2 + m.c2 * c3,
+        m.a3 * c1 + m.b3 * c2 + m.c3 * c3);
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+template <typename TOther>
+aiMatrix3x3t<TReal>::operator aiMatrix3x3t<TOther> () const
+{
+    return aiMatrix3x3t<TOther>(static_cast<TOther>(a1),static_cast<TOther>(a2),static_cast<TOther>(a3),
+        static_cast<TOther>(b1),static_cast<TOther>(b2),static_cast<TOther>(b3),
+        static_cast<TOther>(c1),static_cast<TOther>(c2),static_cast<TOther>(c3));
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal> aiMatrix3x3t<TReal>::operator* (const aiMatrix3x3t<TReal>& m) const
+{
+    aiMatrix3x3t<TReal> temp( *this);
+    temp *= m;
+    return temp;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline TReal* aiMatrix3x3t<TReal>::operator[] (unsigned int p_iIndex) {
+    switch ( p_iIndex ) {
+        case 0:
+            return &a1;
+        case 1:
+            return &b1;
+        case 2:
+            return &c1;
+        default:
+            break;
+    }
+    return &a1;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline const TReal* aiMatrix3x3t<TReal>::operator[] (unsigned int p_iIndex) const {
+    switch ( p_iIndex ) {
+        case 0:
+            return &a1;
+        case 1:
+            return &b1;
+        case 2:
+            return &c1;
+        default:
+            break;
+    }
+    return &a1;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiMatrix3x3t<TReal>::operator== (const aiMatrix4x4t<TReal>& m) const
+{
+    return a1 == m.a1 && a2 == m.a2 && a3 == m.a3 &&
+           b1 == m.b1 && b2 == m.b2 && b3 == m.b3 &&
+           c1 == m.c1 && c2 == m.c2 && c3 == m.c3;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiMatrix3x3t<TReal>::operator!= (const aiMatrix4x4t<TReal>& m) const
+{
+    return !(*this == m);
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline bool aiMatrix3x3t<TReal>::Equal(const aiMatrix4x4t<TReal>& m, TReal epsilon) const {
+    return
+        std::abs(a1 - m.a1) <= epsilon &&
+        std::abs(a2 - m.a2) <= epsilon &&
+        std::abs(a3 - m.a3) <= epsilon &&
+        std::abs(b1 - m.b1) <= epsilon &&
+        std::abs(b2 - m.b2) <= epsilon &&
+        std::abs(b3 - m.b3) <= epsilon &&
+        std::abs(c1 - m.c1) <= epsilon &&
+        std::abs(c2 - m.c2) <= epsilon &&
+        std::abs(c3 - m.c3) <= epsilon;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::Transpose()
+{
+    // (TReal&) don't remove, GCC complains cause of packed fields
+    std::swap( (TReal&)a2, (TReal&)b1);
+    std::swap( (TReal&)a3, (TReal&)c1);
+    std::swap( (TReal&)b3, (TReal&)c2);
+    return *this;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline TReal aiMatrix3x3t<TReal>::Determinant() const
+{
+    return a1*b2*c3 - a1*b3*c2 + a2*b3*c1 - a2*b1*c3 + a3*b1*c2 - a3*b2*c1;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::Inverse()
+{
+    // Compute the reciprocal determinant
+    TReal det = Determinant();
+    if(det == static_cast<TReal>(0.0))
+    {
+        // Matrix not invertible. Setting all elements to nan is not really
+        // correct in a mathematical sense; but at least qnans are easy to
+        // spot. XXX we might throw an exception instead, which would
+        // be even much better to spot :/.
+        const TReal nan = std::numeric_limits<TReal>::quiet_NaN();
+        *this = aiMatrix3x3t<TReal>( nan,nan,nan,nan,nan,nan,nan,nan,nan);
+
+        return *this;
+    }
+
+    TReal invdet = static_cast<TReal>(1.0) / det;
+
+    aiMatrix3x3t<TReal> res;
+    res.a1 = invdet  * (b2 * c3 - b3 * c2);
+    res.a2 = -invdet * (a2 * c3 - a3 * c2);
+    res.a3 = invdet  * (a2 * b3 - a3 * b2);
+    res.b1 = -invdet * (b1 * c3 - b3 * c1);
+    res.b2 = invdet  * (a1 * c3 - a3 * c1);
+    res.b3 = -invdet * (a1 * b3 - a3 * b1);
+    res.c1 = invdet  * (b1 * c2 - b2 * c1);
+    res.c2 = -invdet * (a1 * c2 - a2 * c1);
+    res.c3 = invdet  * (a1 * b2 - a2 * b1);
+    *this = res;
+
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::RotationZ(TReal a, aiMatrix3x3t<TReal>& out)
+{
+    out.a1 = out.b2 = std::cos(a);
+    out.b1 = std::sin(a);
+    out.a2 = - out.b1;
+
+    out.a3 = out.b3 = out.c1 = out.c2 = 0.f;
+    out.c3 = 1.f;
+
+    return out;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns a rotation matrix for a rotation around an arbitrary axis.
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::Rotation( TReal a, const aiVector3t<TReal>& axis, aiMatrix3x3t<TReal>& out)
+{
+  TReal c = std::cos( a), s = std::sin( a), t = 1 - c;
+  TReal x = axis.x, y = axis.y, z = axis.z;
+
+  // Many thanks to MathWorld and Wikipedia
+  out.a1 = t*x*x + c;   out.a2 = t*x*y - s*z; out.a3 = t*x*z + s*y;
+  out.b1 = t*x*y + s*z; out.b2 = t*y*y + c;   out.b3 = t*y*z - s*x;
+  out.c1 = t*x*z - s*y; out.c2 = t*y*z + s*x; out.c3 = t*z*z + c;
+
+  return out;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::Translation( const aiVector2t<TReal>& v, aiMatrix3x3t<TReal>& out)
+{
+    out = aiMatrix3x3t<TReal>();
+    out.a3 = v.x;
+    out.b3 = v.y;
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+/** A function for creating a rotation matrix that rotates a vector called
+ * "from" into another vector called "to".
+ * Input : from[3], to[3] which both must be *normalized* non-zero vectors
+ * Output: mtx[3][3] -- a 3x3 matrix in colum-major form
+ * Authors: Tomas Möller, John Hughes
+ *          "Efficiently Building a Matrix to Rotate One Vector to Another"
+ *          Journal of Graphics Tools, 4(4):1-4, 1999
+ */
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::FromToMatrix(const aiVector3t<TReal>& from,
+    const aiVector3t<TReal>& to, aiMatrix3x3t<TReal>& mtx)
+{
+    const TReal e = from * to;
+    const TReal f = (e < 0)? -e:e;
+
+    if (f > static_cast<TReal>(1.0) - static_cast<TReal>(0.00001))     /* "from" and "to"-vector almost parallel */
+    {
+        aiVector3D u,v;     /* temporary storage vectors */
+        aiVector3D x;       /* vector most nearly orthogonal to "from" */
+
+        x.x = (from.x > 0.0)? from.x : -from.x;
+        x.y = (from.y > 0.0)? from.y : -from.y;
+        x.z = (from.z > 0.0)? from.z : -from.z;
+
+        if (x.x < x.y)
+        {
+            if (x.x < x.z)
+            {
+                x.x = static_cast<TReal>(1.0);
+                x.y = x.z = static_cast<TReal>(0.0);
+            }
+            else
+            {
+                x.z = static_cast<TReal>(1.0);
+                x.x = x.y = static_cast<TReal>(0.0);
+            }
+        }
+        else
+        {
+            if (x.y < x.z)
+            {
+                x.y = static_cast<TReal>(1.0);
+                x.x = x.z = static_cast<TReal>(0.0);
+            }
+            else
+            {
+                x.z = static_cast<TReal>(1.0);
+                x.x = x.y = static_cast<TReal>(0.0);
+            }
+        }
+
+        u.x = x.x - from.x; u.y = x.y - from.y; u.z = x.z - from.z;
+        v.x = x.x - to.x;   v.y = x.y - to.y;   v.z = x.z - to.z;
+
+        const TReal c1_ = static_cast<TReal>(2.0) / (u * u);
+        const TReal c2_ = static_cast<TReal>(2.0) / (v * v);
+        const TReal c3_ = c1_ * c2_  * (u * v);
+
+        for (unsigned int i = 0; i < 3; i++)
+        {
+            for (unsigned int j = 0; j < 3; j++)
+            {
+                mtx[i][j] =  - c1_ * u[i] * u[j] - c2_ * v[i] * v[j]
+                    + c3_ * v[i] * u[j];
+            }
+            mtx[i][i] += static_cast<TReal>(1.0);
+        }
+    }
+    else  /* the most common case, unless "from"="to", or "from"=-"to" */
+    {
+        const aiVector3D v = from ^ to;
+        /* ... use this hand optimized version (9 mults less) */
+        const TReal h = static_cast<TReal>(1.0)/(static_cast<TReal>(1.0) + e);      /* optimization by Gottfried Chen */
+        const TReal hvx = h * v.x;
+        const TReal hvz = h * v.z;
+        const TReal hvxy = hvx * v.y;
+        const TReal hvxz = hvx * v.z;
+        const TReal hvyz = hvz * v.y;
+        mtx[0][0] = e + hvx * v.x;
+        mtx[0][1] = hvxy - v.z;
+        mtx[0][2] = hvxz + v.y;
+
+        mtx[1][0] = hvxy + v.z;
+        mtx[1][1] = e + h * v.y * v.y;
+        mtx[1][2] = hvyz - v.x;
+
+        mtx[2][0] = hvxz - v.y;
+        mtx[2][1] = hvyz + v.x;
+        mtx[2][2] = e + hvz * v.z;
+    }
+    return mtx;
+}
+
+
+#endif // __cplusplus
+#endif // AI_MATRIX3X3_INL_INC

dependencies/assimp/include/assimp/matrix4x4.h

@@ -0,0 +1,280 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file matrix4x4.h
+ *  @brief 4x4 matrix structure, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_MATRIX4X4_H_INC
+#define AI_MATRIX4X4_H_INC
+
+#include "vector3.h"
+#include "defs.h"
+
+#ifdef __cplusplus
+
+template<typename TReal> class aiMatrix3x3t;
+template<typename TReal> class aiQuaterniont;
+
+// ---------------------------------------------------------------------------
+/** @brief Represents a row-major 4x4 matrix, use this for homogeneous
+ *   coordinates.
+ *
+ *  There's much confusion about matrix layouts (column vs. row order).
+ *  This is *always* a row-major matrix. Not even with the
+ *  #aiProcess_ConvertToLeftHanded flag, which absolutely does not affect
+ *  matrix order - it just affects the handedness of the coordinate system
+ *  defined thereby.
+ */
+template<typename TReal>
+class aiMatrix4x4t
+{
+public:
+
+    /** set to identity */
+    aiMatrix4x4t() AI_NO_EXCEPT;
+
+    /** construction from single values */
+    aiMatrix4x4t (  TReal _a1, TReal _a2, TReal _a3, TReal _a4,
+                    TReal _b1, TReal _b2, TReal _b3, TReal _b4,
+                    TReal _c1, TReal _c2, TReal _c3, TReal _c4,
+                    TReal _d1, TReal _d2, TReal _d3, TReal _d4);
+
+
+    /** construction from 3x3 matrix, remaining elements are set to identity */
+    explicit aiMatrix4x4t( const aiMatrix3x3t<TReal>& m);
+
+    /** construction from position, rotation and scaling components
+     * @param scaling The scaling for the x,y,z axes
+     * @param rotation The rotation as a hamilton quaternion
+     * @param position The position for the x,y,z axes
+     */
+    aiMatrix4x4t(const aiVector3t<TReal>& scaling, const aiQuaterniont<TReal>& rotation,
+        const aiVector3t<TReal>& position);
+
+public:
+
+    // array access operators
+	/** @fn TReal* operator[] (unsigned int p_iIndex)
+	 *  @param [in] p_iIndex - index of the row.
+	 *  @return pointer to pointed row.
+	 */
+    TReal* operator[]       (unsigned int p_iIndex);
+
+	/** @fn const TReal* operator[] (unsigned int p_iIndex) const
+	 *  @overload TReal* operator[] (unsigned int p_iIndex)
+	 */
+    const TReal* operator[] (unsigned int p_iIndex) const;
+
+    // comparison operators
+    bool operator== (const aiMatrix4x4t& m) const;
+    bool operator!= (const aiMatrix4x4t& m) const;
+
+    bool Equal(const aiMatrix4x4t& m, TReal epsilon = 1e-6) const;
+
+    // matrix multiplication.
+    aiMatrix4x4t& operator *= (const aiMatrix4x4t& m);
+    aiMatrix4x4t  operator *  (const aiMatrix4x4t& m) const;
+    aiMatrix4x4t operator * (const TReal& aFloat) const;
+    aiMatrix4x4t operator + (const aiMatrix4x4t& aMatrix) const;
+
+    template <typename TOther>
+    operator aiMatrix4x4t<TOther> () const;
+
+public:
+
+    // -------------------------------------------------------------------
+    /** @brief Transpose the matrix */
+    aiMatrix4x4t& Transpose();
+
+    // -------------------------------------------------------------------
+    /** @brief Invert the matrix.
+     *  If the matrix is not invertible all elements are set to qnan.
+     *  Beware, use (f != f) to check whether a TReal f is qnan.
+     */
+    aiMatrix4x4t& Inverse();
+    TReal Determinant() const;
+
+
+    // -------------------------------------------------------------------
+    /** @brief Returns true of the matrix is the identity matrix.
+     *  The check is performed against a not so small epsilon.
+     */
+    inline bool IsIdentity() const;
+
+    // -------------------------------------------------------------------
+    /** @brief Decompose a trafo matrix into its original components
+     *  @param scaling Receives the output scaling for the x,y,z axes
+     *  @param rotation Receives the output rotation as a hamilton
+     *   quaternion
+     *  @param position Receives the output position for the x,y,z axes
+     */
+    void Decompose (aiVector3t<TReal>& scaling, aiQuaterniont<TReal>& rotation,
+        aiVector3t<TReal>& position) const;
+
+	// -------------------------------------------------------------------
+	/** @fn void Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotation, aiVector3t<TReal>& pPosition) const
+     *  @brief Decompose a trafo matrix into its original components.
+     * Thx to good FAQ at http://www.gamedev.ru/code/articles/faq_matrix_quat
+     *  @param [out] pScaling - Receives the output scaling for the x,y,z axes.
+     *  @param [out] pRotation - Receives the output rotation as a Euler angles.
+     *  @param [out] pPosition - Receives the output position for the x,y,z axes.
+     */
+    void Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotation, aiVector3t<TReal>& pPosition) const;
+
+	// -------------------------------------------------------------------
+	/** @fn void Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotationAxis, TReal& pRotationAngle, aiVector3t<TReal>& pPosition) const
+     *  @brief Decompose a trafo matrix into its original components
+	 * Thx to good FAQ at http://www.gamedev.ru/code/articles/faq_matrix_quat
+     *  @param [out] pScaling - Receives the output scaling for the x,y,z axes.
+     *  @param [out] pRotationAxis - Receives the output rotation axis.
+	 *  @param [out] pRotationAngle - Receives the output rotation angle for @ref pRotationAxis.
+     *  @param [out] pPosition - Receives the output position for the x,y,z axes.
+     */
+    void Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotationAxis, TReal& pRotationAngle, aiVector3t<TReal>& pPosition) const;
+
+    // -------------------------------------------------------------------
+    /** @brief Decompose a trafo matrix with no scaling into its
+     *    original components
+     *  @param rotation Receives the output rotation as a hamilton
+     *    quaternion
+     *  @param position Receives the output position for the x,y,z axes
+     */
+    void DecomposeNoScaling (aiQuaterniont<TReal>& rotation,
+        aiVector3t<TReal>& position) const;
+
+
+    // -------------------------------------------------------------------
+    /** @brief Creates a trafo matrix from a set of euler angles
+     *  @param x Rotation angle for the x-axis, in radians
+     *  @param y Rotation angle for the y-axis, in radians
+     *  @param z Rotation angle for the z-axis, in radians
+     */
+    aiMatrix4x4t& FromEulerAnglesXYZ(TReal x, TReal y, TReal z);
+    aiMatrix4x4t& FromEulerAnglesXYZ(const aiVector3t<TReal>& blubb);
+
+public:
+    // -------------------------------------------------------------------
+    /** @brief Returns a rotation matrix for a rotation around the x axis
+     *  @param a Rotation angle, in radians
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& RotationX(TReal a, aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a rotation matrix for a rotation around the y axis
+     *  @param a Rotation angle, in radians
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& RotationY(TReal a, aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a rotation matrix for a rotation around the z axis
+     *  @param a Rotation angle, in radians
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& RotationZ(TReal a, aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** Returns a rotation matrix for a rotation around an arbitrary axis.
+     *  @param a Rotation angle, in radians
+     *  @param axis Rotation axis, should be a normalized vector.
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& Rotation(TReal a, const aiVector3t<TReal>& axis,
+            aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a translation matrix
+     *  @param v Translation vector
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& Translation( const aiVector3t<TReal>& v, 
+            aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief Returns a scaling matrix
+     *  @param v Scaling vector
+     *  @param out Receives the output matrix
+     *  @return Reference to the output matrix
+     */
+    static aiMatrix4x4t& Scaling( const aiVector3t<TReal>& v, aiMatrix4x4t& out);
+
+    // -------------------------------------------------------------------
+    /** @brief A function for creating a rotation matrix that rotates a
+     *  vector called "from" into another vector called "to".
+     * Input : from[3], to[3] which both must be *normalized* non-zero vectors
+     * Output: mtx[3][3] -- a 3x3 matrix in column-major form
+     * Authors: Tomas Mueller, John Hughes
+     *          "Efficiently Building a Matrix to Rotate One Vector to Another"
+     *          Journal of Graphics Tools, 4(4):1-4, 1999
+     */
+    static aiMatrix4x4t& FromToMatrix(const aiVector3t<TReal>& from,
+            const aiVector3t<TReal>& to, aiMatrix4x4t& out);
+
+public:
+    TReal a1, a2, a3, a4;
+    TReal b1, b2, b3, b4;
+    TReal c1, c2, c3, c4;
+    TReal d1, d2, d3, d4;
+};
+
+typedef aiMatrix4x4t<ai_real> aiMatrix4x4;
+
+#else
+
+struct aiMatrix4x4 {
+    ai_real a1, a2, a3, a4;
+    ai_real b1, b2, b3, b4;
+    ai_real c1, c2, c3, c4;
+    ai_real d1, d2, d3, d4;
+};
+
+
+#endif // __cplusplus
+
+#endif // AI_MATRIX4X4_H_INC

dependencies/assimp/include/assimp/matrix4x4.inl

@@ -0,0 +1,685 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file matrix4x4.inl
+ *  @brief Inline implementation of the 4x4 matrix operators
+ */
+#pragma once
+#ifndef AI_MATRIX4X4_INL_INC
+#define AI_MATRIX4X4_INL_INC
+
+#ifdef __cplusplus
+
+#include "matrix4x4.h"
+#include "matrix3x3.h"
+#include "quaternion.h"
+#include "MathFunctions.h"
+
+#include <algorithm>
+#include <limits>
+#include <cmath>
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+aiMatrix4x4t<TReal>::aiMatrix4x4t() AI_NO_EXCEPT :
+    a1(1.0f), a2(), a3(), a4(),
+    b1(), b2(1.0f), b3(), b4(),
+    c1(), c2(), c3(1.0f), c4(),
+    d1(), d2(), d3(), d4(1.0f)
+{
+
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+aiMatrix4x4t<TReal>::aiMatrix4x4t (TReal _a1, TReal _a2, TReal _a3, TReal _a4,
+              TReal _b1, TReal _b2, TReal _b3, TReal _b4,
+              TReal _c1, TReal _c2, TReal _c3, TReal _c4,
+              TReal _d1, TReal _d2, TReal _d3, TReal _d4) :
+    a1(_a1), a2(_a2), a3(_a3), a4(_a4),
+    b1(_b1), b2(_b2), b3(_b3), b4(_b4),
+    c1(_c1), c2(_c2), c3(_c3), c4(_c4),
+    d1(_d1), d2(_d2), d3(_d3), d4(_d4)
+{
+
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+template <typename TOther>
+aiMatrix4x4t<TReal>::operator aiMatrix4x4t<TOther> () const
+{
+    return aiMatrix4x4t<TOther>(static_cast<TOther>(a1),static_cast<TOther>(a2),static_cast<TOther>(a3),static_cast<TOther>(a4),
+        static_cast<TOther>(b1),static_cast<TOther>(b2),static_cast<TOther>(b3),static_cast<TOther>(b4),
+        static_cast<TOther>(c1),static_cast<TOther>(c2),static_cast<TOther>(c3),static_cast<TOther>(c4),
+        static_cast<TOther>(d1),static_cast<TOther>(d2),static_cast<TOther>(d3),static_cast<TOther>(d4));
+}
+
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>::aiMatrix4x4t (const aiMatrix3x3t<TReal>& m)
+{
+    a1 = m.a1; a2 = m.a2; a3 = m.a3; a4 = static_cast<TReal>(0.0);
+    b1 = m.b1; b2 = m.b2; b3 = m.b3; b4 = static_cast<TReal>(0.0);
+    c1 = m.c1; c2 = m.c2; c3 = m.c3; c4 = static_cast<TReal>(0.0);
+    d1 = static_cast<TReal>(0.0); d2 = static_cast<TReal>(0.0); d3 = static_cast<TReal>(0.0); d4 = static_cast<TReal>(1.0);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>::aiMatrix4x4t (const aiVector3t<TReal>& scaling, const aiQuaterniont<TReal>& rotation, const aiVector3t<TReal>& position)
+{
+    // build a 3x3 rotation matrix
+    aiMatrix3x3t<TReal> m = rotation.GetMatrix();
+
+    a1 = m.a1 * scaling.x;
+    a2 = m.a2 * scaling.x;
+    a3 = m.a3 * scaling.x;
+    a4 = position.x;
+
+    b1 = m.b1 * scaling.y;
+    b2 = m.b2 * scaling.y;
+    b3 = m.b3 * scaling.y;
+    b4 = position.y;
+
+    c1 = m.c1 * scaling.z;
+    c2 = m.c2 * scaling.z;
+    c3 = m.c3 * scaling.z;
+    c4= position.z;
+
+    d1 = static_cast<TReal>(0.0);
+    d2 = static_cast<TReal>(0.0);
+    d3 = static_cast<TReal>(0.0);
+    d4 = static_cast<TReal>(1.0);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::operator *= (const aiMatrix4x4t<TReal>& m)
+{
+    *this = aiMatrix4x4t<TReal>(
+        m.a1 * a1 + m.b1 * a2 + m.c1 * a3 + m.d1 * a4,
+        m.a2 * a1 + m.b2 * a2 + m.c2 * a3 + m.d2 * a4,
+        m.a3 * a1 + m.b3 * a2 + m.c3 * a3 + m.d3 * a4,
+        m.a4 * a1 + m.b4 * a2 + m.c4 * a3 + m.d4 * a4,
+        m.a1 * b1 + m.b1 * b2 + m.c1 * b3 + m.d1 * b4,
+        m.a2 * b1 + m.b2 * b2 + m.c2 * b3 + m.d2 * b4,
+        m.a3 * b1 + m.b3 * b2 + m.c3 * b3 + m.d3 * b4,
+        m.a4 * b1 + m.b4 * b2 + m.c4 * b3 + m.d4 * b4,
+        m.a1 * c1 + m.b1 * c2 + m.c1 * c3 + m.d1 * c4,
+        m.a2 * c1 + m.b2 * c2 + m.c2 * c3 + m.d2 * c4,
+        m.a3 * c1 + m.b3 * c2 + m.c3 * c3 + m.d3 * c4,
+        m.a4 * c1 + m.b4 * c2 + m.c4 * c3 + m.d4 * c4,
+        m.a1 * d1 + m.b1 * d2 + m.c1 * d3 + m.d1 * d4,
+        m.a2 * d1 + m.b2 * d2 + m.c2 * d3 + m.d2 * d4,
+        m.a3 * d1 + m.b3 * d2 + m.c3 * d3 + m.d3 * d4,
+        m.a4 * d1 + m.b4 * d2 + m.c4 * d3 + m.d4 * d4);
+    return *this;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal> aiMatrix4x4t<TReal>::operator* (const TReal& aFloat) const
+{
+    aiMatrix4x4t<TReal> temp(
+        a1 * aFloat,
+        a2 * aFloat,
+        a3 * aFloat,
+        a4 * aFloat,
+        b1 * aFloat,
+        b2 * aFloat,
+        b3 * aFloat,
+        b4 * aFloat,
+        c1 * aFloat,
+        c2 * aFloat,
+        c3 * aFloat,
+        c4 * aFloat,
+        d1 * aFloat,
+        d2 * aFloat,
+        d3 * aFloat,
+        d4 * aFloat);
+    return temp;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal> aiMatrix4x4t<TReal>::operator+ (const aiMatrix4x4t<TReal>& m) const
+{
+    aiMatrix4x4t<TReal> temp(
+        m.a1 + a1,
+        m.a2 + a2,
+        m.a3 + a3,
+        m.a4 + a4,
+        m.b1 + b1,
+        m.b2 + b2,
+        m.b3 + b3,
+        m.b4 + b4,
+        m.c1 + c1,
+        m.c2 + c2,
+        m.c3 + c3,
+        m.c4 + c4,
+        m.d1 + d1,
+        m.d2 + d2,
+        m.d3 + d3,
+        m.d4 + d4);
+    return temp;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal> aiMatrix4x4t<TReal>::operator* (const aiMatrix4x4t<TReal>& m) const
+{
+    aiMatrix4x4t<TReal> temp( *this);
+    temp *= m;
+    return temp;
+}
+
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::Transpose()
+{
+    // (TReal&) don't remove, GCC complains cause of packed fields
+    std::swap( (TReal&)b1, (TReal&)a2);
+    std::swap( (TReal&)c1, (TReal&)a3);
+    std::swap( (TReal&)c2, (TReal&)b3);
+    std::swap( (TReal&)d1, (TReal&)a4);
+    std::swap( (TReal&)d2, (TReal&)b4);
+    std::swap( (TReal&)d3, (TReal&)c4);
+    return *this;
+}
+
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline TReal aiMatrix4x4t<TReal>::Determinant() const
+{
+    return a1*b2*c3*d4 - a1*b2*c4*d3 + a1*b3*c4*d2 - a1*b3*c2*d4
+        + a1*b4*c2*d3 - a1*b4*c3*d2 - a2*b3*c4*d1 + a2*b3*c1*d4
+        - a2*b4*c1*d3 + a2*b4*c3*d1 - a2*b1*c3*d4 + a2*b1*c4*d3
+        + a3*b4*c1*d2 - a3*b4*c2*d1 + a3*b1*c2*d4 - a3*b1*c4*d2
+        + a3*b2*c4*d1 - a3*b2*c1*d4 - a4*b1*c2*d3 + a4*b1*c3*d2
+        - a4*b2*c3*d1 + a4*b2*c1*d3 - a4*b3*c1*d2 + a4*b3*c2*d1;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::Inverse()
+{
+    // Compute the reciprocal determinant
+    const TReal det = Determinant();
+    if(det == static_cast<TReal>(0.0))
+    {
+        // Matrix not invertible. Setting all elements to nan is not really
+        // correct in a mathematical sense but it is easy to debug for the
+        // programmer.
+        const TReal nan = std::numeric_limits<TReal>::quiet_NaN();
+        *this = aiMatrix4x4t<TReal>(
+            nan,nan,nan,nan,
+            nan,nan,nan,nan,
+            nan,nan,nan,nan,
+            nan,nan,nan,nan);
+
+        return *this;
+    }
+
+    const TReal invdet = static_cast<TReal>(1.0) / det;
+
+    aiMatrix4x4t<TReal> res;
+    res.a1 = invdet  * (b2 * (c3 * d4 - c4 * d3) + b3 * (c4 * d2 - c2 * d4) + b4 * (c2 * d3 - c3 * d2));
+    res.a2 = -invdet * (a2 * (c3 * d4 - c4 * d3) + a3 * (c4 * d2 - c2 * d4) + a4 * (c2 * d3 - c3 * d2));
+    res.a3 = invdet  * (a2 * (b3 * d4 - b4 * d3) + a3 * (b4 * d2 - b2 * d4) + a4 * (b2 * d3 - b3 * d2));
+    res.a4 = -invdet * (a2 * (b3 * c4 - b4 * c3) + a3 * (b4 * c2 - b2 * c4) + a4 * (b2 * c3 - b3 * c2));
+    res.b1 = -invdet * (b1 * (c3 * d4 - c4 * d3) + b3 * (c4 * d1 - c1 * d4) + b4 * (c1 * d3 - c3 * d1));
+    res.b2 = invdet  * (a1 * (c3 * d4 - c4 * d3) + a3 * (c4 * d1 - c1 * d4) + a4 * (c1 * d3 - c3 * d1));
+    res.b3 = -invdet * (a1 * (b3 * d4 - b4 * d3) + a3 * (b4 * d1 - b1 * d4) + a4 * (b1 * d3 - b3 * d1));
+    res.b4 = invdet  * (a1 * (b3 * c4 - b4 * c3) + a3 * (b4 * c1 - b1 * c4) + a4 * (b1 * c3 - b3 * c1));
+    res.c1 = invdet  * (b1 * (c2 * d4 - c4 * d2) + b2 * (c4 * d1 - c1 * d4) + b4 * (c1 * d2 - c2 * d1));
+    res.c2 = -invdet * (a1 * (c2 * d4 - c4 * d2) + a2 * (c4 * d1 - c1 * d4) + a4 * (c1 * d2 - c2 * d1));
+    res.c3 = invdet  * (a1 * (b2 * d4 - b4 * d2) + a2 * (b4 * d1 - b1 * d4) + a4 * (b1 * d2 - b2 * d1));
+    res.c4 = -invdet * (a1 * (b2 * c4 - b4 * c2) + a2 * (b4 * c1 - b1 * c4) + a4 * (b1 * c2 - b2 * c1));
+    res.d1 = -invdet * (b1 * (c2 * d3 - c3 * d2) + b2 * (c3 * d1 - c1 * d3) + b3 * (c1 * d2 - c2 * d1));
+    res.d2 = invdet  * (a1 * (c2 * d3 - c3 * d2) + a2 * (c3 * d1 - c1 * d3) + a3 * (c1 * d2 - c2 * d1));
+    res.d3 = -invdet * (a1 * (b2 * d3 - b3 * d2) + a2 * (b3 * d1 - b1 * d3) + a3 * (b1 * d2 - b2 * d1));
+    res.d4 = invdet  * (a1 * (b2 * c3 - b3 * c2) + a2 * (b3 * c1 - b1 * c3) + a3 * (b1 * c2 - b2 * c1));
+    *this = res;
+
+    return *this;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline TReal* aiMatrix4x4t<TReal>::operator[](unsigned int p_iIndex) {
+    if (p_iIndex > 3) {
+        return NULL;
+    }
+    switch ( p_iIndex ) {
+        case 0:
+            return &a1;
+        case 1:
+            return &b1;
+        case 2:
+            return &c1;
+        case 3:
+            return &d1;
+        default:
+            break;
+    }
+    return &a1;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline const TReal* aiMatrix4x4t<TReal>::operator[](unsigned int p_iIndex) const {
+    if (p_iIndex > 3) {
+        return NULL;
+    }
+
+    switch ( p_iIndex ) {
+        case 0:
+            return &a1;
+        case 1:
+            return &b1;
+        case 2:
+            return &c1;
+        case 3:
+            return &d1;
+        default:
+            break;
+    }
+    return &a1;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiMatrix4x4t<TReal>::operator== (const aiMatrix4x4t<TReal>& m) const
+{
+    return (a1 == m.a1 && a2 == m.a2 && a3 == m.a3 && a4 == m.a4 &&
+            b1 == m.b1 && b2 == m.b2 && b3 == m.b3 && b4 == m.b4 &&
+            c1 == m.c1 && c2 == m.c2 && c3 == m.c3 && c4 == m.c4 &&
+            d1 == m.d1 && d2 == m.d2 && d3 == m.d3 && d4 == m.d4);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiMatrix4x4t<TReal>::operator!= (const aiMatrix4x4t<TReal>& m) const
+{
+    return !(*this == m);
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline bool aiMatrix4x4t<TReal>::Equal(const aiMatrix4x4t<TReal>& m, TReal epsilon) const {
+    return
+        std::abs(a1 - m.a1) <= epsilon &&
+        std::abs(a2 - m.a2) <= epsilon &&
+        std::abs(a3 - m.a3) <= epsilon &&
+        std::abs(a4 - m.a4) <= epsilon &&
+        std::abs(b1 - m.b1) <= epsilon &&
+        std::abs(b2 - m.b2) <= epsilon &&
+        std::abs(b3 - m.b3) <= epsilon &&
+        std::abs(b4 - m.b4) <= epsilon &&
+        std::abs(c1 - m.c1) <= epsilon &&
+        std::abs(c2 - m.c2) <= epsilon &&
+        std::abs(c3 - m.c3) <= epsilon &&
+        std::abs(c4 - m.c4) <= epsilon &&
+        std::abs(d1 - m.d1) <= epsilon &&
+        std::abs(d2 - m.d2) <= epsilon &&
+        std::abs(d3 - m.d3) <= epsilon &&
+        std::abs(d4 - m.d4) <= epsilon;
+}
+
+// ----------------------------------------------------------------------------------------
+
+#define ASSIMP_MATRIX4_4_DECOMPOSE_PART		\
+	const aiMatrix4x4t<TReal>& _this = *this;/* Create alias for conveniance. */ \
+	\
+	/* extract translation */ \
+	pPosition.x = _this[0][3]; \
+	pPosition.y = _this[1][3]; \
+	pPosition.z = _this[2][3]; \
+	\
+	/* extract the columns of the matrix. */ \
+	aiVector3t<TReal> vCols[3] = { \
+		aiVector3t<TReal>(_this[0][0],_this[1][0],_this[2][0]), \
+		aiVector3t<TReal>(_this[0][1],_this[1][1],_this[2][1]), \
+		aiVector3t<TReal>(_this[0][2],_this[1][2],_this[2][2]) \
+	}; \
+	\
+	/* extract the scaling factors */ \
+	pScaling.x = vCols[0].Length(); \
+	pScaling.y = vCols[1].Length(); \
+	pScaling.z = vCols[2].Length(); \
+	\
+	/* and the sign of the scaling */ \
+	if (Determinant() < 0) pScaling = -pScaling; \
+	\
+	/* and remove all scaling from the matrix */ \
+	if(pScaling.x) vCols[0] /= pScaling.x; \
+	if(pScaling.y) vCols[1] /= pScaling.y; \
+	if(pScaling.z) vCols[2] /= pScaling.z; \
+	\
+	do {} while(false)
+
+
+
+
+template <typename TReal>
+inline void aiMatrix4x4t<TReal>::Decompose (aiVector3t<TReal>& pScaling, aiQuaterniont<TReal>& pRotation,
+    aiVector3t<TReal>& pPosition) const
+{
+	ASSIMP_MATRIX4_4_DECOMPOSE_PART;
+
+    // build a 3x3 rotation matrix
+    aiMatrix3x3t<TReal> m(vCols[0].x,vCols[1].x,vCols[2].x,
+        vCols[0].y,vCols[1].y,vCols[2].y,
+        vCols[0].z,vCols[1].z,vCols[2].z);
+
+    // and generate the rotation quaternion from it
+    pRotation = aiQuaterniont<TReal>(m);
+}
+
+template <typename TReal>
+inline
+void aiMatrix4x4t<TReal>::Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotation, aiVector3t<TReal>& pPosition) const {
+	ASSIMP_MATRIX4_4_DECOMPOSE_PART;
+
+    /*
+    assuming a right-handed coordinate system
+    and post-multiplication of column vectors,
+    the rotation matrix for an euler XYZ rotation is M = Rz * Ry * Rx.
+    combining gives:
+    
+        |  CE  BDE-AF  ADE+BF  0  |
+    M = |  CF  BDF+AE  ADF-BE  0  |
+        |  -D    CB      AC    0  |
+        |   0     0       0    1  |
+
+    where
+	A = cos(angle_x), B = sin(angle_x);
+	C = cos(angle_y), D = sin(angle_y);
+	E = cos(angle_z), F = sin(angle_z);
+	*/
+
+	// Use a small epsilon to solve floating-point inaccuracies
+    const TReal epsilon = Assimp::Math::getEpsilon<TReal>();
+
+	pRotation.y  = std::asin(-vCols[0].z);// D. Angle around oY.
+
+	TReal C = std::cos(pRotation.y);
+
+	if(std::fabs(C) > epsilon)
+	{
+		// Finding angle around oX.
+		TReal tan_x = vCols[2].z / C;// A
+		TReal tan_y = vCols[1].z / C;// B
+
+		pRotation.x = std::atan2(tan_y, tan_x);
+		// Finding angle around oZ.
+		tan_x = vCols[0].x / C;// E
+		tan_y = vCols[0].y / C;// F
+		pRotation.z = std::atan2(tan_y, tan_x);
+	}
+	else
+	{// oY is fixed.
+		pRotation.x = 0;// Set angle around oX to 0. => A == 1, B == 0, C == 0, D == 1.
+
+		// And finding angle around oZ.
+		TReal tan_x =  vCols[1].y;// BDF+AE => E
+		TReal tan_y = -vCols[1].x;// BDE-AF => F
+
+		pRotation.z = std::atan2(tan_y, tan_x);
+	}
+}
+
+#undef ASSIMP_MATRIX4_4_DECOMPOSE_PART
+
+template <typename TReal>
+inline void aiMatrix4x4t<TReal>::Decompose(aiVector3t<TReal>& pScaling, aiVector3t<TReal>& pRotationAxis, TReal& pRotationAngle,
+											aiVector3t<TReal>& pPosition) const
+{
+aiQuaterniont<TReal> pRotation;
+
+	Decompose(pScaling, pRotation, pPosition);
+	pRotation.Normalize();
+
+	TReal angle_cos = pRotation.w;
+	TReal angle_sin = std::sqrt(1.0f - angle_cos * angle_cos);
+
+	pRotationAngle = std::acos(angle_cos) * 2;
+
+	// Use a small epsilon to solve floating-point inaccuracies
+    const TReal epsilon = 10e-3f;
+
+	if(std::fabs(angle_sin) < epsilon) angle_sin = 1;
+
+	pRotationAxis.x = pRotation.x / angle_sin;
+	pRotationAxis.y = pRotation.y / angle_sin;
+	pRotationAxis.z = pRotation.z / angle_sin;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline void aiMatrix4x4t<TReal>::DecomposeNoScaling (aiQuaterniont<TReal>& rotation,
+    aiVector3t<TReal>& position) const
+{
+    const aiMatrix4x4t<TReal>& _this = *this;
+
+    // extract translation
+    position.x = _this[0][3];
+    position.y = _this[1][3];
+    position.z = _this[2][3];
+
+    // extract rotation
+    rotation = aiQuaterniont<TReal>((aiMatrix3x3t<TReal>)_this);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::FromEulerAnglesXYZ(const aiVector3t<TReal>& blubb)
+{
+    return FromEulerAnglesXYZ(blubb.x,blubb.y,blubb.z);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::FromEulerAnglesXYZ(TReal x, TReal y, TReal z)
+{
+    aiMatrix4x4t<TReal>& _this = *this;
+
+    TReal cx = std::cos(x);
+    TReal sx = std::sin(x);
+    TReal cy = std::cos(y);
+    TReal sy = std::sin(y);
+    TReal cz = std::cos(z);
+    TReal sz = std::sin(z);
+
+    // mz*my*mx
+    _this.a1 = cz * cy;
+    _this.a2 = cz * sy * sx - sz * cx;
+    _this.a3 = sz * sx + cz * sy * cx;
+
+    _this.b1 = sz * cy;
+    _this.b2 = cz * cx + sz * sy * sx;
+    _this.b3 = sz * sy * cx - cz * sx;
+
+    _this.c1 = -sy;
+    _this.c2 = cy * sx;
+    _this.c3 = cy * cx;
+
+    return *this;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline bool aiMatrix4x4t<TReal>::IsIdentity() const
+{
+    // Use a small epsilon to solve floating-point inaccuracies
+    const static TReal epsilon = 10e-3f;
+
+    return (a2 <= epsilon && a2 >= -epsilon &&
+            a3 <= epsilon && a3 >= -epsilon &&
+            a4 <= epsilon && a4 >= -epsilon &&
+            b1 <= epsilon && b1 >= -epsilon &&
+            b3 <= epsilon && b3 >= -epsilon &&
+            b4 <= epsilon && b4 >= -epsilon &&
+            c1 <= epsilon && c1 >= -epsilon &&
+            c2 <= epsilon && c2 >= -epsilon &&
+            c4 <= epsilon && c4 >= -epsilon &&
+            d1 <= epsilon && d1 >= -epsilon &&
+            d2 <= epsilon && d2 >= -epsilon &&
+            d3 <= epsilon && d3 >= -epsilon &&
+            a1 <= 1.f+epsilon && a1 >= 1.f-epsilon &&
+            b2 <= 1.f+epsilon && b2 >= 1.f-epsilon &&
+            c3 <= 1.f+epsilon && c3 >= 1.f-epsilon &&
+            d4 <= 1.f+epsilon && d4 >= 1.f-epsilon);
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::RotationX(TReal a, aiMatrix4x4t<TReal>& out)
+{
+    /*
+         |  1  0       0       0 |
+     M = |  0  cos(A) -sin(A)  0 |
+         |  0  sin(A)  cos(A)  0 |
+         |  0  0       0       1 |  */
+    out = aiMatrix4x4t<TReal>();
+    out.b2 = out.c3 = std::cos(a);
+    out.b3 = -(out.c2 = std::sin(a));
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::RotationY(TReal a, aiMatrix4x4t<TReal>& out)
+{
+    /*
+         |  cos(A)  0   sin(A)  0 |
+     M = |  0       1   0       0 |
+         | -sin(A)  0   cos(A)  0 |
+         |  0       0   0       1 |
+        */
+    out = aiMatrix4x4t<TReal>();
+    out.a1 = out.c3 = std::cos(a);
+    out.c1 = -(out.a3 = std::sin(a));
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::RotationZ(TReal a, aiMatrix4x4t<TReal>& out)
+{
+    /*
+         |  cos(A)  -sin(A)   0   0 |
+     M = |  sin(A)   cos(A)   0   0 |
+         |  0        0        1   0 |
+         |  0        0        0   1 |   */
+    out = aiMatrix4x4t<TReal>();
+    out.a1 = out.b2 = std::cos(a);
+    out.a2 = -(out.b1 = std::sin(a));
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+// Returns a rotation matrix for a rotation around an arbitrary axis.
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::Rotation( TReal a, const aiVector3t<TReal>& axis, aiMatrix4x4t<TReal>& out)
+{
+  TReal c = std::cos( a), s = std::sin( a), t = 1 - c;
+  TReal x = axis.x, y = axis.y, z = axis.z;
+
+  // Many thanks to MathWorld and Wikipedia
+  out.a1 = t*x*x + c;   out.a2 = t*x*y - s*z; out.a3 = t*x*z + s*y;
+  out.b1 = t*x*y + s*z; out.b2 = t*y*y + c;   out.b3 = t*y*z - s*x;
+  out.c1 = t*x*z - s*y; out.c2 = t*y*z + s*x; out.c3 = t*z*z + c;
+  out.a4 = out.b4 = out.c4 = static_cast<TReal>(0.0);
+  out.d1 = out.d2 = out.d3 = static_cast<TReal>(0.0);
+  out.d4 = static_cast<TReal>(1.0);
+
+  return out;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::Translation( const aiVector3t<TReal>& v, aiMatrix4x4t<TReal>& out)
+{
+    out = aiMatrix4x4t<TReal>();
+    out.a4 = v.x;
+    out.b4 = v.y;
+    out.c4 = v.z;
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::Scaling( const aiVector3t<TReal>& v, aiMatrix4x4t<TReal>& out)
+{
+    out = aiMatrix4x4t<TReal>();
+    out.a1 = v.x;
+    out.b2 = v.y;
+    out.c3 = v.z;
+    return out;
+}
+
+// ----------------------------------------------------------------------------------------
+/** A function for creating a rotation matrix that rotates a vector called
+ * "from" into another vector called "to".
+ * Input : from[3], to[3] which both must be *normalized* non-zero vectors
+ * Output: mtx[3][3] -- a 3x3 matrix in colum-major form
+ * Authors: Tomas Möller, John Hughes
+ *          "Efficiently Building a Matrix to Rotate One Vector to Another"
+ *          Journal of Graphics Tools, 4(4):1-4, 1999
+ */
+// ----------------------------------------------------------------------------------------
+template <typename TReal>
+inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::FromToMatrix(const aiVector3t<TReal>& from,
+    const aiVector3t<TReal>& to, aiMatrix4x4t<TReal>& mtx)
+{
+    aiMatrix3x3t<TReal> m3;
+    aiMatrix3x3t<TReal>::FromToMatrix(from,to,m3);
+    mtx = aiMatrix4x4t<TReal>(m3);
+    return mtx;
+}
+
+#endif // __cplusplus
+#endif // AI_MATRIX4X4_INL_INC

dependencies/assimp/include/assimp/mesh.h

@@ -0,0 +1,859 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file mesh.h
+ *  @brief Declares the data structures in which the imported geometry is
+    returned by ASSIMP: aiMesh, aiFace and aiBone data structures.
+ */
+#pragma once
+#ifndef AI_MESH_H_INC
+#define AI_MESH_H_INC
+
+#include <assimp/types.h>
+#include <assimp/aabb.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ---------------------------------------------------------------------------
+// Limits. These values are required to match the settings Assimp was
+// compiled against. Therefore, do not redefine them unless you build the
+// library from source using the same definitions.
+// ---------------------------------------------------------------------------
+
+/** @def AI_MAX_FACE_INDICES
+ *  Maximum number of indices per face (polygon). */
+
+#ifndef AI_MAX_FACE_INDICES
+#   define AI_MAX_FACE_INDICES 0x7fff
+#endif
+
+/** @def AI_MAX_BONE_WEIGHTS
+ *  Maximum number of indices per face (polygon). */
+
+#ifndef AI_MAX_BONE_WEIGHTS
+#   define AI_MAX_BONE_WEIGHTS 0x7fffffff
+#endif
+
+/** @def AI_MAX_VERTICES
+ *  Maximum number of vertices per mesh.  */
+
+#ifndef AI_MAX_VERTICES
+#   define AI_MAX_VERTICES 0x7fffffff
+#endif
+
+/** @def AI_MAX_FACES
+ *  Maximum number of faces per mesh. */
+
+#ifndef AI_MAX_FACES
+#   define AI_MAX_FACES 0x7fffffff
+#endif
+
+/** @def AI_MAX_NUMBER_OF_COLOR_SETS
+ *  Supported number of vertex color sets per mesh. */
+
+#ifndef AI_MAX_NUMBER_OF_COLOR_SETS
+#   define AI_MAX_NUMBER_OF_COLOR_SETS 0x8
+#endif // !! AI_MAX_NUMBER_OF_COLOR_SETS
+
+/** @def AI_MAX_NUMBER_OF_TEXTURECOORDS
+ *  Supported number of texture coord sets (UV(W) channels) per mesh */
+
+#ifndef AI_MAX_NUMBER_OF_TEXTURECOORDS
+#   define AI_MAX_NUMBER_OF_TEXTURECOORDS 0x8
+#endif // !! AI_MAX_NUMBER_OF_TEXTURECOORDS
+
+// ---------------------------------------------------------------------------
+/** @brief A single face in a mesh, referring to multiple vertices.
+ *
+ * If mNumIndices is 3, we call the face 'triangle', for mNumIndices > 3
+ * it's called 'polygon' (hey, that's just a definition!).
+ * <br>
+ * aiMesh::mPrimitiveTypes can be queried to quickly examine which types of
+ * primitive are actually present in a mesh. The #aiProcess_SortByPType flag
+ * executes a special post-processing algorithm which splits meshes with
+ * *different* primitive types mixed up (e.g. lines and triangles) in several
+ * 'clean' submeshes. Furthermore there is a configuration option (
+ * #AI_CONFIG_PP_SBP_REMOVE) to force #aiProcess_SortByPType to remove
+ * specific kinds of primitives from the imported scene, completely and forever.
+ * In many cases you'll probably want to set this setting to
+ * @code
+ * aiPrimitiveType_LINE|aiPrimitiveType_POINT
+ * @endcode
+ * Together with the #aiProcess_Triangulate flag you can then be sure that
+ * #aiFace::mNumIndices is always 3.
+ * @note Take a look at the @link data Data Structures page @endlink for
+ * more information on the layout and winding order of a face.
+ */
+struct aiFace
+{
+    //! Number of indices defining this face.
+    //! The maximum value for this member is #AI_MAX_FACE_INDICES.
+    unsigned int mNumIndices;
+
+    //! Pointer to the indices array. Size of the array is given in numIndices.
+    unsigned int* mIndices;
+
+#ifdef __cplusplus
+
+    //! Default constructor
+    aiFace() AI_NO_EXCEPT
+    : mNumIndices( 0 )
+    , mIndices( nullptr ) {
+        // empty
+    }
+
+    //! Default destructor. Delete the index array
+    ~aiFace()
+    {
+        delete [] mIndices;
+    }
+
+    //! Copy constructor. Copy the index array
+    aiFace( const aiFace& o)
+    : mNumIndices(0)
+    , mIndices( nullptr ) {
+        *this = o;
+    }
+
+    //! Assignment operator. Copy the index array
+    aiFace& operator = ( const aiFace& o) {
+        if (&o == this) {
+            return *this;
+        }
+
+        delete[] mIndices;
+        mNumIndices = o.mNumIndices;
+        if (mNumIndices) {
+            mIndices = new unsigned int[mNumIndices];
+            ::memcpy( mIndices, o.mIndices, mNumIndices * sizeof( unsigned int));
+        } else {
+            mIndices = nullptr;
+        }
+
+        return *this;
+    }
+
+    //! Comparison operator. Checks whether the index array
+    //! of two faces is identical
+    bool operator== (const aiFace& o) const {
+        if (mIndices == o.mIndices) {
+            return true;
+        }
+
+        if (nullptr != mIndices && mNumIndices != o.mNumIndices) {
+            return false;
+        }
+
+        if (nullptr == mIndices) {
+            return false;
+        }
+
+        for (unsigned int i = 0; i < this->mNumIndices; ++i) {
+            if (mIndices[i] != o.mIndices[i]) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    //! Inverse comparison operator. Checks whether the index
+    //! array of two faces is NOT identical
+    bool operator != (const aiFace& o) const {
+        return !(*this == o);
+    }
+#endif // __cplusplus
+}; // struct aiFace
+
+
+// ---------------------------------------------------------------------------
+/** @brief A single influence of a bone on a vertex.
+ */
+struct aiVertexWeight {
+    //! Index of the vertex which is influenced by the bone.
+    unsigned int mVertexId;
+
+    //! The strength of the influence in the range (0...1).
+    //! The influence from all bones at one vertex amounts to 1.
+    float mWeight;
+
+#ifdef __cplusplus
+
+    //! Default constructor
+    aiVertexWeight() AI_NO_EXCEPT
+    : mVertexId(0)
+    , mWeight(0.0f) {
+        // empty
+    }
+
+    //! Initialization from a given index and vertex weight factor
+    //! \param pID ID
+    //! \param pWeight Vertex weight factor
+    aiVertexWeight( unsigned int pID, float pWeight )
+    : mVertexId( pID )
+    , mWeight( pWeight ) {
+        // empty
+    }
+
+    bool operator == ( const aiVertexWeight &rhs ) const {
+        return ( mVertexId == rhs.mVertexId && mWeight == rhs.mWeight );
+    }
+
+    bool operator != ( const aiVertexWeight &rhs ) const {
+        return ( *this == rhs );
+    }
+
+#endif // __cplusplus
+};
+
+
+// ---------------------------------------------------------------------------
+/** @brief A single bone of a mesh.
+ *
+ *  A bone has a name by which it can be found in the frame hierarchy and by
+ *  which it can be addressed by animations. In addition it has a number of
+ *  influences on vertices, and a matrix relating the mesh position to the
+ *  position of the bone at the time of binding.
+ */
+struct aiBone {
+    //! The name of the bone.
+    C_STRUCT aiString mName;
+
+    //! The number of vertices affected by this bone.
+    //! The maximum value for this member is #AI_MAX_BONE_WEIGHTS.
+    unsigned int mNumWeights;
+
+    //! The influence weights of this bone, by vertex index.
+    C_STRUCT aiVertexWeight* mWeights;
+
+    /** Matrix that transforms from bone space to mesh space in bind pose.
+     *
+     * This matrix describes the position of the mesh
+     * in the local space of this bone when the skeleton was bound.
+     * Thus it can be used directly to determine a desired vertex position,
+     * given the world-space transform of the bone when animated,
+     * and the position of the vertex in mesh space.
+     *
+     * It is sometimes called an inverse-bind matrix,
+     * or inverse bind pose matrix.
+     */
+    C_STRUCT aiMatrix4x4 mOffsetMatrix;
+
+#ifdef __cplusplus
+
+    //! Default constructor
+    aiBone() AI_NO_EXCEPT
+    : mName()
+    , mNumWeights( 0 )
+    , mWeights( nullptr )
+    , mOffsetMatrix() {
+        // empty
+    }
+
+    //! Copy constructor
+    aiBone(const aiBone& other)
+    : mName( other.mName )
+    , mNumWeights( other.mNumWeights )
+    , mWeights(nullptr)
+    , mOffsetMatrix( other.mOffsetMatrix ) {
+        if (other.mWeights && other.mNumWeights) {
+            mWeights = new aiVertexWeight[mNumWeights];
+            ::memcpy(mWeights,other.mWeights,mNumWeights * sizeof(aiVertexWeight));
+        }
+    }
+
+
+    //! Assignment operator
+    aiBone &operator=(const aiBone& other) {
+        if (this == &other) {
+            return *this;
+        }
+
+        mName         = other.mName;
+        mNumWeights   = other.mNumWeights;
+        mOffsetMatrix = other.mOffsetMatrix;
+
+        if (other.mWeights && other.mNumWeights)
+        {
+            if (mWeights) {
+                delete[] mWeights;
+            }
+
+            mWeights = new aiVertexWeight[mNumWeights];
+            ::memcpy(mWeights,other.mWeights,mNumWeights * sizeof(aiVertexWeight));
+        }
+
+        return *this;
+    }
+
+    bool operator == ( const aiBone &rhs ) const {
+        if ( mName != rhs.mName || mNumWeights != rhs.mNumWeights ) {
+            return false;
+        }
+
+        for ( size_t i = 0; i < mNumWeights; ++i ) {
+            if ( mWeights[ i ] != rhs.mWeights[ i ] ) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+    //! Destructor - deletes the array of vertex weights
+    ~aiBone() {
+        delete [] mWeights;
+    }
+#endif // __cplusplus
+};
+
+
+// ---------------------------------------------------------------------------
+/** @brief Enumerates the types of geometric primitives supported by Assimp.
+ *
+ *  @see aiFace Face data structure
+ *  @see aiProcess_SortByPType Per-primitive sorting of meshes
+ *  @see aiProcess_Triangulate Automatic triangulation
+ *  @see AI_CONFIG_PP_SBP_REMOVE Removal of specific primitive types.
+ */
+enum aiPrimitiveType
+{
+    /** A point primitive.
+     *
+     * This is just a single vertex in the virtual world,
+     * #aiFace contains just one index for such a primitive.
+     */
+    aiPrimitiveType_POINT       = 0x1,
+
+    /** A line primitive.
+     *
+     * This is a line defined through a start and an end position.
+     * #aiFace contains exactly two indices for such a primitive.
+     */
+    aiPrimitiveType_LINE        = 0x2,
+
+    /** A triangular primitive.
+     *
+     * A triangle consists of three indices.
+     */
+    aiPrimitiveType_TRIANGLE    = 0x4,
+
+    /** A higher-level polygon with more than 3 edges.
+     *
+     * A triangle is a polygon, but polygon in this context means
+     * "all polygons that are not triangles". The "Triangulate"-Step
+     * is provided for your convenience, it splits all polygons in
+     * triangles (which are much easier to handle).
+     */
+    aiPrimitiveType_POLYGON     = 0x8,
+
+
+    /** This value is not used. It is just here to force the
+     *  compiler to map this enum to a 32 Bit integer.
+     */
+#ifndef SWIG
+    _aiPrimitiveType_Force32Bit = INT_MAX
+#endif
+}; //! enum aiPrimitiveType
+
+// Get the #aiPrimitiveType flag for a specific number of face indices
+#define AI_PRIMITIVE_TYPE_FOR_N_INDICES(n) \
+    ((n) > 3 ? aiPrimitiveType_POLYGON : (aiPrimitiveType)(1u << ((n)-1)))
+
+
+
+// ---------------------------------------------------------------------------
+/** @brief An AnimMesh is an attachment to an #aiMesh stores per-vertex
+ *  animations for a particular frame.
+ *
+ *  You may think of an #aiAnimMesh as a `patch` for the host mesh, which
+ *  replaces only certain vertex data streams at a particular time.
+ *  Each mesh stores n attached attached meshes (#aiMesh::mAnimMeshes).
+ *  The actual relationship between the time line and anim meshes is
+ *  established by #aiMeshAnim, which references singular mesh attachments
+ *  by their ID and binds them to a time offset.
+*/
+struct aiAnimMesh
+{
+    /**Anim Mesh name */
+    C_STRUCT aiString mName;
+
+    /** Replacement for aiMesh::mVertices. If this array is non-NULL,
+     *  it *must* contain mNumVertices entries. The corresponding
+     *  array in the host mesh must be non-NULL as well - animation
+     *  meshes may neither add or nor remove vertex components (if
+     *  a replacement array is NULL and the corresponding source
+     *  array is not, the source data is taken instead)*/
+    C_STRUCT aiVector3D* mVertices;
+
+    /** Replacement for aiMesh::mNormals.  */
+    C_STRUCT aiVector3D* mNormals;
+
+    /** Replacement for aiMesh::mTangents. */
+    C_STRUCT aiVector3D* mTangents;
+
+    /** Replacement for aiMesh::mBitangents. */
+    C_STRUCT aiVector3D* mBitangents;
+
+    /** Replacement for aiMesh::mColors */
+    C_STRUCT aiColor4D* mColors[AI_MAX_NUMBER_OF_COLOR_SETS];
+
+    /** Replacement for aiMesh::mTextureCoords */
+    C_STRUCT aiVector3D* mTextureCoords[AI_MAX_NUMBER_OF_TEXTURECOORDS];
+
+    /** The number of vertices in the aiAnimMesh, and thus the length of all
+     * the member arrays.
+     *
+     * This has always the same value as the mNumVertices property in the
+     * corresponding aiMesh. It is duplicated here merely to make the length
+     * of the member arrays accessible even if the aiMesh is not known, e.g.
+     * from language bindings.
+     */
+    unsigned int mNumVertices;
+    
+    /** 
+     * Weight of the AnimMesh. 
+     */
+    float mWeight;
+
+#ifdef __cplusplus
+
+    aiAnimMesh() AI_NO_EXCEPT
+        : mVertices( nullptr )
+        , mNormals(nullptr)
+        , mTangents(nullptr)
+        , mBitangents(nullptr)
+        , mColors()
+        , mTextureCoords()
+        , mNumVertices( 0 )
+        , mWeight( 0.0f )
+    {
+        // fixme consider moving this to the ctor initializer list as well
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++){
+            mTextureCoords[a] = nullptr;
+        }
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; a++) {
+            mColors[a] = nullptr;
+        }
+    }
+
+    ~aiAnimMesh()
+    {
+        delete [] mVertices;
+        delete [] mNormals;
+        delete [] mTangents;
+        delete [] mBitangents;
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++) {
+            delete [] mTextureCoords[a];
+        }
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; a++) {
+            delete [] mColors[a];
+        }
+    }
+
+    /** Check whether the anim mesh overrides the vertex positions
+     *  of its host mesh*/
+    bool HasPositions() const {
+        return mVertices != nullptr;
+    }
+
+    /** Check whether the anim mesh overrides the vertex normals
+     *  of its host mesh*/
+    bool HasNormals() const {
+        return mNormals != nullptr;
+    }
+
+    /** Check whether the anim mesh overrides the vertex tangents
+     *  and bitangents of its host mesh. As for aiMesh,
+     *  tangents and bitangents always go together. */
+    bool HasTangentsAndBitangents() const {
+        return mTangents != nullptr;
+    }
+
+    /** Check whether the anim mesh overrides a particular
+     * set of vertex colors on his host mesh.
+     *  @param pIndex 0<index<AI_MAX_NUMBER_OF_COLOR_SETS */
+    bool HasVertexColors( unsigned int pIndex) const    {
+        return pIndex >= AI_MAX_NUMBER_OF_COLOR_SETS ? false : mColors[pIndex] != nullptr;
+    }
+
+    /** Check whether the anim mesh overrides a particular
+     * set of texture coordinates on his host mesh.
+     *  @param pIndex 0<index<AI_MAX_NUMBER_OF_TEXTURECOORDS */
+    bool HasTextureCoords( unsigned int pIndex) const   {
+        return pIndex >= AI_MAX_NUMBER_OF_TEXTURECOORDS ? false : mTextureCoords[pIndex] != nullptr;
+    }
+
+#endif
+};
+
+// ---------------------------------------------------------------------------
+/** @brief Enumerates the methods of mesh morphing supported by Assimp.
+ */
+enum aiMorphingMethod
+{
+    /** Interpolation between morph targets */
+    aiMorphingMethod_VERTEX_BLEND       = 0x1,
+
+    /** Normalized morphing between morph targets  */
+    aiMorphingMethod_MORPH_NORMALIZED   = 0x2,
+
+    /** Relative morphing between morph targets  */
+    aiMorphingMethod_MORPH_RELATIVE     = 0x3,
+
+    /** This value is not used. It is just here to force the
+     *  compiler to map this enum to a 32 Bit integer.
+     */
+#ifndef SWIG
+    _aiMorphingMethod_Force32Bit = INT_MAX
+#endif
+}; //! enum aiMorphingMethod
+
+// ---------------------------------------------------------------------------
+/** @brief A mesh represents a geometry or model with a single material.
+*
+* It usually consists of a number of vertices and a series of primitives/faces
+* referencing the vertices. In addition there might be a series of bones, each
+* of them addressing a number of vertices with a certain weight. Vertex data
+* is presented in channels with each channel containing a single per-vertex
+* information such as a set of texture coords or a normal vector.
+* If a data pointer is non-null, the corresponding data stream is present.
+* From C++-programs you can also use the comfort functions Has*() to
+* test for the presence of various data streams.
+*
+* A Mesh uses only a single material which is referenced by a material ID.
+* @note The mPositions member is usually not optional. However, vertex positions
+* *could* be missing if the #AI_SCENE_FLAGS_INCOMPLETE flag is set in
+* @code
+* aiScene::mFlags
+* @endcode
+*/
+struct aiMesh
+{
+    /** Bitwise combination of the members of the #aiPrimitiveType enum.
+     * This specifies which types of primitives are present in the mesh.
+     * The "SortByPrimitiveType"-Step can be used to make sure the
+     * output meshes consist of one primitive type each.
+     */
+    unsigned int mPrimitiveTypes;
+
+    /** The number of vertices in this mesh.
+    * This is also the size of all of the per-vertex data arrays.
+    * The maximum value for this member is #AI_MAX_VERTICES.
+    */
+    unsigned int mNumVertices;
+
+    /** The number of primitives (triangles, polygons, lines) in this  mesh.
+    * This is also the size of the mFaces array.
+    * The maximum value for this member is #AI_MAX_FACES.
+    */
+    unsigned int mNumFaces;
+
+    /** Vertex positions.
+    * This array is always present in a mesh. The array is
+    * mNumVertices in size.
+    */
+    C_STRUCT aiVector3D* mVertices;
+
+    /** Vertex normals.
+    * The array contains normalized vectors, NULL if not present.
+    * The array is mNumVertices in size. Normals are undefined for
+    * point and line primitives. A mesh consisting of points and
+    * lines only may not have normal vectors. Meshes with mixed
+    * primitive types (i.e. lines and triangles) may have normals,
+    * but the normals for vertices that are only referenced by
+    * point or line primitives are undefined and set to QNaN (WARN:
+    * qNaN compares to inequal to *everything*, even to qNaN itself.
+    * Using code like this to check whether a field is qnan is:
+    * @code
+    * #define IS_QNAN(f) (f != f)
+    * @endcode
+    * still dangerous because even 1.f == 1.f could evaluate to false! (
+    * remember the subtleties of IEEE754 artithmetics). Use stuff like
+    * @c fpclassify instead.
+    * @note Normal vectors computed by Assimp are always unit-length.
+    * However, this needn't apply for normals that have been taken
+    *   directly from the model file.
+    */
+    C_STRUCT aiVector3D* mNormals;
+
+    /** Vertex tangents.
+    * The tangent of a vertex points in the direction of the positive
+    * X texture axis. The array contains normalized vectors, NULL if
+    * not present. The array is mNumVertices in size. A mesh consisting
+    * of points and lines only may not have normal vectors. Meshes with
+    * mixed primitive types (i.e. lines and triangles) may have
+    * normals, but the normals for vertices that are only referenced by
+    * point or line primitives are undefined and set to qNaN.  See
+    * the #mNormals member for a detailed discussion of qNaNs.
+    * @note If the mesh contains tangents, it automatically also
+    * contains bitangents.
+    */
+    C_STRUCT aiVector3D* mTangents;
+
+    /** Vertex bitangents.
+    * The bitangent of a vertex points in the direction of the positive
+    * Y texture axis. The array contains normalized vectors, NULL if not
+    * present. The array is mNumVertices in size.
+    * @note If the mesh contains tangents, it automatically also contains
+    * bitangents.
+    */
+    C_STRUCT aiVector3D* mBitangents;
+
+    /** Vertex color sets.
+    * A mesh may contain 0 to #AI_MAX_NUMBER_OF_COLOR_SETS vertex
+    * colors per vertex. NULL if not present. Each array is
+    * mNumVertices in size if present.
+    */
+    C_STRUCT aiColor4D* mColors[AI_MAX_NUMBER_OF_COLOR_SETS];
+
+    /** Vertex texture coords, also known as UV channels.
+    * A mesh may contain 0 to AI_MAX_NUMBER_OF_TEXTURECOORDS per
+    * vertex. NULL if not present. The array is mNumVertices in size.
+    */
+    C_STRUCT aiVector3D* mTextureCoords[AI_MAX_NUMBER_OF_TEXTURECOORDS];
+
+    /** Specifies the number of components for a given UV channel.
+    * Up to three channels are supported (UVW, for accessing volume
+    * or cube maps). If the value is 2 for a given channel n, the
+    * component p.z of mTextureCoords[n][p] is set to 0.0f.
+    * If the value is 1 for a given channel, p.y is set to 0.0f, too.
+    * @note 4D coords are not supported
+    */
+    unsigned int mNumUVComponents[AI_MAX_NUMBER_OF_TEXTURECOORDS];
+
+    /** The faces the mesh is constructed from.
+    * Each face refers to a number of vertices by their indices.
+    * This array is always present in a mesh, its size is given
+    * in mNumFaces. If the #AI_SCENE_FLAGS_NON_VERBOSE_FORMAT
+    * is NOT set each face references an unique set of vertices.
+    */
+    C_STRUCT aiFace* mFaces;
+
+    /** The number of bones this mesh contains.
+    * Can be 0, in which case the mBones array is NULL.
+    */
+    unsigned int mNumBones;
+
+    /** The bones of this mesh.
+    * A bone consists of a name by which it can be found in the
+    * frame hierarchy and a set of vertex weights.
+    */
+    C_STRUCT aiBone** mBones;
+
+    /** The material used by this mesh.
+     * A mesh uses only a single material. If an imported model uses
+     * multiple materials, the import splits up the mesh. Use this value
+     * as index into the scene's material list.
+     */
+    unsigned int mMaterialIndex;
+
+    /** Name of the mesh. Meshes can be named, but this is not a
+     *  requirement and leaving this field empty is totally fine.
+     *  There are mainly three uses for mesh names:
+     *   - some formats name nodes and meshes independently.
+     *   - importers tend to split meshes up to meet the
+     *      one-material-per-mesh requirement. Assigning
+     *      the same (dummy) name to each of the result meshes
+     *      aids the caller at recovering the original mesh
+     *      partitioning.
+     *   - Vertex animations refer to meshes by their names.
+     **/
+    C_STRUCT aiString mName;
+
+
+    /** The number of attachment meshes. Note! Currently only works with Collada loader. */
+    unsigned int mNumAnimMeshes;
+
+    /** Attachment meshes for this mesh, for vertex-based animation.
+     *  Attachment meshes carry replacement data for some of the
+     *  mesh'es vertex components (usually positions, normals).
+     *  Note! Currently only works with Collada loader.*/
+    C_STRUCT aiAnimMesh** mAnimMeshes;
+
+    /** 
+     *  Method of morphing when animeshes are specified. 
+     */
+    unsigned int mMethod;
+
+    /**
+     *
+     */
+    C_STRUCT aiAABB mAABB;
+	
+#ifdef __cplusplus
+
+    //! Default constructor. Initializes all members to 0
+    aiMesh() AI_NO_EXCEPT
+    : mPrimitiveTypes( 0 )
+    , mNumVertices( 0 )
+    , mNumFaces( 0 )
+    , mVertices( nullptr )
+    , mNormals(nullptr)
+    , mTangents(nullptr)
+    , mBitangents(nullptr)
+    , mColors()
+    , mTextureCoords()
+    , mNumUVComponents()
+    , mFaces(nullptr)
+    , mNumBones( 0 )
+    , mBones(nullptr)
+    , mMaterialIndex( 0 )
+    , mNumAnimMeshes( 0 )
+    , mAnimMeshes(nullptr)
+    , mMethod( 0 )
+    , mAABB() {
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++a ) {
+            mNumUVComponents[a] = 0;
+            mTextureCoords[a] = nullptr;
+        }
+
+        for (unsigned int a = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; ++a) {
+            mColors[a] = nullptr;
+        }
+    }
+
+    //! Deletes all storage allocated for the mesh
+    ~aiMesh() {
+        delete [] mVertices;
+        delete [] mNormals;
+        delete [] mTangents;
+        delete [] mBitangents;
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++) {
+            delete [] mTextureCoords[a];
+        }
+        for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; a++) {
+            delete [] mColors[a];
+        }
+
+        // DO NOT REMOVE THIS ADDITIONAL CHECK
+        if (mNumBones && mBones)    {
+            for( unsigned int a = 0; a < mNumBones; a++) {
+                delete mBones[a];
+            }
+            delete [] mBones;
+        }
+
+        if (mNumAnimMeshes && mAnimMeshes)  {
+            for( unsigned int a = 0; a < mNumAnimMeshes; a++) {
+                delete mAnimMeshes[a];
+            }
+            delete [] mAnimMeshes;
+        }
+
+        delete [] mFaces;
+    }
+
+    //! Check whether the mesh contains positions. Provided no special
+    //! scene flags are set, this will always be true
+    bool HasPositions() const
+        { return mVertices != nullptr && mNumVertices > 0; }
+
+    //! Check whether the mesh contains faces. If no special scene flags
+    //! are set this should always return true
+    bool HasFaces() const
+        { return mFaces != nullptr && mNumFaces > 0; }
+
+    //! Check whether the mesh contains normal vectors
+    bool HasNormals() const
+        { return mNormals != nullptr && mNumVertices > 0; }
+
+    //! Check whether the mesh contains tangent and bitangent vectors
+    //! It is not possible that it contains tangents and no bitangents
+    //! (or the other way round). The existence of one of them
+    //! implies that the second is there, too.
+    bool HasTangentsAndBitangents() const
+        { return mTangents != nullptr && mBitangents != nullptr && mNumVertices > 0; }
+
+    //! Check whether the mesh contains a vertex color set
+    //! \param pIndex Index of the vertex color set
+    bool HasVertexColors( unsigned int pIndex) const {
+        if (pIndex >= AI_MAX_NUMBER_OF_COLOR_SETS) {
+            return false;
+        } else {
+            return mColors[pIndex] != nullptr && mNumVertices > 0;
+        }
+    }
+
+    //! Check whether the mesh contains a texture coordinate set
+    //! \param pIndex Index of the texture coordinates set
+    bool HasTextureCoords( unsigned int pIndex) const {
+        if (pIndex >= AI_MAX_NUMBER_OF_TEXTURECOORDS) {
+            return false;
+        } else {
+            return mTextureCoords[pIndex] != nullptr && mNumVertices > 0;
+        }
+    }
+
+    //! Get the number of UV channels the mesh contains
+    unsigned int GetNumUVChannels() const {
+        unsigned int n( 0 );
+        while (n < AI_MAX_NUMBER_OF_TEXTURECOORDS && mTextureCoords[n]) {
+            ++n;
+        }
+
+        return n;
+    }
+
+    //! Get the number of vertex color channels the mesh contains
+    unsigned int GetNumColorChannels() const {
+        unsigned int n(0);
+        while (n < AI_MAX_NUMBER_OF_COLOR_SETS && mColors[n]) {
+            ++n;
+        }
+        return n;
+    }
+
+    //! Check whether the mesh contains bones
+    bool HasBones() const {
+        return mBones != nullptr && mNumBones > 0;
+    }
+
+#endif // __cplusplus
+};
+
+#ifdef __cplusplus
+}
+#endif //! extern "C"
+#endif // AI_MESH_H_INC
+

dependencies/assimp/include/assimp/metadata.h

@@ -0,0 +1,380 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file metadata.h
+ *  @brief Defines the data structures for holding node meta information.
+ */
+#pragma once
+#ifndef AI_METADATA_H_INC
+#define AI_METADATA_H_INC
+
+#if defined(_MSC_VER) && (_MSC_VER <= 1500)
+#  include "Compiler/pstdint.h"
+#else
+#  include <stdint.h>
+#endif
+
+// -------------------------------------------------------------------------------
+/**
+  * Enum used to distinguish data types
+  */
+ // -------------------------------------------------------------------------------
+typedef enum aiMetadataType {
+    AI_BOOL       = 0,
+    AI_INT32      = 1,
+    AI_UINT64     = 2,
+    AI_FLOAT      = 3,
+    AI_DOUBLE     = 4,
+    AI_AISTRING   = 5,
+    AI_AIVECTOR3D = 6,
+    AI_META_MAX   = 7,
+
+#ifndef SWIG
+    FORCE_32BIT = INT_MAX
+#endif
+} aiMetadataType;
+
+// -------------------------------------------------------------------------------
+/**
+  * Metadata entry
+  *
+  * The type field uniquely identifies the underlying type of the data field
+  */
+ // -------------------------------------------------------------------------------
+struct aiMetadataEntry {
+    aiMetadataType mType;
+    void* mData;
+};
+
+#ifdef __cplusplus
+
+#include <string>
+
+// -------------------------------------------------------------------------------
+/**
+  * Helper functions to get the aiType enum entry for a type
+  */
+ // -------------------------------------------------------------------------------
+
+inline aiMetadataType GetAiType( bool )       { return AI_BOOL; }
+inline aiMetadataType GetAiType( int32_t )    { return AI_INT32; }
+inline aiMetadataType GetAiType( uint64_t )   { return AI_UINT64; }
+inline aiMetadataType GetAiType( float )      { return AI_FLOAT; }
+inline aiMetadataType GetAiType( double )     { return AI_DOUBLE; }
+inline aiMetadataType GetAiType( const aiString & )   { return AI_AISTRING; }
+inline aiMetadataType GetAiType( const aiVector3D & ) { return AI_AIVECTOR3D; }
+
+#endif // __cplusplus
+
+// -------------------------------------------------------------------------------
+/**
+  * Container for holding metadata.
+  *
+  * Metadata is a key-value store using string keys and values.
+  */
+ // -------------------------------------------------------------------------------
+struct aiMetadata {
+    /** Length of the mKeys and mValues arrays, respectively */
+    unsigned int mNumProperties;
+
+    /** Arrays of keys, may not be NULL. Entries in this array may not be NULL as well. */
+    C_STRUCT aiString* mKeys;
+
+    /** Arrays of values, may not be NULL. Entries in this array may be NULL if the
+      * corresponding property key has no assigned value. */
+    C_STRUCT aiMetadataEntry* mValues;
+
+#ifdef __cplusplus
+
+    /** 
+     *  @brief  The default constructor, set all members to zero by default.
+     */
+    aiMetadata() AI_NO_EXCEPT
+    : mNumProperties(0)
+    , mKeys(nullptr)
+    , mValues(nullptr) {
+        // empty
+    }
+
+    aiMetadata( const aiMetadata &rhs )
+    : mNumProperties( rhs.mNumProperties )
+    , mKeys( nullptr )
+    , mValues( nullptr ) {
+        mKeys = new aiString[ mNumProperties ];
+        for ( size_t i = 0; i < static_cast<size_t>( mNumProperties ); ++i ) {
+            mKeys[ i ] = rhs.mKeys[ i ];
+        }
+        mValues = new aiMetadataEntry[ mNumProperties ];
+        for ( size_t i = 0; i < static_cast<size_t>(mNumProperties); ++i ) {
+            mValues[ i ].mType = rhs.mValues[ i ].mType;
+            switch ( rhs.mValues[ i ].mType ) {
+            case AI_BOOL:
+                mValues[ i ].mData = new bool;
+                ::memcpy( mValues[ i ].mData, rhs.mValues[ i ].mData, sizeof(bool) );
+                break;
+            case AI_INT32: {
+                int32_t v;
+                ::memcpy( &v, rhs.mValues[ i ].mData, sizeof( int32_t ) );
+                mValues[ i ].mData = new int32_t( v );
+                }
+                break;
+            case AI_UINT64: {
+                    uint64_t v;
+                    ::memcpy( &v, rhs.mValues[ i ].mData, sizeof( uint64_t ) );
+                    mValues[ i ].mData = new  uint64_t( v );
+                }
+                break;
+            case AI_FLOAT: {
+                    float v;
+                    ::memcpy( &v, rhs.mValues[ i ].mData, sizeof( float ) );
+                    mValues[ i ].mData = new float( v );
+                }
+                break;
+            case AI_DOUBLE: {
+                    double v;
+                    ::memcpy( &v, rhs.mValues[ i ].mData, sizeof( double ) );
+                    mValues[ i ].mData = new double( v );
+                }
+                break;
+            case AI_AISTRING: {
+                    aiString v;
+                    rhs.Get<aiString>( mKeys[ i ], v );
+                    mValues[ i ].mData = new aiString( v );
+                }
+                break;
+            case AI_AIVECTOR3D: {
+                    aiVector3D v;
+                    rhs.Get<aiVector3D>( mKeys[ i ], v );
+                    mValues[ i ].mData = new aiVector3D( v );
+                }
+                break;
+#ifndef SWIG
+            case FORCE_32BIT:
+#endif
+            default:
+                break;
+            }
+
+        }
+    }
+
+    /** 
+     *  @brief The destructor.
+     */
+    ~aiMetadata() {
+        delete [] mKeys;
+        mKeys = nullptr;
+        if (mValues) {
+            // Delete each metadata entry
+            for (unsigned i=0; i<mNumProperties; ++i) {
+                void* data = mValues[i].mData;
+                switch (mValues[i].mType) {
+                case AI_BOOL:
+                    delete static_cast< bool* >( data );
+                    break;
+                case AI_INT32:
+                    delete static_cast< int32_t* >( data );
+                    break;
+                case AI_UINT64:
+                    delete static_cast< uint64_t* >( data );
+                    break;
+                case AI_FLOAT:
+                    delete static_cast< float* >( data );
+                    break;
+                case AI_DOUBLE:
+                    delete static_cast< double* >( data );
+                    break;
+                case AI_AISTRING:
+                    delete static_cast< aiString* >( data );
+                    break;
+                case AI_AIVECTOR3D:
+                    delete static_cast< aiVector3D* >( data );
+                    break;
+#ifndef SWIG
+                case FORCE_32BIT:
+#endif
+                default:
+                    break;
+                }
+            }
+
+            // Delete the metadata array
+            delete [] mValues;
+            mValues = nullptr;
+        }
+    }
+
+    /**
+     *  @brief Allocates property fields + keys.
+     *  @param  numProperties   Number of requested properties.
+     */
+    static inline
+    aiMetadata *Alloc( unsigned int numProperties ) {
+        if ( 0 == numProperties ) {
+            return nullptr;
+        }
+
+        aiMetadata *data = new aiMetadata;
+        data->mNumProperties = numProperties;
+        data->mKeys = new aiString[ data->mNumProperties ]();
+        data->mValues = new aiMetadataEntry[ data->mNumProperties ]();
+
+        return data;
+    }
+
+    /**
+     *  @brief Deallocates property fields + keys.
+     */
+    static inline
+    void Dealloc( aiMetadata *metadata ) {
+        delete metadata;
+    }
+
+	template<typename T>
+	inline
+    void Add(const std::string& key, const T& value) {
+		aiString* new_keys = new aiString[mNumProperties + 1];
+		aiMetadataEntry* new_values = new aiMetadataEntry[mNumProperties + 1];
+
+		for(unsigned int i = 0; i < mNumProperties; ++i)
+		{
+			new_keys[i] = mKeys[i];
+			new_values[i] = mValues[i];
+		}
+
+		delete mKeys;
+		delete mValues;
+
+		mKeys = new_keys;
+		mValues = new_values;
+
+		mNumProperties++;
+
+		Set(mNumProperties - 1, key, value);
+	}
+
+    template<typename T>
+    inline 
+    bool Set( unsigned index, const std::string& key, const T& value ) {
+        // In range assertion
+        if ( index >= mNumProperties ) {
+            return false;
+        }
+
+        // Ensure that we have a valid key.
+        if ( key.empty() ) {
+            return false;
+        }
+
+        // Set metadata key
+        mKeys[index] = key;
+
+        // Set metadata type
+        mValues[index].mType = GetAiType(value);
+        // Copy the given value to the dynamic storage
+        mValues[index].mData = new T(value);
+
+        return true;
+    }
+
+    template<typename T>
+    inline 
+    bool Get( unsigned index, T& value ) const {
+        // In range assertion
+        if ( index >= mNumProperties ) {
+            return false;
+        }
+
+        // Return false if the output data type does
+        // not match the found value's data type
+        if ( GetAiType( value ) != mValues[ index ].mType ) {
+            return false;
+        }
+
+        // Otherwise, output the found value and
+        // return true
+        value = *static_cast<T*>(mValues[index].mData);
+
+        return true;
+    }
+
+    template<typename T>
+    inline 
+    bool Get( const aiString& key, T& value ) const {
+        // Search for the given key
+        for ( unsigned int i = 0; i < mNumProperties; ++i ) {
+            if ( mKeys[ i ] == key ) {
+                return Get( i, value );
+            }
+        }
+        return false;
+    }
+
+    template<typename T>
+    inline
+    bool Get( const std::string& key, T& value ) const {
+        return Get(aiString(key), value);
+    }
+
+	/// Return metadata entry for analyzing it by user.
+	/// \param [in] pIndex - index of the entry.
+	/// \param [out] pKey - pointer to the key value.
+	/// \param [out] pEntry - pointer to the entry: type and value.
+	/// \return false - if pIndex is out of range, else - true.
+	inline
+    bool Get(size_t index, const aiString*& key, const aiMetadataEntry*& entry) const {
+        if ( index >= mNumProperties ) {
+            return false;
+        }
+
+		key = &mKeys[index];
+		entry = &mValues[index];
+
+		return true;
+	}
+
+#endif // __cplusplus
+
+};
+
+#endif // AI_METADATA_H_INC

dependencies/assimp/include/assimp/pbrmaterial.h

@@ -0,0 +1,77 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file pbrmaterial.h
+ *  @brief Defines the material system of the library
+ */
+#ifndef AI_PBRMATERIAL_H_INC
+#define AI_PBRMATERIAL_H_INC
+
+#define AI_MATKEY_GLTF_PBRMETALLICROUGHNESS_BASE_COLOR_FACTOR "$mat.gltf.pbrMetallicRoughness.baseColorFactor", 0, 0
+#define AI_MATKEY_GLTF_PBRMETALLICROUGHNESS_METALLIC_FACTOR "$mat.gltf.pbrMetallicRoughness.metallicFactor", 0, 0
+#define AI_MATKEY_GLTF_PBRMETALLICROUGHNESS_ROUGHNESS_FACTOR "$mat.gltf.pbrMetallicRoughness.roughnessFactor", 0, 0
+#define AI_MATKEY_GLTF_PBRMETALLICROUGHNESS_BASE_COLOR_TEXTURE aiTextureType_DIFFUSE, 1
+#define AI_MATKEY_GLTF_PBRMETALLICROUGHNESS_METALLICROUGHNESS_TEXTURE aiTextureType_UNKNOWN, 0
+#define AI_MATKEY_GLTF_ALPHAMODE "$mat.gltf.alphaMode", 0, 0
+#define AI_MATKEY_GLTF_ALPHACUTOFF "$mat.gltf.alphaCutoff", 0, 0
+#define AI_MATKEY_GLTF_PBRSPECULARGLOSSINESS "$mat.gltf.pbrSpecularGlossiness", 0, 0
+#define AI_MATKEY_GLTF_PBRSPECULARGLOSSINESS_GLOSSINESS_FACTOR "$mat.gltf.pbrMetallicRoughness.glossinessFactor", 0, 0
+#define AI_MATKEY_GLTF_UNLIT "$mat.gltf.unlit", 0, 0
+
+#define _AI_MATKEY_GLTF_TEXTURE_TEXCOORD_BASE "$tex.file.texCoord"
+#define _AI_MATKEY_GLTF_MAPPINGNAME_BASE "$tex.mappingname"
+#define _AI_MATKEY_GLTF_MAPPINGID_BASE "$tex.mappingid"
+#define _AI_MATKEY_GLTF_MAPPINGFILTER_MAG_BASE "$tex.mappingfiltermag"
+#define _AI_MATKEY_GLTF_MAPPINGFILTER_MIN_BASE "$tex.mappingfiltermin"
+#define _AI_MATKEY_GLTF_SCALE_BASE "$tex.scale"
+#define _AI_MATKEY_GLTF_STRENGTH_BASE "$tex.strength"
+
+#define AI_MATKEY_GLTF_TEXTURE_TEXCOORD(type, N) _AI_MATKEY_GLTF_TEXTURE_TEXCOORD_BASE, type, N
+#define AI_MATKEY_GLTF_MAPPINGNAME(type, N) _AI_MATKEY_GLTF_MAPPINGNAME_BASE, type, N
+#define AI_MATKEY_GLTF_MAPPINGID(type, N) _AI_MATKEY_GLTF_MAPPINGID_BASE, type, N
+#define AI_MATKEY_GLTF_MAPPINGFILTER_MAG(type, N) _AI_MATKEY_GLTF_MAPPINGFILTER_MAG_BASE, type, N
+#define AI_MATKEY_GLTF_MAPPINGFILTER_MIN(type, N) _AI_MATKEY_GLTF_MAPPINGFILTER_MIN_BASE, type, N
+#define AI_MATKEY_GLTF_TEXTURE_SCALE(type, N) _AI_MATKEY_GLTF_SCALE_BASE, type, N
+#define AI_MATKEY_GLTF_TEXTURE_STRENGTH(type, N) _AI_MATKEY_GLTF_STRENGTH_BASE, type, N
+
+#endif //!!AI_PBRMATERIAL_H_INC

dependencies/assimp/include/assimp/port/AndroidJNI/AndroidJNIIOSystem.h

@@ -0,0 +1,92 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2016, assimp team
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Android implementation of IOSystem using the standard C file functions.
+ * Aimed to ease the access to android assets */
+
+#if __ANDROID__ and __ANDROID_API__ > 9 and defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)
+#ifndef AI_ANDROIDJNIIOSYSTEM_H_INC
+#define AI_ANDROIDJNIIOSYSTEM_H_INC
+
+#include <assimp/DefaultIOSystem.h>
+#include <android/asset_manager.h>
+#include <android/asset_manager_jni.h>
+#include <android/native_activity.h>
+
+namespace Assimp	{
+
+// ---------------------------------------------------------------------------
+/** Android extension to DefaultIOSystem using the standard C file functions */
+class ASSIMP_API AndroidJNIIOSystem : public DefaultIOSystem
+{
+public:
+
+	/** Initialize android activity data */
+	std::string mApkWorkspacePath;
+	AAssetManager* mApkAssetManager;
+
+	/** Constructor. */
+	AndroidJNIIOSystem(ANativeActivity* activity);
+
+	/** Destructor. */
+	~AndroidJNIIOSystem();
+
+	// -------------------------------------------------------------------
+	/** Tests for the existence of a file at the given path. */
+	bool Exists( const char* pFile) const;
+
+	// -------------------------------------------------------------------
+	/** Opens a file at the given path, with given mode */
+	IOStream* Open( const char* strFile, const char* strMode);
+
+	// ------------------------------------------------------------------------------------------------
+	// Inits Android extractor
+	void AndroidActivityInit(ANativeActivity* activity);
+
+	// ------------------------------------------------------------------------------------------------
+	// Extracts android asset
+	bool AndroidExtractAsset(std::string name);
+
+};
+
+} //!ns Assimp
+
+#endif //AI_ANDROIDJNIIOSYSTEM_H_INC
+#endif //__ANDROID__ and __ANDROID_API__ > 9 and defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)

dependencies/assimp/include/assimp/postprocess.h

@@ -0,0 +1,684 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file postprocess.h
+ *  @brief Definitions for import post processing steps
+ */
+#pragma once
+#ifndef AI_POSTPROCESS_H_INC
+#define AI_POSTPROCESS_H_INC
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// -----------------------------------------------------------------------------------
+/** @enum  aiPostProcessSteps
+ *  @brief Defines the flags for all possible post processing steps.
+ *
+ *  @note Some steps are influenced by properties set on the Assimp::Importer itself
+ *
+ *  @see Assimp::Importer::ReadFile()
+ *  @see Assimp::Importer::SetPropertyInteger()
+ *  @see aiImportFile
+ *  @see aiImportFileEx
+ */
+// -----------------------------------------------------------------------------------
+enum aiPostProcessSteps
+{
+
+    // -------------------------------------------------------------------------
+    /** <hr>Calculates the tangents and bitangents for the imported meshes.
+     *
+     * Does nothing if a mesh does not have normals. You might want this post
+     * processing step to be executed if you plan to use tangent space calculations
+     * such as normal mapping  applied to the meshes. There's an importer property,
+     * <tt>#AI_CONFIG_PP_CT_MAX_SMOOTHING_ANGLE</tt>, which allows you to specify
+     * a maximum smoothing angle for the algorithm. However, usually you'll
+     * want to leave it at the default value.
+     */
+    aiProcess_CalcTangentSpace = 0x1,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Identifies and joins identical vertex data sets within all
+     *  imported meshes.
+     *
+     * After this step is run, each mesh contains unique vertices,
+     * so a vertex may be used by multiple faces. You usually want
+     * to use this post processing step. If your application deals with
+     * indexed geometry, this step is compulsory or you'll just waste rendering
+     * time. <b>If this flag is not specified</b>, no vertices are referenced by
+     * more than one face and <b>no index buffer is required</b> for rendering.
+     */
+    aiProcess_JoinIdenticalVertices = 0x2,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Converts all the imported data to a left-handed coordinate space.
+     *
+     * By default the data is returned in a right-handed coordinate space (which
+     * OpenGL prefers). In this space, +X points to the right,
+     * +Z points towards the viewer, and +Y points upwards. In the DirectX
+     * coordinate space +X points to the right, +Y points upwards, and +Z points
+     * away from the viewer.
+     *
+     * You'll probably want to consider this flag if you use Direct3D for
+     * rendering. The #aiProcess_ConvertToLeftHanded flag supersedes this
+     * setting and bundles all conversions typically required for D3D-based
+     * applications.
+     */
+    aiProcess_MakeLeftHanded = 0x4,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Triangulates all faces of all meshes.
+     *
+     * By default the imported mesh data might contain faces with more than 3
+     * indices. For rendering you'll usually want all faces to be triangles.
+     * This post processing step splits up faces with more than 3 indices into
+     * triangles. Line and point primitives are *not* modified! If you want
+     * 'triangles only' with no other kinds of primitives, try the following
+     * solution:
+     * <ul>
+     * <li>Specify both #aiProcess_Triangulate and #aiProcess_SortByPType </li>
+     * <li>Ignore all point and line meshes when you process assimp's output</li>
+     * </ul>
+     */
+    aiProcess_Triangulate = 0x8,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Removes some parts of the data structure (animations, materials,
+     *  light sources, cameras, textures, vertex components).
+     *
+     * The  components to be removed are specified in a separate
+     * importer property, <tt>#AI_CONFIG_PP_RVC_FLAGS</tt>. This is quite useful
+     * if you don't need all parts of the output structure. Vertex colors
+     * are rarely used today for example... Calling this step to remove unneeded
+     * data from the pipeline as early as possible results in increased
+     * performance and a more optimized output data structure.
+     * This step is also useful if you want to force Assimp to recompute
+     * normals or tangents. The corresponding steps don't recompute them if
+     * they're already there (loaded from the source asset). By using this
+     * step you can make sure they are NOT there.
+     *
+     * This flag is a poor one, mainly because its purpose is usually
+     * misunderstood. Consider the following case: a 3D model has been exported
+     * from a CAD app, and it has per-face vertex colors. Vertex positions can't be
+     * shared, thus the #aiProcess_JoinIdenticalVertices step fails to
+     * optimize the data because of these nasty little vertex colors.
+     * Most apps don't even process them, so it's all for nothing. By using
+     * this step, unneeded components are excluded as early as possible
+     * thus opening more room for internal optimizations.
+     */
+    aiProcess_RemoveComponent = 0x10,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Generates normals for all faces of all meshes.
+     *
+     * This is ignored if normals are already there at the time this flag
+     * is evaluated. Model importers try to load them from the source file, so
+     * they're usually already there. Face normals are shared between all points
+     * of a single face, so a single point can have multiple normals, which
+     * forces the library to duplicate vertices in some cases.
+     * #aiProcess_JoinIdenticalVertices is *senseless* then.
+     *
+     * This flag may not be specified together with #aiProcess_GenSmoothNormals.
+     */
+    aiProcess_GenNormals = 0x20,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Generates smooth normals for all vertices in the mesh.
+    *
+    * This is ignored if normals are already there at the time this flag
+    * is evaluated. Model importers try to load them from the source file, so
+    * they're usually already there.
+    *
+    * This flag may not be specified together with
+    * #aiProcess_GenNormals. There's a importer property,
+    * <tt>#AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE</tt> which allows you to specify
+    * an angle maximum for the normal smoothing algorithm. Normals exceeding
+    * this limit are not smoothed, resulting in a 'hard' seam between two faces.
+    * Using a decent angle here (e.g. 80 degrees) results in very good visual
+    * appearance.
+    */
+    aiProcess_GenSmoothNormals = 0x40,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Splits large meshes into smaller sub-meshes.
+    *
+    * This is quite useful for real-time rendering, where the number of triangles
+    * which can be maximally processed in a single draw-call is limited
+    * by the video driver/hardware. The maximum vertex buffer is usually limited
+    * too. Both requirements can be met with this step: you may specify both a
+    * triangle and vertex limit for a single mesh.
+    *
+    * The split limits can (and should!) be set through the
+    * <tt>#AI_CONFIG_PP_SLM_VERTEX_LIMIT</tt> and <tt>#AI_CONFIG_PP_SLM_TRIANGLE_LIMIT</tt>
+    * importer properties. The default values are <tt>#AI_SLM_DEFAULT_MAX_VERTICES</tt> and
+    * <tt>#AI_SLM_DEFAULT_MAX_TRIANGLES</tt>.
+    *
+    * Note that splitting is generally a time-consuming task, but only if there's
+    * something to split. The use of this step is recommended for most users.
+    */
+    aiProcess_SplitLargeMeshes = 0x80,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Removes the node graph and pre-transforms all vertices with
+    * the local transformation matrices of their nodes.
+    *
+    * The output scene still contains nodes, however there is only a
+    * root node with children, each one referencing only one mesh,
+    * and each mesh referencing one material. For rendering, you can
+    * simply render all meshes in order - you don't need to pay
+    * attention to local transformations and the node hierarchy.
+    * Animations are removed during this step.
+    * This step is intended for applications without a scenegraph.
+    * The step CAN cause some problems: if e.g. a mesh of the asset
+    * contains normals and another, using the same material index, does not,
+    * they will be brought together, but the first meshes's part of
+    * the normal list is zeroed. However, these artifacts are rare.
+    * @note The <tt>#AI_CONFIG_PP_PTV_NORMALIZE</tt> configuration property
+    * can be set to normalize the scene's spatial dimension to the -1...1
+    * range.
+    */
+    aiProcess_PreTransformVertices = 0x100,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Limits the number of bones simultaneously affecting a single vertex
+    *  to a maximum value.
+    *
+    * If any vertex is affected by more than the maximum number of bones, the least
+    * important vertex weights are removed and the remaining vertex weights are
+    * renormalized so that the weights still sum up to 1.
+    * The default bone weight limit is 4 (defined as <tt>#AI_LMW_MAX_WEIGHTS</tt> in
+    * config.h), but you can use the <tt>#AI_CONFIG_PP_LBW_MAX_WEIGHTS</tt> importer
+    * property to supply your own limit to the post processing step.
+    *
+    * If you intend to perform the skinning in hardware, this post processing
+    * step might be of interest to you.
+    */
+    aiProcess_LimitBoneWeights = 0x200,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Validates the imported scene data structure.
+     * This makes sure that all indices are valid, all animations and
+     * bones are linked correctly, all material references are correct .. etc.
+     *
+     * It is recommended that you capture Assimp's log output if you use this flag,
+     * so you can easily find out what's wrong if a file fails the
+     * validation. The validator is quite strict and will find *all*
+     * inconsistencies in the data structure... It is recommended that plugin
+     * developers use it to debug their loaders. There are two types of
+     * validation failures:
+     * <ul>
+     * <li>Error: There's something wrong with the imported data. Further
+     *   postprocessing is not possible and the data is not usable at all.
+     *   The import fails. #Importer::GetErrorString() or #aiGetErrorString()
+     *   carry the error message around.</li>
+     * <li>Warning: There are some minor issues (e.g. 1000000 animation
+     *   keyframes with the same time), but further postprocessing and use
+     *   of the data structure is still safe. Warning details are written
+     *   to the log file, <tt>#AI_SCENE_FLAGS_VALIDATION_WARNING</tt> is set
+     *   in #aiScene::mFlags</li>
+     * </ul>
+     *
+     * This post-processing step is not time-consuming. Its use is not
+     * compulsory, but recommended.
+    */
+    aiProcess_ValidateDataStructure = 0x400,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Reorders triangles for better vertex cache locality.
+     *
+     * The step tries to improve the ACMR (average post-transform vertex cache
+     * miss ratio) for all meshes. The implementation runs in O(n) and is
+     * roughly based on the 'tipsify' algorithm (see <a href="
+     * http://www.cs.princeton.edu/gfx/pubs/Sander_2007_%3ETR/tipsy.pdf">this
+     * paper</a>).
+     *
+     * If you intend to render huge models in hardware, this step might
+     * be of interest to you. The <tt>#AI_CONFIG_PP_ICL_PTCACHE_SIZE</tt>
+     * importer property can be used to fine-tune the cache optimization.
+     */
+    aiProcess_ImproveCacheLocality = 0x800,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Searches for redundant/unreferenced materials and removes them.
+     *
+     * This is especially useful in combination with the
+     * #aiProcess_PreTransformVertices and #aiProcess_OptimizeMeshes flags.
+     * Both join small meshes with equal characteristics, but they can't do
+     * their work if two meshes have different materials. Because several
+     * material settings are lost during Assimp's import filters,
+     * (and because many exporters don't check for redundant materials), huge
+     * models often have materials which are are defined several times with
+     * exactly the same settings.
+     *
+     * Several material settings not contributing to the final appearance of
+     * a surface are ignored in all comparisons (e.g. the material name).
+     * So, if you're passing additional information through the
+     * content pipeline (probably using *magic* material names), don't
+     * specify this flag. Alternatively take a look at the
+     * <tt>#AI_CONFIG_PP_RRM_EXCLUDE_LIST</tt> importer property.
+     */
+    aiProcess_RemoveRedundantMaterials = 0x1000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step tries to determine which meshes have normal vectors
+     * that are facing inwards and inverts them.
+     *
+     * The algorithm is simple but effective:
+     * the bounding box of all vertices + their normals is compared against
+     * the volume of the bounding box of all vertices without their normals.
+     * This works well for most objects, problems might occur with planar
+     * surfaces. However, the step tries to filter such cases.
+     * The step inverts all in-facing normals. Generally it is recommended
+     * to enable this step, although the result is not always correct.
+    */
+    aiProcess_FixInfacingNormals = 0x2000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step splits meshes with more than one primitive type in
+     *  homogeneous sub-meshes.
+     *
+     *  The step is executed after the triangulation step. After the step
+     *  returns, just one bit is set in aiMesh::mPrimitiveTypes. This is
+     *  especially useful for real-time rendering where point and line
+     *  primitives are often ignored or rendered separately.
+     *  You can use the <tt>#AI_CONFIG_PP_SBP_REMOVE</tt> importer property to
+     *  specify which primitive types you need. This can be used to easily
+     *  exclude lines and points, which are rarely used, from the import.
+    */
+    aiProcess_SortByPType = 0x8000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step searches all meshes for degenerate primitives and
+     *  converts them to proper lines or points.
+     *
+     * A face is 'degenerate' if one or more of its points are identical.
+     * To have the degenerate stuff not only detected and collapsed but
+     * removed, try one of the following procedures:
+     * <br><b>1.</b> (if you support lines and points for rendering but don't
+     *    want the degenerates)<br>
+     * <ul>
+     *   <li>Specify the #aiProcess_FindDegenerates flag.
+     *   </li>
+     *   <li>Set the <tt>#AI_CONFIG_PP_FD_REMOVE</tt> importer property to
+     *       1. This will cause the step to remove degenerate triangles from the
+     *       import as soon as they're detected. They won't pass any further
+     *       pipeline steps.
+     *   </li>
+     * </ul>
+     * <br><b>2.</b>(if you don't support lines and points at all)<br>
+     * <ul>
+     *   <li>Specify the #aiProcess_FindDegenerates flag.
+     *   </li>
+     *   <li>Specify the #aiProcess_SortByPType flag. This moves line and
+     *     point primitives to separate meshes.
+     *   </li>
+     *   <li>Set the <tt>#AI_CONFIG_PP_SBP_REMOVE</tt> importer property to
+     *       @code aiPrimitiveType_POINTS | aiPrimitiveType_LINES
+     *       @endcode to cause SortByPType to reject point
+     *       and line meshes from the scene.
+     *   </li>
+     * </ul>
+     *
+     * This step also removes very small triangles with a surface area smaller
+     * than 10^-6. If you rely on having these small triangles, or notice holes
+     * in your model, set the property <tt>#AI_CONFIG_PP_FD_CHECKAREA</tt> to
+     * false.
+     * @note Degenerate polygons are not necessarily evil and that's why
+     * they're not removed by default. There are several file formats which
+     * don't support lines or points, and some exporters bypass the
+     * format specification and write them as degenerate triangles instead.
+    */
+    aiProcess_FindDegenerates = 0x10000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step searches all meshes for invalid data, such as zeroed
+     *  normal vectors or invalid UV coords and removes/fixes them. This is
+     *  intended to get rid of some common exporter errors.
+     *
+     * This is especially useful for normals. If they are invalid, and
+     * the step recognizes this, they will be removed and can later
+     * be recomputed, i.e. by the #aiProcess_GenSmoothNormals flag.<br>
+     * The step will also remove meshes that are infinitely small and reduce
+     * animation tracks consisting of hundreds if redundant keys to a single
+     * key. The <tt>AI_CONFIG_PP_FID_ANIM_ACCURACY</tt> config property decides
+     * the accuracy of the check for duplicate animation tracks.
+    */
+    aiProcess_FindInvalidData = 0x20000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step converts non-UV mappings (such as spherical or
+     *  cylindrical mapping) to proper texture coordinate channels.
+     *
+     * Most applications will support UV mapping only, so you will
+     * probably want to specify this step in every case. Note that Assimp is not
+     * always able to match the original mapping implementation of the
+     * 3D app which produced a model perfectly. It's always better to let the
+     * modelling app compute the UV channels - 3ds max, Maya, Blender,
+     * LightWave, and Modo do this for example.
+     *
+     * @note If this step is not requested, you'll need to process the
+     * <tt>#AI_MATKEY_MAPPING</tt> material property in order to display all assets
+     * properly.
+     */
+    aiProcess_GenUVCoords = 0x40000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step applies per-texture UV transformations and bakes
+     *  them into stand-alone vtexture coordinate channels.
+     *
+     * UV transformations are specified per-texture - see the
+     * <tt>#AI_MATKEY_UVTRANSFORM</tt> material key for more information.
+     * This step processes all textures with
+     * transformed input UV coordinates and generates a new (pre-transformed) UV channel
+     * which replaces the old channel. Most applications won't support UV
+     * transformations, so you will probably want to specify this step.
+     *
+     * @note UV transformations are usually implemented in real-time apps by
+     * transforming texture coordinates at vertex shader stage with a 3x3
+     * (homogenous) transformation matrix.
+    */
+    aiProcess_TransformUVCoords = 0x80000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step searches for duplicate meshes and replaces them
+     *  with references to the first mesh.
+     *
+     *  This step takes a while, so don't use it if speed is a concern.
+     *  Its main purpose is to workaround the fact that many export
+     *  file formats don't support instanced meshes, so exporters need to
+     *  duplicate meshes. This step removes the duplicates again. Please
+     *  note that Assimp does not currently support per-node material
+     *  assignment to meshes, which means that identical meshes with
+     *  different materials are currently *not* joined, although this is
+     *  planned for future versions.
+     */
+    aiProcess_FindInstances = 0x100000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>A post-processing step to reduce the number of meshes.
+     *
+     *  This will, in fact, reduce the number of draw calls.
+     *
+     *  This is a very effective optimization and is recommended to be used
+     *  together with #aiProcess_OptimizeGraph, if possible. The flag is fully
+     *  compatible with both #aiProcess_SplitLargeMeshes and #aiProcess_SortByPType.
+    */
+    aiProcess_OptimizeMeshes  = 0x200000,
+
+
+    // -------------------------------------------------------------------------
+    /** <hr>A post-processing step to optimize the scene hierarchy.
+     *
+     *  Nodes without animations, bones, lights or cameras assigned are
+     *  collapsed and joined.
+     *
+     *  Node names can be lost during this step. If you use special 'tag nodes'
+     *  to pass additional information through your content pipeline, use the
+     *  <tt>#AI_CONFIG_PP_OG_EXCLUDE_LIST</tt> importer property to specify a
+     *  list of node names you want to be kept. Nodes matching one of the names
+     *  in this list won't be touched or modified.
+     *
+     *  Use this flag with caution. Most simple files will be collapsed to a
+     *  single node, so complex hierarchies are usually completely lost. This is not
+     *  useful for editor environments, but probably a very effective
+     *  optimization if you just want to get the model data, convert it to your
+     *  own format, and render it as fast as possible.
+     *
+     *  This flag is designed to be used with #aiProcess_OptimizeMeshes for best
+     *  results.
+     *
+     *  @note 'Crappy' scenes with thousands of extremely small meshes packed
+     *  in deeply nested nodes exist for almost all file formats.
+     *  #aiProcess_OptimizeMeshes in combination with #aiProcess_OptimizeGraph
+     *  usually fixes them all and makes them renderable.
+    */
+    aiProcess_OptimizeGraph  = 0x400000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step flips all UV coordinates along the y-axis and adjusts
+     * material settings and bitangents accordingly.
+     *
+     * <b>Output UV coordinate system:</b>
+     * @code
+     * 0y|0y ---------- 1x|0y
+     * |                 |
+     * |                 |
+     * |                 |
+     * 0x|1y ---------- 1x|1y
+     * @endcode
+     *
+     * You'll probably want to consider this flag if you use Direct3D for
+     * rendering. The #aiProcess_ConvertToLeftHanded flag supersedes this
+     * setting and bundles all conversions typically required for D3D-based
+     * applications.
+    */
+    aiProcess_FlipUVs = 0x800000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step adjusts the output face winding order to be CW.
+     *
+     * The default face winding order is counter clockwise (CCW).
+     *
+     * <b>Output face order:</b>
+     * @code
+     *       x2
+     *
+     *                         x0
+     *  x1
+     * @endcode
+    */
+    aiProcess_FlipWindingOrder  = 0x1000000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step splits meshes with many bones into sub-meshes so that each
+     * sub-mesh has fewer or as many bones as a given limit.
+    */
+    aiProcess_SplitByBoneCount  = 0x2000000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step removes bones losslessly or according to some threshold.
+     *
+     *  In some cases (i.e. formats that require it) exporters are forced to
+     *  assign dummy bone weights to otherwise static meshes assigned to
+     *  animated meshes. Full, weight-based skinning is expensive while
+     *  animating nodes is extremely cheap, so this step is offered to clean up
+     *  the data in that regard.
+     *
+     *  Use <tt>#AI_CONFIG_PP_DB_THRESHOLD</tt> to control this.
+     *  Use <tt>#AI_CONFIG_PP_DB_ALL_OR_NONE</tt> if you want bones removed if and
+     *  only if all bones within the scene qualify for removal.
+    */
+    aiProcess_Debone  = 0x4000000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>This step will perform a global scale of the model.
+    *
+    *  Some importers are providing a mechanism to define a scaling unit for the
+    *  model. This post processing step can be used to do so. You need to get the
+    *  global scaling from your importer settings like in FBX. Use the flag
+    *  AI_CONFIG_GLOBAL_SCALE_FACTOR_KEY from the global property table to configure this.
+    *
+    *  Use <tt>#AI_CONFIG_GLOBAL_SCALE_FACTOR_KEY</tt> to setup the global scaling factor.
+    */
+    aiProcess_GlobalScale = 0x8000000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>A postprocessing step to embed of textures.
+     *
+     *  This will remove external data dependencies for textures.
+     *  If a texture's file does not exist at the specified path
+     *  (due, for instance, to an absolute path generated on another system),
+     *  it will check if a file with the same name exists at the root folder
+     *  of the imported model. And if so, it uses that.
+     */
+    aiProcess_EmbedTextures  = 0x10000000,
+        
+    // aiProcess_GenEntityMeshes = 0x100000,
+    // aiProcess_OptimizeAnimations = 0x200000
+    // aiProcess_FixTexturePaths = 0x200000
+
+
+    aiProcess_ForceGenNormals = 0x20000000,
+
+    // -------------------------------------------------------------------------
+    /** <hr>Drops normals for all faces of all meshes.
+     *
+     * This is ignored if no normals are present.
+     * Face normals are shared between all points of a single face,
+     * so a single point can have multiple normals, which
+     * forces the library to duplicate vertices in some cases.
+     * #aiProcess_JoinIdenticalVertices is *senseless* then.
+     * This process gives sense back to aiProcess_JoinIdenticalVertices
+     */
+    aiProcess_DropNormals = 0x40000000,
+
+    // -------------------------------------------------------------------------
+    /**
+     */
+    aiProcess_GenBoundingBoxes = 0x80000000
+};
+
+
+// ---------------------------------------------------------------------------------------
+/** @def aiProcess_ConvertToLeftHanded
+ *  @brief Shortcut flag for Direct3D-based applications.
+ *
+ *  Supersedes the #aiProcess_MakeLeftHanded and #aiProcess_FlipUVs and
+ *  #aiProcess_FlipWindingOrder flags.
+ *  The output data matches Direct3D's conventions: left-handed geometry, upper-left
+ *  origin for UV coordinates and finally clockwise face order, suitable for CCW culling.
+ *
+ *  @deprecated
+ */
+#define aiProcess_ConvertToLeftHanded ( \
+    aiProcess_MakeLeftHanded     | \
+    aiProcess_FlipUVs            | \
+    aiProcess_FlipWindingOrder   | \
+    0 )
+
+
+// ---------------------------------------------------------------------------------------
+/** @def aiProcessPreset_TargetRealtime_Fast
+ *  @brief Default postprocess configuration optimizing the data for real-time rendering.
+ *
+ *  Applications would want to use this preset to load models on end-user PCs,
+ *  maybe for direct use in game.
+ *
+ * If you're using DirectX, don't forget to combine this value with
+ * the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations
+ * in your application apply the #aiProcess_TransformUVCoords step, too.
+ *  @note Please take the time to read the docs for the steps enabled by this preset.
+ *  Some of them offer further configurable properties, while some of them might not be of
+ *  use for you so it might be better to not specify them.
+ */
+#define aiProcessPreset_TargetRealtime_Fast ( \
+    aiProcess_CalcTangentSpace      |  \
+    aiProcess_GenNormals            |  \
+    aiProcess_JoinIdenticalVertices |  \
+    aiProcess_Triangulate           |  \
+    aiProcess_GenUVCoords           |  \
+    aiProcess_SortByPType           |  \
+    0 )
+
+ // ---------------------------------------------------------------------------------------
+ /** @def aiProcessPreset_TargetRealtime_Quality
+  *  @brief Default postprocess configuration optimizing the data for real-time rendering.
+  *
+  *  Unlike #aiProcessPreset_TargetRealtime_Fast, this configuration
+  *  performs some extra optimizations to improve rendering speed and
+  *  to minimize memory usage. It could be a good choice for a level editor
+  *  environment where import speed is not so important.
+  *
+  *  If you're using DirectX, don't forget to combine this value with
+  *  the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations
+  *  in your application apply the #aiProcess_TransformUVCoords step, too.
+  *  @note Please take the time to read the docs for the steps enabled by this preset.
+  *  Some of them offer further configurable properties, while some of them might not be
+  *  of use for you so it might be better to not specify them.
+  */
+#define aiProcessPreset_TargetRealtime_Quality ( \
+    aiProcess_CalcTangentSpace              |  \
+    aiProcess_GenSmoothNormals              |  \
+    aiProcess_JoinIdenticalVertices         |  \
+    aiProcess_ImproveCacheLocality          |  \
+    aiProcess_LimitBoneWeights              |  \
+    aiProcess_RemoveRedundantMaterials      |  \
+    aiProcess_SplitLargeMeshes              |  \
+    aiProcess_Triangulate                   |  \
+    aiProcess_GenUVCoords                   |  \
+    aiProcess_SortByPType                   |  \
+    aiProcess_FindDegenerates               |  \
+    aiProcess_FindInvalidData               |  \
+    0 )
+
+ // ---------------------------------------------------------------------------------------
+ /** @def aiProcessPreset_TargetRealtime_MaxQuality
+  *  @brief Default postprocess configuration optimizing the data for real-time rendering.
+  *
+  *  This preset enables almost every optimization step to achieve perfectly
+  *  optimized data. It's your choice for level editor environments where import speed
+  *  is not important.
+  *
+  *  If you're using DirectX, don't forget to combine this value with
+  *  the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations
+  *  in your application, apply the #aiProcess_TransformUVCoords step, too.
+  *  @note Please take the time to read the docs for the steps enabled by this preset.
+  *  Some of them offer further configurable properties, while some of them might not be
+  *  of use for you so it might be better to not specify them.
+  */
+#define aiProcessPreset_TargetRealtime_MaxQuality ( \
+    aiProcessPreset_TargetRealtime_Quality   |  \
+    aiProcess_FindInstances                  |  \
+    aiProcess_ValidateDataStructure          |  \
+    aiProcess_OptimizeMeshes                 |  \
+    0 )
+
+
+#ifdef __cplusplus
+} // end of extern "C"
+#endif
+
+#endif // AI_POSTPROCESS_H_INC

dependencies/assimp/include/assimp/qnan.h

@@ -0,0 +1,165 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/**  @file  qnan.h
+ *   @brief Some utilities for our dealings with qnans.
+ *
+ *   @note Some loaders use qnans to mark invalid values tempoarily, also
+ *     Assimp explicitly enforces undefined normals to be set to qnan.
+ *     qnan utilities are available in standard libraries (C99 for example)
+ *     but last time I checked compiler coverage was so bad that I decided
+ *     to reinvent the wheel.
+ */
+
+#ifndef AI_QNAN_H_INCLUDED
+#define AI_QNAN_H_INCLUDED
+
+#include <assimp/defs.h>
+#include <limits>
+#include <stdint.h>
+
+// ---------------------------------------------------------------------------
+/** Data structure to represent the bit pattern of a 32 Bit
+ *         IEEE 754 floating-point number. */
+union _IEEESingle
+{
+    float Float;
+    struct
+    {
+        uint32_t Frac : 23;
+        uint32_t Exp  : 8;
+        uint32_t Sign : 1;
+    } IEEE;
+};
+
+// ---------------------------------------------------------------------------
+/** Data structure to represent the bit pattern of a 64 Bit
+ *         IEEE 754 floating-point number. */
+union _IEEEDouble
+{
+    double Double;
+    struct
+    {
+        uint64_t Frac : 52;
+        uint64_t Exp  : 11;
+        uint64_t Sign : 1;
+    } IEEE;
+};
+
+// ---------------------------------------------------------------------------
+/** Check whether a given float is qNaN.
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_qnan(float in)
+{
+    // the straightforward solution does not work:
+    //   return (in != in);
+    // compiler generates code like this
+    //   load <in> to <register-with-different-width>
+    //   compare <register-with-different-width> against <in>
+
+    // FIXME: Use <float> stuff instead? I think fpclassify needs C99
+    _IEEESingle temp;
+    memcpy(&temp, &in, sizeof(float));
+    return (temp.IEEE.Exp == (1u << 8)-1 &&
+        temp.IEEE.Frac);
+}
+
+// ---------------------------------------------------------------------------
+/** Check whether a given double is qNaN.
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_qnan(double in)
+{
+    // the straightforward solution does not work:
+    //   return (in != in);
+    // compiler generates code like this
+    //   load <in> to <register-with-different-width>
+    //   compare <register-with-different-width> against <in>
+
+    // FIXME: Use <float> stuff instead? I think fpclassify needs C99
+    _IEEEDouble temp;
+    memcpy(&temp, &in, sizeof(in));
+    return (temp.IEEE.Exp == (1u << 11)-1 &&
+        temp.IEEE.Frac);
+}
+
+// ---------------------------------------------------------------------------
+/** @brief check whether a float is either NaN or (+/-) INF.
+ *
+ *  Denorms return false, they're treated like normal values.
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_special_float(float in)
+{
+    _IEEESingle temp;
+    memcpy(&temp, &in, sizeof(float));
+    return (temp.IEEE.Exp == (1u << 8)-1);
+}
+
+// ---------------------------------------------------------------------------
+/** @brief check whether a double is either NaN or (+/-) INF.
+ *
+ *  Denorms return false, they're treated like normal values.
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_special_float(double in)
+{
+   _IEEESingle temp;
+    memcpy(&temp, &in, sizeof(float));
+    return (temp.IEEE.Exp == (1u << 11)-1);
+}
+
+// ---------------------------------------------------------------------------
+/** Check whether a float is NOT qNaN.
+ *  @param in Input value */
+template<class TReal>
+AI_FORCE_INLINE bool is_not_qnan(TReal in)
+{
+    return !is_qnan(in);
+}
+
+// ---------------------------------------------------------------------------
+/** @brief Get a fresh qnan.  */
+AI_FORCE_INLINE ai_real get_qnan()
+{
+    return std::numeric_limits<ai_real>::quiet_NaN();
+}
+
+#endif // !! AI_QNAN_H_INCLUDED

dependencies/assimp/include/assimp/quaternion.h

@@ -0,0 +1,130 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file quaternion.h
+ *  @brief Quaternion structure, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_QUATERNION_H_INC
+#define AI_QUATERNION_H_INC
+
+#ifdef __cplusplus
+
+#include "defs.h"
+
+template <typename TReal> class aiVector3t;
+template <typename TReal> class aiMatrix3x3t;
+
+// ---------------------------------------------------------------------------
+/** Represents a quaternion in a 4D vector. */
+template <typename TReal>
+class aiQuaterniont
+{
+public:
+    aiQuaterniont() AI_NO_EXCEPT : w(1.0), x(), y(), z() {}
+    aiQuaterniont(TReal pw, TReal px, TReal py, TReal pz)
+        : w(pw), x(px), y(py), z(pz) {}
+
+    /** Construct from rotation matrix. Result is undefined if the matrix is not orthonormal. */
+    explicit aiQuaterniont( const aiMatrix3x3t<TReal>& pRotMatrix);
+
+    /** Construct from euler angles */
+    aiQuaterniont( TReal rotx, TReal roty, TReal rotz);
+
+    /** Construct from an axis-angle pair */
+    aiQuaterniont( aiVector3t<TReal> axis, TReal angle);
+
+    /** Construct from a normalized quaternion stored in a vec3 */
+    explicit aiQuaterniont( aiVector3t<TReal> normalized);
+
+    /** Returns a matrix representation of the quaternion */
+    aiMatrix3x3t<TReal> GetMatrix() const;
+
+public:
+
+    bool operator== (const aiQuaterniont& o) const;
+    bool operator!= (const aiQuaterniont& o) const;
+
+    bool Equal(const aiQuaterniont& o, TReal epsilon = 1e-6) const;
+
+public:
+
+    /** Normalize the quaternion */
+    aiQuaterniont& Normalize();
+
+    /** Compute quaternion conjugate */
+    aiQuaterniont& Conjugate ();
+
+    /** Rotate a point by this quaternion */
+    aiVector3t<TReal> Rotate (const aiVector3t<TReal>& in);
+
+    /** Multiply two quaternions */
+    aiQuaterniont operator* (const aiQuaterniont& two) const;
+
+public:
+
+    /** Performs a spherical interpolation between two quaternions and writes the result into the third.
+     * @param pOut Target object to received the interpolated rotation.
+     * @param pStart Start rotation of the interpolation at factor == 0.
+     * @param pEnd End rotation, factor == 1.
+     * @param pFactor Interpolation factor between 0 and 1. Values outside of this range yield undefined results.
+     */
+    static void Interpolate( aiQuaterniont& pOut, const aiQuaterniont& pStart,
+        const aiQuaterniont& pEnd, TReal pFactor);
+
+public:
+
+    //! w,x,y,z components of the quaternion
+    TReal w, x, y, z;
+} ;
+
+typedef aiQuaterniont<ai_real> aiQuaternion;
+
+#else
+
+struct aiQuaternion {
+    ai_real w, x, y, z;
+};
+
+#endif
+
+#endif // AI_QUATERNION_H_INC

dependencies/assimp/include/assimp/quaternion.inl

@@ -0,0 +1,286 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  quaternion.inl
+ *  @brief Inline implementation of aiQuaterniont<TReal> operators
+ */
+#pragma once
+#ifndef AI_QUATERNION_INL_INC
+#define AI_QUATERNION_INL_INC
+
+#ifdef __cplusplus
+#include "quaternion.h"
+
+#include <cmath>
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+bool aiQuaterniont<TReal>::operator== (const aiQuaterniont& o) const
+{
+    return x == o.x && y == o.y && z == o.z && w == o.w;
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+bool aiQuaterniont<TReal>::operator!= (const aiQuaterniont& o) const
+{
+    return !(*this == o);
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline bool aiQuaterniont<TReal>::Equal(const aiQuaterniont& o, TReal epsilon) const {
+    return
+        std::abs(x - o.x) <= epsilon &&
+        std::abs(y - o.y) <= epsilon &&
+        std::abs(z - o.z) <= epsilon &&
+        std::abs(w - o.w) <= epsilon;
+}
+
+// ---------------------------------------------------------------------------
+// Constructs a quaternion from a rotation matrix
+template<typename TReal>
+inline aiQuaterniont<TReal>::aiQuaterniont( const aiMatrix3x3t<TReal> &pRotMatrix)
+{
+    TReal t = pRotMatrix.a1 + pRotMatrix.b2 + pRotMatrix.c3;
+
+    // large enough
+    if( t > static_cast<TReal>(0))
+    {
+        TReal s = std::sqrt(1 + t) * static_cast<TReal>(2.0);
+        x = (pRotMatrix.c2 - pRotMatrix.b3) / s;
+        y = (pRotMatrix.a3 - pRotMatrix.c1) / s;
+        z = (pRotMatrix.b1 - pRotMatrix.a2) / s;
+        w = static_cast<TReal>(0.25) * s;
+    } // else we have to check several cases
+    else if( pRotMatrix.a1 > pRotMatrix.b2 && pRotMatrix.a1 > pRotMatrix.c3 )
+    {
+        // Column 0:
+        TReal s = std::sqrt( static_cast<TReal>(1.0) + pRotMatrix.a1 - pRotMatrix.b2 - pRotMatrix.c3) * static_cast<TReal>(2.0);
+        x = static_cast<TReal>(0.25) * s;
+        y = (pRotMatrix.b1 + pRotMatrix.a2) / s;
+        z = (pRotMatrix.a3 + pRotMatrix.c1) / s;
+        w = (pRotMatrix.c2 - pRotMatrix.b3) / s;
+    }
+    else if( pRotMatrix.b2 > pRotMatrix.c3)
+    {
+        // Column 1:
+        TReal s = std::sqrt( static_cast<TReal>(1.0) + pRotMatrix.b2 - pRotMatrix.a1 - pRotMatrix.c3) * static_cast<TReal>(2.0);
+        x = (pRotMatrix.b1 + pRotMatrix.a2) / s;
+        y = static_cast<TReal>(0.25) * s;
+        z = (pRotMatrix.c2 + pRotMatrix.b3) / s;
+        w = (pRotMatrix.a3 - pRotMatrix.c1) / s;
+    } else
+    {
+        // Column 2:
+        TReal s = std::sqrt( static_cast<TReal>(1.0) + pRotMatrix.c3 - pRotMatrix.a1 - pRotMatrix.b2) * static_cast<TReal>(2.0);
+        x = (pRotMatrix.a3 + pRotMatrix.c1) / s;
+        y = (pRotMatrix.c2 + pRotMatrix.b3) / s;
+        z = static_cast<TReal>(0.25) * s;
+        w = (pRotMatrix.b1 - pRotMatrix.a2) / s;
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Construction from euler angles
+template<typename TReal>
+inline aiQuaterniont<TReal>::aiQuaterniont( TReal fPitch, TReal fYaw, TReal fRoll )
+{
+    const TReal fSinPitch(std::sin(fPitch*static_cast<TReal>(0.5)));
+    const TReal fCosPitch(std::cos(fPitch*static_cast<TReal>(0.5)));
+    const TReal fSinYaw(std::sin(fYaw*static_cast<TReal>(0.5)));
+    const TReal fCosYaw(std::cos(fYaw*static_cast<TReal>(0.5)));
+    const TReal fSinRoll(std::sin(fRoll*static_cast<TReal>(0.5)));
+    const TReal fCosRoll(std::cos(fRoll*static_cast<TReal>(0.5)));
+    const TReal fCosPitchCosYaw(fCosPitch*fCosYaw);
+    const TReal fSinPitchSinYaw(fSinPitch*fSinYaw);
+    x = fSinRoll * fCosPitchCosYaw     - fCosRoll * fSinPitchSinYaw;
+    y = fCosRoll * fSinPitch * fCosYaw + fSinRoll * fCosPitch * fSinYaw;
+    z = fCosRoll * fCosPitch * fSinYaw - fSinRoll * fSinPitch * fCosYaw;
+    w = fCosRoll * fCosPitchCosYaw     + fSinRoll * fSinPitchSinYaw;
+}
+
+// ---------------------------------------------------------------------------
+// Returns a matrix representation of the quaternion
+template<typename TReal>
+inline aiMatrix3x3t<TReal> aiQuaterniont<TReal>::GetMatrix() const
+{
+    aiMatrix3x3t<TReal> resMatrix;
+    resMatrix.a1 = static_cast<TReal>(1.0) - static_cast<TReal>(2.0) * (y * y + z * z);
+    resMatrix.a2 = static_cast<TReal>(2.0) * (x * y - z * w);
+    resMatrix.a3 = static_cast<TReal>(2.0) * (x * z + y * w);
+    resMatrix.b1 = static_cast<TReal>(2.0) * (x * y + z * w);
+    resMatrix.b2 = static_cast<TReal>(1.0) - static_cast<TReal>(2.0) * (x * x + z * z);
+    resMatrix.b3 = static_cast<TReal>(2.0) * (y * z - x * w);
+    resMatrix.c1 = static_cast<TReal>(2.0) * (x * z - y * w);
+    resMatrix.c2 = static_cast<TReal>(2.0) * (y * z + x * w);
+    resMatrix.c3 = static_cast<TReal>(1.0) - static_cast<TReal>(2.0) * (x * x + y * y);
+
+    return resMatrix;
+}
+
+// ---------------------------------------------------------------------------
+// Construction from an axis-angle pair
+template<typename TReal>
+inline aiQuaterniont<TReal>::aiQuaterniont( aiVector3t<TReal> axis, TReal angle)
+{
+    axis.Normalize();
+
+    const TReal sin_a = std::sin( angle / 2 );
+    const TReal cos_a = std::cos( angle / 2 );
+    x    = axis.x * sin_a;
+    y    = axis.y * sin_a;
+    z    = axis.z * sin_a;
+    w    = cos_a;
+}
+// ---------------------------------------------------------------------------
+// Construction from am existing, normalized quaternion
+template<typename TReal>
+inline aiQuaterniont<TReal>::aiQuaterniont( aiVector3t<TReal> normalized)
+{
+    x = normalized.x;
+    y = normalized.y;
+    z = normalized.z;
+
+    const TReal t = static_cast<TReal>(1.0) - (x*x) - (y*y) - (z*z);
+
+    if (t < static_cast<TReal>(0.0)) {
+        w = static_cast<TReal>(0.0);
+    }
+    else w = std::sqrt (t);
+}
+
+// ---------------------------------------------------------------------------
+// Performs a spherical interpolation between two quaternions
+// Implementation adopted from the gmtl project. All others I found on the net fail in some cases.
+// Congrats, gmtl!
+template<typename TReal>
+inline void aiQuaterniont<TReal>::Interpolate( aiQuaterniont& pOut, const aiQuaterniont& pStart, const aiQuaterniont& pEnd, TReal pFactor)
+{
+    // calc cosine theta
+    TReal cosom = pStart.x * pEnd.x + pStart.y * pEnd.y + pStart.z * pEnd.z + pStart.w * pEnd.w;
+
+    // adjust signs (if necessary)
+    aiQuaterniont end = pEnd;
+    if( cosom < static_cast<TReal>(0.0))
+    {
+        cosom = -cosom;
+        end.x = -end.x;   // Reverse all signs
+        end.y = -end.y;
+        end.z = -end.z;
+        end.w = -end.w;
+    }
+
+    // Calculate coefficients
+    TReal sclp, sclq;
+    if( (static_cast<TReal>(1.0) - cosom) > static_cast<TReal>(0.0001)) // 0.0001 -> some epsillon
+    {
+        // Standard case (slerp)
+        TReal omega, sinom;
+        omega = std::acos( cosom); // extract theta from dot product's cos theta
+        sinom = std::sin( omega);
+        sclp  = std::sin( (static_cast<TReal>(1.0) - pFactor) * omega) / sinom;
+        sclq  = std::sin( pFactor * omega) / sinom;
+    } else
+    {
+        // Very close, do linear interp (because it's faster)
+        sclp = static_cast<TReal>(1.0) - pFactor;
+        sclq = pFactor;
+    }
+
+    pOut.x = sclp * pStart.x + sclq * end.x;
+    pOut.y = sclp * pStart.y + sclq * end.y;
+    pOut.z = sclp * pStart.z + sclq * end.z;
+    pOut.w = sclp * pStart.w + sclq * end.w;
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline aiQuaterniont<TReal>& aiQuaterniont<TReal>::Normalize()
+{
+    // compute the magnitude and divide through it
+    const TReal mag = std::sqrt(x*x + y*y + z*z + w*w);
+    if (mag)
+    {
+        const TReal invMag = static_cast<TReal>(1.0)/mag;
+        x *= invMag;
+        y *= invMag;
+        z *= invMag;
+        w *= invMag;
+    }
+    return *this;
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline aiQuaterniont<TReal> aiQuaterniont<TReal>::operator* (const aiQuaterniont& t) const
+{
+    return aiQuaterniont(w*t.w - x*t.x - y*t.y - z*t.z,
+        w*t.x + x*t.w + y*t.z - z*t.y,
+        w*t.y + y*t.w + z*t.x - x*t.z,
+        w*t.z + z*t.w + x*t.y - y*t.x);
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline aiQuaterniont<TReal>& aiQuaterniont<TReal>::Conjugate ()
+{
+    x = -x;
+    y = -y;
+    z = -z;
+    return *this;
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline aiVector3t<TReal> aiQuaterniont<TReal>::Rotate (const aiVector3t<TReal>& v)
+{
+    aiQuaterniont q2(0.f,v.x,v.y,v.z), q = *this, qinv = q;
+    qinv.Conjugate();
+
+    q = q*q2*qinv;
+    return aiVector3t<TReal>(q.x,q.y,q.z);
+}
+
+#endif
+#endif // AI_QUATERNION_INL_INC

dependencies/assimp/include/assimp/scene.h

@@ -0,0 +1,425 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file scene.h
+ *  @brief Defines the data structures in which the imported scene is returned.
+ */
+#pragma once
+#ifndef AI_SCENE_H_INC
+#define AI_SCENE_H_INC
+
+#include "types.h"
+#include "texture.h"
+#include "mesh.h"
+#include "light.h"
+#include "camera.h"
+#include "material.h"
+#include "anim.h"
+#include "metadata.h"
+
+#ifdef __cplusplus
+#  include <cstdlib>
+extern "C" {
+#endif
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wattributes"
+#endif
+
+// -------------------------------------------------------------------------------
+/** 
+ * A node in the imported hierarchy.
+ *
+ * Each node has name, a parent node (except for the root node),
+ * a transformation relative to its parent and possibly several child nodes.
+ * Simple file formats don't support hierarchical structures - for these formats
+ * the imported scene does consist of only a single root node without children.
+ */
+// -------------------------------------------------------------------------------
+struct ASSIMP_API aiNode
+{
+    /** The name of the node.
+     *
+     * The name might be empty (length of zero) but all nodes which
+     * need to be referenced by either bones or animations are named.
+     * Multiple nodes may have the same name, except for nodes which are referenced
+     * by bones (see #aiBone and #aiMesh::mBones). Their names *must* be unique.
+     *
+     * Cameras and lights reference a specific node by name - if there
+     * are multiple nodes with this name, they are assigned to each of them.
+     * <br>
+     * There are no limitations with regard to the characters contained in
+     * the name string as it is usually taken directly from the source file.
+     *
+     * Implementations should be able to handle tokens such as whitespace, tabs,
+     * line feeds, quotation marks, ampersands etc.
+     *
+     * Sometimes assimp introduces new nodes not present in the source file
+     * into the hierarchy (usually out of necessity because sometimes the
+     * source hierarchy format is simply not compatible). Their names are
+     * surrounded by @verbatim <> @endverbatim e.g.
+     *  @verbatim<DummyRootNode> @endverbatim.
+     */
+    C_STRUCT aiString mName;
+
+    /** The transformation relative to the node's parent. */
+    C_STRUCT aiMatrix4x4 mTransformation;
+
+    /** Parent node. NULL if this node is the root node. */
+    C_STRUCT aiNode* mParent;
+
+    /** The number of child nodes of this node. */
+    unsigned int mNumChildren;
+
+    /** The child nodes of this node. NULL if mNumChildren is 0. */
+    C_STRUCT aiNode** mChildren;
+
+    /** The number of meshes of this node. */
+    unsigned int mNumMeshes;
+
+    /** The meshes of this node. Each entry is an index into the
+      * mesh list of the #aiScene.
+      */
+    unsigned int* mMeshes;
+
+    /** Metadata associated with this node or NULL if there is no metadata.
+      *  Whether any metadata is generated depends on the source file format. See the
+      * @link importer_notes @endlink page for more information on every source file
+      * format. Importers that don't document any metadata don't write any.
+      */
+    C_STRUCT aiMetadata* mMetaData;
+
+#ifdef __cplusplus
+    /** Constructor */
+    aiNode();
+
+    /** Construction from a specific name */
+    explicit aiNode(const std::string& name);
+
+    /** Destructor */
+    ~aiNode();
+
+    /** Searches for a node with a specific name, beginning at this
+     *  nodes. Normally you will call this method on the root node
+     *  of the scene.
+     *
+     *  @param name Name to search for
+     *  @return NULL or a valid Node if the search was successful.
+     */
+    inline 
+    const aiNode* FindNode(const aiString& name) const {
+        return FindNode(name.data);
+    }
+
+    inline 
+    aiNode* FindNode(const aiString& name) {
+        return FindNode(name.data);
+    }
+
+    const aiNode* FindNode(const char* name) const;
+
+    aiNode* FindNode(const char* name);
+
+    /**
+     * @brief   Will add new children.
+     * @param   numChildren  Number of children to add.
+     * @param   children     The array with pointers showing to the children.
+     */
+    void addChildren(unsigned int numChildren, aiNode **children);
+#endif // __cplusplus
+};
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
+// -------------------------------------------------------------------------------
+/**
+ * Specifies that the scene data structure that was imported is not complete.
+ * This flag bypasses some internal validations and allows the import
+ * of animation skeletons, material libraries or camera animation paths
+ * using Assimp. Most applications won't support such data.
+ */
+#define AI_SCENE_FLAGS_INCOMPLETE   0x1
+
+/**
+ * This flag is set by the validation postprocess-step (aiPostProcess_ValidateDS)
+ * if the validation is successful. In a validated scene you can be sure that
+ * any cross references in the data structure (e.g. vertex indices) are valid.
+ */
+#define AI_SCENE_FLAGS_VALIDATED    0x2
+
+/**
+ * This flag is set by the validation postprocess-step (aiPostProcess_ValidateDS)
+ * if the validation is successful but some issues have been found.
+ * This can for example mean that a texture that does not exist is referenced
+ * by a material or that the bone weights for a vertex don't sum to 1.0 ... .
+ * In most cases you should still be able to use the import. This flag could
+ * be useful for applications which don't capture Assimp's log output.
+ */
+#define AI_SCENE_FLAGS_VALIDATION_WARNING   0x4
+
+/**
+ * This flag is currently only set by the aiProcess_JoinIdenticalVertices step.
+ * It indicates that the vertices of the output meshes aren't in the internal
+ * verbose format anymore. In the verbose format all vertices are unique,
+ * no vertex is ever referenced by more than one face.
+ */
+#define AI_SCENE_FLAGS_NON_VERBOSE_FORMAT   0x8
+
+ /**
+ * Denotes pure height-map terrain data. Pure terrains usually consist of quads,
+ * sometimes triangles, in a regular grid. The x,y coordinates of all vertex
+ * positions refer to the x,y coordinates on the terrain height map, the z-axis
+ * stores the elevation at a specific point.
+ *
+ * TER (Terragen) and HMP (3D Game Studio) are height map formats.
+ * @note Assimp is probably not the best choice for loading *huge* terrains -
+ * fully triangulated data takes extremely much free store and should be avoided
+ * as long as possible (typically you'll do the triangulation when you actually
+ * need to render it).
+ */
+#define AI_SCENE_FLAGS_TERRAIN 0x10
+
+ /**
+ * Specifies that the scene data can be shared between structures. For example:
+ * one vertex in few faces. \ref AI_SCENE_FLAGS_NON_VERBOSE_FORMAT can not be
+ * used for this because \ref AI_SCENE_FLAGS_NON_VERBOSE_FORMAT has internal
+ * meaning about postprocessing steps.
+ */
+#define AI_SCENE_FLAGS_ALLOW_SHARED			0x20
+
+// -------------------------------------------------------------------------------
+/** The root structure of the imported data.
+ *
+ *  Everything that was imported from the given file can be accessed from here.
+ *  Objects of this class are generally maintained and owned by Assimp, not
+ *  by the caller. You shouldn't want to instance it, nor should you ever try to
+ *  delete a given scene on your own.
+ */
+// -------------------------------------------------------------------------------
+struct aiScene
+{
+    /** Any combination of the AI_SCENE_FLAGS_XXX flags. By default
+    * this value is 0, no flags are set. Most applications will
+    * want to reject all scenes with the AI_SCENE_FLAGS_INCOMPLETE
+    * bit set.
+    */
+    unsigned int mFlags;
+
+    /** The root node of the hierarchy.
+    *
+    * There will always be at least the root node if the import
+    * was successful (and no special flags have been set).
+    * Presence of further nodes depends on the format and content
+    * of the imported file.
+    */
+    C_STRUCT aiNode* mRootNode;
+
+    /** The number of meshes in the scene. */
+    unsigned int mNumMeshes;
+
+    /** The array of meshes.
+    *
+    * Use the indices given in the aiNode structure to access
+    * this array. The array is mNumMeshes in size. If the
+    * AI_SCENE_FLAGS_INCOMPLETE flag is not set there will always
+    * be at least ONE material.
+    */
+    C_STRUCT aiMesh** mMeshes;
+
+    /** The number of materials in the scene. */
+    unsigned int mNumMaterials;
+
+    /** The array of materials.
+    *
+    * Use the index given in each aiMesh structure to access this
+    * array. The array is mNumMaterials in size. If the
+    * AI_SCENE_FLAGS_INCOMPLETE flag is not set there will always
+    * be at least ONE material.
+    */
+    C_STRUCT aiMaterial** mMaterials;
+
+    /** The number of animations in the scene. */
+    unsigned int mNumAnimations;
+
+    /** The array of animations.
+    *
+    * All animations imported from the given file are listed here.
+    * The array is mNumAnimations in size.
+    */
+    C_STRUCT aiAnimation** mAnimations;
+
+    /** The number of textures embedded into the file */
+    unsigned int mNumTextures;
+
+    /** The array of embedded textures.
+    *
+    * Not many file formats embed their textures into the file.
+    * An example is Quake's MDL format (which is also used by
+    * some GameStudio versions)
+    */
+    C_STRUCT aiTexture** mTextures;
+
+    /** The number of light sources in the scene. Light sources
+    * are fully optional, in most cases this attribute will be 0
+        */
+    unsigned int mNumLights;
+
+    /** The array of light sources.
+    *
+    * All light sources imported from the given file are
+    * listed here. The array is mNumLights in size.
+    */
+    C_STRUCT aiLight** mLights;
+
+    /** The number of cameras in the scene. Cameras
+    * are fully optional, in most cases this attribute will be 0
+        */
+    unsigned int mNumCameras;
+
+    /** The array of cameras.
+    *
+    * All cameras imported from the given file are listed here.
+    * The array is mNumCameras in size. The first camera in the
+    * array (if existing) is the default camera view into
+    * the scene.
+    */
+    C_STRUCT aiCamera** mCameras;
+
+    /**
+     *  @brief  The global metadata assigned to the scene itself.
+     *
+     *  This data contains global metadata which belongs to the scene like 
+     *  unit-conversions, versions, vendors or other model-specific data. This 
+     *  can be used to store format-specific metadata as well.
+     */
+    C_STRUCT aiMetadata* mMetaData;
+
+
+#ifdef __cplusplus
+
+    //! Default constructor - set everything to 0/NULL
+    ASSIMP_API aiScene();
+
+    //! Destructor
+    ASSIMP_API ~aiScene();
+
+    //! Check whether the scene contains meshes
+    //! Unless no special scene flags are set this will always be true.
+    inline bool HasMeshes() const { 
+        return mMeshes != NULL && mNumMeshes > 0; 
+    }
+
+    //! Check whether the scene contains materials
+    //! Unless no special scene flags are set this will always be true.
+    inline bool HasMaterials() const { 
+        return mMaterials != NULL && mNumMaterials > 0; 
+    }
+
+    //! Check whether the scene contains lights
+    inline bool HasLights() const { 
+        return mLights != NULL && mNumLights > 0; 
+    }
+
+    //! Check whether the scene contains textures
+    inline bool HasTextures() const {
+        return mTextures != NULL && mNumTextures > 0; 
+    }
+
+    //! Check whether the scene contains cameras
+    inline bool HasCameras() const {
+        return mCameras != NULL && mNumCameras > 0; 
+    }
+
+    //! Check whether the scene contains animations
+    inline bool HasAnimations() const { 
+        return mAnimations != NULL && mNumAnimations > 0; 
+    }
+
+    //! Returns a short filename from a full path
+    static const char* GetShortFilename(const char* filename) {
+        const char* lastSlash = strrchr(filename, '/');
+        if (lastSlash == nullptr) {
+            lastSlash = strrchr(filename, '\\');
+        }
+        const char* shortFilename = lastSlash != nullptr ? lastSlash + 1 : filename;
+        return shortFilename;
+    }
+
+    //! Returns an embedded texture
+    const aiTexture* GetEmbeddedTexture(const char* filename) const {
+        // lookup using texture ID (if referenced like: "*1", "*2", etc.)
+        if ('*' == *filename) {
+            int index = std::atoi(filename + 1);
+            if (0 > index || mNumTextures <= static_cast<unsigned>(index))
+                return nullptr;
+            return mTextures[index];
+        }
+        // lookup using filename
+        const char* shortFilename = GetShortFilename(filename);
+        for (unsigned int i = 0; i < mNumTextures; i++) {
+            const char* shortTextureFilename = GetShortFilename(mTextures[i]->mFilename.C_Str());
+            if (strcmp(shortTextureFilename, shortFilename) == 0) {
+                return mTextures[i];
+            }
+        }
+        return nullptr;
+    }
+#endif // __cplusplus
+
+    /**  Internal data, do not touch */
+#ifdef __cplusplus
+    void* mPrivate;
+#else
+    char* mPrivate;
+#endif
+
+};
+
+#ifdef __cplusplus
+} //! namespace Assimp
+#endif
+
+#endif // AI_SCENE_H_INC

dependencies/assimp/include/assimp/texture.h

@@ -0,0 +1,227 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file texture.h
+ *  @brief Defines texture helper structures for the library
+ *
+ * Used for file formats which embed their textures into the model file.
+ * Supported are both normal textures, which are stored as uncompressed
+ * pixels, and "compressed" textures, which are stored in a file format
+ * such as PNG or TGA.
+ */
+#pragma once
+#ifndef AI_TEXTURE_H_INC
+#define AI_TEXTURE_H_INC
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+// --------------------------------------------------------------------------------
+
+/** \def AI_EMBEDDED_TEXNAME_PREFIX
+ * \ref AI_MAKE_EMBEDDED_TEXNAME
+ */
+#ifndef AI_EMBEDDED_TEXNAME_PREFIX
+#   define AI_EMBEDDED_TEXNAME_PREFIX	"*"
+#endif
+
+/** @def AI_MAKE_EMBEDDED_TEXNAME
+ *  Used to build the reserved path name used by the material system to
+ *  reference textures that are embedded into their corresponding
+ *  model files. The parameter specifies the index of the texture
+ *  (zero-based, in the aiScene::mTextures array)
+ */
+#if (!defined AI_MAKE_EMBEDDED_TEXNAME)
+#   define AI_MAKE_EMBEDDED_TEXNAME(_n_) AI_EMBEDDED_TEXNAME_PREFIX # _n_
+#endif
+
+
+#include "./Compiler/pushpack1.h"
+
+// --------------------------------------------------------------------------------
+/** @brief Helper structure to represent a texel in a ARGB8888 format
+*
+*  Used by aiTexture.
+*/
+struct aiTexel
+{
+    unsigned char b,g,r,a;
+
+#ifdef __cplusplus
+    //! Comparison operator
+    bool operator== (const aiTexel& other) const
+    {
+        return b == other.b && r == other.r &&
+               g == other.g && a == other.a;
+    }
+
+    //! Inverse comparison operator
+    bool operator!= (const aiTexel& other) const
+    {
+        return b != other.b || r != other.r ||
+               g != other.g || a != other.a;
+    }
+
+    //! Conversion to a floating-point 4d color
+    operator aiColor4D() const
+    {
+        return aiColor4D(r/255.f,g/255.f,b/255.f,a/255.f);
+    }
+#endif // __cplusplus
+
+} PACK_STRUCT;
+
+#include "./Compiler/poppack1.h"
+
+#define HINTMAXTEXTURELEN 9
+
+// --------------------------------------------------------------------------------
+/** Helper structure to describe an embedded texture
+ *
+ * Normally textures are contained in external files but some file formats embed
+ * them directly in the model file. There are two types of embedded textures:
+ * 1. Uncompressed textures. The color data is given in an uncompressed format.
+ * 2. Compressed textures stored in a file format like png or jpg. The raw file
+ * bytes are given so the application must utilize an image decoder (e.g. DevIL) to
+ * get access to the actual color data.
+ *
+ * Embedded textures are referenced from materials using strings like "*0", "*1", etc.
+ * as the texture paths (a single asterisk character followed by the
+ * zero-based index of the texture in the aiScene::mTextures array).
+ */
+struct aiTexture {
+    /** Width of the texture, in pixels
+     *
+     * If mHeight is zero the texture is compressed in a format
+     * like JPEG. In this case mWidth specifies the size of the
+     * memory area pcData is pointing to, in bytes.
+     */
+    unsigned int mWidth;
+
+    /** Height of the texture, in pixels
+     *
+     * If this value is zero, pcData points to an compressed texture
+     * in any format (e.g. JPEG).
+     */
+    unsigned int mHeight;
+
+    /** A hint from the loader to make it easier for applications
+     *  to determine the type of embedded textures.
+     *
+     * If mHeight != 0 this member is show how data is packed. Hint will consist of
+     * two parts: channel order and channel bitness (count of the bits for every
+     * color channel). For simple parsing by the viewer it's better to not omit
+     * absent color channel and just use 0 for bitness. For example:
+     * 1. Image contain RGBA and 8 bit per channel, achFormatHint == "rgba8888";
+     * 2. Image contain ARGB and 8 bit per channel, achFormatHint == "argb8888";
+     * 3. Image contain RGB and 5 bit for R and B channels and 6 bit for G channel, achFormatHint == "rgba5650";
+     * 4. One color image with B channel and 1 bit for it, achFormatHint == "rgba0010";
+     * If mHeight == 0 then achFormatHint is set set to '\\0\\0\\0\\0' if the loader has no additional
+     * information about the texture file format used OR the
+     * file extension of the format without a trailing dot. If there
+     * are multiple file extensions for a format, the shortest
+     * extension is chosen (JPEG maps to 'jpg', not to 'jpeg').
+     * E.g. 'dds\\0', 'pcx\\0', 'jpg\\0'.  All characters are lower-case.
+     * The fourth character will always be '\\0'.
+     */
+    char achFormatHint[ HINTMAXTEXTURELEN ];// 8 for string + 1 for terminator.
+
+    /** Data of the texture.
+     *
+     * Points to an array of mWidth * mHeight aiTexel's.
+     * The format of the texture data is always ARGB8888 to
+     * make the implementation for user of the library as easy
+     * as possible. If mHeight = 0 this is a pointer to a memory
+     * buffer of size mWidth containing the compressed texture
+     * data. Good luck, have fun!
+     */
+    C_STRUCT aiTexel* pcData;
+
+    /** Texture original filename
+    *
+    * Used to get the texture reference
+    */
+    C_STRUCT aiString mFilename;
+
+#ifdef __cplusplus
+
+    //! For compressed textures (mHeight == 0): compare the
+    //! format hint against a given string.
+    //! @param s Input string. 3 characters are maximally processed.
+    //!        Example values: "jpg", "png"
+    //! @return true if the given string matches the format hint
+    bool CheckFormat(const char* s) const {
+        if (nullptr == s) {
+            return false;
+        }
+
+		return (0 == ::strncmp(achFormatHint, s, sizeof(achFormatHint)));
+    }
+
+    // Construction
+    aiTexture() AI_NO_EXCEPT
+    : mWidth(0)
+    , mHeight(0)
+    , pcData(nullptr)
+    , mFilename() {
+        achFormatHint[0] = achFormatHint[1] = 0;
+        achFormatHint[2] = achFormatHint[3] = 0;
+    }
+
+    // Destruction
+    ~aiTexture () {
+        delete[] pcData;
+    }
+#endif
+};
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // AI_TEXTURE_H_INC

dependencies/assimp/include/assimp/types.h

@@ -0,0 +1,541 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file types.h
+ *  Basic data types and primitives, such as vectors or colors.
+ */
+#pragma once
+#ifndef AI_TYPES_H_INC
+#define AI_TYPES_H_INC
+
+// Some runtime headers
+#include <sys/types.h>
+#include <stddef.h>
+#include <string.h>
+#include <limits.h>
+#include <stdint.h>
+
+// Our compile configuration
+#include "defs.h"
+
+// Some types moved to separate header due to size of operators
+#include "vector3.h"
+#include "vector2.h"
+#include "color4.h"
+#include "matrix3x3.h"
+#include "matrix4x4.h"
+#include "quaternion.h"
+
+typedef int32_t ai_int32;
+typedef uint32_t ai_uint32 ;
+
+#ifdef __cplusplus
+#include <cstring>
+#include <new>      // for std::nothrow_t
+#include <string>   // for aiString::Set(const std::string&)
+
+
+namespace Assimp    {
+    //! @cond never
+namespace Intern        {
+    // --------------------------------------------------------------------
+    /** @brief Internal helper class to utilize our internal new/delete
+     *    routines for allocating object of this and derived classes.
+     *
+     * By doing this you can safely share class objects between Assimp
+     * and the application - it works even over DLL boundaries. A good
+     * example is the #IOSystem where the application allocates its custom
+     * #IOSystem, then calls #Importer::SetIOSystem(). When the Importer
+     * destructs, Assimp calls operator delete on the stored #IOSystem.
+     * If it lies on a different heap than Assimp is working with,
+     * the application is determined to crash.
+     */
+    // --------------------------------------------------------------------
+#ifndef SWIG
+    struct ASSIMP_API AllocateFromAssimpHeap    {
+        // http://www.gotw.ca/publications/mill15.htm
+
+        // new/delete overload
+        void *operator new    ( size_t num_bytes) /* throw( std::bad_alloc ) */;
+        void *operator new    ( size_t num_bytes, const std::nothrow_t& ) throw();
+        void  operator delete ( void* data);
+
+        // array new/delete overload
+        void *operator new[]    ( size_t num_bytes) /* throw( std::bad_alloc ) */;
+        void *operator new[]    ( size_t num_bytes, const std::nothrow_t& )  throw();
+        void  operator delete[] ( void* data);
+
+    }; // struct AllocateFromAssimpHeap
+#endif
+} // namespace Intern
+    //! @endcond
+} // namespace Assimp
+
+extern "C" {
+#endif
+
+/** Maximum dimension for strings, ASSIMP strings are zero terminated. */
+#ifdef __cplusplus
+    static const size_t MAXLEN = 1024;
+#else
+#   define MAXLEN 1024
+#endif
+
+// ----------------------------------------------------------------------------------
+/** Represents a plane in a three-dimensional, euclidean space
+*/
+struct aiPlane {
+#ifdef __cplusplus
+    aiPlane () AI_NO_EXCEPT : a(0.f), b(0.f), c(0.f), d(0.f) {}
+    aiPlane (ai_real _a, ai_real _b, ai_real _c, ai_real _d)
+        : a(_a), b(_b), c(_c), d(_d) {}
+
+    aiPlane (const aiPlane& o) : a(o.a), b(o.b), c(o.c), d(o.d) {}
+
+#endif // !__cplusplus
+
+    //! Plane equation
+    ai_real a,b,c,d;
+}; // !struct aiPlane
+
+// ----------------------------------------------------------------------------------
+/** Represents a ray
+*/
+struct aiRay {
+#ifdef __cplusplus
+    aiRay () AI_NO_EXCEPT {}
+    aiRay (const aiVector3D& _pos, const aiVector3D& _dir)
+        : pos(_pos), dir(_dir) {}
+
+    aiRay (const aiRay& o) : pos (o.pos), dir (o.dir) {}
+
+#endif // !__cplusplus
+
+    //! Position and direction of the ray
+    C_STRUCT aiVector3D pos, dir;
+}; // !struct aiRay
+
+// ----------------------------------------------------------------------------------
+/** Represents a color in Red-Green-Blue space.
+*/
+struct aiColor3D
+{
+#ifdef __cplusplus
+    aiColor3D () AI_NO_EXCEPT : r(0.0f), g(0.0f), b(0.0f) {}
+    aiColor3D (ai_real _r, ai_real _g, ai_real _b) : r(_r), g(_g), b(_b) {}
+    explicit aiColor3D (ai_real _r) : r(_r), g(_r), b(_r) {}
+    aiColor3D (const aiColor3D& o) : r(o.r), g(o.g), b(o.b) {}
+
+	aiColor3D &operator=(const aiColor3D &o) {
+		r = o.r;
+		g = o.g;
+		b = o.b;
+		return *this;
+	}
+
+	/** Component-wise comparison */
+    // TODO: add epsilon?
+    bool operator == (const aiColor3D& other) const
+        {return r == other.r && g == other.g && b == other.b;}
+
+    /** Component-wise inverse comparison */
+    // TODO: add epsilon?
+    bool operator != (const aiColor3D& other) const
+        {return r != other.r || g != other.g || b != other.b;}
+
+    /** Component-wise comparison */
+    // TODO: add epsilon?
+    bool operator < (const aiColor3D& other) const {
+        return r < other.r || ( r == other.r && (g < other.g || (g == other.g && b < other.b ) ) );
+    }
+
+    /** Component-wise addition */
+    aiColor3D operator+(const aiColor3D& c) const {
+        return aiColor3D(r+c.r,g+c.g,b+c.b);
+    }
+
+    /** Component-wise subtraction */
+    aiColor3D operator-(const aiColor3D& c) const {
+        return aiColor3D(r-c.r,g-c.g,b-c.b);
+    }
+
+    /** Component-wise multiplication */
+    aiColor3D operator*(const aiColor3D& c) const {
+        return aiColor3D(r*c.r,g*c.g,b*c.b);
+    }
+
+    /** Multiply with a scalar */
+    aiColor3D operator*(ai_real f) const {
+        return aiColor3D(r*f,g*f,b*f);
+    }
+
+    /** Access a specific color component */
+    ai_real operator[](unsigned int i) const {
+        return *(&r + i);
+    }
+
+    /** Access a specific color component */
+    ai_real& operator[](unsigned int i) {
+        if ( 0 == i ) {
+            return r;
+        } else if ( 1 == i ) {
+            return g;
+        } else if ( 2 == i ) {
+            return b;
+        }
+        return r;
+    }
+
+    /** Check whether a color is black */
+    bool IsBlack() const {
+        static const ai_real epsilon = ai_real(10e-3);
+        return std::fabs( r ) < epsilon && std::fabs( g ) < epsilon && std::fabs( b ) < epsilon;
+    }
+
+#endif // !__cplusplus
+
+    //! Red, green and blue color values
+    ai_real r, g, b;
+};  // !struct aiColor3D
+
+// ----------------------------------------------------------------------------------
+/** Represents an UTF-8 string, zero byte terminated.
+ *
+ *  The character set of an aiString is explicitly defined to be UTF-8. This Unicode
+ *  transformation was chosen in the belief that most strings in 3d files are limited
+ *  to ASCII, thus the character set needed to be strictly ASCII compatible.
+ *
+ *  Most text file loaders provide proper Unicode input file handling, special unicode
+ *  characters are correctly transcoded to UTF8 and are kept throughout the libraries'
+ *  import pipeline.
+ *
+ *  For most applications, it will be absolutely sufficient to interpret the
+ *  aiString as ASCII data and work with it as one would work with a plain char*.
+ *  Windows users in need of proper support for i.e asian characters can use the
+ *  MultiByteToWideChar(), WideCharToMultiByte() WinAPI functionality to convert the
+ *  UTF-8 strings to their working character set (i.e. MBCS, WideChar).
+ *
+ *  We use this representation instead of std::string to be C-compatible. The
+ *  (binary) length of such a string is limited to MAXLEN characters (including the
+ *  the terminating zero).
+*/
+struct aiString
+{
+#ifdef __cplusplus
+    /** Default constructor, the string is set to have zero length */
+    aiString() AI_NO_EXCEPT
+    : length( 0 ) {
+        data[0] = '\0';
+
+#ifdef ASSIMP_BUILD_DEBUG
+        // Debug build: overwrite the string on its full length with ESC (27)
+        memset(data+1,27,MAXLEN-1);
+#endif
+    }
+
+    /** Copy constructor */
+    aiString(const aiString& rOther)
+    : length(rOther.length)
+    {
+        // Crop the string to the maximum length
+        length = length>=MAXLEN?MAXLEN-1:length;
+        memcpy( data, rOther.data, length);
+        data[length] = '\0';
+    }
+
+    /** Constructor from std::string */
+    explicit aiString(const std::string& pString) :
+        length( (ai_uint32) pString.length())
+    {
+        length = length>=MAXLEN?MAXLEN-1:length;
+        memcpy( data, pString.c_str(), length);
+        data[length] = '\0';
+    }
+
+    /** Copy a std::string to the aiString */
+    void Set( const std::string& pString) {
+        if( pString.length() > MAXLEN - 1) {
+            return;
+        }
+        length = (ai_uint32)pString.length();
+        memcpy( data, pString.c_str(), length);
+        data[length] = 0;
+    }
+
+    /** Copy a const char* to the aiString */
+    void Set( const char* sz) {
+        const ai_int32 len = (ai_uint32) ::strlen(sz);
+        if( len > (ai_int32)MAXLEN - 1) {
+            return;
+        }
+        length = len;
+        memcpy( data, sz, len);
+        data[len] = 0;
+    }
+
+
+    /** Assignment operator */
+    aiString& operator = (const aiString &rOther) {
+        if (this == &rOther) {
+            return *this;
+        }
+
+        length = rOther.length;;
+        memcpy( data, rOther.data, length);
+        data[length] = '\0';
+        return *this;
+    }
+
+
+    /** Assign a const char* to the string */
+    aiString& operator = (const char* sz) {
+        Set(sz);
+        return *this;
+    }
+
+    /** Assign a cstd::string to the string */
+    aiString& operator = ( const std::string& pString) {
+        Set(pString);
+        return *this;
+    }
+
+    /** Comparison operator */
+    bool operator==(const aiString& other) const {
+        return  (length == other.length && 0 == memcmp(data,other.data,length));
+    }
+
+    /** Inverse comparison operator */
+    bool operator!=(const aiString& other) const {
+        return  (length != other.length || 0 != memcmp(data,other.data,length));
+    }
+
+    /** Append a string to the string */
+    void Append (const char* app)   {
+        const ai_uint32 len = (ai_uint32) ::strlen(app);
+        if (!len) {
+            return;
+        }
+        if (length + len >= MAXLEN) {
+            return;
+        }
+
+        memcpy(&data[length],app,len+1);
+        length += len;
+    }
+
+    /** Clear the string - reset its length to zero */
+    void Clear ()   {
+        length  = 0;
+        data[0] = '\0';
+
+#ifdef ASSIMP_BUILD_DEBUG
+        // Debug build: overwrite the string on its full length with ESC (27)
+        memset(data+1,27,MAXLEN-1);
+#endif
+    }
+
+    /** Returns a pointer to the underlying zero-terminated array of characters */
+    const char* C_Str() const {
+        return data;
+    }
+
+#endif // !__cplusplus
+
+    /** Binary length of the string excluding the terminal 0. This is NOT the
+     *  logical length of strings containing UTF-8 multi-byte sequences! It's
+     *  the number of bytes from the beginning of the string to its end.*/
+    ai_uint32 length;
+
+    /** String buffer. Size limit is MAXLEN */
+    char data[MAXLEN];
+} ;  // !struct aiString
+
+
+// ----------------------------------------------------------------------------------
+/** Standard return type for some library functions.
+ * Rarely used, and if, mostly in the C API.
+ */
+typedef enum aiReturn
+{
+    /** Indicates that a function was successful */
+    aiReturn_SUCCESS = 0x0,
+
+    /** Indicates that a function failed */
+    aiReturn_FAILURE = -0x1,
+
+    /** Indicates that not enough memory was available
+     * to perform the requested operation
+     */
+    aiReturn_OUTOFMEMORY = -0x3,
+
+    /** @cond never
+     *  Force 32-bit size enum
+     */
+    _AI_ENFORCE_ENUM_SIZE = 0x7fffffff
+
+    /// @endcond
+} aiReturn;  // !enum aiReturn
+
+// just for backwards compatibility, don't use these constants anymore
+#define AI_SUCCESS     aiReturn_SUCCESS
+#define AI_FAILURE     aiReturn_FAILURE
+#define AI_OUTOFMEMORY aiReturn_OUTOFMEMORY
+
+// ----------------------------------------------------------------------------------
+/** Seek origins (for the virtual file system API).
+ *  Much cooler than using SEEK_SET, SEEK_CUR or SEEK_END.
+ */
+enum aiOrigin
+{
+    /** Beginning of the file */
+    aiOrigin_SET = 0x0,
+
+    /** Current position of the file pointer */
+    aiOrigin_CUR = 0x1,
+
+    /** End of the file, offsets must be negative */
+    aiOrigin_END = 0x2,
+
+    /**  @cond never
+     *   Force 32-bit size enum
+     */
+    _AI_ORIGIN_ENFORCE_ENUM_SIZE = 0x7fffffff
+
+    /// @endcond
+}; // !enum aiOrigin
+
+// ----------------------------------------------------------------------------------
+/** @brief Enumerates predefined log streaming destinations.
+ *  Logging to these streams can be enabled with a single call to
+ *   #LogStream::createDefaultStream.
+ */
+enum aiDefaultLogStream
+{
+    /** Stream the log to a file */
+    aiDefaultLogStream_FILE = 0x1,
+
+    /** Stream the log to std::cout */
+    aiDefaultLogStream_STDOUT = 0x2,
+
+    /** Stream the log to std::cerr */
+    aiDefaultLogStream_STDERR = 0x4,
+
+    /** MSVC only: Stream the log the the debugger
+     * (this relies on OutputDebugString from the Win32 SDK)
+     */
+    aiDefaultLogStream_DEBUGGER = 0x8,
+
+    /** @cond never
+     *  Force 32-bit size enum
+     */
+    _AI_DLS_ENFORCE_ENUM_SIZE = 0x7fffffff
+    /// @endcond
+}; // !enum aiDefaultLogStream
+
+// just for backwards compatibility, don't use these constants anymore
+#define DLS_FILE     aiDefaultLogStream_FILE
+#define DLS_STDOUT   aiDefaultLogStream_STDOUT
+#define DLS_STDERR   aiDefaultLogStream_STDERR
+#define DLS_DEBUGGER aiDefaultLogStream_DEBUGGER
+
+// ----------------------------------------------------------------------------------
+/** Stores the memory requirements for different components (e.g. meshes, materials,
+ *  animations) of an import. All sizes are in bytes.
+ *  @see Importer::GetMemoryRequirements()
+*/
+struct aiMemoryInfo
+{
+#ifdef __cplusplus
+
+    /** Default constructor */
+    aiMemoryInfo() AI_NO_EXCEPT
+        : textures   (0)
+        , materials  (0)
+        , meshes     (0)
+        , nodes      (0)
+        , animations (0)
+        , cameras    (0)
+        , lights     (0)
+        , total      (0)
+    {}
+
+#endif
+
+    /** Storage allocated for texture data */
+    unsigned int textures;
+
+    /** Storage allocated for material data  */
+    unsigned int materials;
+
+    /** Storage allocated for mesh data */
+    unsigned int meshes;
+
+    /** Storage allocated for node data */
+    unsigned int nodes;
+
+    /** Storage allocated for animation data */
+    unsigned int animations;
+
+    /** Storage allocated for camera data */
+    unsigned int cameras;
+
+    /** Storage allocated for light data */
+    unsigned int lights;
+
+    /** Total storage allocated for the full import. */
+    unsigned int total;
+}; // !struct aiMemoryInfo
+
+#ifdef __cplusplus
+}
+#endif //!  __cplusplus
+
+// Include implementation files
+#include "vector2.inl"
+#include "vector3.inl"
+#include "color4.inl"
+#include "quaternion.inl"
+#include "matrix3x3.inl"
+#include "matrix4x4.inl"
+
+#endif // AI_TYPES_H_INC

dependencies/assimp/include/assimp/vector2.h

@@ -0,0 +1,107 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file vector2.h
+ *  @brief 2D vector structure, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_VECTOR2D_H_INC
+#define AI_VECTOR2D_H_INC
+
+#ifdef __cplusplus
+#   include <cmath>
+#else
+#   include <math.h>
+#endif
+
+#include "defs.h"
+
+// ----------------------------------------------------------------------------------
+/** Represents a two-dimensional vector.
+ */
+
+#ifdef __cplusplus
+template <typename TReal>
+class aiVector2t {
+public:
+    aiVector2t () : x(), y() {}
+    aiVector2t (TReal _x, TReal _y) : x(_x), y(_y) {}
+    explicit aiVector2t (TReal _xyz) : x(_xyz), y(_xyz) {}
+    aiVector2t (const aiVector2t& o) = default;
+
+    void Set( TReal pX, TReal pY);
+    TReal SquareLength() const ;
+    TReal Length() const ;
+    aiVector2t& Normalize();
+
+    const aiVector2t& operator += (const aiVector2t& o);
+    const aiVector2t& operator -= (const aiVector2t& o);
+    const aiVector2t& operator *= (TReal f);
+    const aiVector2t& operator /= (TReal f);
+
+    TReal operator[](unsigned int i) const;
+
+    bool operator== (const aiVector2t& other) const;
+    bool operator!= (const aiVector2t& other) const;
+
+    bool Equal(const aiVector2t& other, TReal epsilon = 1e-6) const;
+
+    aiVector2t& operator= (TReal f);
+    const aiVector2t SymMul(const aiVector2t& o);
+
+    template <typename TOther>
+    operator aiVector2t<TOther> () const;
+
+    TReal x, y;
+};
+
+typedef aiVector2t<ai_real> aiVector2D;
+
+#else
+
+struct aiVector2D {
+    ai_real x, y;
+};
+
+#endif // __cplusplus
+
+#endif // AI_VECTOR2D_H_INC

dependencies/assimp/include/assimp/vector2.inl

@@ -0,0 +1,244 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  vector2.inl
+ *  @brief Inline implementation of aiVector2t<TReal> operators
+ */
+#pragma once
+#ifndef AI_VECTOR2D_INL_INC
+#define AI_VECTOR2D_INL_INC
+
+#ifdef __cplusplus
+#include "vector2.h"
+
+#include <cmath>
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+template <typename TOther>
+aiVector2t<TReal>::operator aiVector2t<TOther> () const {
+    return aiVector2t<TOther>(static_cast<TOther>(x),static_cast<TOther>(y));
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+void aiVector2t<TReal>::Set( TReal pX, TReal pY) {
+    x = pX; y = pY;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+TReal aiVector2t<TReal>::SquareLength() const {
+    return x*x + y*y;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+TReal aiVector2t<TReal>::Length() const {
+    return std::sqrt( SquareLength());
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+aiVector2t<TReal>& aiVector2t<TReal>::Normalize() {
+    *this /= Length();
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+const aiVector2t<TReal>& aiVector2t<TReal>::operator += (const aiVector2t& o) {
+    x += o.x; y += o.y;
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+const aiVector2t<TReal>& aiVector2t<TReal>::operator -= (const aiVector2t& o) {
+    x -= o.x; y -= o.y;
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+const aiVector2t<TReal>& aiVector2t<TReal>::operator *= (TReal f) {
+    x *= f; y *= f;
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+const aiVector2t<TReal>& aiVector2t<TReal>::operator /= (TReal f) {
+    x /= f; y /= f;
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+TReal aiVector2t<TReal>::operator[](unsigned int i) const {
+	switch (i) {
+		case 0:
+			return x;
+		case 1:
+			return y;
+		default:
+			break;
+
+    }
+    return x;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+bool aiVector2t<TReal>::operator== (const aiVector2t& other) const {
+    return x == other.x && y == other.y;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+bool aiVector2t<TReal>::operator!= (const aiVector2t& other) const {
+    return x != other.x || y != other.y;
+}
+
+// ---------------------------------------------------------------------------
+template<typename TReal>
+inline
+bool aiVector2t<TReal>::Equal(const aiVector2t& other, TReal epsilon) const {
+    return
+        std::abs(x - other.x) <= epsilon &&
+        std::abs(y - other.y) <= epsilon;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+aiVector2t<TReal>& aiVector2t<TReal>::operator= (TReal f)   {
+    x = y = f;
+    return *this;
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+inline
+const aiVector2t<TReal> aiVector2t<TReal>::SymMul(const aiVector2t& o) {
+    return aiVector2t(x*o.x,y*o.y);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// symmetric addition
+template <typename TReal>
+inline
+aiVector2t<TReal> operator + (const aiVector2t<TReal>& v1, const aiVector2t<TReal>& v2) {
+    return aiVector2t<TReal>( v1.x + v2.x, v1.y + v2.y);
+}
+
+// ------------------------------------------------------------------------------------------------
+// symmetric subtraction
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator - (const aiVector2t<TReal>& v1, const aiVector2t<TReal>& v2) {
+    return aiVector2t<TReal>( v1.x - v2.x, v1.y - v2.y);
+}
+
+// ------------------------------------------------------------------------------------------------
+// scalar product
+template <typename TReal>
+inline 
+TReal operator * (const aiVector2t<TReal>& v1, const aiVector2t<TReal>& v2) {
+    return v1.x*v2.x + v1.y*v2.y;
+}
+
+// ------------------------------------------------------------------------------------------------
+// scalar multiplication
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator * ( TReal f, const aiVector2t<TReal>& v) {
+    return aiVector2t<TReal>( f*v.x, f*v.y);
+}
+
+// ------------------------------------------------------------------------------------------------
+// and the other way around
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator * ( const aiVector2t<TReal>& v, TReal f) {
+    return aiVector2t<TReal>( f*v.x, f*v.y);
+}
+
+// ------------------------------------------------------------------------------------------------
+// scalar division
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator / ( const aiVector2t<TReal>& v, TReal f) {
+    return v * (1/f);
+}
+
+// ------------------------------------------------------------------------------------------------
+// vector division
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator / ( const aiVector2t<TReal>& v, const aiVector2t<TReal>& v2) {
+    return aiVector2t<TReal>(v.x / v2.x,v.y / v2.y);
+}
+
+// ------------------------------------------------------------------------------------------------
+// vector negation
+template <typename TReal>
+inline 
+aiVector2t<TReal> operator - ( const aiVector2t<TReal>& v) {
+    return aiVector2t<TReal>( -v.x, -v.y);
+}
+
+#endif
+
+#endif // AI_VECTOR2D_INL_INC

dependencies/assimp/include/assimp/vector3.h

@@ -0,0 +1,146 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+/** @file vector3.h
+ *  @brief 3D vector structure, including operators when compiling in C++
+ */
+#pragma once
+#ifndef AI_VECTOR3D_H_INC
+#define AI_VECTOR3D_H_INC
+
+#ifdef __cplusplus
+#   include <cmath>
+#else
+#   include <math.h>
+#endif
+
+#include "defs.h"
+
+#ifdef __cplusplus
+
+template<typename TReal> class aiMatrix3x3t;
+template<typename TReal> class aiMatrix4x4t;
+
+// ---------------------------------------------------------------------------
+/** Represents a three-dimensional vector. */
+template <typename TReal>
+class aiVector3t
+{
+public:
+    aiVector3t() AI_NO_EXCEPT : x(), y(), z() {}
+    aiVector3t(TReal _x, TReal _y, TReal _z) : x(_x), y(_y), z(_z) {}
+    explicit aiVector3t (TReal _xyz ) : x(_xyz), y(_xyz), z(_xyz) {}
+    aiVector3t( const aiVector3t& o ) = default;
+
+public:
+
+    // combined operators
+    const aiVector3t& operator += (const aiVector3t& o);
+    const aiVector3t& operator -= (const aiVector3t& o);
+    const aiVector3t& operator *= (TReal f);
+    const aiVector3t& operator /= (TReal f);
+
+    // transform vector by matrix
+    aiVector3t& operator *= (const aiMatrix3x3t<TReal>& mat);
+    aiVector3t& operator *= (const aiMatrix4x4t<TReal>& mat);
+
+    // access a single element
+    TReal operator[](unsigned int i) const;
+    TReal& operator[](unsigned int i);
+
+    // comparison
+    bool operator== (const aiVector3t& other) const;
+    bool operator!= (const aiVector3t& other) const;
+    bool operator < (const aiVector3t& other) const;
+
+    bool Equal(const aiVector3t& other, TReal epsilon = 1e-6) const;
+
+    template <typename TOther>
+    operator aiVector3t<TOther> () const;
+
+public:
+    /** @brief Set the components of a vector
+     *  @param pX X component
+     *  @param pY Y component
+     *  @param pZ Z component  */
+    void Set( TReal pX, TReal pY, TReal pZ);
+
+    /** @brief Get the squared length of the vector
+     *  @return Square length */
+    TReal SquareLength() const;
+
+    /** @brief Get the length of the vector
+     *  @return length */
+    TReal Length() const;
+
+
+    /** @brief Normalize the vector */
+    aiVector3t& Normalize();
+
+    /** @brief Normalize the vector with extra check for zero vectors */
+    aiVector3t& NormalizeSafe();
+
+    /** @brief Componentwise multiplication of two vectors
+     *
+     *  Note that vec*vec yields the dot product.
+     *  @param o Second factor */
+    const aiVector3t SymMul(const aiVector3t& o);
+
+    TReal x, y, z;
+};
+
+
+typedef aiVector3t<ai_real> aiVector3D;
+
+#else
+
+struct aiVector3D {
+    ai_real x, y, z;
+};
+
+#endif // __cplusplus
+
+#ifdef __cplusplus
+
+#endif // __cplusplus
+
+#endif // AI_VECTOR3D_H_INC

dependencies/assimp/include/assimp/vector3.inl

@@ -0,0 +1,309 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  vector3.inl
+ *  @brief Inline implementation of aiVector3t<TReal> operators
+ */
+#pragma once
+#ifndef AI_VECTOR3D_INL_INC
+#define AI_VECTOR3D_INL_INC
+
+#ifdef __cplusplus
+#include "vector3.h"
+
+#include <cmath>
+
+// ------------------------------------------------------------------------------------------------
+/** Transformation of a vector by a 3x3 matrix */
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator * (const aiMatrix3x3t<TReal>& pMatrix, const aiVector3t<TReal>& pVector) {
+    aiVector3t<TReal> res;
+    res.x = pMatrix.a1 * pVector.x + pMatrix.a2 * pVector.y + pMatrix.a3 * pVector.z;
+    res.y = pMatrix.b1 * pVector.x + pMatrix.b2 * pVector.y + pMatrix.b3 * pVector.z;
+    res.z = pMatrix.c1 * pVector.x + pMatrix.c2 * pVector.y + pMatrix.c3 * pVector.z;
+    return res;
+}
+
+// ------------------------------------------------------------------------------------------------
+/** Transformation of a vector by a 4x4 matrix */
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator * (const aiMatrix4x4t<TReal>& pMatrix, const aiVector3t<TReal>& pVector) {
+    aiVector3t<TReal> res;
+    res.x = pMatrix.a1 * pVector.x + pMatrix.a2 * pVector.y + pMatrix.a3 * pVector.z + pMatrix.a4;
+    res.y = pMatrix.b1 * pVector.x + pMatrix.b2 * pVector.y + pMatrix.b3 * pVector.z + pMatrix.b4;
+    res.z = pMatrix.c1 * pVector.x + pMatrix.c2 * pVector.y + pMatrix.c3 * pVector.z + pMatrix.c4;
+    return res;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+template <typename TOther>
+aiVector3t<TReal>::operator aiVector3t<TOther> () const {
+    return aiVector3t<TOther>(static_cast<TOther>(x),static_cast<TOther>(y),static_cast<TOther>(z));
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+void aiVector3t<TReal>::Set( TReal pX, TReal pY, TReal pZ) {
+    x = pX;
+    y = pY;
+    z = pZ;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+TReal aiVector3t<TReal>::SquareLength() const {
+    return x*x + y*y + z*z;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+TReal aiVector3t<TReal>::Length() const {
+    return std::sqrt( SquareLength());
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal>& aiVector3t<TReal>::Normalize() {
+    *this /= Length();
+
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal>& aiVector3t<TReal>::NormalizeSafe() {
+    TReal len = Length();
+    if ( len > static_cast< TReal >( 0 ) ) {
+        *this /= len;
+    }
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+const aiVector3t<TReal>& aiVector3t<TReal>::operator += (const aiVector3t<TReal>& o) {
+    x += o.x;
+    y += o.y;
+    z += o.z;
+
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+const aiVector3t<TReal>& aiVector3t<TReal>::operator -= (const aiVector3t<TReal>& o) {
+    x -= o.x;
+    y -= o.y;
+    z -= o.z;
+
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+const aiVector3t<TReal>& aiVector3t<TReal>::operator *= (TReal f) {
+    x *= f;
+    y *= f;
+    z *= f;
+
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+const aiVector3t<TReal>& aiVector3t<TReal>::operator /= (TReal f) {
+    const TReal invF = (TReal) 1.0 / f;
+    x *= invF;
+    y *= invF;
+    z *= invF;
+
+    return *this;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal>& aiVector3t<TReal>::operator *= (const aiMatrix3x3t<TReal>& mat){
+    return (*this =  mat * (*this));
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal>& aiVector3t<TReal>::operator *= (const aiMatrix4x4t<TReal>& mat){
+    return (*this = mat * (*this));
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+TReal aiVector3t<TReal>::operator[](unsigned int i) const {
+    switch (i) {
+        case 0:
+            return x;
+        case 1:
+            return y;
+        case 2:
+            return z;
+        default:
+            break;
+    }
+    return x;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+TReal& aiVector3t<TReal>::operator[](unsigned int i) {
+//    return *(&x + i);
+    switch (i) {
+        case 0:
+            return x;
+        case 1:
+            return y;
+        case 2:
+            return z;
+        default:
+            break;
+    }
+    return x;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+bool aiVector3t<TReal>::operator== (const aiVector3t<TReal>& other) const {
+    return x == other.x && y == other.y && z == other.z;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+bool aiVector3t<TReal>::operator!= (const aiVector3t<TReal>& other) const {
+    return x != other.x || y != other.y || z != other.z;
+}
+// ---------------------------------------------------------------------------
+template<typename TReal>
+AI_FORCE_INLINE
+bool aiVector3t<TReal>::Equal(const aiVector3t<TReal>& other, TReal epsilon) const {
+    return
+        std::abs(x - other.x) <= epsilon &&
+        std::abs(y - other.y) <= epsilon &&
+        std::abs(z - other.z) <= epsilon;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+bool aiVector3t<TReal>::operator < (const aiVector3t<TReal>& other) const {
+    return x != other.x ? x < other.x : y != other.y ? y < other.y : z < other.z;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
+AI_FORCE_INLINE
+const aiVector3t<TReal> aiVector3t<TReal>::SymMul(const aiVector3t<TReal>& o) {
+    return aiVector3t<TReal>(x*o.x,y*o.y,z*o.z);
+}
+// ------------------------------------------------------------------------------------------------
+// symmetric addition
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator + (const aiVector3t<TReal>& v1, const aiVector3t<TReal>& v2) {
+    return aiVector3t<TReal>( v1.x + v2.x, v1.y + v2.y, v1.z + v2.z);
+}
+// ------------------------------------------------------------------------------------------------
+// symmetric subtraction
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator - (const aiVector3t<TReal>& v1, const aiVector3t<TReal>& v2) {
+    return aiVector3t<TReal>( v1.x - v2.x, v1.y - v2.y, v1.z - v2.z);
+}
+// ------------------------------------------------------------------------------------------------
+// scalar product
+template <typename TReal>
+AI_FORCE_INLINE
+TReal operator * (const aiVector3t<TReal>& v1, const aiVector3t<TReal>& v2) {
+    return v1.x*v2.x + v1.y*v2.y + v1.z*v2.z;
+}
+// ------------------------------------------------------------------------------------------------
+// scalar multiplication
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator * ( TReal f, const aiVector3t<TReal>& v) {
+    return aiVector3t<TReal>( f*v.x, f*v.y, f*v.z);
+}
+// ------------------------------------------------------------------------------------------------
+// and the other way around
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator * ( const aiVector3t<TReal>& v, TReal f) {
+    return aiVector3t<TReal>( f*v.x, f*v.y, f*v.z);
+}
+// ------------------------------------------------------------------------------------------------
+// scalar division
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator / ( const aiVector3t<TReal>& v, TReal f) {
+    return v * (1/f);
+}
+// ------------------------------------------------------------------------------------------------
+// vector division
+template <typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator / ( const aiVector3t<TReal>& v, const aiVector3t<TReal>& v2) {
+    return aiVector3t<TReal>(v.x / v2.x,v.y / v2.y,v.z / v2.z);
+}
+// ------------------------------------------------------------------------------------------------
+// cross product
+template<typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator ^ ( const aiVector3t<TReal>& v1, const aiVector3t<TReal>& v2) {
+    return aiVector3t<TReal>( v1.y*v2.z - v1.z*v2.y, v1.z*v2.x - v1.x*v2.z, v1.x*v2.y - v1.y*v2.x);
+}
+// ------------------------------------------------------------------------------------------------
+// vector negation
+template<typename TReal>
+AI_FORCE_INLINE
+aiVector3t<TReal> operator - ( const aiVector3t<TReal>& v) {
+    return aiVector3t<TReal>( -v.x, -v.y, -v.z);
+}
+
+// ------------------------------------------------------------------------------------------------
+
+#endif // __cplusplus
+#endif // AI_VECTOR3D_INL_INC

dependencies/assimp/include/assimp/version.h

@@ -0,0 +1,115 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+/** @file  version.h
+ *  @brief Functions to query the version of the Assimp runtime, check
+ *    compile flags, ...
+ */
+#pragma once
+#ifndef AI_VERSION_H_INC
+#define AI_VERSION_H_INC
+
+#include "defs.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ---------------------------------------------------------------------------
+/** @brief Returns a string with legal copyright and licensing information
+ *  about Assimp. The string may include multiple lines.
+ *  @return Pointer to static string.
+ */
+ASSIMP_API const char*  aiGetLegalString  (void);
+
+// ---------------------------------------------------------------------------
+/** @brief Returns the current minor version number of Assimp.
+ *  @return Minor version of the Assimp runtime the application was
+ *    linked/built against
+ */
+ASSIMP_API unsigned int aiGetVersionMinor (void);
+
+// ---------------------------------------------------------------------------
+/** @brief Returns the current major version number of Assimp.
+ *  @return Major version of the Assimp runtime the application was
+ *    linked/built against
+ */
+ASSIMP_API unsigned int aiGetVersionMajor (void);
+
+// ---------------------------------------------------------------------------
+/** @brief Returns the repository revision of the Assimp runtime.
+ *  @return SVN Repository revision number of the Assimp runtime the
+ *          application was linked/built against.
+ */
+ASSIMP_API unsigned int aiGetVersionRevision (void);
+
+// ---------------------------------------------------------------------------
+/** @brief Returns the branchname of the Assimp runtime.
+ *  @return The current branch name.
+ */
+ASSIMP_API const char *aiGetBranchName();
+
+//! Assimp was compiled as a shared object (Windows: DLL)
+#define ASSIMP_CFLAGS_SHARED  0x1
+//! Assimp was compiled against STLport
+#define ASSIMP_CFLAGS_STLPORT 0x2
+//! Assimp was compiled as a debug build
+#define ASSIMP_CFLAGS_DEBUG   0x4
+
+//! Assimp was compiled with ASSIMP_BUILD_BOOST_WORKAROUND defined
+#define ASSIMP_CFLAGS_NOBOOST           0x8
+//! Assimp was compiled with ASSIMP_BUILD_SINGLETHREADED defined
+#define ASSIMP_CFLAGS_SINGLETHREADED    0x10
+
+// ---------------------------------------------------------------------------
+/** @brief Returns assimp's compile flags
+ *  @return Any bitwise combination of the ASSIMP_CFLAGS_xxx constants.
+ */
+ASSIMP_API unsigned int aiGetCompileFlags (void);
+
+#ifdef __cplusplus
+} // end extern "C"
+#endif
+
+#endif // !! #ifndef AI_VERSION_H_INC
+