108 lines
3.8 KiB
C
108 lines
3.8 KiB
C
/*
|
|
Open Asset Import Library (ASSIMP)
|
|
----------------------------------------------------------------------
|
|
|
|
Copyright (c) 2006-2008, 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 uint32_t SuperFastHash (const char * data, unsigned int len = 0, uint32_t hash = 0) {
|
|
uint32_t 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
|