refactor out boring code

opengl_test35.cpp

@@ -13,6 +13,8 @@
 
 #include <iostream>
 
+GLFWwindow *initialize_glfw_window(void);
+
 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 void mouse_callback(GLFWwindow* window, double xpos, double ypos);
 void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
@@ -36,57 +38,14 @@ float lastFrame = 0.0f;
 
 int main()
 {
-    // glfw: initialize and configure
+    if ((GLFWwindow *window = initialize_glfw_window()) == nullptr)
-    // ------------------------------
-    glfwInit();
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-
-#ifdef __APPLE__
-    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
-#endif
-
-    // glfw window creation
-    // --------------------
-    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
-    if (window == NULL)
-    {
-        std::cout << "Failed to create GLFW window" << std::endl;
-        glfwTerminate();
         return -1;
-    }
-    glfwMakeContextCurrent(window);
-    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
-    glfwSetCursorPosCallback(window, mouse_callback);
-    glfwSetScrollCallback(window, scroll_callback);
 
-    // tell GLFW to capture our mouse
+    // load objects and shaders
-    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+    Shader kniedeShader("9.2.geometry_shader.vert", "9.2.geometry_shader.frag");
+    Model kniedeModel("../resources/objects/kniede/kniede.obj");
 
-    // glad: load all OpenGL function pointers
+    Shader cubemapShader("6.2.cubemaps.vert", "6.2.cubemaps.frag");
-    // ---------------------------------------
-    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
-    {
-        std::cout << "Failed to initialize GLAD" << std::endl;
-        return -1;
-    }
-
-    // configure global opengl state
-    // -----------------------------
-    glEnable(GL_DEPTH_TEST);
-
-
-    // build and compile shaders
-    // -------------------------
-    Shader nanosuitShader("9.2.geometry_shader.vert", "9.2.geometry_shader.frag");
-    //Model nanosuitModel("../resources/objects/nanosuit/nanosuit.obj");
-    Model nanosuitModel("../resources/objects/kniede/kniede.obj");
-
-
-    // build and compile shaders
-    // -------------------------
-    Shader shader("6.2.cubemaps.vert", "6.2.cubemaps.frag");
     Shader skyboxShader("6.2.skybox.vert", "6.2.skybox.frag");
 
     // set up vertex data (and buffer(s)) and configure vertex attributes
@@ -191,6 +150,7 @@ int main()
     glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
     glEnableVertexAttribArray(1);
     glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
+
     // skybox VAO
     unsigned int skyboxVAO, skyboxVBO;
     glGenVertexArrays(1, &skyboxVAO);
@@ -219,8 +179,8 @@ int main()
 
     // shader configuration
     // --------------------
-    shader.use();
+    cubemapShader.use();
-    shader.setInt("skybox", 0);
+    cubemapShader.setInt("skybox", 0);
 
     skyboxShader.use();
     skyboxShader.setInt("skybox", 0);
@@ -234,39 +194,34 @@ int main()
         float currentFrame = glfwGetTime();
         deltaTime = currentFrame - lastFrame;
         lastFrame = currentFrame;
-
-        // input
-        // -----
         processInput(window);
 
-        // render
-        // ------
         glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
         // draw scene as normal
+        glm::mat4 model = glm::mat4(1.0f);
         glm::mat4 view = camera.GetViewMatrix();
         glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
-        glm::mat4 model = glm::mat4(1.0f);
+
 //        model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f)); // translate it down so it's at the center of the scene
 //        model = glm::scale(model, glm::vec3(1.0f, 1.0f, 1.0f));	// it's a bit too big for our scene, so scale it down
         model = glm::rotate(model, glm::radians(-90.0f), glm::vec3(1.0f, 0.0f, 0.0f));
-        nanosuitShader.use();
+        kniedeShader.use();
-        nanosuitShader.setMat4("projection", projection);
+        kniedeShader.setMat4("model", model);
-        nanosuitShader.setMat4("view", view);
+        kniedeShader.setMat4("view", view);
-        nanosuitShader.setMat4("model", model);
+        kniedeShader.setMat4("projection", projection);
-        nanosuitModel.Draw(nanosuitShader);
+        kniedeModel.Draw(kniedeShader);
 
 
         // draw scene as normal
-        shader.use();
         model = glm::mat4(1.0f);
-        view = camera.GetViewMatrix();
+        cubemapShader.use();
-        projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+        cubemapShader.setMat4("model", model);
-        shader.setMat4("model", model);
+        cubemapShader.setMat4("view", view);
-        shader.setMat4("view", view);
+        cubemapShader.setMat4("projection", projection);
-        shader.setMat4("projection", projection);
+        cubemapShader.setVec3("cameraPos", camera.Position);
-        shader.setVec3("cameraPos", camera.Position);
+
         // cubes
         glBindVertexArray(cubeVAO);
         glActiveTexture(GL_TEXTURE0);
@@ -280,6 +235,7 @@ int main()
         view = glm::mat4(glm::mat3(camera.GetViewMatrix())); // remove translation from the view matrix
         skyboxShader.setMat4("view", view);
         skyboxShader.setMat4("projection", projection);
+
         // skybox cube
         glBindVertexArray(skyboxVAO);
         glActiveTexture(GL_TEXTURE0);
@@ -294,17 +250,58 @@ int main()
         glfwPollEvents();
     }
 
-    // optional: de-allocate all resources once they've outlived their purpose:
-    // ------------------------------------------------------------------------
-    glDeleteVertexArrays(1, &cubeVAO);
-    glDeleteVertexArrays(1, &skyboxVAO);
-    glDeleteBuffers(1, &cubeVBO);
-    glDeleteBuffers(1, &skyboxVAO);
-
     glfwTerminate();
     return 0;
 }
 
+// initialize GLFW window and OpenGL context with glew
+// ---------------------------------------------------------------------------------------------------------
+GLFWwindow *initialize_glfw_window(void)
+{
+    // glfw: initialize and configure
+    // ------------------------------
+    glfwInit();
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+#ifdef __APPLE__
+    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+#endif
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return nullptr;
+    }
+    glfwMakeContextCurrent(window);
+    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+    glfwSetCursorPosCallback(window, mouse_callback);
+    glfwSetScrollCallback(window, scroll_callback);
+
+    // tell GLFW to capture our mouse
+    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+    // glad: load all OpenGL function pointers
+    // ---------------------------------------
+    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+    {
+        std::cout << "Failed to initialize GLAD" << std::endl;
+        return nullptr;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    return window;
+}
+
+
 // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
 // ---------------------------------------------------------------------------------------------------------
 void processInput(GLFWwindow *window)