SDL_Flip - Swaps screen buffers
#include "SDL.h"
int SDL_Flip(SDL_Surface *screen);
On hardware that supports double-buffering, this function sets up a flip and
returns. The hardware will wait for vertical retrace, and then swap video
buffers before the next video surface blit or lock will return. On hardware
that doesn't support double-buffering, this is equivalent to calling
SDL_UpdateRect(screen, 0, 0, 0, 0)
The SDL_DOUBLEBUF flag must have been passed to
SDL_SetVideoMode, when setting the video mode for this function to
perform hardware flipping.
This function returns 0 if successful, or -1 if there was an
error.
SDL_SetVideoMode, SDL_UpdateRect,
SDL_Surface