1 /* GDK - The GIMP Drawing Kit
2 * Copyright (C) 2005 Red Hat, Inc.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 */
19
20 #include "gdkcairo.h"
21 #include "gdkdrawable.h"
22 #include "gdkinternals.h"
23 #include "gdkregion-generic.h"
24 #include "gdkalias.h"
25
26 static void
gdk_ensure_surface_flush(gpointer surface)27 gdk_ensure_surface_flush (gpointer surface)
28 {
29 cairo_surface_flush (surface);
30 cairo_surface_destroy (surface);
31 }
32
33 /**
34 * gdk_cairo_create:
35 * @drawable: a #GdkDrawable
36 *
37 * Creates a Cairo context for drawing to @drawable.
38 *
39 * <note><para>
40 * Note that due to double-buffering, Cairo contexts created
41 * in a GTK+ expose event handler cannot be cached and reused
42 * between different expose events.
43 * </para></note>
44 *
45 * Return value: A newly created Cairo context. Free with
46 * cairo_destroy() when you are done drawing.
47 *
48 * Since: 2.8
49 **/
50 cairo_t *
gdk_cairo_create(GdkDrawable * drawable)51 gdk_cairo_create (GdkDrawable *drawable)
52 {
53 static const cairo_user_data_key_t key;
54 cairo_surface_t *surface;
55 cairo_t *cr;
56
57 g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
58
59 surface = _gdk_drawable_ref_cairo_surface (drawable);
60 cr = cairo_create (surface);
61
62 if (GDK_DRAWABLE_GET_CLASS (drawable)->set_cairo_clip)
63 GDK_DRAWABLE_GET_CLASS (drawable)->set_cairo_clip (drawable, cr);
64
65 /* Ugly workaround for GTK not ensuring to flush surfaces before
66 * directly accessing the drawable backed by the surface. Not visible
67 * on X11 (where flushing is a no-op). For details, see
68 * https://bugzilla.gnome.org/show_bug.cgi?id=628291
69 */
70 cairo_set_user_data (cr, &key, surface, gdk_ensure_surface_flush);
71
72 return cr;
73 }
74
75 /**
76 * gdk_cairo_reset_clip:
77 * @cr: a #cairo_t
78 * @drawable: a #GdkDrawable
79 *
80 * Resets the clip region for a Cairo context created by gdk_cairo_create().
81 *
82 * This resets the clip region to the "empty" state for the given drawable.
83 * This is required for non-native windows since a direct call to
84 * cairo_reset_clip() would unset the clip region inherited from the
85 * drawable (i.e. the window clip region), and thus let you e.g.
86 * draw outside your window.
87 *
88 * This is rarely needed though, since most code just create a new cairo_t
89 * using gdk_cairo_create() each time they want to draw something.
90 *
91 * Since: 2.18
92 **/
93 void
gdk_cairo_reset_clip(cairo_t * cr,GdkDrawable * drawable)94 gdk_cairo_reset_clip (cairo_t *cr,
95 GdkDrawable *drawable)
96 {
97 cairo_reset_clip (cr);
98
99 if (GDK_DRAWABLE_GET_CLASS (drawable)->set_cairo_clip)
100 GDK_DRAWABLE_GET_CLASS (drawable)->set_cairo_clip (drawable, cr);
101 }
102
103 /**
104 * gdk_cairo_set_source_color:
105 * @cr: a #cairo_t
106 * @color: a #GdkColor
107 *
108 * Sets the specified #GdkColor as the source color of @cr.
109 *
110 * Since: 2.8
111 **/
112 void
gdk_cairo_set_source_color(cairo_t * cr,const GdkColor * color)113 gdk_cairo_set_source_color (cairo_t *cr,
114 const GdkColor *color)
115 {
116 g_return_if_fail (cr != NULL);
117 g_return_if_fail (color != NULL);
118
119 cairo_set_source_rgb (cr,
120 color->red / 65535.,
121 color->green / 65535.,
122 color->blue / 65535.);
123 }
124
125 /**
126 * gdk_cairo_rectangle:
127 * @cr: a #cairo_t
128 * @rectangle: a #GdkRectangle
129 *
130 * Adds the given rectangle to the current path of @cr.
131 *
132 * Since: 2.8
133 **/
134 void
gdk_cairo_rectangle(cairo_t * cr,const GdkRectangle * rectangle)135 gdk_cairo_rectangle (cairo_t *cr,
136 const GdkRectangle *rectangle)
137 {
138 g_return_if_fail (cr != NULL);
139 g_return_if_fail (rectangle != NULL);
140
141 cairo_rectangle (cr,
142 rectangle->x, rectangle->y,
143 rectangle->width, rectangle->height);
144 }
145
146 /**
147 * gdk_cairo_region:
148 * @cr: a #cairo_t
149 * @region: a #GdkRegion
150 *
151 * Adds the given region to the current path of @cr.
152 *
153 * Since: 2.8
154 **/
155 void
gdk_cairo_region(cairo_t * cr,const GdkRegion * region)156 gdk_cairo_region (cairo_t *cr,
157 const GdkRegion *region)
158 {
159 GdkRegionBox *boxes;
160 gint n_boxes, i;
161
162 g_return_if_fail (cr != NULL);
163 g_return_if_fail (region != NULL);
164
165 boxes = region->rects;
166 n_boxes = region->numRects;
167
168 for (i = 0; i < n_boxes; i++)
169 cairo_rectangle (cr,
170 boxes[i].x1,
171 boxes[i].y1,
172 boxes[i].x2 - boxes[i].x1,
173 boxes[i].y2 - boxes[i].y1);
174 }
175
176 /**
177 * gdk_cairo_set_source_pixbuf:
178 * @cr: a #Cairo context
179 * @pixbuf: a #GdkPixbuf
180 * @pixbuf_x: X coordinate of location to place upper left corner of @pixbuf
181 * @pixbuf_y: Y coordinate of location to place upper left corner of @pixbuf
182 *
183 * Sets the given pixbuf as the source pattern for the Cairo context.
184 * The pattern has an extend mode of %CAIRO_EXTEND_NONE and is aligned
185 * so that the origin of @pixbuf is @pixbuf_x, @pixbuf_y
186 *
187 * Since: 2.8
188 **/
189 void
gdk_cairo_set_source_pixbuf(cairo_t * cr,const GdkPixbuf * pixbuf,double pixbuf_x,double pixbuf_y)190 gdk_cairo_set_source_pixbuf (cairo_t *cr,
191 const GdkPixbuf *pixbuf,
192 double pixbuf_x,
193 double pixbuf_y)
194 {
195 gint width = gdk_pixbuf_get_width (pixbuf);
196 gint height = gdk_pixbuf_get_height (pixbuf);
197 guchar *gdk_pixels = gdk_pixbuf_get_pixels (pixbuf);
198 int gdk_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
199 int n_channels = gdk_pixbuf_get_n_channels (pixbuf);
200 int cairo_stride;
201 guchar *cairo_pixels;
202 cairo_format_t format;
203 cairo_surface_t *surface;
204 static const cairo_user_data_key_t key;
205 cairo_status_t status;
206 int j;
207
208 if (n_channels == 3)
209 format = CAIRO_FORMAT_RGB24;
210 else
211 format = CAIRO_FORMAT_ARGB32;
212
213 cairo_stride = cairo_format_stride_for_width (format, width);
214 cairo_pixels = g_malloc_n (height, cairo_stride);
215 surface = cairo_image_surface_create_for_data ((unsigned char *)cairo_pixels,
216 format,
217 width, height, cairo_stride);
218
219 status = cairo_surface_set_user_data (surface, &key,
220 cairo_pixels, (cairo_destroy_func_t)g_free);
221 if (status != CAIRO_STATUS_SUCCESS)
222 {
223 g_free (cairo_pixels);
224 goto out;
225 }
226
227 for (j = height; j; j--)
228 {
229 guchar *p = gdk_pixels;
230 guchar *q = cairo_pixels;
231
232 if (n_channels == 3)
233 {
234 guchar *end = p + 3 * width;
235
236 while (p < end)
237 {
238 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
239 q[0] = p[2];
240 q[1] = p[1];
241 q[2] = p[0];
242 #else
243 q[1] = p[0];
244 q[2] = p[1];
245 q[3] = p[2];
246 #endif
247 p += 3;
248 q += 4;
249 }
250 }
251 else
252 {
253 guchar *end = p + 4 * width;
254 guint t1,t2,t3;
255
256 #define MULT(d,c,a,t) G_STMT_START { t = c * a + 0x80; d = ((t >> 8) + t) >> 8; } G_STMT_END
257
258 while (p < end)
259 {
260 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
261 MULT(q[0], p[2], p[3], t1);
262 MULT(q[1], p[1], p[3], t2);
263 MULT(q[2], p[0], p[3], t3);
264 q[3] = p[3];
265 #else
266 q[0] = p[3];
267 MULT(q[1], p[0], p[3], t1);
268 MULT(q[2], p[1], p[3], t2);
269 MULT(q[3], p[2], p[3], t3);
270 #endif
271
272 p += 4;
273 q += 4;
274 }
275
276 #undef MULT
277 }
278
279 gdk_pixels += gdk_rowstride;
280 cairo_pixels += cairo_stride;
281 }
282
283 out:
284 cairo_set_source_surface (cr, surface, pixbuf_x, pixbuf_y);
285 cairo_surface_destroy (surface);
286 }
287
288 /**
289 * gdk_cairo_set_source_pixmap:
290 * @cr: a #Cairo context
291 * @pixmap: a #GdkPixmap
292 * @pixmap_x: X coordinate of location to place upper left corner of @pixmap
293 * @pixmap_y: Y coordinate of location to place upper left corner of @pixmap
294 *
295 * Sets the given pixmap as the source pattern for the Cairo context.
296 * The pattern has an extend mode of %CAIRO_EXTEND_NONE and is aligned
297 * so that the origin of @pixmap is @pixmap_x, @pixmap_y
298 *
299 * Since: 2.10
300 *
301 * Deprecated: 2.24: This function is being removed in GTK+ 3 (together
302 * with #GdkPixmap). Instead, use gdk_cairo_set_source_window() where
303 * appropriate.
304 **/
305 void
gdk_cairo_set_source_pixmap(cairo_t * cr,GdkPixmap * pixmap,double pixmap_x,double pixmap_y)306 gdk_cairo_set_source_pixmap (cairo_t *cr,
307 GdkPixmap *pixmap,
308 double pixmap_x,
309 double pixmap_y)
310 {
311 cairo_surface_t *surface;
312
313 surface = _gdk_drawable_ref_cairo_surface (GDK_DRAWABLE (pixmap));
314 cairo_set_source_surface (cr, surface, pixmap_x, pixmap_y);
315 cairo_surface_destroy (surface);
316 }
317
318 /**
319 * gdk_cairo_set_source_window:
320 * @cr: a #Cairo context
321 * @window: a #GdkWindow
322 * @x: X coordinate of location to place upper left corner of @window
323 * @y: Y coordinate of location to place upper left corner of @window
324 *
325 * Sets the given window as the source pattern for the Cairo context.
326 * The pattern has an extend mode of %CAIRO_EXTEND_NONE and is aligned
327 * so that the origin of @window is @x, @y. The window contains all its
328 * subwindows when rendering.
329 *
330 * Note that the contents of @window are undefined outside of the
331 * visible part of @window, so use this function with care.
332 *
333 * Since: 2.24
334 **/
335 void
gdk_cairo_set_source_window(cairo_t * cr,GdkWindow * window,double x,double y)336 gdk_cairo_set_source_window (cairo_t *cr,
337 GdkWindow *window,
338 double x,
339 double y)
340 {
341 cairo_surface_t *surface;
342
343 g_return_if_fail (cr != NULL);
344 g_return_if_fail (GDK_IS_WINDOW (window));
345
346 surface = _gdk_drawable_ref_cairo_surface (GDK_DRAWABLE (window));
347 cairo_set_source_surface (cr, surface, x, y);
348 cairo_surface_destroy (surface);
349 }
350
351
352 #define __GDK_CAIRO_C__
353 #include "gdkaliasdef.c"
354