/********************************************************************************
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
* Copyright (c) 2010-2013 Daniel Chappuis                                       *
*********************************************************************************
*                                                                               *
* 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.    *
*                                                                               *
********************************************************************************/

#ifndef REACTPHYSICS3D_OVERLAPPING_PAIR_H
#define	REACTPHYSICS3D_OVERLAPPING_PAIR_H

// Libraries
#include "ContactManifold.h"

/// ReactPhysics3D namespace
namespace reactphysics3d {

// Class OverlappingPair
/**
 * This class represents a pair of two bodies that are overlapping
 * during the broad-phase collision detection. It is created when
 * the two bodies start to overlap and is destroyed when they do not
 * overlap anymore. This class contains a contact manifold that
 * store all the contact points between the two bodies.
 */
class OverlappingPair {

    private:

        // -------------------- Attributes -------------------- //

        /// Pointer to the first body of the contact
        CollisionBody* mBody1;

        /// Pointer to the second body of the contact
        CollisionBody* mBody2;

        /// Persistent contact manifold
        ContactManifold mContactManifold;

        /// Cached previous separating axis
        Vector3 mCachedSeparatingAxis;
        
        // -------------------- Methods -------------------- //

        /// Private copy-constructor
        OverlappingPair(const OverlappingPair& pair);

        /// Private assignment operator
        OverlappingPair& operator=(const OverlappingPair& pair);

    public:

        // -------------------- Methods -------------------- //

        /// Constructor
        OverlappingPair(CollisionBody* body1, CollisionBody* body2,
                        MemoryAllocator& memoryAllocator);

        /// Destructor
        ~OverlappingPair();
        
        /// Return the pointer to first body
        CollisionBody* const getBody1() const;

        /// Return the pointer to second body
        CollisionBody* const getBody2() const;

        /// Add a contact to the contact cache
        void addContact(ContactPoint* contact);

        /// Update the contact cache
        void update();

        /// Return the cached separating axis
        Vector3 getCachedSeparatingAxis() const;

        /// Set the cached separating axis
        void setCachedSeparatingAxis(const Vector3& axis);

        /// Return the number of contacts in the cache
        uint getNbContactPoints() const;

        /// Return the contact manifold
        ContactManifold* getContactManifold();

        // -------------------- Friendship -------------------- //

        friend class DynamicsWorld;
};

// Return the pointer to first body
inline CollisionBody* const OverlappingPair::getBody1() const {
    return mBody1;
}          

// Return the pointer to second body
inline CollisionBody* const OverlappingPair::getBody2() const {
    return mBody2;
}                

// Add a contact to the contact manifold
inline void OverlappingPair::addContact(ContactPoint* contact) {
    mContactManifold.addContactPoint(contact);
}

// Update the contact manifold
inline void OverlappingPair::update() {
    mContactManifold.update(mBody1->getTransform(), mBody2->getTransform());
}

// Return the cached separating axis
inline Vector3 OverlappingPair::getCachedSeparatingAxis() const {
    return mCachedSeparatingAxis;
}

// Set the cached separating axis
inline void OverlappingPair::setCachedSeparatingAxis(const Vector3& axis) {
    mCachedSeparatingAxis = axis;
}


// Return the number of contact points in the contact manifold
inline uint OverlappingPair::getNbContactPoints() const {
    return mContactManifold.getNbContactPoints();
}

// Return the contact manifold
inline ContactManifold* OverlappingPair::getContactManifold() {
    return &mContactManifold;
}

}

#endif