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Diffstat (limited to '3rdparty/assimp/code/Hash.h')
-rw-r--r-- | 3rdparty/assimp/code/Hash.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/3rdparty/assimp/code/Hash.h b/3rdparty/assimp/code/Hash.h new file mode 100644 index 000000000..9ba79c512 --- /dev/null +++ b/3rdparty/assimp/code/Hash.h @@ -0,0 +1,108 @@ +/* +Open Asset Import Library (ASSIMP) +---------------------------------------------------------------------- + +Copyright (c) 2006-2010, ASSIMP Development Team +All rights reserved. + +Redistribution and use of this software 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 the ASSIMP team, nor the names of its + contributors may be used to endorse or promote products + derived from this software without specific prior + written permission of the ASSIMP Development Team. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"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. + +---------------------------------------------------------------------- +*/ + +#ifndef AI_HASH_H_INCLUDED +#define AI_HASH_H_INCLUDED + +// ------------------------------------------------------------------------------------------------ +// hashing function taken from +// http://www.azillionmonkeys.com/qed/hash.html +// (incremental version of the hashing function) +// (stdint.h should have been been included here) +// ------------------------------------------------------------------------------------------------ +#undef get16bits +#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \ + || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__) +#define get16bits(d) (*((const uint16_t *) (d))) +#endif + +#if !defined (get16bits) +#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\ + +(uint32_t)(((const uint8_t *)(d))[0]) ) +#endif + +// ------------------------------------------------------------------------------------------------ +inline unsigned int SuperFastHash (const char * data, unsigned int len = 0, unsigned int hash = 0) { +unsigned int tmp; +int rem; + + if (!data) return 0; + if (!len)len = (unsigned int)::strlen(data); + + rem = len & 3; + len >>= 2; + + /* Main loop */ + for (;len > 0; len--) { + hash += get16bits (data); + tmp = (get16bits (data+2) << 11) ^ hash; + hash = (hash << 16) ^ tmp; + data += 2*sizeof (uint16_t); + hash += hash >> 11; + } + + /* Handle end cases */ + switch (rem) { + case 3: hash += get16bits (data); + hash ^= hash << 16; + hash ^= data[sizeof (uint16_t)] << 18; + hash += hash >> 11; + break; + case 2: hash += get16bits (data); + hash ^= hash << 11; + hash += hash >> 17; + break; + case 1: hash += *data; + hash ^= hash << 10; + hash += hash >> 1; + } + + /* Force "avalanching" of final 127 bits */ + hash ^= hash << 3; + hash += hash >> 5; + hash ^= hash << 4; + hash += hash >> 17; + hash ^= hash << 25; + hash += hash >> 6; + + return hash; +} + +#endif // !! AI_HASH_H_INCLUDED |