/*
* $Id$
* This file is a part of the Arakhne Foundation Classes, http://www.arakhne.org/afc
*
* Copyright (c) 2000-2012 Stephane GALLAND.
* Copyright (c) 2005-10, Multiagent Team, Laboratoire Systemes et Transports,
* Universite de Technologie de Belfort-Montbeliard.
* Copyright (c) 2013-2016 The original authors, and other authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.arakhne.afc.agentmotion.kinematic;
import java.io.Serializable;
import org.eclipse.xtext.xbase.lib.Pure;
import org.arakhne.afc.agentmotion.ArrivingMotionAlgorithm;
import org.arakhne.afc.math.geometry.d2.Point2D;
import org.arakhne.afc.math.geometry.d2.Vector2D;
import org.arakhne.afc.math.geometry.d2.d.Vector2d;
import org.arakhne.afc.vmutil.asserts.AssertMessages;
/** Agent is changing its position for arriving (stopping) the target point.
*
* <p>This algorithm uses speeds.
*
* @author $Author: sgalland$
* @version $FullVersion$
* @mavengroupid $GroupId$
* @mavenartifactid $ArtifactId$
* @since 14.0
*/
public class ArrivingKinematicAlgorithm implements ArrivingMotionAlgorithm, Serializable, Cloneable {
private static final long serialVersionUID = -8318025671219960417L;
/** Square distance to the target under which the agent could stop.
*/
protected final double stopSquaredDistance;
/** Constructor.
*
* @param stopDistance the distance to the target under which the agent could stop.
*/
public ArrivingKinematicAlgorithm(double stopDistance) {
assert stopDistance >= 0. : AssertMessages.positiveOrZeroParameter();
this.stopSquaredDistance = stopDistance * stopDistance;
}
@Pure
@Override
public ArrivingKinematicAlgorithm clone() {
try {
return (ArrivingKinematicAlgorithm) super.clone();
} catch (CloneNotSupportedException e) {
throw new Error(e);
}
}
@Override
public Vector2D<?, ?> calculate(Point2D<?, ?> position, double linearSpeed, double maxLinearSpeed,
Point2D<?, ?> target) {
final Vector2d v = new Vector2d(
target.getX() - position.getX(),
target.getY() - position.getY());
if (v.getLengthSquared() <= this.stopSquaredDistance) {
return new Vector2d();
}
v.setLength(maxLinearSpeed);
return v;
}
}