/*
* __ .__ .__ ._____.
* _/ |_ _______ __|__| ____ | | |__\_ |__ ______
* \ __\/ _ \ \/ / |/ ___\| | | || __ \ / ___/
* | | ( <_> > <| \ \___| |_| || \_\ \\___ \
* |__| \____/__/\_ \__|\___ >____/__||___ /____ >
* \/ \/ \/ \/
*
* Copyright (c) 2006-2011 Karsten Schmidt
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* http://creativecommons.org/licenses/LGPL/2.1/
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
package toxi.physics3d.constraints;
import toxi.geom.Sphere;
import toxi.geom.Vec3D;
import toxi.physics3d.VerletParticle3D;
/**
* This class implements a spherical constraint for 3D
* {@linkplain VerletParticle3D}s. The constraint can be configured in two ways: A
* bounding sphere not allowing particles to escape or alternatively does not
* allow particles to enter the space occupied by the sphere.
*/
public class SphereConstraint implements ParticleConstraint3D {
public Sphere sphere;
public boolean isBoundingSphere;
public final static boolean INSIDE = true;
public final static boolean OUTSIDE = false;
/**
* Creates a new instance using the sphere definition and constraint mode
* given.
*
* @param sphere
* sphere instance
* @param isBoundary
* constraint mode. Use {@linkplain #INSIDE} or
* {@linkplain #OUTSIDE} to specify constraint behaviour.
*/
public SphereConstraint(Sphere sphere, boolean isBoundary) {
this.sphere = sphere;
this.isBoundingSphere = isBoundary;
}
/**
* Creates a new instance using the sphere definition and constraint mode
* given.
*
* @param origin
* sphere origin
* @param radius
* sphere radius
* @param isBoundary
* constraint mode. Use {@linkplain #INSIDE} or
* {@linkplain #OUTSIDE} to specify constraint behaviour.
*/
public SphereConstraint(Vec3D origin, float radius, boolean isBoundary) {
sphere = new Sphere(origin, radius);
this.isBoundingSphere = isBoundary;
}
/*
* (non-Javadoc)
*
* @see
* toxi.physics.constraints.ParticleConstraint#apply(toxi.physics.VerletParticle
* )
*/
public void apply(VerletParticle3D p) {
boolean isInside = sphere.containsPoint(p);
if ((isBoundingSphere && !isInside) || (!isBoundingSphere && isInside)) {
p.set(sphere.add(p.subSelf(sphere).normalizeTo(sphere.radius)));
}
}
}