Set an OpenGL window attribute before window creation.
int SDL_GL_SetAttribute(SDL_GLattr attr, int value);| attr | an SDL_GLattr enum value specifying the OpenGL attribute to set |
| value | the desired value for the attribute |
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
This function sets the OpenGL attribute attr to value. The requested attributes should be set before creating an OpenGL window. You should use SDL_GL_GetAttribute() to check the values after creating the OpenGL context, since the values obtained can differ from the requested ones.
This function is available since SDL 3.0.0.
SDL_Window *window;
SDL_GLContext context;
SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
window = SDL_CreateWindow("OpenGL Window", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_OPENGL);
if (!window) {
fprintf(stderr, "Couldn't create window: %s\n", SDL_GetError());
return;
}
context = SDL_GL_CreateContext(window);
if (!context) {
fprintf(stderr, "Couldn't create context: %s\n", SDL_GetError());
return;
}
int r, g, b;
SDL_GL_GetAttribute(SDL_GL_RED_SIZE, &r);
SDL_GL_GetAttribute(SDL_GL_GREEN_SIZE, &g);
SDL_GL_GetAttribute(SDL_GL_BLUE_SIZE, &b);
printf("Red size: %d, Green size: %d, Blue size: %d\n", r, g, b);