blender/intern/cycles/util/util_hash.h
2014-05-05 02:19:08 +10:00

66 lines
1.3 KiB
C

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
#ifndef __UTIL_HASH_H__
#define __UTIL_HASH_H__
#include "util_types.h"
CCL_NAMESPACE_BEGIN
static inline uint hash_int_2d(uint kx, uint ky)
{
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
uint a, b, c;
a = b = c = 0xdeadbeef + (2 << 2) + 13;
a += kx;
b += ky;
c ^= b; c -= rot(b,14);
a ^= c; a -= rot(c,11);
b ^= a; b -= rot(a,25);
c ^= b; c -= rot(b,16);
a ^= c; a -= rot(c,4);
b ^= a; b -= rot(a,14);
c ^= b; c -= rot(b,24);
return c;
#undef rot
}
static inline uint hash_int(uint k)
{
return hash_int_2d(k, 0);
}
static inline uint hash_string(const char *str)
{
uint i = 0, c;
while ((c = *str++))
i = i * 37 + c;
return i;
}
CCL_NAMESPACE_END
#endif /* __UTIL_HASH_H__ */