/// <summary>
/// Returns the closest point on the line to the given point.
/// </summary>
/// <param name="p">The point which the returned point is the closest point on the line to</param>
/// <param name="mustBeOnSegment">If true the returned point is contained by the segment ends, otherwise it can be anywhere on the projected line.</param>
/// <returns></returns>
public Point3D ClosestPointTo(Point3D p, bool mustBeOnSegment)
{
Vector3D v = (p - this.StartPoint);
double dotProduct = v.DotProduct(this.Direction);
if (mustBeOnSegment)
{
if (dotProduct < 0)
{
dotProduct = 0;
}
if (dotProduct > this.Length)
{
dotProduct = this.Length;
}
}
Vector3D alongVector = dotProduct * this.Direction;
return(this.StartPoint + alongVector);
}
/// <summary>
/// Returns the shortes line to a point
/// </summary>
/// <param name="p"></param>
/// <param name="mustStartBetweenStartAndEnd">If false the startpoint can be on the line extending beyond the start and endpoint of the line</param>
/// <returns></returns>
public Line3D LineTo(Point3D p, bool mustStartBetweenStartAndEnd)
{
Vector3D v = this.StartPoint.VectorTo(p);
double dotProduct = v.DotProduct(this.Direction);
if (mustStartBetweenStartAndEnd)
{
if (dotProduct < 0)
{
dotProduct = 0;
}
var l = this.Length;
if (dotProduct > l)
{
dotProduct = l;
}
}
var alongVector = dotProduct * this.Direction;
return(new Line3D(this.StartPoint + alongVector, p));
}
