51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
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/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef __UTIL_HASH_H__
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#define __UTIL_HASH_H__
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CCL_NAMESPACE_BEGIN
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static unsigned int hash_int_2d(unsigned int kx, unsigned int ky)
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{
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#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
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unsigned int a, b, c;
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a = b = c = 0xdeadbeef + (2 << 2) + 13;
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a += kx;
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b += ky;
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c ^= b; c -= rot(b,14);
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a ^= c; a -= rot(c,11);
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b ^= a; b -= rot(a,25);
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c ^= b; c -= rot(b,16);
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a ^= c; a -= rot(c,4);
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b ^= a; b -= rot(a,14);
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c ^= b; c -= rot(b,24);
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return c;
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#undef rot
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}
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CCL_NAMESPACE_END
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#endif /* __UTIL_HASH_H__ */
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