source: code/archive/tutorial/src/external/bullet/BulletCollision/BroadphaseCollision/btSimpleBroadphase.h

/*
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.
*/

#ifndef SIMPLE_BROADPHASE_H
#define SIMPLE_BROADPHASE_H


#include "btOverlappingPairCache.h"


struct btSimpleBroadphaseProxy : public btBroadphaseProxy
{
        int                     m_nextFree;
        
//      int                     m_handleId;

        
        btSimpleBroadphaseProxy() {};

        btSimpleBroadphaseProxy(const btVector3& minpt,const btVector3& maxpt,int shapeType,void* userPtr,short int collisionFilterGroup,short int collisionFilterMask,void* multiSapProxy)
        :btBroadphaseProxy(minpt,maxpt,userPtr,collisionFilterGroup,collisionFilterMask,multiSapProxy)
        {
                (void)shapeType;
        }
        
        
        SIMD_FORCE_INLINE void SetNextFree(int next) {m_nextFree = next;}
        SIMD_FORCE_INLINE int GetNextFree() const {return m_nextFree;}

        


};

///The SimpleBroadphase is just a unit-test for btAxisSweep3, bt32BitAxisSweep3, or btDbvtBroadphase, so use those classes instead.
///It is a brute force aabb culling broadphase based on O(n^2) aabb checks
class btSimpleBroadphase : public btBroadphaseInterface
{

protected:

        int             m_numHandles;                                           // number of active handles
        int             m_maxHandles;                                           // max number of handles
        int             m_LastHandleIndex;                                                      
        
        btSimpleBroadphaseProxy* m_pHandles;                                            // handles pool

        void* m_pHandlesRawPtr;
        int             m_firstFreeHandle;              // free handles list
        
        int allocHandle()
        {
                btAssert(m_numHandles < m_maxHandles);
                int freeHandle = m_firstFreeHandle;
                m_firstFreeHandle = m_pHandles[freeHandle].GetNextFree();
                m_numHandles++;
                if(freeHandle > m_LastHandleIndex)
                {
                        m_LastHandleIndex = freeHandle;
                }
                return freeHandle;
        }

        void freeHandle(btSimpleBroadphaseProxy* proxy)
        {
                int handle = int(proxy-m_pHandles);
                btAssert(handle >= 0 && handle < m_maxHandles);
                if(handle == m_LastHandleIndex)
                {
                        m_LastHandleIndex--;
                }
                proxy->SetNextFree(m_firstFreeHandle);
                m_firstFreeHandle = handle;

                proxy->m_clientObject = 0;

                m_numHandles--;
        }

        btOverlappingPairCache* m_pairCache;
        bool    m_ownsPairCache;

        int     m_invalidPair;

        
        
        inline btSimpleBroadphaseProxy* getSimpleProxyFromProxy(btBroadphaseProxy* proxy)
        {
                btSimpleBroadphaseProxy* proxy0 = static_cast<btSimpleBroadphaseProxy*>(proxy);
                return proxy0;
        }

        inline const btSimpleBroadphaseProxy*   getSimpleProxyFromProxy(btBroadphaseProxy* proxy) const
        {
                const btSimpleBroadphaseProxy* proxy0 = static_cast<const btSimpleBroadphaseProxy*>(proxy);
                return proxy0;
        }

        ///reset broadphase internal structures, to ensure determinism/reproducability
        virtual void resetPool(btDispatcher* dispatcher);


        void    validate();

protected:


        

public:
        btSimpleBroadphase(int maxProxies=16384,btOverlappingPairCache* overlappingPairCache=0);
        virtual ~btSimpleBroadphase();


                static bool     aabbOverlap(btSimpleBroadphaseProxy* proxy0,btSimpleBroadphaseProxy* proxy1);


        virtual btBroadphaseProxy*      createProxy(  const btVector3& aabbMin,  const btVector3& aabbMax,int shapeType,void* userPtr ,short int collisionFilterGroup,short int collisionFilterMask, btDispatcher* dispatcher,void* multiSapProxy);

        virtual void    calculateOverlappingPairs(btDispatcher* dispatcher);

        virtual void    destroyProxy(btBroadphaseProxy* proxy,btDispatcher* dispatcher);
        virtual void    setAabb(btBroadphaseProxy* proxy,const btVector3& aabbMin,const btVector3& aabbMax, btDispatcher* dispatcher);
        virtual void    getAabb(btBroadphaseProxy* proxy,btVector3& aabbMin, btVector3& aabbMax ) const;

        virtual void    rayTest(const btVector3& rayFrom,const btVector3& rayTo, btBroadphaseRayCallback& rayCallback, const btVector3& aabbMin=btVector3(0,0,0),const btVector3& aabbMax=btVector3(0,0,0));
                
        btOverlappingPairCache* getOverlappingPairCache()
        {
                return m_pairCache;
        }
        const btOverlappingPairCache*   getOverlappingPairCache() const
        {
                return m_pairCache;
        }

        bool    testAabbOverlap(btBroadphaseProxy* proxy0,btBroadphaseProxy* proxy1);


        ///getAabb returns the axis aligned bounding box in the 'global' coordinate frame
        ///will add some transform later
        virtual void getBroadphaseAabb(btVector3& aabbMin,btVector3& aabbMax) const
        {
                aabbMin.setValue(-1e30f,-1e30f,-1e30f);
                aabbMax.setValue(1e30f,1e30f,1e30f);
        }

        virtual void    printStats()
        {
//              printf("btSimpleBroadphase.h\n");
//              printf("numHandles = %d, maxHandles = %d\n",m_numHandles,m_maxHandles);
        }
};



#endif //SIMPLE_BROADPHASE_H