is point in polygon.as

	public static function isPointInPolygon(point:Vector3D, polygon:Vector.<Vector3D>):Boolean {
		var i:int, j:int, nvert:int = polygon.length;
		var result:Boolean = false;

		for (i = 0, j = nvert - 1; i < nvert; j = i++) {
			if (((polygon[i].z) >= point.z != (polygon[j].z >= point.z)) &&
					(point.x <= (polygon[j].x - polygon[i].x) * (point.z - polygon[i].z) / (polygon[j].z - polygon[i].z) + polygon[i].x))
				result = !result;
		}

		return result;
	}