class HKalGeomTools: public TObject

 Calculates the distance between two points.

 Calculates the distance of vector pos to the plane.

 Calculates the distance between a test point and a line defined by two points.
 This function also find the point on the segment that is closest to the test point.
 For method used see:
 http://www.geometrictools.com/Documentation/DistancePointLine.pdf

 return value: Distance of the test point to the segment.
 output parameters:
 pca:          The point on the line that is closest to the test point.
 iFlag:        =0 if the PCA is on the segment,
               =1 the PCA is one of the segment end points.
 input parameters:
 point:        Find the distance of this test point to the line segment.
 segPoint1, segPoint2: The two points defining the line segment.

 Calculates the distance between a test point and a line segment.
 For method used see:
 http://www.geometrictools.com/Documentation/DistancePointLine.pdf

 input:
 point: the test point
 segPoint1, segPoint2: The two points defining the line segment.

 Calculates the distance between a test point and a line segment defined by two points.
 This function also find the point on the segment that is closest to the test point.
 For method used see:
 http://www.geometrictools.com/Documentation/DistancePointLine.pdf

 return value: Distance of the test point to the segment.
 output parameters:
 pca:          The point on the line segment that is closest to the test point.
 iFlag:        =0 if the PCA is on the segment,
               =1 the PCA is one of the segment end points.
 input parameters:
 point:        Find the distance of this test point to the line segment.
 segPoint1, segPoint2: The two points defining the line segment.

 Finds the intersection point of a straight line with any plane.
 pointIntersect: the intersection point (return value).
 pos:            a point on the straight line.
 dir:            direction of the straight line.
 planeCenter:    a point on the plane.
 planeNormal:    normal vector of the plane.

 Checks if point is on the plane.

 Calculates the distance of a test point to the plane.
 The signed distance is positive if the origin of the coordinate system and the test point
 are on opposite sides of the plane and negative if they are on the same side.

 input parameters:
 point: test point
 planeCenter: a point on the plane
 planeNormal: normal vector of the plane

 Code from GEANE.

 Closest approach to a line from 2 GEANE points

 METHOD: the nearest points on the two lines
         x1,x2 and w1,w2 is found.
         The method is described in:
  http://softsurfer.com/Archive/algorithm_0106/algorithm_0106.htm
  http://www.geometrictools.com/Documentation/DistanceLine3Line3.pdf.

 INPUT: x1, x2   closest appoach GEANE points
        w1, w2   points of the line  (wire)  to approach

 OUTPUT: Pfinal  point of closest approach on the track
         Pwire    point of closest approach on the wire
         Dist    distance between Pfian and w1
         Length  arc length to add to the GEANE length of x1
         Iflag   =1 when Pwire is outside [w1,w2]
                 In this case, when w1 and w2 are the extremes
                 of the wire, the user could remake the procedure
                 by calling Track3ToPoint or Track2ToPoint, where the
                 Point is w1 or w2;
                 = 2 when the two lines are parallel and the solution
                 does not exists.

 Authors: Andrea Fontana and Alberto Rotondi 20 MAy 2007