summaryrefslogtreecommitdiffstats
path: root/libgimpwidgets/gimpcairo-utils.c
blob: a956f28d11d3b4ea51aaf0d8095927d71505b491 (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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/* LIBGIMP - The GIMP Library
 * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
 *
 * gimpcairo-utils.c
 * Copyright (C) 2007 Sven Neumann <sven@gimp.org>
 *
 * This library is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see
 * <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>

#include <gegl.h>
#include <gtk/gtk.h>

#include "libgimpbase/gimpbase.h"
#include "libgimpcolor/gimpcolor.h"

#include "gimpcairo-utils.h"


/**
 * SECTION: gimpcairo-utils
 * @title: GimpCairo-utils
 * @short_description: Utility functions for cairo
 *
 * Utility functions that make cairo easier to use with common
 * GIMP data types.
 **/


/**
 * gimp_cairo_set_focus_line_pattern:
 * @cr:     Cairo context
 * @widget: widget to draw the focus indicator on
 *
 * Sets color and dash pattern for stroking a focus line on the given
 * @cr. The line pattern is taken from @widget.
 *
 * Return value: %TRUE if the widget style has a focus line pattern,
 *               %FALSE otherwise
 *
 * Since: 2.6
 **/
gboolean
gimp_cairo_set_focus_line_pattern (cairo_t   *cr,
                                   GtkWidget *widget)
{
  gint8    *dash_list;
  gboolean  retval = FALSE;

  g_return_val_if_fail (cr != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);

  gtk_widget_style_get (widget,
                        "focus-line-pattern", (gchar *) &dash_list,
                        NULL);

  if (dash_list[0])
    {
      /* Taken straight from gtk_default_draw_focus()
       */
      gint     n_dashes     = strlen ((const gchar *) dash_list);
      gdouble *dashes       = g_new (gdouble, n_dashes);
      gdouble  total_length = 0;
      gint     i;

      for (i = 0; i < n_dashes; i++)
        {
          dashes[i] = dash_list[i];
          total_length += dash_list[i];
        }

      cairo_set_dash (cr, dashes, n_dashes, 0.5);

      g_free (dashes);

      retval = TRUE;
    }

  g_free (dash_list);

  return retval;
}

/**
 * gimp_cairo_surface_create_from_pixbuf:
 * @pixbuf: a #GdkPixbuf
 *
 * Create a Cairo image surface from a GdkPixbuf.
 *
 * You should avoid calling this function as there are probably more
 * efficient ways of achieving the result you are looking for.
 *
 * Returns: a #cairo_surface_t.
 *
 * Since: 2.6
 **/
cairo_surface_t *
gimp_cairo_surface_create_from_pixbuf (GdkPixbuf *pixbuf)
{
  cairo_surface_t *surface;
  cairo_format_t   format;
  guchar          *dest;
  const guchar    *src;
  gint             width;
  gint             height;
  gint             src_stride;
  gint             dest_stride;
  gint             y;

  g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);

  width  = gdk_pixbuf_get_width (pixbuf);
  height = gdk_pixbuf_get_height (pixbuf);

  switch (gdk_pixbuf_get_n_channels (pixbuf))
    {
    case 3:
      format = CAIRO_FORMAT_RGB24;
      break;
    case 4:
      format = CAIRO_FORMAT_ARGB32;
      break;
    default:
      g_assert_not_reached ();
      break;
    }

  surface = cairo_image_surface_create (format, width, height);

  cairo_surface_flush (surface);

  src         = gdk_pixbuf_get_pixels (pixbuf);
  src_stride  = gdk_pixbuf_get_rowstride (pixbuf);

  dest        = cairo_image_surface_get_data (surface);
  dest_stride = cairo_image_surface_get_stride (surface);

  switch (format)
    {
    case CAIRO_FORMAT_RGB24:
      for (y = 0; y < height; y++)
        {
          const guchar *s = src;
          guchar       *d = dest;
          gint          w = width;

          while (w--)
            {
              GIMP_CAIRO_RGB24_SET_PIXEL (d, s[0], s[1], s[2]);

              s += 3;
              d += 4;
            }

          src  += src_stride;
          dest += dest_stride;
        }
      break;

    case CAIRO_FORMAT_ARGB32:
      for (y = 0; y < height; y++)
        {
          const guchar *s = src;
          guchar       *d = dest;
          gint          w = width;

          while (w--)
            {
              GIMP_CAIRO_ARGB32_SET_PIXEL (d, s[0], s[1], s[2], s[3]);

              s += 4;
              d += 4;
            }

          src  += src_stride;
          dest += dest_stride;
        }
      break;

    default:
      break;
    }

  cairo_surface_mark_dirty (surface);

  return surface;
}