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

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.
*/


#include "CollisionDispatcher.h"


#include "BroadphaseCollision/CollisionAlgorithm.h"
#include "CollisionDispatch/ConvexConvexAlgorithm.h"
#include "CollisionDispatch/EmptyCollisionAlgorithm.h"
#include "CollisionDispatch/ConvexConcaveCollisionAlgorithm.h"
#include "CollisionDispatch/CompoundCollisionAlgorithm.h"
#include "CollisionShapes/CollisionShape.h"
#include "CollisionDispatch/CollisionObject.h"
#include <algorithm>
#include "BroadphaseCollision/OverlappingPairCache.h"

int gNumManifold = 0;


	

	
CollisionDispatcher::CollisionDispatcher (): 
	m_useIslands(true),
		m_defaultManifoldResult(0,0,0),
		m_count(0)
{
	int i;
	
	//default CreationFunctions, filling the m_doubleDispatch table
	m_convexConvexCreateFunc = new ConvexConvexAlgorithm::CreateFunc;
	m_convexConcaveCreateFunc = new ConvexConcaveCollisionAlgorithm::CreateFunc;
	m_swappedConvexConcaveCreateFunc = new ConvexConcaveCollisionAlgorithm::SwappedCreateFunc;
	m_compoundCreateFunc = new CompoundCollisionAlgorithm::CreateFunc;
	m_swappedCompoundCreateFunc = new CompoundCollisionAlgorithm::SwappedCreateFunc;
	m_emptyCreateFunc = new EmptyAlgorithm::CreateFunc;

	for (i=0;i<MAX_BROADPHASE_COLLISION_TYPES;i++)
	{
		for (int j=0;j<MAX_BROADPHASE_COLLISION_TYPES;j++)
		{
			m_doubleDispatch[i][j] = InternalFindCreateFunc(i,j);
			assert(m_doubleDispatch[i][j]);
		}
	}
	
	
};

void CollisionDispatcher::RegisterCollisionCreateFunc(int proxyType0, int proxyType1, CollisionAlgorithmCreateFunc *createFunc)
{
	m_doubleDispatch[proxyType0][proxyType1] = createFunc;
}

CollisionDispatcher::~CollisionDispatcher()
{
	delete m_convexConvexCreateFunc;
	delete m_convexConcaveCreateFunc;
	delete m_swappedConvexConcaveCreateFunc;
	delete m_compoundCreateFunc;
	delete m_swappedCompoundCreateFunc;
	delete m_emptyCreateFunc;
}

PersistentManifold*	CollisionDispatcher::GetNewManifold(void* b0,void* b1) 
{ 
	gNumManifold++;
	
	//ASSERT(gNumManifold < 65535);
	

	CollisionObject* body0 = (CollisionObject*)b0;
	CollisionObject* body1 = (CollisionObject*)b1;
	
	PersistentManifold* manifold = new PersistentManifold (body0,body1);
	m_manifoldsPtr.push_back(manifold);

	return manifold;
}

void CollisionDispatcher::ClearManifold(PersistentManifold* manifold)
{
	manifold->ClearManifold();
}

	
void CollisionDispatcher::ReleaseManifold(PersistentManifold* manifold)
{
	
	gNumManifold--;

	//printf("ReleaseManifold: gNumManifold %d\n",gNumManifold);

	ClearManifold(manifold);

	std::vector<PersistentManifold*>::iterator i =
		std::find(m_manifoldsPtr.begin(), m_manifoldsPtr.end(), manifold);
	if (!(i == m_manifoldsPtr.end()))
	{
		std::swap(*i, m_manifoldsPtr.back());
		m_manifoldsPtr.pop_back();
		delete manifold;

	}
	
	
}

	

CollisionAlgorithm* CollisionDispatcher::FindAlgorithm(BroadphaseProxy& proxy0,BroadphaseProxy& proxy1)
{
#define USE_DISPATCH_REGISTRY_ARRAY 1
#ifdef USE_DISPATCH_REGISTRY_ARRAY
	CollisionObject* body0 = (CollisionObject*)proxy0.m_clientObject;
	CollisionObject* body1 = (CollisionObject*)proxy1.m_clientObject;
	CollisionAlgorithmConstructionInfo ci;
	ci.m_dispatcher = this;
	CollisionAlgorithm* algo = m_doubleDispatch[body0->m_collisionShape->GetShapeType()][body1->m_collisionShape->GetShapeType()]
	->CreateCollisionAlgorithm(ci,&proxy0,&proxy1);
#else
	CollisionAlgorithm* algo = InternalFindAlgorithm(proxy0,proxy1);
#endif //USE_DISPATCH_REGISTRY_ARRAY
	return algo;
}


CollisionAlgorithmCreateFunc* CollisionDispatcher::InternalFindCreateFunc(int proxyType0,int proxyType1)
{
	
	if (BroadphaseProxy::IsConvex(proxyType0) && BroadphaseProxy::IsConvex(proxyType1))
	{
		return m_convexConvexCreateFunc;
	}

	if (BroadphaseProxy::IsConvex(proxyType0) && BroadphaseProxy::IsConcave(proxyType1))
	{
		return m_convexConcaveCreateFunc;
	}

	if (BroadphaseProxy::IsConvex(proxyType1) && BroadphaseProxy::IsConcave(proxyType0))
	{
		return m_swappedConvexConcaveCreateFunc;
	}

	if (BroadphaseProxy::IsCompound(proxyType0))
	{
		return m_compoundCreateFunc;
	} else
	{
		if (BroadphaseProxy::IsCompound(proxyType1))
		{
			return m_swappedCompoundCreateFunc;
		}
	}

	//failed to find an algorithm
	return m_emptyCreateFunc;
}



CollisionAlgorithm* CollisionDispatcher::InternalFindAlgorithm(BroadphaseProxy& proxy0,BroadphaseProxy& proxy1)
{
	m_count++;
	CollisionObject* body0 = (CollisionObject*)proxy0.m_clientObject;
	CollisionObject* body1 = (CollisionObject*)proxy1.m_clientObject;

	CollisionAlgorithmConstructionInfo ci;
	ci.m_dispatcher = this;
	
	if (body0->m_collisionShape->IsConvex() && body1->m_collisionShape->IsConvex() )
	{
		return new ConvexConvexAlgorithm(0,ci,&proxy0,&proxy1);			
	}

	if (body0->m_collisionShape->IsConvex() && body1->m_collisionShape->IsConcave())
	{
		return new ConvexConcaveCollisionAlgorithm(ci,&proxy0,&proxy1);
	}

	if (body1->m_collisionShape->IsConvex() && body0->m_collisionShape->IsConcave())
	{
		return new ConvexConcaveCollisionAlgorithm(ci,&proxy1,&proxy0);
	}

	if (body0->m_collisionShape->IsCompound())
	{
		return new CompoundCollisionAlgorithm(ci,&proxy0,&proxy1);
	} else
	{
		if (body1->m_collisionShape->IsCompound())
		{
			return new CompoundCollisionAlgorithm(ci,&proxy1,&proxy0);
		}
	}

	//failed to find an algorithm
	return new EmptyAlgorithm(ci);
	
}

bool	CollisionDispatcher::NeedsResponse(const  CollisionObject& colObj0,const CollisionObject& colObj1)
{

	
	//here you can do filtering
	bool hasResponse = 
		(!(colObj0.m_collisionFlags & CollisionObject::noContactResponse)) &&
		(!(colObj1.m_collisionFlags & CollisionObject::noContactResponse));
	hasResponse = hasResponse &&
		(colObj0.IsActive() || colObj1.IsActive());
	return hasResponse;
}

bool	CollisionDispatcher::NeedsCollision(BroadphaseProxy& proxy0,BroadphaseProxy& proxy1)
{

	CollisionObject* body0 = (CollisionObject*)proxy0.m_clientObject;
	CollisionObject* body1 = (CollisionObject*)proxy1.m_clientObject;

	assert(body0);
	assert(body1);

	bool needsCollision = true;

	if ((body0->m_collisionFlags & CollisionObject::isStatic) && 
		(body1->m_collisionFlags & CollisionObject::isStatic))
		needsCollision = false;
		
	if ((!body0->IsActive()) && (!body1->IsActive()))
		needsCollision = false;
	
	return needsCollision ;

}

///allows the user to get contact point callbacks 
ManifoldResult*	CollisionDispatcher::GetNewManifoldResult(CollisionObject* obj0,CollisionObject* obj1,PersistentManifold* manifold)
{


	//in-place, this prevents parallel dispatching, but just adding a list would fix that.
	ManifoldResult* manifoldResult = new (&m_defaultManifoldResult)	ManifoldResult(obj0,obj1,manifold);
	return manifoldResult;
}
	
///allows the user to get contact point callbacks 
void	CollisionDispatcher::ReleaseManifoldResult(ManifoldResult*)
{

}


class CollisionPairCallback : public OverlapCallback
{
	DispatcherInfo& m_dispatchInfo;
	CollisionDispatcher*	m_dispatcher;
	int		m_dispatcherId;
public:

	CollisionPairCallback(DispatcherInfo& dispatchInfo,CollisionDispatcher*	dispatcher,int		dispatcherId)
	:m_dispatchInfo(dispatchInfo),
	m_dispatcher(dispatcher),
	m_dispatcherId(dispatcherId)
	{
	}

	virtual bool	ProcessOverlap(BroadphasePair& pair)
	{
		if (m_dispatcherId>= 0)
		{
			//dispatcher will keep algorithms persistent in the collision pair
			if (!pair.m_algorithms[m_dispatcherId])
			{
				pair.m_algorithms[m_dispatcherId] = m_dispatcher->FindAlgorithm(
					*pair.m_pProxy0,
					*pair.m_pProxy1);
			}

			if (pair.m_algorithms[m_dispatcherId])
			{
				if (m_dispatchInfo.m_dispatchFunc == 		DispatcherInfo::DISPATCH_DISCRETE)
				{
					pair.m_algorithms[m_dispatcherId]->ProcessCollision(pair.m_pProxy0,pair.m_pProxy1,m_dispatchInfo);
				} else
				{
					float toi = pair.m_algorithms[m_dispatcherId]->CalculateTimeOfImpact(pair.m_pProxy0,pair.m_pProxy1,m_dispatchInfo);
					if (m_dispatchInfo.m_timeOfImpact > toi)
						m_dispatchInfo.m_timeOfImpact = toi;

				}
			}
		} else
		{
			//non-persistent algorithm dispatcher
			CollisionAlgorithm* algo = m_dispatcher->FindAlgorithm(
				*pair.m_pProxy0,
				*pair.m_pProxy1);

			if (algo)
			{
				if (m_dispatchInfo.m_dispatchFunc == 		DispatcherInfo::DISPATCH_DISCRETE)
				{
					algo->ProcessCollision(pair.m_pProxy0,pair.m_pProxy1,m_dispatchInfo);
				} else
				{
					float toi = algo->CalculateTimeOfImpact(pair.m_pProxy0,pair.m_pProxy1,m_dispatchInfo);
					if (m_dispatchInfo.m_timeOfImpact > toi)
						m_dispatchInfo.m_timeOfImpact = toi;
				}
			}
		}
		return false;

	}
};


void	CollisionDispatcher::DispatchAllCollisionPairs(OverlappingPairCache* pairCache,DispatcherInfo& dispatchInfo)
{
	//m_blockedForChanges = true;

	int i;

	int dispatcherId = GetUniqueId();

	CollisionPairCallback	collisionCallback(dispatchInfo,this,dispatcherId);

	pairCache->ProcessAllOverlappingPairs(&collisionCallback);

	//m_blockedForChanges = false;

}