/**
* barsuift-simlife is a life simulator programm
*
* Copyright (C) 2010 Cyrille GACHOT
*
* This file is part of barsuift-simlife.
*
* barsuift-simlife is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* barsuift-simlife is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with barsuift-simlife. If not, see
* <http://www.gnu.org/licenses/>.
*/
package barsuift.simLife.j3d.util;
import javax.vecmath.Point3d;
public final class BarycentreHelper {
private BarycentreHelper() {
// private constructor to enforce static access
}
/**
* Return a point on the line between startPoint and endPoint, located at the given distance from the startPoint.
* <p>
* The returned point is always on the line, between the 2 given points. If distance is too low (negative), then the
* start point is returned. If distance is too high, then the end point is returned.
* </p>
*
* @param startPoint
* @param endPoint
* @param distance
* @return
*/
public static Point3d getBarycentre(Point3d startPoint, Point3d endPoint, double distance) {
double maxDistance = startPoint.distance(endPoint);
double distanceToUse = computeDistanceToUse(maxDistance, distance);
double ratio = distanceToUse / maxDistance;
Point3d result = new Point3d();
result.interpolate(startPoint, endPoint, ratio);
return result;
}
/**
* Bounds the given distance between 0 and maxDistance
*
* @param maxDistance
* @param distance
* @return
*/
static double computeDistanceToUse(double maxDistance, double distance) {
if (distance < 0) {
return 0;
}
if (distance > maxDistance) {
return maxDistance;
}
return distance;
}
}