PxAlloca.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 PX_ALLOCA_H
#define PX_ALLOCA_H
 
#include "foundation/PxTempAllocator.h"
 
#if !PX_DOXYGEN
namespace physx
{
#endif
template <typename T, typename Alloc = PxTempAllocator>
class PxScopedPointer : private Alloc
{
  public:
    ~PxScopedPointer()
    {
        if(mOwned)
            Alloc::deallocate(mPointer);
    }
 
    operator T*() const
    {
        return mPointer;
    }
 
    T* mPointer;
    bool mOwned;
};
 
#if !PX_DOXYGEN
} // namespace physx
#endif
 
  // Don't use inline for alloca !!!
#if PX_WINDOWS_FAMILY
#include <malloc.h>
#define PxAlloca(x) _alloca(x)
#elif PX_LINUX
#include <malloc.h>
#define PxAlloca(x) alloca(x)
#elif PX_APPLE_FAMILY
#include <alloca.h>
#define PxAlloca(x) alloca(x)
#elif PX_SWITCH
#include <malloc.h>
#define PxAlloca(x) alloca(x)
#endif
 
#define PxAllocaAligned(x, alignment) ((size_t(PxAlloca(x + alignment)) + (alignment - 1)) & ~size_t(alignment - 1))
 
#define PX_ALLOCA(var, type, count)                                                                                    \
    physx::PxScopedPointer<type> var;                                                                            \
    {                                                                                                                  \
        uint32_t size = sizeof(type) * (count);                                                                        \
        var.mOwned = size > 1024;                                                                                      \
        if(var.mOwned)                                                                                                 \
            var.mPointer = reinterpret_cast<type*>(physx::PxTempAllocator().allocate(size, __FILE__, __LINE__)); \
        else                                                                                                           \
            var.mPointer = reinterpret_cast<type*>(PxAlloca(size));                                                    \
    }
#endif