SDL_UpdateRects -- Makes sure the given list of rectangles is updated on the given screen.
#include "SDL.h" void SDL_UpdateRects(SDL_Surface *screen, int numrects, SDL_Rect *rects);
Makes sure the given list of rectangles is updated on the given screen. The rectangles must all be confined within the screen boundaries (no clipping is done). WARNING : passing rectangles not confined within the screen boundaries to this function can cause very nasty crashes, at least with SDL 1.2.8, at least in Windows and Linux.
This function should not be called while screen is locked.
Note: It is advised to call this function only once per frame, since each call has some processing overhead. This is no restriction since you can pass any number of rectangles each time.
The rectangles are not automatically merged or checked for overlap. In general, the programmer can use his or her knowledge about his or her particular rectangles to merge them in an efficient way, to avoid overdraw.