/*  call-seq:
 *     Screen.get_surface
 *
 *  Returns the current display window, or raises SDLError if it
 *  fails to get it (for example, if it doesn't exist yet).
 */
VALUE rbgm_screen_getsurface(VALUE module)
{
  SDL_Surface *surface;
  surface = SDL_GetVideoSurface();
  if(surface==NULL)
        {
                rb_raise(eSDLError,"Couldn't get video surface: %s",SDL_GetError());
        }
  return Data_Wrap_Struct( cScreen,0,0,surface );
}