tornavis/source/blender/blenlib/BLI_hash.h

93 lines
2.0 KiB
C

/*
* 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.
*/
#pragma once
/** \file
* \ingroup bli
*/
#include "BLI_utildefines.h"
#ifdef __cplusplus
extern "C" {
#endif
BLI_INLINE unsigned int BLI_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
}
BLI_INLINE unsigned int BLI_hash_string(const char *str)
{
unsigned int i = 0, c;
while ((c = *str++)) {
i = i * 37 + c;
}
return i;
}
BLI_INLINE unsigned int BLI_hash_int(unsigned int k)
{
return BLI_hash_int_2d(k, 0);
}
BLI_INLINE float BLI_hash_int_01(unsigned int k)
{
return (float)BLI_hash_int(k) * (1.0f / (float)0xFFFFFFFF);
}
BLI_INLINE void BLI_hash_pointer_to_color(const void *ptr, int *r, int *g, int *b)
{
size_t val = (size_t)ptr;
const size_t hash_a = BLI_hash_int(val & 0x0000ffff);
const size_t hash_b = BLI_hash_int((uint)((val & 0xffff0000) >> 16));
const size_t hash = hash_a ^ (hash_b + 0x9e3779b9 + (hash_a << 6) + (hash_a >> 2));
*r = (hash & 0xff0000) >> 16;
*g = (hash & 0x00ff00) >> 8;
*b = hash & 0x0000ff;
}
#ifdef __cplusplus
}
#endif