This is easiest way to make screenshoots of your game.

[cairnswm]

If using SDL and OpenGL you may not actually be in OpenGL - in which case the SDL_SaveBMP is needed instead

not sure what you mean.. if you have a sdl opengl ap running and call that code, it will work.

But if its not OpenGL? This solution works for OpenGL windows - not SDL windows (unless using OpenGL)