bullet3/Bullet/BroadphaseCollision/OverlappingPairCache.cpp

/*
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 "OverlappingPairCache.h"

#include "Dispatcher.h"
#include "CollisionAlgorithm.h"


OverlappingPairCache::OverlappingPairCache(int maxOverlap):
m_blockedForChanges(false),
//m_NumOverlapBroadphasePair(0),
m_maxOverlap(maxOverlap)
{
}


OverlappingPairCache::~OverlappingPairCache()
{
	//todo/test: show we erase/delete data, or is it automatic
}


void	OverlappingPairCache::RemoveOverlappingPair(BroadphasePair& pair)
{
	CleanOverlappingPair(pair);
	std::set<BroadphasePair>::iterator it = m_overlappingPairSet.find(pair);
//	assert(it != m_overlappingPairSet.end());

	if (it != m_overlappingPairSet.end())
	{
		m_overlappingPairSet.erase(it);
	}
}


void	OverlappingPairCache::CleanOverlappingPair(BroadphasePair& pair)
{
	for (int dispatcherId=0;dispatcherId<SIMPLE_MAX_ALGORITHMS;dispatcherId++)
	{
		if (pair.m_algorithms[dispatcherId])
		{
			{
				delete pair.m_algorithms[dispatcherId];
				pair.m_algorithms[dispatcherId]=0;
			}
		}
	}
}





void	OverlappingPairCache::AddOverlappingPair(BroadphaseProxy* proxy0,BroadphaseProxy* proxy1)
{
	//don't add overlap with own
	assert(proxy0 != proxy1);

	if (!NeedsCollision(proxy0,proxy1))
		return;


	BroadphasePair pair(*proxy0,*proxy1);
	
	m_overlappingPairSet.insert(pair);
	
}

///this FindPair becomes really slow. Either sort the list to speedup the query, or
///use a different solution. It is mainly used for Removing overlapping pairs. Removal could be delayed.
///we could keep a linked list in each proxy, and store pair in one of the proxies (with lowest memory address)
///Also we can use a 2D bitmap, which can be useful for a future GPU implementation
 BroadphasePair*	OverlappingPairCache::FindPair(BroadphaseProxy* proxy0,BroadphaseProxy* proxy1)
{
	if (!NeedsCollision(proxy0,proxy1))
		return 0;

	BroadphasePair tmpPair(*proxy0,*proxy1);
	std::set<BroadphasePair>::iterator it = m_overlappingPairSet.find(tmpPair);
	if ((it == m_overlappingPairSet.end()))
		return 0;

	//assert(it != m_overlappingPairSet.end());
	 BroadphasePair* pair = (BroadphasePair*)(&(*it));
	return pair;
}





void	OverlappingPairCache::CleanProxyFromPairs(BroadphaseProxy* proxy)
{

	class	CleanPairCallback : public OverlapCallback
	{
		BroadphaseProxy* m_cleanProxy;
		OverlappingPairCache*	m_pairCache;

	public:
		CleanPairCallback(BroadphaseProxy* cleanProxy,OverlappingPairCache* pairCache)
			:m_cleanProxy(cleanProxy),
			m_pairCache(pairCache)
		{
		}
		virtual	bool	ProcessOverlap(BroadphasePair& pair)
		{
			if ((pair.m_pProxy0 == m_cleanProxy) ||
				(pair.m_pProxy1 == m_cleanProxy))
			{
				m_pairCache->CleanOverlappingPair(pair);
			}
			return false;
		}
		
	};

	CleanPairCallback cleanPairs(proxy,this);

	ProcessAllOverlappingPairs(&cleanPairs);

}



void	OverlappingPairCache::RemoveOverlappingPairsContainingProxy(BroadphaseProxy* proxy)
{

	class	RemovePairCallback : public OverlapCallback
	{
		BroadphaseProxy* m_obsoleteProxy;

	public:
		RemovePairCallback(BroadphaseProxy* obsoleteProxy)
			:m_obsoleteProxy(obsoleteProxy)
		{
		}
		virtual	bool	ProcessOverlap(BroadphasePair& pair)
		{
			return ((pair.m_pProxy0 == m_obsoleteProxy) ||
				(pair.m_pProxy1 == m_obsoleteProxy));
		}
		
	};


	RemovePairCallback removeCallback(proxy);

	ProcessAllOverlappingPairs(&removeCallback);
}



void	OverlappingPairCache::ProcessAllOverlappingPairs(OverlapCallback* callback)
{
	std::set<BroadphasePair>::iterator it = m_overlappingPairSet.begin();
	for (; !(it==m_overlappingPairSet.end());)
	{
	
		BroadphasePair* pair = (BroadphasePair*)(&(*it));
		if (callback->ProcessOverlap(*pair))
		{
			CleanOverlappingPair(*pair);
\		
			std::set<BroadphasePair>::iterator it2 = it;
			it++;
			//why does next line not compile under OS X??
			//it = m_overlappingPairSet.erase(it2);
			m_overlappingPairSet.erase(it2);
		} else
		{
			it++;
		}
	}
}