public void renderBackground(int xScroll, int yScroll, Screen screen){
		int xo = xScroll >> 4;
		int yo = yScroll >> 4;
		
		int w = (screen.w + 15) >> 4;
		int h = (screen.h + 15) >> 4;
		
		screen.setOffs(xScroll,yScroll);
		for (int y = yo; y <= h + yo; y++){
			for (int x = xo; x <= w + xo; x++){
				getTile(x,y).render(x,y,screen);
			}
			
		}
		screen.setOffs(0,0);
	}