/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  https://bulletphysics.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.
*/

#ifndef BT_GJK_PAIR_DETECTOR_H
#define BT_GJK_PAIR_DETECTOR_H

#include "btDiscreteCollisionDetectorInterface.h"
#include "../CollisionShapes/btCollisionMargin.h"

class btConvexShape;
#include "btSimplexSolverInterface.h"
class btConvexPenetrationDepthSolver;

/// btGjkPairDetector uses GJK to implement the btDiscreteCollisionDetectorInterface
class btGjkPairDetector : public btDiscreteCollisionDetectorInterface
{
public:
	btVector3 m_cachedSeparatingAxis;
	btConvexPenetrationDepthSolver* m_penetrationDepthSolver;
	btSimplexSolverInterface* m_simplexSolver;
	const btConvexShape* m_minkowskiA;
	const btConvexShape* m_minkowskiB;
	int m_shapeTypeA;
	int m_shapeTypeB;
	btScalar m_marginA;
	btScalar m_marginB;
	bool m_ignoreMargin;
	btScalar m_cachedSeparatingDistance;

	//some debugging to fix degeneracy problems
	int m_lastUsedMethod;
	int m_curIter;
	int m_degenerateSimplex;
	int m_catchDegeneracies;
	int m_fixContactNormalDirection;

	btGjkPairDetector(const btConvexShape* objectA, const btConvexShape* objectB, btSimplexSolverInterface* simplexSolver, btConvexPenetrationDepthSolver* penetrationDepthSolver);
	btGjkPairDetector(const btConvexShape* objectA, const btConvexShape* objectB, int shapeTypeA, int shapeTypeB, btScalar marginA, btScalar marginB, btSimplexSolverInterface* simplexSolver, btConvexPenetrationDepthSolver* penetrationDepthSolver);
	virtual ~btGjkPairDetector(){};

	virtual void getClosestPoints(const ClosestPointInput& input, Result& output, bool swapResults = false);

	void getClosestPointsNonVirtual(const ClosestPointInput& input, Result& output);

	void setMinkowskiA(const btConvexShape* minkA)
	{
		m_minkowskiA = minkA;
	}

	void setMinkowskiB(const btConvexShape* minkB)
	{
		m_minkowskiB = minkB;
	}
	void setCachedSeparatingAxis(const btVector3& separatingAxis)
	{
		m_cachedSeparatingAxis = separatingAxis;
	}

	const btVector3& getCachedSeparatingAxis() const
	{
		return m_cachedSeparatingAxis;
	}
	btScalar getCachedSeparatingDistance() const
	{
		return m_cachedSeparatingDistance;
	}

	void setPenetrationDepthSolver(btConvexPenetrationDepthSolver* penetrationDepthSolver)
	{
		m_penetrationDepthSolver = penetrationDepthSolver;
	}

	///don't use setIgnoreMargin, it's for Bullet's internal use
	void setIgnoreMargin(bool ignoreMargin)
	{
		m_ignoreMargin = ignoreMargin;
	}
};

#endif  //BT_GJK_PAIR_DETECTOR_H