btAlignedObjectArray.h

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/*
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 BT_OBJECT_ARRAY__
#define BT_OBJECT_ARRAY__
 
#include "btScalar.h"  // has definitions like SIMD_FORCE_INLINE
#include "btAlignedAllocator.h"

 
#define BT_USE_PLACEMENT_NEW 1
//#define BT_USE_MEMCPY 1 //disable, because it is cumbersome to find out for each platform where memcpy is defined. It can be in <memory.h> or <string.h> or otherwise...
#define BT_ALLOW_ARRAY_COPY_OPERATOR  // enabling this can accidently perform deep copies of data if you are not careful
 
#ifdef BT_USE_MEMCPY
#include <memory.h>
#include <string.h>
#endif  //BT_USE_MEMCPY
 
#ifdef BT_USE_PLACEMENT_NEW
#include <new>  //for placement new
#endif          //BT_USE_PLACEMENT_NEW

template <typename T>
//template <class T>
class btAlignedObjectArray
{
    btAlignedAllocator<T, 16> m_allocator;
 
    int m_size;
    int m_capacity;
    T* m_data;
    //PCK: added this line
    bool m_ownsMemory;
 
#ifdef BT_ALLOW_ARRAY_COPY_OPERATOR
public:
    SIMD_FORCE_INLINE btAlignedObjectArray<T>& operator=(const btAlignedObjectArray<T>& other)
    {
        copyFromArray(other);
        return *this;
    }
#else   //BT_ALLOW_ARRAY_COPY_OPERATOR
private:
    SIMD_FORCE_INLINE btAlignedObjectArray<T>& operator=(const btAlignedObjectArray<T>& other);
#endif  //BT_ALLOW_ARRAY_COPY_OPERATOR
 
protected:
    SIMD_FORCE_INLINE int allocSize(int size)
    {
        return (size ? size * 2 : 1);
    }
    SIMD_FORCE_INLINE void copy(int start, int end, T* dest) const
    {
        int i;
        for (i = start; i < end; ++i)
#ifdef BT_USE_PLACEMENT_NEW
            new (&dest[i]) T(m_data[i]);
#else
            dest[i] = m_data[i];
#endif  //BT_USE_PLACEMENT_NEW
    }
 
    SIMD_FORCE_INLINE void init()
    {
        //PCK: added this line
        m_ownsMemory = true;
        m_data = 0;
        m_size = 0;
        m_capacity = 0;
    }
    SIMD_FORCE_INLINE void destroy(int first, int last)
    {
        int i;
        for (i = first; i < last; i++)
        {
            m_data[i].~T();
        }
    }
 
    SIMD_FORCE_INLINE void* allocate(int size)
    {
        if (size)
            return m_allocator.allocate(size);
        return 0;
    }
 
    SIMD_FORCE_INLINE void deallocate()
    {
        if (m_data)
        {
            //PCK: enclosed the deallocation in this block
            if (m_ownsMemory)
            {
                m_allocator.deallocate(m_data);
            }
            m_data = 0;
        }
    }
 
public:
    btAlignedObjectArray()
    {
        init();
    }
 
    ~btAlignedObjectArray()
    {
        clear();
    }

    btAlignedObjectArray(const btAlignedObjectArray& otherArray)
    {
        init();
 
        int otherSize = otherArray.size();
        resize(otherSize);
        otherArray.copy(0, otherSize, m_data);
    }

    SIMD_FORCE_INLINE int size() const
    {
        return m_size;
    }
 
    SIMD_FORCE_INLINE const T& at(int n) const
    {
        btAssert(n >= 0);
        btAssert(n < size());
        return m_data[n];
    }
 
    SIMD_FORCE_INLINE T& at(int n)
    {
        btAssert(n >= 0);
        btAssert(n < size());
        return m_data[n];
    }
 
    SIMD_FORCE_INLINE const T& operator[](int n) const
    {
        btAssert(n >= 0);
        btAssert(n < size());
        return m_data[n];
    }
 
    SIMD_FORCE_INLINE T& operator[](int n)
    {
        btAssert(n >= 0);
        btAssert(n < size());
        return m_data[n];
    }

    SIMD_FORCE_INLINE void clear()
    {
        destroy(0, size());
 
        deallocate();
 
        init();
    }
 
    SIMD_FORCE_INLINE void pop_back()
    {
        btAssert(m_size > 0);
        m_size--;
        m_data[m_size].~T();
    }

    SIMD_FORCE_INLINE void resizeNoInitialize(int newsize)
    {
        if (newsize > size())
        {
            reserve(newsize);
        }
        m_size = newsize;
    }
 
    SIMD_FORCE_INLINE void resize(int newsize, const T& fillData = T())
    {
        const int curSize = size();
 
        if (newsize < curSize)
        {
            for (int i = newsize; i < curSize; i++)
            {
                m_data[i].~T();
            }
        }
        else
        {
            if (newsize > curSize)
            {
                reserve(newsize);
            }
#ifdef BT_USE_PLACEMENT_NEW
            for (int i = curSize; i < newsize; i++)
            {
                new (&m_data[i]) T(fillData);
            }
#endif  //BT_USE_PLACEMENT_NEW
        }
 
        m_size = newsize;
    }
    SIMD_FORCE_INLINE T& expandNonInitializing()
    {
        const int sz = size();
        if (sz == capacity())
        {
            reserve(allocSize(size()));
        }
        m_size++;
 
        return m_data[sz];
    }
 
    SIMD_FORCE_INLINE T& expand(const T& fillValue = T())
    {
        const int sz = size();
        if (sz == capacity())
        {
            reserve(allocSize(size()));
        }
        m_size++;
#ifdef BT_USE_PLACEMENT_NEW
        new (&m_data[sz]) T(fillValue);  //use the in-place new (not really allocating heap memory)
#endif
 
        return m_data[sz];
    }
 
    SIMD_FORCE_INLINE void push_back(const T& _Val)
    {
        const int sz = size();
        if (sz == capacity())
        {
            reserve(allocSize(size()));
        }
 
#ifdef BT_USE_PLACEMENT_NEW
        new (&m_data[m_size]) T(_Val);
#else
        m_data[size()] = _Val;
#endif  //BT_USE_PLACEMENT_NEW
 
        m_size++;
    }

    SIMD_FORCE_INLINE int capacity() const
    {
        return m_capacity;
    }
 
    SIMD_FORCE_INLINE void reserve(int _Count)
    {  // determine new minimum length of allocated storage
        if (capacity() < _Count)
        {  // not enough room, reallocate
            T* s = (T*)allocate(_Count);
 
            copy(0, size(), s);
 
            destroy(0, size());
 
            deallocate();
 
            //PCK: added this line
            m_ownsMemory = true;
 
            m_data = s;
 
            m_capacity = _Count;
        }
    }
 
    class less
    {
    public:
        bool operator()(const T& a, const T& b) const
        {
            return (a < b);
        }
    };
 
    template <typename L>
    void quickSortInternal(const L& CompareFunc, int lo, int hi)
    {
        //  lo is the lower index, hi is the upper index
        //  of the region of array a that is to be sorted
        int i = lo, j = hi;
        T x = m_data[(lo + hi) / 2];
 
        //  partition
        do
        {
            while (CompareFunc(m_data[i], x))
                i++;
            while (CompareFunc(x, m_data[j]))
                j--;
            if (i <= j)
            {
                swap(i, j);
                i++;
                j--;
            }
        } while (i <= j);
 
        //  recursion
        if (lo < j)
            quickSortInternal(CompareFunc, lo, j);
        if (i < hi)
            quickSortInternal(CompareFunc, i, hi);
    }
 
    template <typename L>
    void quickSort(const L& CompareFunc)
    {
        //don't sort 0 or 1 elements
        if (size() > 1)
        {
            quickSortInternal(CompareFunc, 0, size() - 1);
        }
    }

    template <typename L>
    void downHeap(T* pArr, int k, int n, const L& CompareFunc)
    {
        /*  PRE: a[k+1..N] is a heap */
        /* POST:  a[k..N]  is a heap */
 
        T temp = pArr[k - 1];
        /* k has child(s) */
        while (k <= n / 2)
        {
            int child = 2 * k;
 
            if ((child < n) && CompareFunc(pArr[child - 1], pArr[child]))
            {
                child++;
            }
            /* pick larger child */
            if (CompareFunc(temp, pArr[child - 1]))
            {
                /* move child up */
                pArr[k - 1] = pArr[child - 1];
                k = child;
            }
            else
            {
                break;
            }
        }
        pArr[k - 1] = temp;
    } /*downHeap*/
 
    void swap(int index0, int index1)
    {
#ifdef BT_USE_MEMCPY
        char temp[sizeof(T)];
        memcpy(temp, &m_data[index0], sizeof(T));
        memcpy(&m_data[index0], &m_data[index1], sizeof(T));
        memcpy(&m_data[index1], temp, sizeof(T));
#else
        T temp = m_data[index0];
        m_data[index0] = m_data[index1];
        m_data[index1] = temp;
#endif  //BT_USE_PLACEMENT_NEW
    }
 
    template <typename L>
    void heapSort(const L& CompareFunc)
    {
        /* sort a[0..N-1],  N.B. 0 to N-1 */
        int k;
        int n = m_size;
        for (k = n / 2; k > 0; k--)
        {
            downHeap(m_data, k, n, CompareFunc);
        }
 
        /* a[1..N] is now a heap */
        while (n >= 1)
        {
            swap(0, n - 1); /* largest of a[0..n-1] */
 
            n = n - 1;
            /* restore a[1..i-1] heap */
            downHeap(m_data, 1, n, CompareFunc);
        }
    }

    int findBinarySearch(const T& key) const
    {
        int first = 0;
        int last = size() - 1;
 
        //assume sorted array
        while (first <= last)
        {
            int mid = (first + last) / 2;  // compute mid point.
            if (key > m_data[mid])
                first = mid + 1;  // repeat search in top half.
            else if (key < m_data[mid])
                last = mid - 1;  // repeat search in bottom half.
            else
                return mid;  // found it. return position /////
        }
        return size();  // failed to find key
    }
 
    int findLinearSearch(const T& key) const
    {
        int index = size();
        int i;
 
        for (i = 0; i < size(); i++)
        {
            if (m_data[i] == key)
            {
                index = i;
                break;
            }
        }
        return index;
    }
 
    // If the key is not in the array, return -1 instead of 0,
    // since 0 also means the first element in the array.
    int findLinearSearch2(const T& key) const
    {
        int index = -1;
        int i;
 
        for (i = 0; i < size(); i++)
        {
            if (m_data[i] == key)
            {
                index = i;
                break;
            }
        }
        return index;
    }
 
    void removeAtIndex(int index)
    {
        if (index < size())
        {
            swap(index, size() - 1);
            pop_back();
        }
    }
    void remove(const T& key)
    {
        int findIndex = findLinearSearch(key);
        removeAtIndex(findIndex);
    }
 
    //PCK: whole function
    void initializeFromBuffer(void* buffer, int size, int capacity)
    {
        clear();
        m_ownsMemory = false;
        m_data = (T*)buffer;
        m_size = size;
        m_capacity = capacity;
    }
 
    void copyFromArray(const btAlignedObjectArray& otherArray)
    {
        int otherSize = otherArray.size();
        resize(otherSize);
        otherArray.copy(0, otherSize, m_data);
    }
};
 
#endif  //BT_OBJECT_ARRAY__