public static bool IntersectsOtherLineSegment(this LineSegment2D lineSegment, LineSegment2D otherLineSegment, out Point2D?intersectionPoint)
{
var line0 = new Line2D(lineSegment);
var line1 = new Line2D(otherLineSegment);
if (line0.IntersectsOtherLine(line1, out intersectionPoint))
{
var lineSegmentSquaredLength = lineSegment.SquaredLength();
if ((intersectionPoint.Value - line0.PointA).SquaredLength() > lineSegmentSquaredLength ||
(intersectionPoint.Value - line0.PointB).SquaredLength() > lineSegmentSquaredLength)
{
intersectionPoint = null;
return(false);
}
var lineSegmentSquaredLength1 = otherLineSegment.SquaredLength();
if ((intersectionPoint.Value - line1.PointA).SquaredLength() > lineSegmentSquaredLength1 ||
(intersectionPoint.Value - line1.PointB).SquaredLength() > lineSegmentSquaredLength1)
{
intersectionPoint = null;
return(false);
}
return(true);
}
return(false);
}
public static double ShortestSquaredDistanceToPoint(this LineSegment2D lineSegment, Point2D point, out Point2D pointOnSegment)
{
var lineSegmentSquaredLength = lineSegment.SquaredLength();
var pA = lineSegment.PointA;
var pB = lineSegment.PointB;
if (lineSegmentSquaredLength == 0)
{
pointOnSegment = pA;
return((point - pA).SquaredLength());
}
var t = ((point.X - pA.X) * (pB.X - pA.X) + (point.Y - pA.Y) * (pB.Y - pA.Y)) / lineSegmentSquaredLength;
t = Math.Max(0, Math.Min(1, t));
pointOnSegment = new Point2D(pA.X + t * (pB.X - pA.X), pA.Y + t * (pB.Y - pA.Y));
return((pointOnSegment - point).SquaredLength());
}
