Revision control
- //
- // 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
- // notice, this list of conditions and the following disclaimer in the
- // 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
- // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- // OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- // (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) 2008-2021 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_PSHASH_H
- #define PSFOUNDATION_PSHASH_H
-
- #include "Ps.h"
- #include "PsBasicTemplates.h"
-
- #if PX_VC
- #pragma warning(push)
- #pragma warning(disable : 4302)
- #endif
-
- #if PX_LINUX
- #include "foundation/PxSimpleTypes.h"
- #endif
-
- /*!
- Central definition of hash functions
- */
-
- namespace physx
- {
- namespace shdfnd
- {
- // Hash functions
-
- // Thomas Wang's 32 bit mix
- // http://www.cris.com/~Ttwang/tech/inthash.htm
- PX_FORCE_INLINE uint32_t hash(const uint32_t key)
- {
- uint32_t k = key;
- k += ~(k << 15);
- k ^= (k >> 10);
- k += (k << 3);
- k ^= (k >> 6);
- k += ~(k << 11);
- k ^= (k >> 16);
- return uint32_t(k);
- }
-
- // Thomas Wang's 64 bit mix
- // http://www.cris.com/~Ttwang/tech/inthash.htm
- PX_FORCE_INLINE uint32_t hash(const uint64_t key)
- {
- uint64_t k = key;
- k += ~(k << 32);
- k ^= (k >> 22);
- k += ~(k << 13);
- k ^= (k >> 8);
- k += (k << 3);
- k ^= (k >> 15);
- k += ~(k << 27);
- k ^= (k >> 31);
- return uint32_t(UINT32_MAX & k);
- }
-
- // Hash function for pointers
- template <typename T>
- PX_INLINE uint32_t hash(T* ptr)
- {
- #if PX_P64_FAMILY
- return hash(uint64_t(ptr));
- #else
- return hash(uint32_t(UINT32_MAX & size_t(ptr)));
- #endif
- }
-
- // Hash function for pairs
- template <typename F, typename S>
- PX_INLINE uint32_t hash(const Pair<F, S>& p)
- {
- uint32_t seed = 0x876543;
- uint32_t m = 1000007;
- return hash(p.second) ^ (m * (hash(p.first) ^ (m * seed)));
- }
-
- template <typename T>
- PX_FORCE_INLINE uint32_t hash(const T key)
- {
- if (sizeof(T) == 4)
- return hash(uint32_t(key));
- return hash(uint64_t(key));
- }
-
- // hash object for hash map template parameter
- template <class Key>
- struct Hash
- {
- uint32_t operator()(const Key& k) const
- {
- return hash(k);
- }
- bool equal(const Key& k0, const Key& k1) const
- {
- return k0 == k1;
- }
- };
-
- // specialization for strings
- template <>
- struct Hash<const char*>
- {
- public:
- uint32_t operator()(const char* _string) const
- {
- // "DJB" string hash
- const uint8_t* string = reinterpret_cast<const uint8_t*>(_string);
- uint32_t h = 5381;
- for(const uint8_t* ptr = string; *ptr; ptr++)
- h = ((h << 5) + h) ^ uint32_t(*ptr);
- return h;
- }
- bool equal(const char* string0, const char* string1) const
- {
- return !strcmp(string0, string1);
- }
- };
-
- } // namespace shdfnd
- } // namespace physx
-
- #if PX_VC
- #pragma warning(pop)
- #endif
-
- #endif // #ifndef PSFOUNDATION_PSHASH_H