@Override
	public int compareTo(Object o) {
		if(o == this)
			return 0;
		TileXY other = (TileXY)o;
		if(this.y == other.y){
			if(this.x == other.x)
				return 0;
			if(this.x > other.x)
				return 1;
			else
				return -1;
		}
		if(this.y > other.y)
			return 1;
		return -1;
	}