Initial Mercurial commit.

src/modules/physics/box2d/Source/Collision/b2PairManager.h

@@ -0,0 +1,121 @@
+/*
+* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
+*
+* 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.
+*/
+
+// The pair manager is used by the broad-phase to quickly add/remove/find pairs
+// of overlapping proxies. It is based closely on code provided by Pierre Terdiman.
+// http://www.codercorner.com/IncrementalSAP.txt
+
+#ifndef B2_PAIR_MANAGER_H
+#define B2_PAIR_MANAGER_H
+
+#include "../Common/b2Settings.h"
+#include "../Common/b2Math.h"
+
+#include <climits>
+
+class b2BroadPhase;
+struct b2Proxy;
+
+const uint16 b2_nullPair = USHRT_MAX;
+const uint16 b2_nullProxy = USHRT_MAX;
+const int32 b2_tableCapacity = b2_maxPairs;	// must be a power of two
+const int32 b2_tableMask = b2_tableCapacity - 1;
+
+struct b2Pair
+{
+	enum
+	{
+		e_pairBuffered	= 0x0001,
+		e_pairRemoved	= 0x0002,
+		e_pairFinal		= 0x0004,
+	};
+
+	void SetBuffered()		{ status |= e_pairBuffered; }
+	void ClearBuffered()	{ status &= ~e_pairBuffered; }
+	bool IsBuffered()		{ return (status & e_pairBuffered) == e_pairBuffered; }
+
+	void SetRemoved()		{ status |= e_pairRemoved; }
+	void ClearRemoved()		{ status &= ~e_pairRemoved; }
+	bool IsRemoved()		{ return (status & e_pairRemoved) == e_pairRemoved; }
+
+	void SetFinal()		{ status |= e_pairFinal; }
+	bool IsFinal()		{ return (status & e_pairFinal) == e_pairFinal; }
+
+	void* userData;
+	uint16 proxyId1;
+	uint16 proxyId2;
+	uint16 next;
+	uint16 status;
+};
+
+struct b2BufferedPair
+{
+	uint16 proxyId1;
+	uint16 proxyId2;
+};
+
+class b2PairCallback
+{
+public:
+	virtual ~b2PairCallback() {}
+
+	// This should return the new pair user data. It is ok if the
+	// user data is null.
+	virtual void* PairAdded(void* proxyUserData1, void* proxyUserData2) = 0;
+
+	// This should free the pair's user data. In extreme circumstances, it is possible
+	// this will be called with null pairUserData because the pair never existed.
+	virtual void PairRemoved(void* proxyUserData1, void* proxyUserData2, void* pairUserData) = 0;
+};
+
+class b2PairManager
+{
+public:
+	b2PairManager();
+
+	void Initialize(b2BroadPhase* broadPhase, b2PairCallback* callback);
+
+	void AddBufferedPair(int32 proxyId1, int32 proxyId2);
+	void RemoveBufferedPair(int32 proxyId1, int32 proxyId2);
+
+	void Commit();
+
+private:
+	b2Pair* Find(int32 proxyId1, int32 proxyId2);
+	b2Pair* Find(int32 proxyId1, int32 proxyId2, uint32 hashValue);
+
+	b2Pair* AddPair(int32 proxyId1, int32 proxyId2);
+	void* RemovePair(int32 proxyId1, int32 proxyId2);
+
+	void ValidateBuffer();
+	void ValidateTable();
+
+public:
+	b2BroadPhase *m_broadPhase;
+	b2PairCallback *m_callback;
+	b2Pair m_pairs[b2_maxPairs];
+	uint16 m_freePair;
+	int32 m_pairCount;
+
+	b2BufferedPair m_pairBuffer[b2_maxPairs];
+	int32 m_pairBufferCount;
+
+	uint16 m_hashTable[b2_tableCapacity];
+};
+
+#endif