Util.java Source code

Introduction

Here is the source code for Util.java

Source

import java.awt.Point;

public class Util {

    /**
     * Returns closest point on segment to point
     * 
     * @param ss
     *            segment start point
     * @param se
     *            segment end point
     * @param p
     *            point to found closest point on segment
     * @return closest point on segment to p
     */
    public static Point getClosestPointOnSegment(Point ss, Point se, Point p) {
        return getClosestPointOnSegment(ss.x, ss.y, se.x, se.y, p.x, p.y);
    }

    /**
     * Returns closest point on segment to point
     * 
     * @param sx1
     *            segment x coord 1
     * @param sy1
     *            segment y coord 1
     * @param sx2
     *            segment x coord 2
     * @param sy2
     *            segment y coord 2
     * @param px
     *            point x coord
     * @param py
     *            point y coord
     * @return closets point on segment to point
     */
    public static Point getClosestPointOnSegment(int sx1, int sy1, int sx2, int sy2, int px, int py) {
        double xDelta = sx2 - sx1;
        double yDelta = sy2 - sy1;

        if ((xDelta == 0) && (yDelta == 0)) {
            throw new IllegalArgumentException("Segment start equals segment end");
        }

        double u = ((px - sx1) * xDelta + (py - sy1) * yDelta) / (xDelta * xDelta + yDelta * yDelta);

        final Point closestPoint;
        if (u < 0) {
            closestPoint = new Point(sx1, sy1);
        } else if (u > 1) {
            closestPoint = new Point(sx2, sy2);
        } else {
            closestPoint = new Point((int) Math.round(sx1 + u * xDelta), (int) Math.round(sy1 + u * yDelta));
        }

        return closestPoint;
    }
}