public static Point3d?GetOrthoNormalPoint(this Polyline pline, Point3d point, Plane plane, bool nullForOutOfRange = true)
{
point = point.OrthoProject(pline.GetPlane());
List <Point3d> res = new List <Point3d>();
var segments = pline.GetSegments();
int i = 0;
foreach (var s in segments)
{
if (point.IsEqualTo(s.StartPoint, Tolerance.Global))
{
return(point);
}
Vector3d vector = point - s.StartPoint;
Vector3d segmVector = s.EndPoint - s.StartPoint;
double cos = segmVector.GetCos2d(vector);
double length = s.GetLength(s.GetParameterOf(s.StartPoint),
s.GetParameterOf(s.EndPoint), Tolerance.Global.EqualPoint);
///////////////////////////////////////////////
if (!nullForOutOfRange)
{
if (i == 0 && cos < 0d)
{
return(s.StartPoint);
}
if (i == segments.Count() - 1 && cos > 0 && cos * vector.Length > segmVector.Length)
{
return(s.EndPoint);
}
i++;
}
///////////////////////////////////////////////
if (cos >= 0d && cos * vector.Length <= segmVector.Length)
{
if (s is CircularArc3d)
{
CircularArc3d arc3d = (CircularArc3d)s;
Arc arc = arc3d.ConvertToArc();
Point3d? normalPoint = arc.GetOrthoNormalPoint(point, nullForOutOfRange);
if (normalPoint.HasValue)
{
res.Add(normalPoint.Value);
}
}
else if (s is LineSegment3d)
{
LineSegment3d line3d = (LineSegment3d)s;
Line line = line3d.ConvertToLine();
Point3d? normalPoint = line.GetOrthoNormalPoint(point, plane, nullForOutOfRange);
if (normalPoint.HasValue)
{
res.Add(normalPoint.Value);
}
}
}
}
if (res.Count == 0)
{
return(null);
}
else
{
res.Sort((p1, p2) => Comparer <double> .Default.Compare((point - p1).Length, (point - p2).Length));
return(res[0]);
}
}