diff options
Diffstat (limited to 'intern/cycles/util/util_hash.h')
| -rw-r--r-- | intern/cycles/util/util_hash.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/intern/cycles/util/util_hash.h b/intern/cycles/util/util_hash.h new file mode 100644 index 00000000000..16901dab38e --- /dev/null +++ b/intern/cycles/util/util_hash.h @@ -0,0 +1,55 @@ +/* + * Copyright 2011, Blender Foundation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef __UTIL_HASH_H__ +#define __UTIL_HASH_H__ + +CCL_NAMESPACE_BEGIN + +static inline unsigned int hash_int_2d(unsigned int kx, unsigned int ky) +{ + #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) + + unsigned int 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 unsigned int hash_int(unsigned int k) +{ + return hash_int_2d(k, 0); +} + +CCL_NAMESPACE_END + +#endif /* __UTIL_HASH_H__ */ + |