72 lines
1.7 KiB
C++
72 lines
1.7 KiB
C++
/*
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* ***** BEGIN GPL LICENSE BLOCK *****
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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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* ***** END GPL LICENSE BLOCK *****
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*/
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#ifndef __BLI_HASH_H__
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#define __BLI_HASH_H__
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/** \file BLI_hash.h
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* \ingroup bli
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*/
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BLI_INLINE unsigned int BLI_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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BLI_INLINE unsigned int BLI_hash_string(const char *str)
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{
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unsigned int i = 0, c;
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while ((c = *str++)) {
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i = i * 37 + c;
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}
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return i;
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}
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BLI_INLINE unsigned int BLI_hash_int(unsigned int k)
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{
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return BLI_hash_int_2d(k, 0);
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}
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BLI_INLINE float BLI_hash_int_01(unsigned int k)
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{
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return (float)BLI_hash_int(k) * (1.0f / (float)0xFFFFFFFF);
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}
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#endif // __BLI_HASH_H__
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