#include <glad/glad.h> #include <GLFW/glfw3.h> #include <learnopengl/shader_s.h> #include <iostream> void framebuffer_size_callback(GLFWwindow* window, int width, int height); void processInput(GLFWwindow *window); // settings const unsigned int SCR_WIDTH = 800; const unsigned int SCR_HEIGHT = 600; int main() { // 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 -1; }  glfwMakeContextCurrent(window); glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); // glad: load all OpenGL function pointers // --------------------------------------- if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; } // build and compile our shader program // ------------------------------------ Shader ourShader("3.3.shader.vs", "3.3.shader.fs"); // you can name your shader files however you like // set up vertex data (and buffer(s)) and configure vertex attributes // ------------------------------------------------------------------ float vertices[] = { // positions // colors 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom right -0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // bottom left 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f // top }; unsigned int VBO, VAO;  glGenVertexArrays(1, &VAO);  glGenBuffers(1, &VBO); // bind the Vertex Array Object first, then bind and set vertex buffer(s), and then configure vertex attributes(s).  glBindVertexArray(VAO);  glBindBuffer(GL_ARRAY_BUFFER, VBO);  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); // position attribute  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);  glEnableVertexAttribArray(0); // color attribute  glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));  glEnableVertexAttribArray(1); // You can unbind the VAO afterwards so other VAO calls won't accidentally modify this VAO, but this rarely happens. Modifying other // VAOs requires a call to glBindVertexArray anyways so we generally don't unbind VAOs (nor VBOs) when it's not directly necessary. // glBindVertexArray(0); // render loop // ----------- while (!glfwWindowShouldClose(window)) { // input // ----- processInput(window); // render // ------  glClearColor(0.2f, 0.3f, 0.3f, 1.0f);  glClear(GL_COLOR_BUFFER_BIT); // render the triangle ourShader.use();  glBindVertexArray(VAO);  glDrawArrays(GL_TRIANGLES, 0, 3); // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) // -------------------------------------------------------------------------------  glfwSwapBuffers(window);  glfwPollEvents(); } // optional: de-allocate all resources once they've outlived their purpose: // ------------------------------------------------------------------------ glDeleteVertexArrays(1, &VAO); glDeleteBuffers(1, &VBO); // glfw: terminate, clearing all previously allocated GLFW resources. // ------------------------------------------------------------------  glfwTerminate(); return 0; } // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly // --------------------------------------------------------------------------------------------------------- void processInput(GLFWwindow *window) { if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); } // glfw: whenever the window size changed (by OS or user resize) this callback function executes // --------------------------------------------------------------------------------------------- void framebuffer_size_callback(GLFWwindow* window, int width, int height) { // make sure the viewport matches the new window dimensions; note that width and // height will be significantly larger than specified on retina displays.  glViewport(0, 0, width, height); }