/*
* Phys2D - a 2D physics engine based on the work of Erin Catto.
*
* This source is provided under the terms of the BSD License.
*
* Copyright (c) 2006, Phys2D
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of the Phys2D/New Dawn Software nor the names of
* its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*/
package net.phys2d.raw.collide;
import net.phys2d.math.MathUtil;
import net.phys2d.math.Vector2f;
import net.phys2d.raw.Body;
import net.phys2d.raw.Contact;
/**
* A collider wrapper that swaps the collision result of the collider.
* This is very useful to get rid of code duplication for colliders like
* CircleBoxCollider and BoxCircleCollider.
*
* @author Gideon Smeding
*
*/
public class SwapCollider implements Collider {
/** The wrapped collider of which the result will be swapped */
private Collider collider;
/**
* Create a collider that swaps the result of the wrapped
* collider.
*
* @param collider The collider of which to swap the result
*/
public SwapCollider(Collider collider) {
this.collider = collider;
}
/**
* @see net.phys2d.raw.collide.Collider#collide(net.phys2d.raw.Contact[], net.phys2d.raw.Body, net.phys2d.raw.Body)
*/
public int collide(Contact[] contacts, Body bodyA, Body bodyB) {
int count = collider.collide(contacts, bodyB, bodyA);
// reverse the collision results by inverting normals
for ( int i = 0; i < count; i++ ) {
Vector2f vec = MathUtil.scale(contacts[i].getNormal(),-1);
contacts[i].setNormal(vec);
}
return count;
}
}