/********************************************************************************
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
* Copyright (c) 2010 Daniel Chappuis                                            *
*********************************************************************************
*                                                                               *
* Permission is hereby granted, free of charge, to any person obtaining a copy  *
* of this software and associated documentation files (the "Software"), to deal *
* in the Software without restriction, including without limitation the rights  *
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* copies of the Software, and to permit persons to whom the Software is         *
* furnished to do so, subject to the following conditions:                      *
*                                                                               *
* The above copyright notice and this permission notice shall be included in    *
* all copies or substantial portions of the Software.                           *
*                                                                               *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR    *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,      *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE   *
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, *
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* THE SOFTWARE.                                                                 *
********************************************************************************/

#ifndef GJKALGORITHM_H
#define GJKALGORITHM_H

// Libraries
#include "NarrowPhaseAlgorithm.h"
#include "ContactInfo.h"
#include "../body/NarrowBoundingVolume.h"


// ReactPhysics3D namespace
namespace reactphysics3d {

// Constants
const double REL_ERROR = 1.0e-3;
const double REL_ERROR_SQUARE = REL_ERROR * REL_ERROR;

 // TODO : Improve the description here
/*  -------------------------------------------------------------------
    Class GJKAlgorithm :
        This class implements a narrow-phase collision detection algorithm. This
        algorithm uses the ISA-GJK algorithm and the EPA algorithm. This
        implementation is based on the implementation discussed in the book
        "Collision Detection in 3D Environments".
    -------------------------------------------------------------------
*/
class GJKAlgorithm : public NarrowPhaseAlgorithm {
    private :
        // TODO : Implement frame coherence. For each pair of body, store
        //        the last separating axis and use it to initialize the v vector
        Vector3D lastSeparatingAxis;

    public :
        GJKAlgorithm();           // Constructor
        ~GJKAlgorithm();          // Destructor

        virtual bool testCollision(const NarrowBoundingVolume* const boundingVolume1,
                                   const NarrowBoundingVolume* const boundingVolume2,
                                   ContactInfo*& contactInfo);                          // Return true and compute a contact info if the two bounding volume collide
};

} // End of the ReactPhysics3D namespace

// TODO : Check what would be a correct value for the OBJECT_MARGIN constant

#endif