opencl/random.cl

   1 /* This file is part of GEGL
   2  *
   3  * GEGL is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 3 of the License, or (at your option) any later version.
   7  *
   8  * GEGL is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with GEGL; if not, see <https://www.gnu.org/licenses/>.
  15  *
  16  * Copyright 2013 Carlos Zubieta (czubieta.dev@gmail.com)
  17  */
  18
  19 /* XXX: this file should be kept in sync with gegl-random. */
  20
  21 typedef ushort4 GeglRandom;
  22
  23 unsigned int _gegl_cl_random_int (__global const int *cl_random_data,
  24                                   const GeglRandom  rand,
  25                                   int x,
  26                                   int y,
  27                                   int z,
  28                                   int n);
  29
  30 unsigned int gegl_cl_random_int  (__global const int *cl_random_data,
  31                                   const GeglRandom  rand,
  32                                   int x,
  33                                   int y,
  34                                   int z,
  35                                   int n);
  36
  37 int gegl_cl_random_int_range     (__global const int  *cl_random_data,
  38                                   const GeglRandom  rand,
  39                                   int x,
  40                                   int y,
  41                                   int z,
  42                                   int n,
  43                                   int min,
  44                                   int max);
  45
  46 float gegl_cl_random_float       (__global const int  *cl_random_data,
  47                                   const GeglRandom  rand,
  48                                   int x,
  49                                   int y,
  50                                   int z,
  51                                   int n);
  52
  53 float gegl_cl_random_float_range (__global const int  *cl_random_data,
  54                                   const GeglRandom  rand,
  55                                   int x,
  56                                   int y,
  57                                   int z,
  58                                   int n,
  59                                   float min,
  60                                   float max);
  61
  62 unsigned int
  63 _gegl_cl_random_int (__global const int  *cl_random_data,
  64                      const GeglRandom    rand,
  65                      int                 x,
  66                      int                 y,
  67                      int                 z,
  68                      int                 n)
  69 {
  70   const long XPRIME = 103423;
  71   const long YPRIME = 101359;
  72   const long NPRIME = 101111;
  73
  74   unsigned long idx = x * XPRIME +
  75                       y * YPRIME * XPRIME +
  76                       n * NPRIME * YPRIME * XPRIME;
  77
  78   int r0 = cl_random_data[idx % rand.x],
  79       r1 = cl_random_data[rand.x + (idx % rand.y)],
  80       r2 = cl_random_data[rand.x + rand.y + (idx % rand.z)];
  81   return r0 ^ r1 ^ r2;
  82 }
  83
  84 unsigned int
  85 gegl_cl_random_int (__global const int *cl_random_data,
  86                     const GeglRandom    rand,
  87                     int                 x,
  88                     int                 y,
  89                     int                 z,
  90                     int                 n)
  91 {
  92   return _gegl_cl_random_int (cl_random_data, rand, x, y, z, n);
  93 }
  94
  95 int
  96 gegl_cl_random_int_range (__global const int  *cl_random_data,
  97                           const GeglRandom    rand,
  98                           int                 x,
  99                           int                 y,
 100                           int                 z,
 101                           int                 n,
 102                           int                 min,
 103                           int                 max)
 104 {
 105   int ret = _gegl_cl_random_int (cl_random_data, rand, x, y, z, n);
 106   return (ret % (max-min)) + min;
 107 }
 108
 109
 110 #define G_RAND_FLOAT_TRANSFORM  0.00001525902189669642175f
 111
 112 float
 113 gegl_cl_random_float (__global const int *cl_random_data,
 114                       const GeglRandom    rand,
 115                       int                 x,
 116                       int                 y,
 117                       int                 z,
 118                       int                 n)
 119 {
 120   int u = _gegl_cl_random_int (cl_random_data, rand, x, y, z, n);
 121   return (u & 0xffff) * G_RAND_FLOAT_TRANSFORM;
 122 }
 123
 124 float
 125 gegl_cl_random_float_range (__global const int *cl_random_data,
 126                             const GeglRandom    rand,
 127                             int                 x,
 128                             int                 y,
 129                             int                 z,
 130                             int                 n,
 131                             float               min,
 132                             float               max)
 133 {
 134   float f = gegl_cl_random_float (cl_random_data, rand, x, y, z, n);
 135   return f * (max - min) + min;
 136 }