private static bool IsBelowThreshold(Pnt3D sourcePoint, Pnt3D touchPoint,
Pnt3D nonIntersectingTargetPnt, double tolerance)
{
// Target starts (just?) after source, target touches source interior
//Pnt3D touchPoint = targetLine.GetPointAlong(_source1Factor, true);
double distanceFromStartToTouchPoint =
touchPoint.GetDistance(sourcePoint, true);
double alpha =
GeomUtils.GetAngle2DInRad(sourcePoint, touchPoint, nonIntersectingTargetPnt);
if (alpha < Math.PI / 2) // smaller 90°
{
double threshold = tolerance / Math.Sin(alpha);
if (distanceFromStartToTouchPoint < threshold)
{
return(true);
}
}
return(false);
}
/// <summary>
/// The perpendicular distance of the infinite line defined by the Start/End points of this
/// line to the specified point.
/// </summary>
/// <param name="point"></param>
/// <param name="inXY"></param>
/// <param name="distanceAlongRatio">The distance-along-ratio of the closest point on the line.</param>
/// <param name="pointOnLine"></param>
/// <returns></returns>
public double GetDistancePerpendicular(Pnt3D point, bool inXY,
out double distanceAlongRatio,
out Pnt3D pointOnLine)
{
// http://geomalgorithms.com/a02-_lines.html#Distance-to-Infinite-Line
Pnt3D w = point - StartPoint;
double c1, c2;
if (inXY)
{
c1 = GeomUtils.DotProduct(w.X, w.Y, 0, DirectionVector.X,
DirectionVector.Y, 0);
c2 = DirectionVector.Length2DSquared;
}
else
{
c1 = GeomUtils.DotProduct(w, DirectionVector);
c2 = DirectionVector.LengthSquared;
}
if (c2 < double.Epsilon)
{
// 0-length line: Distance to StartPoint
distanceAlongRatio = 0;
pointOnLine = (Pnt3D)StartPoint.Clone();
return(StartPoint.GetDistance(point, inXY));
}
distanceAlongRatio = c1 / c2;
pointOnLine = (Pnt3D)(StartPoint + distanceAlongRatio * DirectionVector);
return(pointOnLine.GetDistance(point, inXY));
}