public void render(int xOffset, int yOffset){
		for(int y=0;y<height;y++){
			int yy = y+yOffset;
			if(yy< 0 || yy>=height) continue;
			for(int x=0;x<width;x++){
				int xx= x+xOffset;
				if(xx<0 || xx>=width) continue;
				int tileIndex = ((xx>>4)&MAP_SIZE_MASK)+((yy>>4)&MAP_SIZE_MASK)*MAP_SIZE;
				pixels[xx+yy*width]=Sprite.grass.pixels[(x&15)+(y&15)*Sprite.grass.SIZE];//tiles[tileIndex];
			}
		}
	}