physxCAPI/physxCDLL/include/foundation/PxSort.h
2023-08-11 10:55:58 +08:00

132 lines
4.0 KiB
C++

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
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// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2008-2023 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
#ifndef PX_SORT_H
#define PX_SORT_H
/** \addtogroup foundation
@{
*/
#include "foundation/PxSortInternals.h"
#include "foundation/PxAlloca.h"
#define PX_SORT_PARANOIA PX_DEBUG
/**
\brief Sorts an array of objects in ascending order, assuming
that the predicate implements the < operator:
@see PxLess, PxGreater
*/
#if PX_VC
#pragma warning(push)
#pragma warning(disable : 4706) // disable the warning that we did an assignment within a conditional expression, as
// this was intentional.
#endif
#if !PX_DOXYGEN
namespace physx
{
#endif
template <class T, class Predicate, class PxAllocator>
void PxSort(T* elements, uint32_t count, const Predicate& compare, const PxAllocator& inAllocator,
const uint32_t initialStackSize = 32)
{
static const uint32_t SMALL_SORT_CUTOFF = 5; // must be >= 3 since we need 3 for median
PX_ALLOCA(stackMem, int32_t, initialStackSize);
PxStack<PxAllocator> stack(stackMem, initialStackSize, inAllocator);
int32_t first = 0, last = int32_t(count - 1);
if(last > first)
{
for(;;)
{
while(last > first)
{
PX_ASSERT(first >= 0 && last < int32_t(count));
if(uint32_t(last - first) < SMALL_SORT_CUTOFF)
{
PxSmallSort(elements, first, last, compare);
break;
}
else
{
const int32_t partIndex = PxPartition(elements, first, last, compare);
// push smaller sublist to minimize stack usage
if((partIndex - first) < (last - partIndex))
{
stack.push(first, partIndex - 1);
first = partIndex + 1;
}
else
{
stack.push(partIndex + 1, last);
last = partIndex - 1;
}
}
}
if(stack.empty())
break;
stack.pop(first, last);
}
}
#if PX_SORT_PARANOIA
for(uint32_t i = 1; i < count; i++)
PX_ASSERT(!compare(elements[i], elements[i - 1]));
#endif
}
template <class T, class Predicate>
void PxSort(T* elements, uint32_t count, const Predicate& compare)
{
PxSort(elements, count, compare, typename PxAllocatorTraits<T>::Type());
}
template <class T>
void PxSort(T* elements, uint32_t count)
{
PxSort(elements, count, PxLess<T>(), typename PxAllocatorTraits<T>::Type());
}
#if !PX_DOXYGEN
} // namespace physx
#endif
#if PX_VC
#pragma warning(pop)
#endif
/** @} */
#endif