summaryrefslogtreecommitdiffstats
path: root/app/operations/gimpoperationthresholdalpha.c
blob: 94cbaf51a0dbdee07c86ba375bbe9328eead701c (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
176
177
178
/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * gimpoperationthresholdalpha.c
 * Copyright (C) 2012 Michael Natterer <mitch@gimp.org>
 *
 * 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/>.
 *
 * Ported from the threshold-alpha plug-in
 * Copyright (C) 1997 Shuji Narazaki <narazaki@InetQ.or.jp>
 */

#include "config.h"

#include <gegl.h>

#include "operations-types.h"

#include "gimpoperationthresholdalpha.h"

#include "gimp-intl.h"


enum
{
  PROP_0,
  PROP_VALUE
};


static void       gimp_operation_threshold_alpha_get_property (GObject             *object,
                                                               guint                property_id,
                                                               GValue              *value,
                                                               GParamSpec          *pspec);
static void       gimp_operation_threshold_alpha_set_property (GObject             *object,
                                                               guint                property_id,
                                                               const GValue        *value,
                                                               GParamSpec          *pspec);

static void       gimp_operation_threshold_alpha_prepare      (GeglOperation       *operation);
static gboolean   gimp_operation_threshold_alpha_process      (GeglOperation       *operation,
                                                               void                *in_buf,
                                                               void                *out_buf,
                                                               glong                samples,
                                                               const GeglRectangle *roi,
                                                               gint                 level);


G_DEFINE_TYPE (GimpOperationThresholdAlpha, gimp_operation_threshold_alpha,
               GEGL_TYPE_OPERATION_POINT_FILTER)

#define parent_class gimp_operation_threshold_alpha_parent_class


static void
gimp_operation_threshold_alpha_class_init (GimpOperationThresholdAlphaClass *klass)
{
  GObjectClass                  *object_class    = G_OBJECT_CLASS (klass);
  GeglOperationClass            *operation_class = GEGL_OPERATION_CLASS (klass);
  GeglOperationPointFilterClass *point_class     = GEGL_OPERATION_POINT_FILTER_CLASS (klass);

  object_class->set_property = gimp_operation_threshold_alpha_set_property;
  object_class->get_property = gimp_operation_threshold_alpha_get_property;

  gegl_operation_class_set_keys (operation_class,
                                 "name",        "gimp:threshold-alpha",
                                 "categories",  "color",
                                 "description",
                                 _("Make transparency all-or-nothing, by "
                                   "thresholding the alpha channel to a value"),
                                 NULL);

  operation_class->prepare = gimp_operation_threshold_alpha_prepare;

  point_class->process     = gimp_operation_threshold_alpha_process;

  g_object_class_install_property (object_class, PROP_VALUE,
                                   g_param_spec_double ("value",
                                                        _("Value"),
                                                        _("The alpha value"),
                                                        0.0, 1.0, 0.5,
                                                        G_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));
}

static void
gimp_operation_threshold_alpha_init (GimpOperationThresholdAlpha *self)
{
}

static void
gimp_operation_threshold_alpha_get_property (GObject    *object,
                                             guint       property_id,
                                             GValue     *value,
                                             GParamSpec *pspec)
{
  GimpOperationThresholdAlpha *self = GIMP_OPERATION_THRESHOLD_ALPHA (object);

  switch (property_id)
    {
    case PROP_VALUE:
      g_value_set_double (value, self->value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
gimp_operation_threshold_alpha_set_property (GObject      *object,
                                             guint         property_id,
                                             const GValue *value,
                                             GParamSpec   *pspec)
{
  GimpOperationThresholdAlpha *self = GIMP_OPERATION_THRESHOLD_ALPHA (object);

  switch (property_id)
    {
    case PROP_VALUE:
      self->value = g_value_get_double (value);
      break;

   default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
gimp_operation_threshold_alpha_prepare (GeglOperation *operation)
{
  const Babl *space = gegl_operation_get_source_space (operation, "input");
  gegl_operation_set_format (operation, "input",  babl_format_with_space ("RGBA float", space));
  gegl_operation_set_format (operation, "output", babl_format_with_space ("RGBA float", space));
}

static gboolean
gimp_operation_threshold_alpha_process (GeglOperation       *operation,
                                        void                *in_buf,
                                        void                *out_buf,
                                        glong                samples,
                                        const GeglRectangle *roi,
                                        gint                 level)
{
  GimpOperationThresholdAlpha *self = GIMP_OPERATION_THRESHOLD_ALPHA (operation);
  gfloat                      *src  = in_buf;
  gfloat                      *dest = out_buf;

  while (samples--)
    {
      dest[RED]   = src[RED];
      dest[GREEN] = src[GREEN];
      dest[BLUE]  = src[BLUE];

      if (src[ALPHA] > self->value)
        dest[ALPHA] = 1.0;
      else
        dest[ALPHA] = 0.0;

      src  += 4;
      dest += 4;
    }

  return TRUE;
}