/*
 * JBox2D - A Java Port of Erin Catto's Box2D
 * 
 * JBox2D homepage: http://jbox2d.sourceforge.net/ 
 * Box2D homepage: http://www.box2d.org
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

package org.jbox2d.dynamics.contacts;

import java.util.ArrayList;
import java.util.List;

import org.jbox2d.collision.CircleShape;
import org.jbox2d.collision.CollideCircle;
import org.jbox2d.collision.Collision;
import org.jbox2d.collision.ContactID;
import org.jbox2d.collision.Manifold;
import org.jbox2d.collision.ManifoldPoint;
import org.jbox2d.collision.PolygonShape;
import org.jbox2d.collision.Shape;
import org.jbox2d.collision.ShapeType;
import org.jbox2d.common.XForm;
import org.jbox2d.dynamics.Body;
import org.jbox2d.dynamics.ContactListener;


class PolyAndCircleContact extends Contact implements ContactCreateFcn {

    Manifold m_manifold;

    public PolyAndCircleContact(Shape s1, Shape s2) {
        super(s1, s2);
        assert (m_shape1.m_type == ShapeType.POLYGON_SHAPE);
        assert (m_shape2.m_type == ShapeType.CIRCLE_SHAPE);
        m_manifold = new Manifold();
        m_manifoldCount = 0;
        // These should not be necessary, manifold was
        // just created...
        //m_manifold.points[0].normalForce = 0.0f;
    	//m_manifold.points[0].tangentForce = 0.0f;
    }

    public PolyAndCircleContact() {
        super();
        m_manifold = new Manifold();
        m_manifoldCount = 0;
    }

    public Contact clone() {
        PolyAndCircleContact newC = new PolyAndCircleContact(this.m_shape1,
                this.m_shape2);
        newC.m_manifold = new Manifold(this.m_manifold);
        newC.m_manifoldCount = this.m_manifoldCount;
        // The parent world.
        newC.m_world = this.m_world;

        // World pool and list pointers.
        newC.m_prev = this.m_prev;
        newC.m_next = this.m_next;

        // Nodes for connecting bodies.
        newC.m_node1 = this.m_node1;
        newC.m_node2 = this.m_node2;

        // Combined friction
        newC.m_friction = this.m_friction;
        newC.m_restitution = this.m_restitution;

        newC.m_flags = this.m_flags;
        return newC;
    }

    public Contact create(Shape shape1, Shape shape2) {
        return new PolyAndCircleContact(shape1, shape2);
    }

    @Override
    public List<Manifold> getManifolds() {
        List<Manifold> ret = new ArrayList<Manifold>(1);
        if (m_manifold != null) {
            ret.add(m_manifold);
        }
        return ret;
    }

    public void evaluate(ContactListener listener) {
    	
    	Body b1 = m_shape1.getBody();
    	Body b2 = m_shape2.getBody();

    	//memcpy(&m0, &m_manifold, sizeof(b2Manifold));
    	Manifold m0 = new Manifold(m_manifold);
        for (int k = 0; k < m_manifold.pointCount; k++) {
            m0.points[k] = new ManifoldPoint(m_manifold.points[k]);
            m0.points[k].normalForce = m_manifold.points[k].normalForce;
            m0.points[k].tangentForce = m_manifold.points[k].tangentForce;
            m0.points[k].separation = m_manifold.points[k].separation;
            //m0.points[k].id.key = m_manifold.points[k].id.key;
            m0.points[k].id.features.set(m_manifold.points[k].id.features);
            //System.out.println(m_manifold.points[k].id.key);
        }
        m0.pointCount = m_manifold.pointCount;
    	
    	CollideCircle.collidePolygonAndCircle(m_manifold, (PolygonShape)m_shape1, b1.m_xf, (CircleShape)m_shape2, b2.m_xf);

    	if (m_manifold.pointCount > 0) {
    		m_manifoldCount = 1;
    		if (m0.pointCount == 0) {
    			m_manifold.points[0].id.features.flip |= Collision.NEW_POINT;
    		} else {
    			m_manifold.points[0].id.features.flip &= ~Collision.NEW_POINT;
    		}
    	} else {
    		m_manifoldCount = 0;
    		if (m0.pointCount > 0 && (listener != null)) {
    			ContactPoint cp = new ContactPoint();
    			cp.shape1 = m_shape1;
    			cp.shape2 = m_shape2;
    			cp.normal = m0.normal;
    			cp.position = XForm.mul(b1.m_xf, m0.points[0].localPoint1);
    			cp.separation = m0.points[0].separation;
    			cp.normalForce = m0.points[0].normalForce;
    			cp.tangentForce = m0.points[0].tangentForce;
    			cp.id = new ContactID(m0.points[0].id);
    			listener.remove(cp);
    		}
    	}
    	
    }
}