adjustPosition(obj) {
		// only adjust position if obj.gid is defined
		if (typeof obj.gid === "number") {
			// Tiled objects origin point is "bottom-left" in Tiled,
			// "top-left" in melonJS)
			obj.y -= obj.height;
		}
	}
fix the position of Objects to match
the way Tiled places them
@ignore