Space-Project/dependencies/physx-4.1/source/foundation/include/PsSort.h
2021-01-16 17:11:39 +01:00

131 lines
3.9 KiB
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//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
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// * 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.
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// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
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// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// Copyright (c) 2008-2019 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 PSFOUNDATION_PSSORT_H
#define PSFOUNDATION_PSSORT_H
/** \addtogroup foundation
@{
*/
#include "PsSortInternals.h"
#include "PsAlloca.h"
#define PX_SORT_PARANOIA PX_DEBUG
/**
\brief Sorts an array of objects in ascending order, assuming
that the predicate implements the < operator:
\see Less, Greater
*/
#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
namespace physx
{
namespace shdfnd
{
template <class T, class Predicate, class Allocator>
void sort(T* elements, uint32_t count, const Predicate& compare, const Allocator& 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);
internal::Stack<Allocator> 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)
{
internal::smallSort(elements, first, last, compare);
break;
}
else
{
const int32_t partIndex = internal::partition(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 sort(T* elements, uint32_t count, const Predicate& compare)
{
sort(elements, count, compare, typename shdfnd::AllocatorTraits<T>::Type());
}
template <class T>
void sort(T* elements, uint32_t count)
{
sort(elements, count, shdfnd::Less<T>(), typename shdfnd::AllocatorTraits<T>::Type());
}
} // namespace shdfnd
} // namespace physx
#if PX_VC
#pragma warning(pop)
#endif
#endif // #ifndef PSFOUNDATION_PSSORT_H