summaryrefslogtreecommitdiff
path: root/doc/public/html/cairo-cairo-surface-t.html
blob: e199a85a9eb7feaea9395352310ac18aeb13a557 (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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>cairo_surface_t</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2">
<link rel="start" href="index.html" title="Cairo: A Vector Graphics Library">
<link rel="up" href="Surfaces.html" title="Surfaces">
<link rel="prev" href="Surfaces.html" title="Surfaces">
<link rel="next" href="cairo-Image-Surfaces.html" title="Image Surfaces">
<meta name="generator" content="GTK-Doc V1.9 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
<link rel="part" href="pt01.html" title="Part&#160;I.&#160;Tutorial">
<link rel="part" href="pt02.html" title="Part&#160;II.&#160;Reference">
<link rel="chapter" href="Drawing.html" title="Drawing">
<link rel="chapter" href="Fonts.html" title="Fonts">
<link rel="chapter" href="Surfaces.html" title="Surfaces">
<link rel="chapter" href="Support.html" title="Utilities">
<link rel="index" href="ix01.html" title="Index">
<link rel="index" href="index-1.2.html" title="Index of new symbols in 1.2">
<link rel="index" href="index-1.4.html" title="Index of new symbols in 1.4">
<link rel="appendix" href="language-bindings.html" title="Appendix&#160;A.&#160;Creating a language binding for cairo">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2">
<tr valign="middle">
<td><a accesskey="p" href="Surfaces.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="Surfaces.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">Cairo: A Vector Graphics Library</th>
<td><a accesskey="n" href="cairo-Image-Surfaces.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr>
<tr><td colspan="5" class="shortcuts"><nobr><a href="#id2577626" class="shortcut">Top</a>
                  &#160;|&#160;
                  <a href="#id2656888" class="shortcut">Description</a></nobr></td></tr>
</table>
<div class="refentry" lang="en">
<a name="cairo-cairo-surface-t"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2>
<a name="id2577626"></a><span class="refentrytitle">cairo_surface_t</span>
</h2>
<p>cairo_surface_t &#8212; Base class for surfaces</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<pre class="synopsis">



typedef             <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>;
enum                <a class="link" href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a>;
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>*    <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-create-similar">cairo_surface_create_similar</a>        (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *other,
                                                         <a class="link" href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> content,
                                                         int width,
                                                         int height);
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>*    <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-reference">cairo_surface_reference</a>             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-destroy">cairo_surface_destroy</a>               (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
<a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-status">cairo_surface_status</a>                (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-finish">cairo_surface_finish</a>                (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-flush">cairo_surface_flush</a>                 (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-font-options">cairo_surface_get_font_options</a>      (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         <a class="link" href="cairo-Font-Options.html#cairo-font-options-t">cairo_font_options_t</a> *options);
<a class="link" href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a>     <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-content">cairo_surface_get_content</a>           (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty">cairo_surface_mark_dirty</a>            (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty-rectangle">cairo_surface_mark_dirty_rectangle</a>  (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         int x,
                                                         int y,
                                                         int width,
                                                         int height);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-set-device-offset">cairo_surface_set_device_offset</a>     (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double x_offset,
                                                         double y_offset);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-device-offset">cairo_surface_get_device_offset</a>     (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double *x_offset,
                                                         double *y_offset);
void                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-set-fallback-resolution">cairo_surface_set_fallback_resolution</a>
                                                        (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double x_pixels_per_inch,
                                                         double y_pixels_per_inch);
enum                <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a>;
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a> <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-type">cairo_surface_get_type</a>             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
unsigned int        <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-reference-count">cairo_surface_get_reference_count</a>   (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
<a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-set-user-data">cairo_surface_set_user_data</a>         (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         const <a class="link" href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key,
                                                         void *user_data,
                                                         <a class="link" href="cairo-Types.html#cairo-destroy-func-t">cairo_destroy_func_t</a> destroy);
void*               <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-user-data">cairo_surface_get_user_data</a>         (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         const <a class="link" href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key);
<a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-copy-page">cairo_surface_copy_page</a>             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
<a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-show-page">cairo_surface_show_page</a>             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
</pre>
</div>
<div class="refsect1" lang="en">
<a name="id2656888"></a><h2>Description</h2>
<p>

</p>
</div>
<div class="refsect1" lang="en">
<a name="id2656904"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2656914"></a><h3>
<a name="cairo-surface-t"></a>cairo_surface_t</h3>
<a class="indexterm" name="id2656927"></a><pre class="programlisting">typedef struct _cairo_surface cairo_surface_t;
</pre>
<p>
A <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> represents an image, either as the destination
of a drawing operation or as source when drawing onto another
surface.  To draw to a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>, create a cairo context
with the surface as the target, using <a class="link" href="cairo-cairo-t.html#cairo-create"><code class="function">cairo_create()</code></a>.
</p>
<p>
There are different subtypes of <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> for
different drawing backends; for example, <a class="link" href="cairo-Image-Surfaces.html#cairo-image-surface-create"><code class="function">cairo_image_surface_create()</code></a>
creates a bitmap image in memory.
The type of a surface can be queried with <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-type"><code class="function">cairo_surface_get_type()</code></a>.
</p>
<p>
Memory management of <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> is done with
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-reference"><code class="function">cairo_surface_reference()</code></a> and <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a>.</p>
<p>

</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2653728"></a><h3>
<a name="cairo-content-t"></a>enum cairo_content_t</h3>
<a class="indexterm" name="id2653740"></a><pre class="programlisting">typedef enum _cairo_content {
    CAIRO_CONTENT_COLOR		= 0x1000,
    CAIRO_CONTENT_ALPHA		= 0x2000,
    CAIRO_CONTENT_COLOR_ALPHA	= 0x3000
} cairo_content_t;
</pre>
<p>
<a class="link" href="cairo-cairo-surface-t.html#cairo-content-t"><span class="type">cairo_content_t</span></a> is used to describe the content that a surface will
contain, whether color information, alpha information (translucence
vs. opacity), or both.
</p>
<p>
Note: The large values here are designed to keep cairo_content_t
values distinct from cairo_format_t values so that the
implementation can detect the error if users confuse the two types.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><a name="CAIRO-CONTENT-COLOR:CAPS"></a><code class="literal">CAIRO_CONTENT_COLOR</code></span></p></td>
<td> The surface will hold color content only.
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-CONTENT-ALPHA:CAPS"></a><code class="literal">CAIRO_CONTENT_ALPHA</code></span></p></td>
<td> The surface will hold alpha content only.
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-CONTENT-COLOR-ALPHA:CAPS"></a><code class="literal">CAIRO_CONTENT_COLOR_ALPHA</code></span></p></td>
<td> The surface will hold color and alpha content.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2653846"></a><h3>
<a name="cairo-surface-create-similar"></a>cairo_surface_create_similar ()</h3>
<a class="indexterm" name="id2653857"></a><pre class="programlisting"><a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>*    cairo_surface_create_similar        (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *other,
                                                         <a class="link" href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> content,
                                                         int width,
                                                         int height);</pre>
<p>
Create a new surface that is as compatible as possible with an
existing surface. For example the new surface will have the same
fallback resolution and font options as <em class="parameter"><code>other</code></em>. Generally, the new
surface will also use the same backend as <em class="parameter"><code>other</code></em>, unless that is
not possible for some reason. The type of the returned surface may
be examined with <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-type"><code class="function">cairo_surface_get_type()</code></a>.
</p>
<p>
Initially the surface contents are all 0 (transparent if contents
have transparency, black otherwise.)</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>other</code></em>&#160;:</span></p></td>
<td> an existing surface used to select the backend of the new surface
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>content</code></em>&#160;:</span></p></td>
<td> the content for the new surface
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td> width of the new surface, (in device-space units)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td> height of the new surface (in device-space units)
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> a pointer to the newly allocated surface. The caller
owns the surface and should call cairo_surface_destroy when done
with it.

This function always returns a valid pointer, but it will return a
pointer to a "nil" surface if <em class="parameter"><code>other</code></em> is already in an error state
or any other error occurs.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2658731"></a><h3>
<a name="cairo-surface-reference"></a>cairo_surface_reference ()</h3>
<a class="indexterm" name="id2658742"></a><pre class="programlisting"><a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>*    cairo_surface_reference             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Increases the reference count on <em class="parameter"><code>surface</code></em> by one. This prevents
<em class="parameter"><code>surface</code></em> from being destroyed until a matching call to
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a> is made.
</p>
<p>
The number of references to a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> can be get using
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-reference-count"><code class="function">cairo_surface_get_reference_count()</code></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> the referenced <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2658853"></a><h3>
<a name="cairo-surface-destroy"></a>cairo_surface_destroy ()</h3>
<a class="indexterm" name="id2658865"></a><pre class="programlisting">void                cairo_surface_destroy               (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Decreases the reference count on <em class="parameter"><code>surface</code></em> by one. If the result is
zero, then <em class="parameter"><code>surface</code></em> and all associated resources are freed.  See
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-reference"><code class="function">cairo_surface_reference()</code></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2658925"></a><h3>
<a name="cairo-surface-status"></a>cairo_surface_status ()</h3>
<a class="indexterm" name="id2658935"></a><pre class="programlisting"><a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      cairo_surface_status                (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Checks whether an error has previously occurred for this
surface.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-SUCCESS:CAPS"
><code class="literal">CAIRO_STATUS_SUCCESS</code></a>, <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-NULL-POINTER:CAPS"
><code class="literal">CAIRO_STATUS_NULL_POINTER</code></a>,
<a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"
><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a>, <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-READ-ERROR:CAPS"
><code class="literal">CAIRO_STATUS_READ_ERROR</code></a>,
<a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-INVALID-CONTENT:CAPS"
><code class="literal">CAIRO_STATUS_INVALID_CONTENT</code></a>, <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-INVALID-FORMAT:CAPS"
><code class="literal">CAIRO_STATUS_INVALID_FORMAT</code></a>, or
<a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-INVALID-VISUAL:CAPS"
><code class="literal">CAIRO_STATUS_INVALID_VISUAL</code></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659058"></a><h3>
<a name="cairo-surface-finish"></a>cairo_surface_finish ()</h3>
<a class="indexterm" name="id2659068"></a><pre class="programlisting">void                cairo_surface_finish                (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
This function finishes the surface and drops all references to
external resources.  For example, for the Xlib backend it means
that cairo will no longer access the drawable, which can be freed.
After calling <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-finish"><code class="function">cairo_surface_finish()</code></a> the only valid operations on a
surface are getting and setting user data and referencing and
destroying it.  Further drawing to the surface will not affect the
surface but will instead trigger a CAIRO_STATUS_SURFACE_FINISHED
error.
</p>
<p>
When the last call to <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a> decreases the
reference count to zero, cairo will call <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-finish"><code class="function">cairo_surface_finish()</code></a> if
it hasn't been called already, before freeing the resources
associated with the surface.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> the <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> to finish
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659157"></a><h3>
<a name="cairo-surface-flush"></a>cairo_surface_flush ()</h3>
<a class="indexterm" name="id2659167"></a><pre class="programlisting">void                cairo_surface_flush                 (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Do any pending drawing for the surface and also restore any
temporary modification's cairo has made to the surface's
state. This function must be called before switching from
drawing on the surface with cairo to drawing on it directly
with native APIs. If the surface doesn't support direct access,
then this function does nothing.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659223"></a><h3>
<a name="cairo-surface-get-font-options"></a>cairo_surface_get_font_options ()</h3>
<a class="indexterm" name="id2659236"></a><pre class="programlisting">void                cairo_surface_get_font_options      (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         <a class="link" href="cairo-Font-Options.html#cairo-font-options-t">cairo_font_options_t</a> *options);</pre>
<p>
Retrieves the default font rendering options for the surface.
This allows display surfaces to report the correct subpixel order
for rendering on them, print surfaces to disable hinting of
metrics and so forth. The result can then be used with
<a class="link" href="cairo-Scaled-Fonts.html#cairo-scaled-font-create"><code class="function">cairo_scaled_font_create()</code></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>options</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-Font-Options.html#cairo-font-options-t"><span class="type">cairo_font_options_t</span></a> object into which to store
  the retrieved options. All existing values are overwritten
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659326"></a><h3>
<a name="cairo-surface-get-content"></a>cairo_surface_get_content ()</h3>
<a class="indexterm" name="id2659339"></a><pre class="programlisting"><a class="link" href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a>     cairo_surface_get_content           (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
This function returns the content type of <em class="parameter"><code>surface</code></em> which indicates
whether the surface contains color and/or alpha information. See
<a class="link" href="cairo-cairo-surface-t.html#cairo-content-t"><span class="type">cairo_content_t</span></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> The content type of <em class="parameter"><code>surface</code></em>.

</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659424"></a><h3>
<a name="cairo-surface-mark-dirty"></a>cairo_surface_mark_dirty ()</h3>
<a class="indexterm" name="id2659434"></a><pre class="programlisting">void                cairo_surface_mark_dirty            (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Tells cairo that drawing has been done to surface using means other
than cairo, and that cairo should reread any cached areas. Note
that you must call <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-flush"><code class="function">cairo_surface_flush()</code></a> before doing such drawing.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659496"></a><h3>
<a name="cairo-surface-mark-dirty-rectangle"></a>cairo_surface_mark_dirty_rectangle ()</h3>
<a class="indexterm" name="id2659509"></a><pre class="programlisting">void                cairo_surface_mark_dirty_rectangle  (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         int x,
                                                         int y,
                                                         int width,
                                                         int height);</pre>
<p>
Like <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty"><code class="function">cairo_surface_mark_dirty()</code></a>, but drawing has been done only to
the specified rectangle, so that cairo can retain cached contents
for other parts of the surface.
</p>
<p>
Any cached clip set on the surface will be reset by this function,
to make sure that future cairo calls have the clip set that they
expect.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em>&#160;:</span></p></td>
<td> X coordinate of dirty rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em>&#160;:</span></p></td>
<td> Y coordinate of dirty rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td> width of dirty rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td> height of dirty rectangle
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659653"></a><h3>
<a name="cairo-surface-set-device-offset"></a>cairo_surface_set_device_offset ()</h3>
<a class="indexterm" name="id2659666"></a><pre class="programlisting">void                cairo_surface_set_device_offset     (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double x_offset,
                                                         double y_offset);</pre>
<p>
Sets an offset that is added to the device coordinates determined
by the CTM when drawing to <em class="parameter"><code>surface</code></em>. One use case for this function
is when we want to create a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> that redirects drawing
for a portion of an onscreen surface to an offscreen surface in a
way that is completely invisible to the user of the cairo
API. Setting a transformation via <a class="link" href="cairo-Transformations.html#cairo-translate"><code class="function">cairo_translate()</code></a> isn't
sufficient to do this, since functions like
<a class="link" href="cairo-Transformations.html#cairo-device-to-user"><code class="function">cairo_device_to_user()</code></a> will expose the hidden offset.
</p>
<p>
Note that the offset affects drawing to the surface as well as
using the surface in a source pattern.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x_offset</code></em>&#160;:</span></p></td>
<td> the offset in the X direction, in device units
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y_offset</code></em>&#160;:</span></p></td>
<td> the offset in the Y direction, in device units
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659798"></a><h3>
<a name="cairo-surface-get-device-offset"></a>cairo_surface_get_device_offset ()</h3>
<a class="indexterm" name="id2659812"></a><pre class="programlisting">void                cairo_surface_get_device_offset     (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double *x_offset,
                                                         double *y_offset);</pre>
<p>
This function returns the previous device offset set by
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-set-device-offset"><code class="function">cairo_surface_set_device_offset()</code></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x_offset</code></em>&#160;:</span></p></td>
<td> the offset in the X direction, in device units
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y_offset</code></em>&#160;:</span></p></td>
<td> the offset in the Y direction, in device units
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2659920"></a><h3>
<a name="cairo-surface-set-fallback-resolution"></a>cairo_surface_set_fallback_resolution ()</h3>
<a class="indexterm" name="id2659935"></a><pre class="programlisting">void                cairo_surface_set_fallback_resolution
                                                        (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         double x_pixels_per_inch,
                                                         double y_pixels_per_inch);</pre>
<p>
Set the horizontal and vertical resolution for image fallbacks.
</p>
<p>
When certain operations aren't supported natively by a backend,
cairo will fallback by rendering operations to an image and then
overlaying that image onto the output. For backends that are
natively vector-oriented, this function can be used to set the
resolution used for these image fallbacks, (larger values will
result in more detailed images, but also larger file sizes).
</p>
<p>
Some examples of natively vector-oriented backends are the ps, pdf,
and svg backends.
</p>
<p>
For backends that are natively raster-oriented, image fallbacks are
still possible, but they are always performed at the native
device resolution. So this function has no effect on those
backends.
</p>
<p>
NOTE: The fallback resolution only takes effect at the time of
completing a page (with <a class="link" href="cairo-cairo-t.html#cairo-show-page"><code class="function">cairo_show_page()</code></a> or <a class="link" href="cairo-cairo-t.html#cairo-copy-page"><code class="function">cairo_copy_page()</code></a>) so
there is currently no way to have more than one fallback resolution
in effect on a single page.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x_pixels_per_inch</code></em>&#160;:</span></p></td>
<td> horizontal setting for pixels per inch
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y_pixels_per_inch</code></em>&#160;:</span></p></td>
<td> vertical setting for pixels per inch
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660079"></a><h3>
<a name="cairo-surface-type-t"></a>enum cairo_surface_type_t</h3>
<a class="indexterm" name="id2660091"></a><pre class="programlisting">typedef enum _cairo_surface_type {
    CAIRO_SURFACE_TYPE_IMAGE,
    CAIRO_SURFACE_TYPE_PDF,
    CAIRO_SURFACE_TYPE_PS,
    CAIRO_SURFACE_TYPE_XLIB,
    CAIRO_SURFACE_TYPE_XCB,
    CAIRO_SURFACE_TYPE_GLITZ,
    CAIRO_SURFACE_TYPE_QUARTZ,
    CAIRO_SURFACE_TYPE_WIN32,
    CAIRO_SURFACE_TYPE_BEOS,
    CAIRO_SURFACE_TYPE_DIRECTFB,
    CAIRO_SURFACE_TYPE_SVG,
    CAIRO_SURFACE_TYPE_OS2,
    CAIRO_SURFACE_TYPE_WIN32_PRINTING
} cairo_surface_type_t;
</pre>
<p>
<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-type-t"><span class="type">cairo_surface_type_t</span></a> is used to describe the type of a given
surface. The surface types are also known as "backends" or "surface
backends" within cairo.
</p>
<p>
The type of a surface is determined by the function used to create
it, which will generally be of the form cairo_<span class="emphasis"><em>type</em></span>_surface_create,
(though see cairo_surface_create_similar as well).
</p>
<p>
The surface type can be queried with <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-get-type"><code class="function">cairo_surface_get_type()</code></a>
</p>
<p>
The various cairo_surface functions can be used with surfaces of
any type, but some backends also provide type-specific functions
that must only be called with a surface of the appropriate
type. These functions have names that begin with
cairo_<span class="emphasis"><em>type</em></span>_surface such as <a class="link" href="cairo-Image-Surfaces.html#cairo-image-surface-get-width"><code class="function">cairo_image_surface_get_width()</code></a>.
</p>
<p>
The behavior of calling a type-specific function with a surface of
the wrong type is undefined.
</p>
<p>
New entries may be added in future versions.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-IMAGE:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_IMAGE</code></span></p></td>
<td> The surface is of type image
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-PDF:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_PDF</code></span></p></td>
<td> The surface is of type pdf
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-PS:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_PS</code></span></p></td>
<td> The surface is of type ps
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-XLIB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_XLIB</code></span></p></td>
<td> The surface is of type xlib
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-XCB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_XCB</code></span></p></td>
<td> The surface is of type xcb
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-GLITZ:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_GLITZ</code></span></p></td>
<td> The surface is of type glitz
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-QUARTZ:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_QUARTZ</code></span></p></td>
<td> The surface is of type quartz
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-WIN32:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_WIN32</code></span></p></td>
<td> The surface is of type win32
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-BEOS:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_BEOS</code></span></p></td>
<td> The surface is of type beos
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-DIRECTFB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_DIRECTFB</code></span></p></td>
<td> The surface is of type directfb
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-SVG:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_SVG</code></span></p></td>
<td> The surface is of type svg
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-OS2:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_OS2</code></span></p></td>
<td> The surface is of type os2
</td>
</tr>
<tr>
<td><p><span class="term"><a name="CAIRO-SURFACE-TYPE-WIN32-PRINTING:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_WIN32_PRINTING</code></span></p></td>
<td> The surface is a win32 printing surface
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660450"></a><h3>
<a name="cairo-surface-get-type"></a>cairo_surface_get_type ()</h3>
<a class="indexterm" name="id2660462"></a><pre class="programlisting"><a class="link" href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a> cairo_surface_get_type             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
This function returns the type of the backend used to create
a surface. See <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-type-t"><span class="type">cairo_surface_type_t</span></a> for available types.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> The type of <em class="parameter"><code>surface</code></em>.

</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660541"></a><h3>
<a name="cairo-surface-get-reference-count"></a>cairo_surface_get_reference_count ()</h3>
<a class="indexterm" name="id2660556"></a><pre class="programlisting">unsigned int        cairo_surface_get_reference_count   (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Returns the current reference count of <em class="parameter"><code>surface</code></em>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> the current reference count of <em class="parameter"><code>surface</code></em>.  If the
object is a nil object, 0 will be returned.

</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.4
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660636"></a><h3>
<a name="cairo-surface-set-user-data"></a>cairo_surface_set_user_data ()</h3>
<a class="indexterm" name="id2660647"></a><pre class="programlisting"><a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      cairo_surface_set_user_data         (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         const <a class="link" href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key,
                                                         void *user_data,
                                                         <a class="link" href="cairo-Types.html#cairo-destroy-func-t">cairo_destroy_func_t</a> destroy);</pre>
<p>
Attach user data to <em class="parameter"><code>surface</code></em>.  To remove user data from a surface,
call this function with the key that was used to set it and <code class="literal">NULL</code>
for <em class="parameter"><code>data</code></em>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>key</code></em>&#160;:</span></p></td>
<td> the address of a <a class="link" href="cairo-Types.html#cairo-user-data-key-t"><span class="type">cairo_user_data_key_t</span></a> to attach the user data to
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>user_data</code></em>&#160;:</span></p></td>
<td> the user data to attach to the surface
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>destroy</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-Types.html#cairo-destroy-func-t"><span class="type">cairo_destroy_func_t</span></a> which will be called when the
surface is destroyed or when new user data is attached using the
same key.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-SUCCESS:CAPS"
><code class="literal">CAIRO_STATUS_SUCCESS</code></a> or <a
href="../cairo/cairo-Error-Handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"
><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a> if a
slot could not be allocated for the user data.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660818"></a><h3>
<a name="cairo-surface-get-user-data"></a>cairo_surface_get_user_data ()</h3>
<a class="indexterm" name="id2660829"></a><pre class="programlisting">void*               cairo_surface_get_user_data         (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
                                                         const <a class="link" href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key);</pre>
<p>
Return user data previously attached to <em class="parameter"><code>surface</code></em> using the specified
key.  If no user data has been attached with the given key this
function returns <code class="literal">NULL</code>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>key</code></em>&#160;:</span></p></td>
<td> the address of the <a class="link" href="cairo-Types.html#cairo-user-data-key-t"><span class="type">cairo_user_data_key_t</span></a> the user data was
attached to
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> the user data previously attached or <code class="literal">NULL</code>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2660940"></a><h3>
<a name="cairo-surface-copy-page"></a>cairo_surface_copy_page ()</h3>
<a class="indexterm" name="id2660953"></a><pre class="programlisting"><a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      cairo_surface_copy_page             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Emits the current page for backends that support multiple pages,
but doesn't clear it, so that the contents of the current page will
be retained for the next page.  Use <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-show-page"><code class="function">cairo_surface_show_page()</code></a> if you
want to get an empty page after the emission.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>


</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.6
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2661024"></a><h3>
<a name="cairo-surface-show-page"></a>cairo_surface_show_page ()</h3>
<a class="indexterm" name="id2661037"></a><pre class="programlisting"><a class="link" href="cairo-Error-Handling.html#cairo-status-t">cairo_status_t</a>      cairo_surface_show_page             (<a class="link" href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Emits and clears the current page for backends that support multiple
pages.  Use <a class="link" href="cairo-cairo-surface-t.html#cairo-surface-copy-page"><code class="function">cairo_surface_copy_page()</code></a> if you don't want to clear the page.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>surface</code></em>&#160;:</span></p></td>
<td> a <span class="type">cairo_Surface_t</span>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>


</td>
</tr>
</tbody>
</table></div>
<p class="since">Since  1.6
</p>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id2661114"></a><div class="refsect2" lang="en"><a name="id2661115"></a></div>
<hr>
<div class="refsect2" lang="en"><a name="id2661116"></a></div>
</div>
</div>
</body>
</html>