Added btGhostObject and btPairCachingGhostObject functionality.

It is a fast way to keep track of overlapping objects in an area, and doing rayTest and convexSweepTest for overlapping objects, instead of btCollisionWorld::rayTest/convexSweepTest.

Updated KinematicCharacterController to use btPairCachingGhostObject.

src/BulletCollision/BroadphaseCollision/btOverlappingPairCache.cpp

@@ -33,7 +33,8 @@ int gFindPairs =0;
 
 btHashedOverlappingPairCache::btHashedOverlappingPairCache():
 	m_overlapFilterCallback(0),
-	m_blockedForChanges(false)
+	m_blockedForChanges(false),
+	m_ghostPairCallback(0)
 {
 	int initialAllocatedSize= 2;
 	m_overlappingPairArray.reserve(initialAllocatedSize);
@@ -238,6 +239,11 @@ btBroadphasePair* btHashedOverlappingPairCache::internalAddPair(btBroadphaseProx
 	int count = m_overlappingPairArray.size();
 	int oldCapacity = m_overlappingPairArray.capacity();
 	void* mem = &m_overlappingPairArray.expand();
+
+	//this is where we add an actual pair, so also call the 'ghost'
+	if (m_ghostPairCallback)
+		m_ghostPairCallback->addOverlappingPair(proxy0,proxy1);
+
 	int newCapacity = m_overlappingPairArray.capacity();
 
 	if (oldCapacity < newCapacity)
@@ -317,6 +323,9 @@ void* btHashedOverlappingPairCache::removeOverlappingPair(btBroadphaseProxy* pro
 
 	int lastPairIndex = m_overlappingPairArray.size() - 1;
 
+	if (m_ghostPairCallback)
+		m_ghostPairCallback->removeOverlappingPair(proxy0, proxy1,dispatcher);
+
 	// If the removed pair is the last pair, we are done.
 	if (lastPairIndex == pairIndex)
 	{
@@ -399,6 +408,8 @@ void*	btSortedOverlappingPairCache::removeOverlappingPair(btBroadphaseProxy* pro
 			btBroadphasePair& pair = m_overlappingPairArray[findIndex];
 			void* userData = pair.m_userInfo;
 			cleanOverlappingPair(pair,dispatcher);
+			if (m_ghostPairCallback)
+				m_ghostPairCallback->removeOverlappingPair(proxy0, proxy1,dispatcher);
 			
 			m_overlappingPairArray.swap(findIndex,m_overlappingPairArray.capacity()-1);
 			m_overlappingPairArray.pop_back();
@@ -426,8 +437,12 @@ btBroadphasePair*	btSortedOverlappingPairCache::addOverlappingPair(btBroadphaseP
 	
 	void* mem = &m_overlappingPairArray.expand();
 	btBroadphasePair* pair = new (mem) btBroadphasePair(*proxy0,*proxy1);
+	
 	gOverlappingPairs++;
 	gAddedPairs++;
+	
+	if (m_ghostPairCallback)
+		m_ghostPairCallback->addOverlappingPair(proxy0, proxy1);
 	return pair;
 	
 }
@@ -493,7 +508,8 @@ void	btSortedOverlappingPairCache::processAllOverlappingPairs(btOverlapCallback*
 btSortedOverlappingPairCache::btSortedOverlappingPairCache():
 	m_blockedForChanges(false),
 	m_hasDeferredRemoval(true),
-	m_overlapFilterCallback(0)
+	m_overlapFilterCallback(0),
+	m_ghostPairCallback(0)
 {
 	int initialAllocatedSize= 2;
 	m_overlappingPairArray.reserve(initialAllocatedSize);

src/BulletCollision/BroadphaseCollision/btOverlappingPairCache.h

@@ -83,6 +83,8 @@ public:
 
 	virtual bool	hasDeferredRemoval() = 0;
 
+	virtual	void	setInternalGhostPairCallback(btOverlappingPairCallback* ghostPairCallback)=0;
+
 };
 
 /// Hash-space based Pair Cache, thanks to Erin Catto, Box2D, http://www.box2d.org, and Pierre Terdiman, Codercorner, http://codercorner.com
@@ -253,10 +255,16 @@ private:
 		return false;
 	}
 
+	virtual	void	setInternalGhostPairCallback(btOverlappingPairCallback* ghostPairCallback)
+	{
+		m_ghostPairCallback = ghostPairCallback;
+	}
+
 public:
 	
 	btAlignedObjectArray<int>	m_hashTable;
 	btAlignedObjectArray<int>	m_next;
+	btOverlappingPairCallback*	m_ghostPairCallback;
 	
 };
 
@@ -280,6 +288,8 @@ class	btSortedOverlappingPairCache : public btOverlappingPairCache
 		//if set, use the callback instead of the built in filter in needBroadphaseCollision
 		btOverlapFilterCallback* m_overlapFilterCallback;
 
+		btOverlappingPairCallback*	m_ghostPairCallback;
+
 	public:
 			
 		btSortedOverlappingPairCache();	
@@ -355,12 +365,17 @@ class	btSortedOverlappingPairCache : public btOverlappingPairCache
 			return m_hasDeferredRemoval;
 		}
 
+		virtual	void	setInternalGhostPairCallback(btOverlappingPairCallback* ghostPairCallback)
+		{
+			m_ghostPairCallback = ghostPairCallback;
+		}
+
 
 };
 
 
 
-///btNullPairCache skips add/removal of overlapping pairs. Userful for benchmarking and testing.
+///btNullPairCache skips add/removal of overlapping pairs. Userful for benchmarking and unit testing.
 class btNullPairCache : public btOverlappingPairCache
 {
 
@@ -414,6 +429,10 @@ public:
 		return true;
 	}
 
+	virtual	void	setInternalGhostPairCallback(btOverlappingPairCallback* ghostPairCallback)
+	{
+	}
+
 	virtual btBroadphasePair*	addOverlappingPair(btBroadphaseProxy* /*proxy0*/,btBroadphaseProxy* /*proxy1*/)
 	{
 		return 0;
@@ -427,6 +446,7 @@ public:
 	virtual void	removeOverlappingPairsContainingProxy(btBroadphaseProxy* /*proxy0*/,btDispatcher* /*dispatcher*/)
 	{
 	}
+	
 
 
 };