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;
}
}