Slock (screen);
	Uint32 *bufp;
	Uint32 color = 0xFFFFFF;
	SDL_Rect dst = {0,0,1,1};
	for (int y=0; y<600; y++)
		{
		int y800 = y*800;
		for (int x=0; x<800; x++)
			{
			dst.x = x;
			dst.y = y;
			bufp = (Uint32*)screen->pixels + y800 + x;
			*bufp = color;
			}
		}
	Sulock (screen);

	/*
	Uint32 color = 0xFFFFFF;
	SDL_Rect dst = {0,0,1,1};
	for (int y=0; y<600; y++)
		{
		for (int x=0; x<800; x++)
			{
			dst.x = x;
			dst.y = y;
			SDL_FillRect (screen, &dst, color);
			}
		}
		*/