Returns a specific point from segments of points

gistfile1.as

public function getPointAt(progress : Number) : Point
{
	var i : int;
	var length : int = _points.length;
	var pointProgress : Number;
	var totalProgress : Number = 0;
	
	for(i = 1 ; i < length; i++)
	{
		pointProgress = Point.distance(_points[i], _points[i - 1]) / _length;
		totalProgress += pointProgress;
		if(totalProgress >= progress)
		{
			return Point.interpolate(_points[i - 1], _points[i], (totalProgress - progress) / pointProgress);
		}
	}
	return null;
}