ExtMultiList.h

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// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.  
 
 
#ifndef EXT_MULTI_LIST_H
#define EXT_MULTI_LIST_H
 
// MM: Multiple linked lists in a common array with a free list
 
#include "foundation/PxArray.h"
 
namespace physx
{
    namespace Ext
    {
 
        //-----------------------------------------------------------------------------
        template <class T>
        class MultiList {
        public:
            MultiList(PxI32 maxId = 0) {
                firstFree = -1;
                if (maxId > 0)
                    first.reserve(maxId + 1);
            }
            void reserve(int maxId) {
                first.reserve(maxId + 1);
            }
            void clear();
            PxI32 add(PxI32 id, const T &item);
            bool addUnique(PxI32 id, const T &item);
            bool exists(PxI32 id, const T &item) const;
            void remove(PxI32 id, const T &item);
            void removeAll(PxI32 id);
            PxI32 size(PxI32 id) const;
            PxI32 getPairNr(PxI32 id, const T &item) const;
 
            void replace(PxI32 id, const T &before, const T &after);
 
            void getItems(PxI32 id) const;
            mutable PxArray<T> queryItems;
 
            void initIteration(PxI32 id, PxI32& iterator);
            bool iterate(T& item, PxI32& iterator);
 
            void getPointers(PxI32 id);
            mutable PxArray<T*> queryPointers;
 
        private:
            PxArray<PxI32> first;
            PxArray<T> items;
            PxArray<PxI32> next;
            PxI32 firstFree;
        };
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::clear()
        {
            first.clear();
            next.clear();
            items.clear();
            queryItems.clear();
            queryPointers.clear();
            firstFree = -1;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        PxI32 MultiList<T>::add(PxI32 id, const T &item)
        {
            if (id >= PxI32(first.size()))
                first.resize(id + 1, -1);
            PxI32 pos = firstFree;
            if (pos >= 0)
                firstFree = next[firstFree];
            else 
            {
                pos = PxI32(items.size());
                items.resize(items.size() + 1);
                next.resize(items.size() + 1);
            }
            next[pos] = first[id];
            first[id] = pos;
            items[pos] = item;
            return pos;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        bool MultiList<T>::addUnique(PxI32 id, const T &item)
        {
            if (exists(id, item))
                return false;
            add(id, item);
            return true;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        bool MultiList<T>::exists(PxI32 id, const T &item) const
        {
            return getPairNr(id, item) >= 0;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        PxI32 MultiList<T>::size(PxI32 id) const
        {
            if (id >= PxI32(first.size()))
                return 0;
 
            PxI32 num = 0;
            PxI32 nr = first[id];
            while (nr >= 0)
            {
                num++;
                nr = next[nr];
            }
            return num;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        PxI32 MultiList<T>::getPairNr(PxI32 id, const T &item) const
        {
            if (id < 0 || id >= PxI32(first.size()))
                return -1;
            PxI32 nr = first[id];
            while (nr >= 0) 
            {
                if (items[nr] == item)
                    return nr;
                nr = next[nr];
            }
            return -1;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::remove(PxI32 id, const T &itemNr)
        {
            PxI32 nr = first[id];
            PxI32 prev = -1;
            while (nr >= 0 && items[nr] != itemNr) 
            {
                prev = nr;
                nr = next[nr];
            }
            if (nr < 0)
                return;
            if (prev >= 0)
                next[prev] = next[nr];
            else
                first[id] = next[nr];
            next[nr] = firstFree;
            firstFree = nr;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::replace(PxI32 id, const T &before, const T &after)
        {
            PxI32 nr = first[id];
            while (nr >= 0) 
            {
                if (items[nr] == before)
                    items[nr] = after;
                nr = next[nr];
            }
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::removeAll(PxI32 id)
        {
            if (id >= PxI32(first.size()))
                return;
 
            PxI32 nr = first[id];
            if (nr < 0)
                return;
 
            PxI32 prev = -1;
            while (nr >= 0) 
            {
                prev = nr;
                nr = next[nr];
            }
            next[prev] = firstFree;
            firstFree = first[id];
            first[id] = -1;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::getItems(PxI32 id) const
        {
            queryItems.clear();
            if (id >= PxI32(first.size()))
                return;
            PxI32 nr = first[id];
            while (nr >= 0)
            {
                queryItems.push_back(items[nr]);
                nr = next[nr];
            }
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::initIteration(PxI32 id, PxI32& iterator)
        {
            if (id >= PxI32(first.size()))
                iterator = -1;
            else
                iterator = first[id];
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        bool MultiList<T>::iterate(T& item, PxI32& iterator)
        {
            if (iterator >= 0) 
            {
                item = items[iterator];
                iterator = next[iterator];
                return true;
            }
            return false;
        }
 
        //-----------------------------------------------------------------------------
        template <class T>
        void MultiList<T>::getPointers(PxI32 id)
        {
            queryPointers.clear();
            if (id >= PxI32(first.size()))
                return;
            PxI32 nr = first[id];
            while (nr >= 0) 
            {
                queryPointers.push_back(&items[nr]);
                nr = next[nr];
            }
        }
 
    }
}
 
#endif