1 /* cairo-fdr - a 'flight data recorder', a black box, for cairo
2 *
3 * Copyright © 2009 Chris Wilson
4 *
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #define _GNU_SOURCE
20
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24
25 #include <cairo.h>
26 #include <cairo-script.h>
27 #include <cairo-tee.h>
28 #include <stdlib.h>
29 #include <stdint.h>
30 #include <assert.h>
31 #include <unistd.h>
32 #include <errno.h>
33
34 #include <dlfcn.h>
35
36 static void *_dlhandle = RTLD_NEXT;
37 #define DLCALL(name, args...) ({ \
38 static typeof (&name) name##_real; \
39 if (name##_real == NULL) { \
40 name##_real = dlsym (_dlhandle, #name); \
41 if (name##_real == NULL && _dlhandle == RTLD_NEXT) { \
42 _dlhandle = dlopen ("libcairo.so", RTLD_LAZY); \
43 name##_real = dlsym (_dlhandle, #name); \
44 assert (name##_real != NULL); \
45 } \
46 } \
47 (*name##_real) (args); \
48 })
49
50 static cairo_device_t *fdr_context;
51 static const cairo_user_data_key_t fdr_key;
52
53 static void
fdr_get_extents(cairo_surface_t * surface,cairo_rectangle_t * extents)54 fdr_get_extents (cairo_surface_t *surface,
55 cairo_rectangle_t *extents)
56 {
57 cairo_t *cr;
58
59 cr = DLCALL (cairo_create, surface);
60 DLCALL (cairo_clip_extents, cr,
61 &extents->x, &extents->y, &extents->width, &extents->height);
62 DLCALL (cairo_destroy, cr);
63
64 extents->width -= extents->x;
65 extents->height -= extents->y;
66 }
67
68 static void
fdr_surface_destroy(void * surface)69 fdr_surface_destroy (void *surface)
70 {
71 DLCALL (cairo_surface_destroy, surface);
72 }
73
74 static void
fdr_surface_reference(void * surface)75 fdr_surface_reference (void *surface)
76 {
77 DLCALL (cairo_surface_reference, surface);
78 }
79
80 static cairo_surface_t *
fdr_surface_get_tee(cairo_surface_t * surface)81 fdr_surface_get_tee (cairo_surface_t *surface)
82 {
83 return DLCALL (cairo_surface_get_user_data, surface, &fdr_key);
84 }
85
86 static cairo_surface_t *
fdr_tee_surface_index(cairo_surface_t * surface,int index)87 fdr_tee_surface_index (cairo_surface_t *surface, int index)
88 {
89 return DLCALL (cairo_tee_surface_index, surface, index);
90 }
91
92 static cairo_status_t
fdr_write(void * closure,const unsigned char * data,unsigned int len)93 fdr_write (void *closure, const unsigned char *data, unsigned int len)
94 {
95 int fd = (int) (intptr_t) closure;
96 while (len) {
97 int ret = write (fd, data, len);
98 if (ret < 0) {
99 switch (errno) {
100 case EAGAIN:
101 case EINTR:
102 continue;
103 default:
104 return CAIRO_STATUS_WRITE_ERROR;
105 }
106 } else if (ret == 0) {
107 return CAIRO_STATUS_WRITE_ERROR;
108 } else {
109 data += ret;
110 len -= ret;
111 }
112 }
113 return CAIRO_STATUS_SUCCESS;
114 }
115
116 cairo_t *
cairo_create(cairo_surface_t * surface)117 cairo_create (cairo_surface_t *surface)
118 {
119 cairo_surface_t *tee;
120
121 tee = fdr_surface_get_tee (surface);
122 if (tee == NULL) {
123 cairo_surface_t *script;
124 cairo_rectangle_t extents;
125 cairo_content_t content;
126
127 if (fdr_context == NULL) {
128 const char *env = getenv ("CAIRO_SPHINX_FD");
129 int fd = env ? atoi (env) : 1;
130 fdr_context = DLCALL (cairo_script_create_for_stream,
131 fdr_write, (void *) (intptr_t) fd);
132 }
133
134 fdr_get_extents (surface, &extents);
135 content = DLCALL (cairo_surface_get_content, surface);
136
137 tee = DLCALL (cairo_tee_surface_create, surface);
138 script = DLCALL (cairo_script_surface_create,
139 fdr_context, content, extents.width, extents.height);
140 DLCALL (cairo_tee_surface_add, tee, script);
141
142 DLCALL (cairo_surface_set_user_data, surface,
143 &fdr_key, tee, fdr_surface_destroy);
144 }
145
146 return DLCALL (cairo_create, tee);
147 }
148
149 static void
fdr_remove_tee(cairo_surface_t * surface)150 fdr_remove_tee (cairo_surface_t *surface)
151 {
152 fdr_surface_reference (surface);
153 DLCALL (cairo_surface_set_user_data, surface, &fdr_key, NULL, NULL);
154 fdr_surface_destroy (surface);
155 }
156
157 void
cairo_destroy(cairo_t * cr)158 cairo_destroy (cairo_t *cr)
159 {
160 cairo_surface_t *tee;
161
162 tee = DLCALL (cairo_get_target, cr);
163 DLCALL (cairo_destroy, cr);
164
165 if (DLCALL (cairo_surface_get_reference_count, tee) == 1)
166 fdr_remove_tee (fdr_tee_surface_index (tee, 0));
167 }
168
169 void
cairo_pattern_destroy(cairo_pattern_t * pattern)170 cairo_pattern_destroy (cairo_pattern_t *pattern)
171 {
172 if (DLCALL (cairo_pattern_get_type, pattern) == CAIRO_PATTERN_TYPE_SURFACE) {
173 cairo_surface_t *surface;
174
175 if (DLCALL (cairo_pattern_get_surface, pattern, &surface) == CAIRO_STATUS_SUCCESS &&
176 DLCALL (cairo_surface_get_type, surface) == CAIRO_SURFACE_TYPE_TEE &&
177 DLCALL (cairo_surface_get_reference_count, surface) == 2)
178 {
179 fdr_remove_tee (fdr_tee_surface_index (surface, 0));
180 }
181 }
182
183 DLCALL (cairo_pattern_destroy, pattern);
184 }
185
186 cairo_surface_t *
cairo_get_target(cairo_t * cr)187 cairo_get_target (cairo_t *cr)
188 {
189 cairo_surface_t *tee;
190
191 tee = DLCALL (cairo_get_target, cr);
192 return fdr_tee_surface_index (tee, 0);
193 }
194
195 cairo_surface_t *
cairo_get_group_target(cairo_t * cr)196 cairo_get_group_target (cairo_t *cr)
197 {
198 cairo_surface_t *tee;
199
200 tee = DLCALL (cairo_get_group_target, cr);
201 return fdr_tee_surface_index (tee, 0);
202 }
203
204 cairo_pattern_t *
cairo_pattern_create_for_surface(cairo_surface_t * surface)205 cairo_pattern_create_for_surface (cairo_surface_t *surface)
206 {
207 cairo_surface_t *tee;
208
209 tee = fdr_surface_get_tee (surface);
210 if (tee != NULL)
211 surface = tee;
212
213 return DLCALL (cairo_pattern_create_for_surface, surface);
214 }
215
216 cairo_status_t
cairo_pattern_get_surface(cairo_pattern_t * pattern,cairo_surface_t ** surface)217 cairo_pattern_get_surface (cairo_pattern_t *pattern,
218 cairo_surface_t **surface)
219 {
220 cairo_status_t status;
221 cairo_surface_t *tee;
222
223 status = DLCALL (cairo_pattern_get_surface, pattern, surface);
224 if (status != CAIRO_STATUS_SUCCESS)
225 return status;
226
227 tee = fdr_surface_get_tee (*surface);
228 if (tee != NULL)
229 *surface = tee;
230
231 return CAIRO_STATUS_SUCCESS;
232 }
233
234 void
cairo_set_source_surface(cairo_t * cr,cairo_surface_t * surface,double x,double y)235 cairo_set_source_surface (cairo_t *cr,
236 cairo_surface_t *surface,
237 double x, double y)
238 {
239 cairo_surface_t *tee;
240
241 tee = fdr_surface_get_tee (surface);
242 if (tee != NULL)
243 surface = tee;
244
245 DLCALL (cairo_set_source_surface, cr, surface, x, y);
246 }
247
248 cairo_surface_t *
cairo_surface_create_similar(cairo_surface_t * surface,cairo_content_t content,int width,int height)249 cairo_surface_create_similar (cairo_surface_t *surface,
250 cairo_content_t content,
251 int width, int height)
252 {
253 cairo_surface_t *tee;
254
255 tee = fdr_surface_get_tee (surface);
256 if (tee != NULL)
257 surface = tee;
258
259 return DLCALL (cairo_surface_create_similar,
260 surface, content, width, height);
261 }
262