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fraktal/include/image_DXT.h
2021-02-08 22:56:15 +01:00

124 lines
3.0 KiB
C

/*
Jonathan Dummer
2007-07-31-10.32
simple DXT compression / decompression code
public domain
*/
#ifndef HEADER_IMAGE_DXT
#define HEADER_IMAGE_DXT
/**
Converts an image from an array of unsigned chars (RGB or RGBA) to
DXT1 or DXT5, then saves the converted image to disk.
\return 0 if failed, otherwise returns 1
**/
int
save_image_as_DDS
(
const char *filename,
int width, int height, int channels,
const unsigned char *const data
);
/**
take an image and convert it to DXT1 (no alpha)
**/
unsigned char*
convert_image_to_DXT1
(
const unsigned char *const uncompressed,
int width, int height, int channels,
int *out_size
);
/**
take an image and convert it to DXT5 (with alpha)
**/
unsigned char*
convert_image_to_DXT5
(
const unsigned char *const uncompressed,
int width, int height, int channels,
int *out_size
);
/** A bunch of DirectDraw Surface structures and flags **/
typedef struct
{
unsigned int dwMagic;
unsigned int dwSize;
unsigned int dwFlags;
unsigned int dwHeight;
unsigned int dwWidth;
unsigned int dwPitchOrLinearSize;
unsigned int dwDepth;
unsigned int dwMipMapCount;
unsigned int dwReserved1[ 11 ];
/* DDPIXELFORMAT */
struct
{
unsigned int dwSize;
unsigned int dwFlags;
unsigned int dwFourCC;
unsigned int dwRGBBitCount;
unsigned int dwRBitMask;
unsigned int dwGBitMask;
unsigned int dwBBitMask;
unsigned int dwAlphaBitMask;
}
sPixelFormat;
/* DDCAPS2 */
struct
{
unsigned int dwCaps1;
unsigned int dwCaps2;
unsigned int dwDDSX;
unsigned int dwReserved;
}
sCaps;
unsigned int dwReserved2;
}
DDS_header ;
/* the following constants were copied directly off the MSDN website */
/* The dwFlags member of the original DDSURFACEDESC2 structure
can be set to one or more of the following values. */
#define DDSD_CAPS 0x00000001
#define DDSD_HEIGHT 0x00000002
#define DDSD_WIDTH 0x00000004
#define DDSD_PITCH 0x00000008
#define DDSD_PIXELFORMAT 0x00001000
#define DDSD_MIPMAPCOUNT 0x00020000
#define DDSD_LINEARSIZE 0x00080000
#define DDSD_DEPTH 0x00800000
/* DirectDraw Pixel Format */
#define DDPF_ALPHAPIXELS 0x00000001
#define DDPF_FOURCC 0x00000004
#define DDPF_RGB 0x00000040
/* The dwCaps1 member of the DDSCAPS2 structure can be
set to one or more of the following values. */
#define DDSCAPS_COMPLEX 0x00000008
#define DDSCAPS_TEXTURE 0x00001000
#define DDSCAPS_MIPMAP 0x00400000
/* The dwCaps2 member of the DDSCAPS2 structure can be
set to one or more of the following values. */
#define DDSCAPS2_CUBEMAP 0x00000200
#define DDSCAPS2_CUBEMAP_POSITIVEX 0x00000400
#define DDSCAPS2_CUBEMAP_NEGATIVEX 0x00000800
#define DDSCAPS2_CUBEMAP_POSITIVEY 0x00001000
#define DDSCAPS2_CUBEMAP_NEGATIVEY 0x00002000
#define DDSCAPS2_CUBEMAP_POSITIVEZ 0x00004000
#define DDSCAPS2_CUBEMAP_NEGATIVEZ 0x00008000
#define DDSCAPS2_VOLUME 0x00200000
#endif /* HEADER_IMAGE_DXT */