hep.wired.heprep.util

Class NearestPoint

java.lang.Object

hep.wired.heprep.util.NearestPoint

public class NearestPoint
extends Object

Calculates the nearest point on a straight line or on a cubic bezier curve. Calculations for the Bezier parts come from: "Solving the Nearest Point-on-Curve Problem" and "A Bezier Curve-Based Root-Finder" by Philip J. Schneider from "Graphics Gems", Academic Press, 1990.

Version:

$Id: NearestPoint.java 8598 2006-08-14 20:38:02Z duns $

Author:

Mark Donszelmann

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(String[] args) Test for onCurve
static double	onCurve(CubicCurve2D c, Point2D pa, Point2D pn) Return the nearest point (pn) on cubic bezier curve c nearest to point pa.
static double	onLine(Point2D p1, Point2D p2, Point2D pa, Point2D pn) Returns the nearest point (pn) on line p1 - p2 nearest to point pa.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

onLine

public static double onLine(Point2D p1,
            Point2D p2,
            Point2D pa,
            Point2D pn)

Returns the nearest point (pn) on line p1 - p2 nearest to point pa.

Parameters:

p1 - start point of line

p2 - end point of line

pa - arbitrary point

pn - nearest point (return param)

Returns:

distance squared between pa and nearest point (pn)

onCurve

public static double onCurve(CubicCurve2D c,
             Point2D pa,
             Point2D pn)

Return the nearest point (pn) on cubic bezier curve c nearest to point pa.

Parameters:

c - cubice curve

pa - arbitrary point

pn - nearest point found (return param)

Returns:

distance squared between pa and nearest point (pn)

main

public static void main(String[] args)

Test for onCurve