summaryrefslogtreecommitdiffstats
path: root/app/operations/layer-modes/gimpoperationdissolve.c
blob: fb4b1d09f0dc9ccc88f713cae7f9763d3487a11a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * gimpoperationdissolve.c
 * Copyright (C) 2012 Ville Sokk <ville.sokk@gmail.com>
 *               2012 Øyvind Kolås <pippin@gimp.org>
 *               2003 Helvetix Victorinox
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gegl-plugin.h>

#include "../operations-types.h"

#include "gimpoperationdissolve.h"


#define RANDOM_TABLE_SIZE 4096


static gboolean                   gimp_operation_dissolve_process             (GeglOperation          *op,
                                                                               void                   *in,
                                                                               void                   *layer,
                                                                               void                   *mask,
                                                                               void                   *out,
                                                                               glong                   samples,
                                                                               const GeglRectangle    *result,
                                                                               gint                    level);
static GimpLayerCompositeRegion   gimp_operation_dissolve_get_affected_region (GimpOperationLayerMode *layer_mode);


G_DEFINE_TYPE (GimpOperationDissolve, gimp_operation_dissolve,
               GIMP_TYPE_OPERATION_LAYER_MODE)


static gint32 random_table[RANDOM_TABLE_SIZE];


static void
gimp_operation_dissolve_class_init (GimpOperationDissolveClass *klass)
{
  GeglOperationClass          *operation_class  = GEGL_OPERATION_CLASS (klass);
  GimpOperationLayerModeClass *layer_mode_class = GIMP_OPERATION_LAYER_MODE_CLASS (klass);
  GRand                       *gr;
  gint                         i;

  gegl_operation_class_set_keys (operation_class,
                                 "name",        "gimp:dissolve",
                                 "description", "GIMP dissolve mode operation",
                                 "categories",  "compositors",
                                 NULL);

  layer_mode_class->process             = gimp_operation_dissolve_process;
  layer_mode_class->get_affected_region = gimp_operation_dissolve_get_affected_region;

  /* generate a table of random seeds */
  gr = g_rand_new_with_seed (314159265);
  for (i = 0; i < RANDOM_TABLE_SIZE; i++)
    random_table[i] = g_rand_int (gr);

  g_rand_free (gr);
}

static void
gimp_operation_dissolve_init (GimpOperationDissolve *self)
{
}

static gboolean
gimp_operation_dissolve_process (GeglOperation       *op,
                                 void                *in_p,
                                 void                *layer_p,
                                 void                *mask_p,
                                 void                *out_p,
                                 glong                samples,
                                 const GeglRectangle *result,
                                 gint                 level)
{
  GimpOperationLayerMode *layer_mode = (gpointer) op;
  gfloat                 *in         = in_p;
  gfloat                 *out        = out_p;
  gfloat                 *layer      = layer_p;
  gfloat                 *mask       = mask_p;
  gfloat                  opacity    = layer_mode->opacity;
  const gboolean          has_mask   = mask != NULL;
  gint                    x, y;

  for (y = result->y; y < result->y + result->height; y++)
    {
      GRand *gr;

      /* The offset can be negative. I could just abs() the result, but we
       * probably prefer to use different indexes of the table when possible for
       * nicer randomization, so let's cycle the modulo so that -1 is the last
       * table index.
       */
      gr = g_rand_new_with_seed (random_table[((y % RANDOM_TABLE_SIZE) + RANDOM_TABLE_SIZE) % RANDOM_TABLE_SIZE]);

      /* fast forward through the rows pseudo random sequence */
      for (x = 0; x < result->x; x++)
        g_rand_int (gr);

      for (x = result->x; x < result->x + result->width; x++)
        {
          gfloat value = layer[ALPHA] * opacity * 255;

          if (has_mask)
            value *= *mask;

          if (g_rand_int_range (gr, 0, 255) >= value)
            {
              out[0] = in[0];
              out[1] = in[1];
              out[2] = in[2];

              if (layer_mode->composite_mode == GIMP_LAYER_COMPOSITE_UNION ||
                  layer_mode->composite_mode == GIMP_LAYER_COMPOSITE_CLIP_TO_BACKDROP)
                {
                  out[3] = in[3];
                }
              else
                {
                  out[3] = 0.0f;
                }
            }
          else
            {
              out[0] = layer[0];
              out[1] = layer[1];
              out[2] = layer[2];

              if (layer_mode->composite_mode == GIMP_LAYER_COMPOSITE_UNION ||
                  layer_mode->composite_mode == GIMP_LAYER_COMPOSITE_CLIP_TO_LAYER)
                {
                  out[3] = 1.0f;
                }
              else
                {
                  out[3] = in[3];
                }
            }

          in    += 4;
          layer += 4;
          out   += 4;

          if (has_mask)
            mask++;
        }

      g_rand_free (gr);
    }

  return TRUE;
}

static GimpLayerCompositeRegion
gimp_operation_dissolve_get_affected_region (GimpOperationLayerMode *layer_mode)
{
  return GIMP_LAYER_COMPOSITE_REGION_SOURCE;
}