跨平臺 OpenGL 上下文建立（使用 SDL2）

使用 OpenGL 上下文建立視窗（通過 GLEW 載入擴充套件 ）：

#define GLEW_STATIC

#include <GL/glew.h>
#include <SDL2/SDL.h>

int main(int argc, char* argv[])
{
    SDL_Init(SDL_INIT_VIDEO); /* Initialises Video Subsystem in SDL */

    /* Setting up OpenGL version and profile details for context creation */
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
    
    /* A 800x600 window. Pretty! */
    SDL_Window* window = SDL_CreateWindow
        (
        "SDL Context",
        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
        800, 600,
        SDL_WINDOW_OPENGL
        );
    
    /* Creating OpenGL Context */
    SDL_GLContext gl_context = SDL_GL_CreateContext(window);

    /* Loading Extensions */
    glewExperimental = GL_TRUE;
    glewInit();

    /* The following code is for error checking. 
    *  If OpenGL has initialised properly, this should print 1.
    *  Remove it in production code.
    */
    GLuint vertex_buffer;
    glGenBuffers(1, &vertex_buffer);
    printf("%u
", vertex_buffer);
    /* Error checking ends here */

    /* Main Loop */
    SDL_Event window_event;
    while(1) {
        if (SDL_PollEvent(&window_event)) {
            if (window_event.type == SDL_QUIT) {
                /* If user is exiting the application */
                break;
            }
        }
        /* Swap the front and back buffer for flicker-free rendering */
        SDL_GL_SwapWindow(window);
    }
    
    /* Freeing Memory */
    glDeleteBuffers(1, &vertex_buffer);
    SDL_GL_DeleteContext(gl_context);
    SDL_Quit();

    return 0;
}