/// <summary>
/// Returns the parameter value of point.
/// </summary>
/// <param name="pt">The Point 2d whose get the PolylineSegment parameter at.</param>
/// <returns>A double between 0.0 and 1.0, or -1.0 if the point does not lie on the segment.</returns>
public double GetParameterOf(Point2d pt)
{
if (IsLinear)
{
LineSegment2d line = ToLineSegment();
return(line.IsOn(pt) ? _startPoint.GetDistanceTo(pt) / line.Length : -1.0);
}
else
{
CircularArc2d arc = ToCircularArc();
return(arc.IsOn(pt) ?
arc.GetLength(arc.GetParameterOf(_startPoint), arc.GetParameterOf(pt)) /
arc.GetLength(arc.GetParameterOf(_startPoint), arc.GetParameterOf(_endPoint)) :
-1.0);
}
}
