summaryrefslogtreecommitdiffstats
path: root/gfx/cairo/libpixman/src/pixman.c
blob: 184f0c4e6ac4646a10066ec2e63d4e17b8c8a76b (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
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
/* -*- Mode: c; c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t; -*- */
/*
 * Copyright © 2000 SuSE, Inc.
 * Copyright © 2007 Red Hat, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of SuSE not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  SuSE makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author:  Keith Packard, SuSE, Inc.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "pixman-private.h"

#include <stdlib.h>

pixman_implementation_t *global_implementation;

#ifdef TOOLCHAIN_SUPPORTS_ATTRIBUTE_CONSTRUCTOR
static void __attribute__((constructor))
pixman_constructor (void)
{
    global_implementation = _pixman_choose_implementation ();
}
#endif

typedef struct operator_info_t operator_info_t;

struct operator_info_t
{
    uint8_t	opaque_info[4];
};

#define PACK(neither, src, dest, both)			\
    {{	    (uint8_t)PIXMAN_OP_ ## neither,		\
	    (uint8_t)PIXMAN_OP_ ## src,			\
	    (uint8_t)PIXMAN_OP_ ## dest,		\
	    (uint8_t)PIXMAN_OP_ ## both		}}

static const operator_info_t operator_table[] =
{
    /*    Neither Opaque         Src Opaque             Dst Opaque             Both Opaque */
    PACK (CLEAR,                 CLEAR,                 CLEAR,                 CLEAR),
    PACK (SRC,                   SRC,                   SRC,                   SRC),
    PACK (DST,                   DST,                   DST,                   DST),
    PACK (OVER,                  SRC,                   OVER,                  SRC),
    PACK (OVER_REVERSE,          OVER_REVERSE,          DST,                   DST),
    PACK (IN,                    IN,                    SRC,                   SRC),
    PACK (IN_REVERSE,            DST,                   IN_REVERSE,            DST),
    PACK (OUT,                   OUT,                   CLEAR,                 CLEAR),
    PACK (OUT_REVERSE,           CLEAR,                 OUT_REVERSE,           CLEAR),
    PACK (ATOP,                  IN,                    OVER,                  SRC),
    PACK (ATOP_REVERSE,          OVER_REVERSE,          IN_REVERSE,            DST),
    PACK (XOR,                   OUT,                   OUT_REVERSE,           CLEAR),
    PACK (ADD,                   ADD,                   ADD,                   ADD),
    PACK (SATURATE,              OVER_REVERSE,          DST,                   DST),

    {{ 0 /* 0x0e */ }},
    {{ 0 /* 0x0f */ }},

    PACK (CLEAR,                 CLEAR,                 CLEAR,                 CLEAR),
    PACK (SRC,                   SRC,                   SRC,                   SRC),
    PACK (DST,                   DST,                   DST,                   DST),
    PACK (DISJOINT_OVER,         DISJOINT_OVER,         DISJOINT_OVER,         DISJOINT_OVER),
    PACK (DISJOINT_OVER_REVERSE, DISJOINT_OVER_REVERSE, DISJOINT_OVER_REVERSE, DISJOINT_OVER_REVERSE),
    PACK (DISJOINT_IN,           DISJOINT_IN,           DISJOINT_IN,           DISJOINT_IN),
    PACK (DISJOINT_IN_REVERSE,   DISJOINT_IN_REVERSE,   DISJOINT_IN_REVERSE,   DISJOINT_IN_REVERSE),
    PACK (DISJOINT_OUT,          DISJOINT_OUT,          DISJOINT_OUT,          DISJOINT_OUT),
    PACK (DISJOINT_OUT_REVERSE,  DISJOINT_OUT_REVERSE,  DISJOINT_OUT_REVERSE,  DISJOINT_OUT_REVERSE),
    PACK (DISJOINT_ATOP,         DISJOINT_ATOP,         DISJOINT_ATOP,         DISJOINT_ATOP),
    PACK (DISJOINT_ATOP_REVERSE, DISJOINT_ATOP_REVERSE, DISJOINT_ATOP_REVERSE, DISJOINT_ATOP_REVERSE),
    PACK (DISJOINT_XOR,          DISJOINT_XOR,          DISJOINT_XOR,          DISJOINT_XOR),

    {{ 0 /* 0x1c */ }},
    {{ 0 /* 0x1d */ }},
    {{ 0 /* 0x1e */ }},
    {{ 0 /* 0x1f */ }},

    PACK (CLEAR,                 CLEAR,                 CLEAR,                 CLEAR),
    PACK (SRC,                   SRC,                   SRC,                   SRC),
    PACK (DST,                   DST,                   DST,                   DST),
    PACK (CONJOINT_OVER,         CONJOINT_OVER,         CONJOINT_OVER,         CONJOINT_OVER),
    PACK (CONJOINT_OVER_REVERSE, CONJOINT_OVER_REVERSE, CONJOINT_OVER_REVERSE, CONJOINT_OVER_REVERSE),
    PACK (CONJOINT_IN,           CONJOINT_IN,           CONJOINT_IN,           CONJOINT_IN),
    PACK (CONJOINT_IN_REVERSE,   CONJOINT_IN_REVERSE,   CONJOINT_IN_REVERSE,   CONJOINT_IN_REVERSE),
    PACK (CONJOINT_OUT,          CONJOINT_OUT,          CONJOINT_OUT,          CONJOINT_OUT),
    PACK (CONJOINT_OUT_REVERSE,  CONJOINT_OUT_REVERSE,  CONJOINT_OUT_REVERSE,  CONJOINT_OUT_REVERSE),
    PACK (CONJOINT_ATOP,         CONJOINT_ATOP,         CONJOINT_ATOP,         CONJOINT_ATOP),
    PACK (CONJOINT_ATOP_REVERSE, CONJOINT_ATOP_REVERSE, CONJOINT_ATOP_REVERSE, CONJOINT_ATOP_REVERSE),
    PACK (CONJOINT_XOR,          CONJOINT_XOR,          CONJOINT_XOR,          CONJOINT_XOR),

    {{ 0 /* 0x2c */ }},
    {{ 0 /* 0x2d */ }},
    {{ 0 /* 0x2e */ }},
    {{ 0 /* 0x2f */ }},

    PACK (MULTIPLY,              MULTIPLY,              MULTIPLY,              MULTIPLY),
    PACK (SCREEN,                SCREEN,                SCREEN,                SCREEN),
    PACK (OVERLAY,               OVERLAY,               OVERLAY,               OVERLAY),
    PACK (DARKEN,                DARKEN,                DARKEN,                DARKEN),
    PACK (LIGHTEN,               LIGHTEN,               LIGHTEN,               LIGHTEN),
    PACK (COLOR_DODGE,           COLOR_DODGE,           COLOR_DODGE,           COLOR_DODGE),
    PACK (COLOR_BURN,            COLOR_BURN,            COLOR_BURN,            COLOR_BURN),
    PACK (HARD_LIGHT,            HARD_LIGHT,            HARD_LIGHT,            HARD_LIGHT),
    PACK (SOFT_LIGHT,            SOFT_LIGHT,            SOFT_LIGHT,            SOFT_LIGHT),
    PACK (DIFFERENCE,            DIFFERENCE,            DIFFERENCE,            DIFFERENCE),
    PACK (EXCLUSION,             EXCLUSION,             EXCLUSION,             EXCLUSION),
    PACK (HSL_HUE,               HSL_HUE,               HSL_HUE,               HSL_HUE),
    PACK (HSL_SATURATION,        HSL_SATURATION,        HSL_SATURATION,        HSL_SATURATION),
    PACK (HSL_COLOR,             HSL_COLOR,             HSL_COLOR,             HSL_COLOR),
    PACK (HSL_LUMINOSITY,        HSL_LUMINOSITY,        HSL_LUMINOSITY,        HSL_LUMINOSITY),
};

/*
 * Optimize the current operator based on opacity of source or destination
 * The output operator should be mathematically equivalent to the source.
 */
static pixman_op_t
optimize_operator (pixman_op_t     op,
		   uint32_t        src_flags,
		   uint32_t        mask_flags,
		   uint32_t        dst_flags)
{
    pixman_bool_t is_source_opaque, is_dest_opaque;

#define OPAQUE_SHIFT 13
    
    COMPILE_TIME_ASSERT (FAST_PATH_IS_OPAQUE == (1 << OPAQUE_SHIFT));
    
    is_dest_opaque = (dst_flags & FAST_PATH_IS_OPAQUE);
    is_source_opaque = ((src_flags & mask_flags) & FAST_PATH_IS_OPAQUE);

    is_dest_opaque >>= OPAQUE_SHIFT - 1;
    is_source_opaque >>= OPAQUE_SHIFT;

    return operator_table[op].opaque_info[is_dest_opaque | is_source_opaque];
}

/*
 * Computing composite region
 */
static inline pixman_bool_t
clip_general_image (pixman_region32_t * region,
                    pixman_region32_t * clip,
                    int                 dx,
                    int                 dy)
{
    if (pixman_region32_n_rects (region) == 1 &&
        pixman_region32_n_rects (clip) == 1)
    {
	pixman_box32_t *  rbox = pixman_region32_rectangles (region, NULL);
	pixman_box32_t *  cbox = pixman_region32_rectangles (clip, NULL);
	int v;

	if (rbox->x1 < (v = cbox->x1 + dx))
	    rbox->x1 = v;
	if (rbox->x2 > (v = cbox->x2 + dx))
	    rbox->x2 = v;
	if (rbox->y1 < (v = cbox->y1 + dy))
	    rbox->y1 = v;
	if (rbox->y2 > (v = cbox->y2 + dy))
	    rbox->y2 = v;
	if (rbox->x1 >= rbox->x2 || rbox->y1 >= rbox->y2)
	{
	    pixman_region32_init (region);
	    return FALSE;
	}
    }
    else if (!pixman_region32_not_empty (clip))
    {
	return FALSE;
    }
    else
    {
	if (dx || dy)
	    pixman_region32_translate (region, -dx, -dy);

	if (!pixman_region32_intersect (region, region, clip))
	    return FALSE;

	if (dx || dy)
	    pixman_region32_translate (region, dx, dy);
    }

    return pixman_region32_not_empty (region);
}

static inline pixman_bool_t
clip_source_image (pixman_region32_t * region,
                   pixman_image_t *    image,
                   int                 dx,
                   int                 dy)
{
    /* Source clips are ignored, unless they are explicitly turned on
     * and the clip in question was set by an X client. (Because if
     * the clip was not set by a client, then it is a hierarchy
     * clip and those should always be ignored for sources).
     */
    if (!image->common.clip_sources || !image->common.client_clip)
	return TRUE;

    return clip_general_image (region,
                               &image->common.clip_region,
                               dx, dy);
}

/*
 * returns FALSE if the final region is empty.  Indistinguishable from
 * an allocation failure, but rendering ignores those anyways.
 */
pixman_bool_t
_pixman_compute_composite_region32 (pixman_region32_t * region,
				    pixman_image_t *    src_image,
				    pixman_image_t *    mask_image,
				    pixman_image_t *    dest_image,
				    int32_t             src_x,
				    int32_t             src_y,
				    int32_t             mask_x,
				    int32_t             mask_y,
				    int32_t             dest_x,
				    int32_t             dest_y,
				    int32_t             width,
				    int32_t             height)
{
    region->extents.x1 = dest_x;
    region->extents.x2 = dest_x + width;
    region->extents.y1 = dest_y;
    region->extents.y2 = dest_y + height;

    region->extents.x1 = MAX (region->extents.x1, 0);
    region->extents.y1 = MAX (region->extents.y1, 0);
    region->extents.x2 = MIN (region->extents.x2, dest_image->bits.width);
    region->extents.y2 = MIN (region->extents.y2, dest_image->bits.height);

    region->data = 0;

    /* Check for empty operation */
    if (region->extents.x1 >= region->extents.x2 ||
        region->extents.y1 >= region->extents.y2)
    {
	region->extents.x1 = 0;
	region->extents.x2 = 0;
	region->extents.y1 = 0;
	region->extents.y2 = 0;
	return FALSE;
    }

    if (dest_image->common.have_clip_region)
    {
	if (!clip_general_image (region, &dest_image->common.clip_region, 0, 0))
	    return FALSE;
    }

    if (dest_image->common.alpha_map)
    {
	if (!pixman_region32_intersect_rect (region, region,
					     dest_image->common.alpha_origin_x,
					     dest_image->common.alpha_origin_y,
					     dest_image->common.alpha_map->width,
					     dest_image->common.alpha_map->height))
	{
	    return FALSE;
	}
	if (!pixman_region32_not_empty (region))
	    return FALSE;
	if (dest_image->common.alpha_map->common.have_clip_region)
	{
	    if (!clip_general_image (region, &dest_image->common.alpha_map->common.clip_region,
				     -dest_image->common.alpha_origin_x,
				     -dest_image->common.alpha_origin_y))
	    {
		return FALSE;
	    }
	}
    }

    /* clip against src */
    if (src_image->common.have_clip_region)
    {
	if (!clip_source_image (region, src_image, dest_x - src_x, dest_y - src_y))
	    return FALSE;
    }
    if (src_image->common.alpha_map && src_image->common.alpha_map->common.have_clip_region)
    {
	if (!clip_source_image (region, (pixman_image_t *)src_image->common.alpha_map,
	                        dest_x - (src_x - src_image->common.alpha_origin_x),
	                        dest_y - (src_y - src_image->common.alpha_origin_y)))
	{
	    return FALSE;
	}
    }
    /* clip against mask */
    if (mask_image && mask_image->common.have_clip_region)
    {
	if (!clip_source_image (region, mask_image, dest_x - mask_x, dest_y - mask_y))
	    return FALSE;

	if (mask_image->common.alpha_map && mask_image->common.alpha_map->common.have_clip_region)
	{
	    if (!clip_source_image (region, (pixman_image_t *)mask_image->common.alpha_map,
	                            dest_x - (mask_x - mask_image->common.alpha_origin_x),
	                            dest_y - (mask_y - mask_image->common.alpha_origin_y)))
	    {
		return FALSE;
	    }
	}
    }

    return TRUE;
}

typedef struct
{
    pixman_fixed_48_16_t	x1;
    pixman_fixed_48_16_t	y1;
    pixman_fixed_48_16_t	x2;
    pixman_fixed_48_16_t	y2;
} box_48_16_t;

static pixman_bool_t
compute_transformed_extents (pixman_transform_t *transform,
			     const pixman_box32_t *extents,
			     box_48_16_t *transformed)
{
    pixman_fixed_48_16_t tx1, ty1, tx2, ty2;
    pixman_fixed_t x1, y1, x2, y2;
    int i;

    x1 = pixman_int_to_fixed (extents->x1) + pixman_fixed_1 / 2;
    y1 = pixman_int_to_fixed (extents->y1) + pixman_fixed_1 / 2;
    x2 = pixman_int_to_fixed (extents->x2) - pixman_fixed_1 / 2;
    y2 = pixman_int_to_fixed (extents->y2) - pixman_fixed_1 / 2;

    if (!transform)
    {
	transformed->x1 = x1;
	transformed->y1 = y1;
	transformed->x2 = x2;
	transformed->y2 = y2;

	return TRUE;
    }

    tx1 = ty1 = INT64_MAX;
    tx2 = ty2 = INT64_MIN;

    for (i = 0; i < 4; ++i)
    {
	pixman_fixed_48_16_t tx, ty;
	pixman_vector_t v;

	v.vector[0] = (i & 0x01)? x1 : x2;
	v.vector[1] = (i & 0x02)? y1 : y2;
	v.vector[2] = pixman_fixed_1;

	if (!pixman_transform_point (transform, &v))
	    return FALSE;

	tx = (pixman_fixed_48_16_t)v.vector[0];
	ty = (pixman_fixed_48_16_t)v.vector[1];

	if (tx < tx1)
	    tx1 = tx;
	if (ty < ty1)
	    ty1 = ty;
	if (tx > tx2)
	    tx2 = tx;
	if (ty > ty2)
	    ty2 = ty;
    }

    transformed->x1 = tx1;
    transformed->y1 = ty1;
    transformed->x2 = tx2;
    transformed->y2 = ty2;

    return TRUE;
}

#define IS_16BIT(x) (((x) >= INT16_MIN) && ((x) <= INT16_MAX))
#define ABS(f)      (((f) < 0)?  (-(f)) : (f))
#define IS_16_16(f) (((f) >= pixman_min_fixed_48_16 && ((f) <= pixman_max_fixed_48_16)))

static pixman_bool_t
analyze_extent (pixman_image_t       *image,
		const pixman_box32_t *extents,
		uint32_t             *flags)
{
    pixman_transform_t *transform;
    pixman_fixed_t x_off, y_off;
    pixman_fixed_t width, height;
    pixman_fixed_t *params;
    box_48_16_t transformed;
    pixman_box32_t exp_extents;

    if (!image)
	return TRUE;

    /* Some compositing functions walk one step
     * outside the destination rectangle, so we
     * check here that the expanded-by-one source
     * extents in destination space fits in 16 bits
     */
    if (!IS_16BIT (extents->x1 - 1)		||
	!IS_16BIT (extents->y1 - 1)		||
	!IS_16BIT (extents->x2 + 1)		||
	!IS_16BIT (extents->y2 + 1))
    {
	return FALSE;
    }

    transform = image->common.transform;
    if (image->common.type == BITS)
    {
	/* During repeat mode calculations we might convert the
	 * width/height of an image to fixed 16.16, so we need
	 * them to be smaller than 16 bits.
	 */
	if (image->bits.width >= 0x7fff	|| image->bits.height >= 0x7fff)
	    return FALSE;

	if ((image->common.flags & FAST_PATH_ID_TRANSFORM) == FAST_PATH_ID_TRANSFORM &&
	    extents->x1 >= 0 &&
	    extents->y1 >= 0 &&
	    extents->x2 <= image->bits.width &&
	    extents->y2 <= image->bits.height)
	{
	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;
	    return TRUE;
	}

	switch (image->common.filter)
	{
	case PIXMAN_FILTER_CONVOLUTION:
	    params = image->common.filter_params;
	    x_off = - pixman_fixed_e - ((params[0] - pixman_fixed_1) >> 1);
	    y_off = - pixman_fixed_e - ((params[1] - pixman_fixed_1) >> 1);
	    width = params[0];
	    height = params[1];
	    break;

	case PIXMAN_FILTER_SEPARABLE_CONVOLUTION:
	    params = image->common.filter_params;
	    x_off = - pixman_fixed_e - ((params[0] - pixman_fixed_1) >> 1);
	    y_off = - pixman_fixed_e - ((params[1] - pixman_fixed_1) >> 1);
	    width = params[0];
	    height = params[1];
	    break;
	    
	case PIXMAN_FILTER_GOOD:
	case PIXMAN_FILTER_BEST:
	case PIXMAN_FILTER_BILINEAR:
	    x_off = - pixman_fixed_1 / 2;
	    y_off = - pixman_fixed_1 / 2;
	    width = pixman_fixed_1;
	    height = pixman_fixed_1;
	    break;

	case PIXMAN_FILTER_FAST:
	case PIXMAN_FILTER_NEAREST:
	    x_off = - pixman_fixed_e;
	    y_off = - pixman_fixed_e;
	    width = 0;
	    height = 0;
	    break;

	default:
	    return FALSE;
	}
    }
    else
    {
	x_off = 0;
	y_off = 0;
	width = 0;
	height = 0;
    }

    if (!compute_transformed_extents (transform, extents, &transformed))
	return FALSE;

    /* Expand the source area by a tiny bit so account of different rounding that
     * may happen during sampling. Note that (8 * pixman_fixed_e) is very far from
     * 0.5 so this won't cause the area computed to be overly pessimistic.
     */
    transformed.x1 -= 8 * pixman_fixed_e;
    transformed.y1 -= 8 * pixman_fixed_e;
    transformed.x2 += 8 * pixman_fixed_e;
    transformed.y2 += 8 * pixman_fixed_e;

    if (image->common.type == BITS)
    {
	if (pixman_fixed_to_int (transformed.x1) >= 0			&&
	    pixman_fixed_to_int (transformed.y1) >= 0			&&
	    pixman_fixed_to_int (transformed.x2) < image->bits.width	&&
	    pixman_fixed_to_int (transformed.y2) < image->bits.height)
	{
	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;
	}

	if (pixman_fixed_to_int (transformed.x1 - pixman_fixed_1 / 2) >= 0		  &&
	    pixman_fixed_to_int (transformed.y1 - pixman_fixed_1 / 2) >= 0		  &&
	    pixman_fixed_to_int (transformed.x2 + pixman_fixed_1 / 2) < image->bits.width &&
	    pixman_fixed_to_int (transformed.y2 + pixman_fixed_1 / 2) < image->bits.height)
	{
	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP_BILINEAR;
	}
    }

    /* Check we don't overflow when the destination extents are expanded by one.
     * This ensures that compositing functions can simply walk the source space
     * using 16.16 variables without worrying about overflow.
     */
    exp_extents = *extents;
    exp_extents.x1 -= 1;
    exp_extents.y1 -= 1;
    exp_extents.x2 += 1;
    exp_extents.y2 += 1;

    if (!compute_transformed_extents (transform, &exp_extents, &transformed))
	return FALSE;
    
    if (!IS_16_16 (transformed.x1 + x_off - 8 * pixman_fixed_e)	||
	!IS_16_16 (transformed.y1 + y_off - 8 * pixman_fixed_e)	||
	!IS_16_16 (transformed.x2 + x_off + 8 * pixman_fixed_e + width)	||
	!IS_16_16 (transformed.y2 + y_off + 8 * pixman_fixed_e + height))
    {
	return FALSE;
    }

    return TRUE;
}

/*
 * Work around GCC bug causing crashes in Mozilla with SSE2
 *
 * When using -msse, gcc generates movdqa instructions assuming that
 * the stack is 16 byte aligned. Unfortunately some applications, such
 * as Mozilla and Mono, end up aligning the stack to 4 bytes, which
 * causes the movdqa instructions to fail.
 *
 * The __force_align_arg_pointer__ makes gcc generate a prologue that
 * realigns the stack pointer to 16 bytes.
 *
 * On x86-64 this is not necessary because the standard ABI already
 * calls for a 16 byte aligned stack.
 *
 * See https://bugs.freedesktop.org/show_bug.cgi?id=15693
 */
#if defined (USE_SSE2) && defined(__GNUC__) && !defined(__x86_64__) && !defined(__amd64__)
__attribute__((__force_align_arg_pointer__))
#endif
PIXMAN_EXPORT void
pixman_image_composite32 (pixman_op_t      op,
                          pixman_image_t * src,
                          pixman_image_t * mask,
                          pixman_image_t * dest,
                          int32_t          src_x,
                          int32_t          src_y,
                          int32_t          mask_x,
                          int32_t          mask_y,
                          int32_t          dest_x,
                          int32_t          dest_y,
                          int32_t          width,
                          int32_t          height)
{
    pixman_format_code_t src_format, mask_format, dest_format;
    pixman_region32_t region;
    pixman_box32_t extents;
    pixman_implementation_t *imp;
    pixman_composite_func_t func;
    pixman_composite_info_t info;
    const pixman_box32_t *pbox;
    int n;

    _pixman_image_validate (src);
    if (mask)
	_pixman_image_validate (mask);
    _pixman_image_validate (dest);

    src_format = src->common.extended_format_code;
    info.src_flags = src->common.flags;

    if (mask && !(mask->common.flags & FAST_PATH_IS_OPAQUE))
    {
	mask_format = mask->common.extended_format_code;
	info.mask_flags = mask->common.flags;
    }
    else
    {
	mask_format = PIXMAN_null;
	info.mask_flags = FAST_PATH_IS_OPAQUE;
    }

    dest_format = dest->common.extended_format_code;
    info.dest_flags = dest->common.flags;

    /* Check for pixbufs */
    if ((mask_format == PIXMAN_a8r8g8b8 || mask_format == PIXMAN_a8b8g8r8) &&
	(src->type == BITS && src->bits.bits == mask->bits.bits)	   &&
	(src->common.repeat == mask->common.repeat)			   &&
	(info.src_flags & info.mask_flags & FAST_PATH_ID_TRANSFORM)	   &&
	(src_x == mask_x && src_y == mask_y))
    {
	if (src_format == PIXMAN_x8b8g8r8)
	    src_format = mask_format = PIXMAN_pixbuf;
	else if (src_format == PIXMAN_x8r8g8b8)
	    src_format = mask_format = PIXMAN_rpixbuf;
    }

    pixman_region32_init (&region);

    if (!_pixman_compute_composite_region32 (
	    &region, src, mask, dest,
	    src_x, src_y, mask_x, mask_y, dest_x, dest_y, width, height))
    {
	goto out;
    }

    extents = *pixman_region32_extents (&region);

    extents.x1 -= dest_x - src_x;
    extents.y1 -= dest_y - src_y;
    extents.x2 -= dest_x - src_x;
    extents.y2 -= dest_y - src_y;

    if (!analyze_extent (src, &extents, &info.src_flags))
	goto out;

    extents.x1 -= src_x - mask_x;
    extents.y1 -= src_y - mask_y;
    extents.x2 -= src_x - mask_x;
    extents.y2 -= src_y - mask_y;

    if (!analyze_extent (mask, &extents, &info.mask_flags))
	goto out;

    /* If the clip is within the source samples, and the samples are
     * opaque, then the source is effectively opaque.
     */
#define NEAREST_OPAQUE	(FAST_PATH_SAMPLES_OPAQUE |			\
			 FAST_PATH_NEAREST_FILTER |			\
			 FAST_PATH_SAMPLES_COVER_CLIP_NEAREST)
#define BILINEAR_OPAQUE	(FAST_PATH_SAMPLES_OPAQUE |			\
			 FAST_PATH_BILINEAR_FILTER |			\
			 FAST_PATH_SAMPLES_COVER_CLIP_BILINEAR)

    if ((info.src_flags & NEAREST_OPAQUE) == NEAREST_OPAQUE ||
	(info.src_flags & BILINEAR_OPAQUE) == BILINEAR_OPAQUE)
    {
	info.src_flags |= FAST_PATH_IS_OPAQUE;
    }

    if ((info.mask_flags & NEAREST_OPAQUE) == NEAREST_OPAQUE ||
	(info.mask_flags & BILINEAR_OPAQUE) == BILINEAR_OPAQUE)
    {
	info.mask_flags |= FAST_PATH_IS_OPAQUE;
    }

    /*
     * Check if we can replace our operator by a simpler one
     * if the src or dest are opaque. The output operator should be
     * mathematically equivalent to the source.
     */
    info.op = optimize_operator (op, info.src_flags, info.mask_flags, info.dest_flags);

    _pixman_implementation_lookup_composite (
	get_implementation (), info.op,
	src_format, info.src_flags,
	mask_format, info.mask_flags,
	dest_format, info.dest_flags,
	&imp, &func);

    info.src_image = src;
    info.mask_image = mask;
    info.dest_image = dest;

    pbox = pixman_region32_rectangles (&region, &n);

    while (n--)
    {
	info.src_x = pbox->x1 + src_x - dest_x;
	info.src_y = pbox->y1 + src_y - dest_y;
	info.mask_x = pbox->x1 + mask_x - dest_x;
	info.mask_y = pbox->y1 + mask_y - dest_y;
	info.dest_x = pbox->x1;
	info.dest_y = pbox->y1;
	info.width = pbox->x2 - pbox->x1;
	info.height = pbox->y2 - pbox->y1;

	func (imp, &info);

	pbox++;
    }

out:
    pixman_region32_fini (&region);
}

PIXMAN_EXPORT void
pixman_image_composite (pixman_op_t      op,
                        pixman_image_t * src,
                        pixman_image_t * mask,
                        pixman_image_t * dest,
                        int16_t          src_x,
                        int16_t          src_y,
                        int16_t          mask_x,
                        int16_t          mask_y,
                        int16_t          dest_x,
                        int16_t          dest_y,
                        uint16_t         width,
                        uint16_t         height)
{
    pixman_image_composite32 (op, src, mask, dest, src_x, src_y, 
                              mask_x, mask_y, dest_x, dest_y, width, height);
}

PIXMAN_EXPORT pixman_bool_t
pixman_blt (uint32_t *src_bits,
            uint32_t *dst_bits,
            int       src_stride,
            int       dst_stride,
            int       src_bpp,
            int       dst_bpp,
            int       src_x,
            int       src_y,
            int       dest_x,
            int       dest_y,
            int       width,
            int       height)
{
    return _pixman_implementation_blt (get_implementation(),
				       src_bits, dst_bits, src_stride, dst_stride,
                                       src_bpp, dst_bpp,
                                       src_x, src_y,
                                       dest_x, dest_y,
                                       width, height);
}

PIXMAN_EXPORT pixman_bool_t
pixman_fill (uint32_t *bits,
             int       stride,
             int       bpp,
             int       x,
             int       y,
             int       width,
             int       height,
             uint32_t  filler)
{
    return _pixman_implementation_fill (
	get_implementation(), bits, stride, bpp, x, y, width, height, filler);
}

static uint32_t
color_to_uint32 (const pixman_color_t *color)
{
    return
        (color->alpha >> 8 << 24) |
        (color->red >> 8 << 16) |
        (color->green & 0xff00) |
        (color->blue >> 8);
}

static pixman_bool_t
color_to_pixel (const pixman_color_t *color,
                uint32_t *            pixel,
                pixman_format_code_t  format)
{
    uint32_t c = color_to_uint32 (color);

    if (!(format == PIXMAN_a8r8g8b8     ||
          format == PIXMAN_x8r8g8b8     ||
          format == PIXMAN_a8b8g8r8     ||
          format == PIXMAN_x8b8g8r8     ||
          format == PIXMAN_b8g8r8a8     ||
          format == PIXMAN_b8g8r8x8     ||
          format == PIXMAN_r8g8b8a8     ||
          format == PIXMAN_r8g8b8x8     ||
          format == PIXMAN_r5g6b5       ||
          format == PIXMAN_b5g6r5       ||
          format == PIXMAN_a8           ||
          format == PIXMAN_a1))
    {
	return FALSE;
    }

    if (PIXMAN_FORMAT_TYPE (format) == PIXMAN_TYPE_ABGR)
    {
	c = ((c & 0xff000000) >>  0) |
	    ((c & 0x00ff0000) >> 16) |
	    ((c & 0x0000ff00) >>  0) |
	    ((c & 0x000000ff) << 16);
    }
    if (PIXMAN_FORMAT_TYPE (format) == PIXMAN_TYPE_BGRA)
    {
	c = ((c & 0xff000000) >> 24) |
	    ((c & 0x00ff0000) >>  8) |
	    ((c & 0x0000ff00) <<  8) |
	    ((c & 0x000000ff) << 24);
    }
    if (PIXMAN_FORMAT_TYPE (format) == PIXMAN_TYPE_RGBA)
	c = ((c & 0xff000000) >> 24) | (c << 8);

    if (format == PIXMAN_a1)
	c = c >> 31;
    else if (format == PIXMAN_a8)
	c = c >> 24;
    else if (format == PIXMAN_r5g6b5 ||
             format == PIXMAN_b5g6r5)
	c = convert_8888_to_0565 (c);

#if 0
    printf ("color: %x %x %x %x\n", color->alpha, color->red, color->green, color->blue);
    printf ("pixel: %x\n", c);
#endif

    *pixel = c;
    return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_image_fill_rectangles (pixman_op_t                 op,
                              pixman_image_t *            dest,
			      const pixman_color_t *      color,
                              int                         n_rects,
                              const pixman_rectangle16_t *rects)
{
    pixman_box32_t stack_boxes[6];
    pixman_box32_t *boxes;
    pixman_bool_t result;
    int i;

    if (n_rects > 6)
    {
        boxes = pixman_malloc_ab (sizeof (pixman_box32_t), n_rects);
        if (boxes == NULL)
            return FALSE;
    }
    else
    {
        boxes = stack_boxes;
    }

    for (i = 0; i < n_rects; ++i)
    {
        boxes[i].x1 = rects[i].x;
        boxes[i].y1 = rects[i].y;
        boxes[i].x2 = boxes[i].x1 + rects[i].width;
        boxes[i].y2 = boxes[i].y1 + rects[i].height;
    }

    result = pixman_image_fill_boxes (op, dest, color, n_rects, boxes);

    if (boxes != stack_boxes)
        free (boxes);
    
    return result;
}

PIXMAN_EXPORT pixman_bool_t
pixman_image_fill_boxes (pixman_op_t           op,
                         pixman_image_t *      dest,
                         const pixman_color_t *color,
                         int                   n_boxes,
                         const pixman_box32_t *boxes)
{
    pixman_image_t *solid;
    pixman_color_t c;
    int i;

    _pixman_image_validate (dest);
    
    if (color->alpha == 0xffff)
    {
        if (op == PIXMAN_OP_OVER)
            op = PIXMAN_OP_SRC;
    }

    if (op == PIXMAN_OP_CLEAR)
    {
        c.red = 0;
        c.green = 0;
        c.blue = 0;
        c.alpha = 0;

        color = &c;

        op = PIXMAN_OP_SRC;
    }

    if (op == PIXMAN_OP_SRC)
    {
        uint32_t pixel;

        if (color_to_pixel (color, &pixel, dest->bits.format))
        {
            pixman_region32_t fill_region;
            int n_rects, j;
            pixman_box32_t *rects;

            if (!pixman_region32_init_rects (&fill_region, boxes, n_boxes))
                return FALSE;

            if (dest->common.have_clip_region)
            {
                if (!pixman_region32_intersect (&fill_region,
                                                &fill_region,
                                                &dest->common.clip_region))
                    return FALSE;
            }

            rects = pixman_region32_rectangles (&fill_region, &n_rects);
            for (j = 0; j < n_rects; ++j)
            {
                const pixman_box32_t *rect = &(rects[j]);
                pixman_fill (dest->bits.bits, dest->bits.rowstride, PIXMAN_FORMAT_BPP (dest->bits.format),
                             rect->x1, rect->y1, rect->x2 - rect->x1, rect->y2 - rect->y1,
                             pixel);
            }

            pixman_region32_fini (&fill_region);
            return TRUE;
        }
    }

    solid = pixman_image_create_solid_fill (color);
    if (!solid)
        return FALSE;

    for (i = 0; i < n_boxes; ++i)
    {
        const pixman_box32_t *box = &(boxes[i]);

        pixman_image_composite32 (op, solid, NULL, dest,
                                  0, 0, 0, 0,
                                  box->x1, box->y1,
                                  box->x2 - box->x1, box->y2 - box->y1);
    }

    pixman_image_unref (solid);

    return TRUE;
}

/**
 * pixman_version:
 *
 * Returns the version of the pixman library encoded in a single
 * integer as per %PIXMAN_VERSION_ENCODE. The encoding ensures that
 * later versions compare greater than earlier versions.
 *
 * A run-time comparison to check that pixman's version is greater than
 * or equal to version X.Y.Z could be performed as follows:
 *
 * <informalexample><programlisting>
 * if (pixman_version() >= PIXMAN_VERSION_ENCODE(X,Y,Z)) {...}
 * </programlisting></informalexample>
 *
 * See also pixman_version_string() as well as the compile-time
 * equivalents %PIXMAN_VERSION and %PIXMAN_VERSION_STRING.
 *
 * Return value: the encoded version.
 **/
PIXMAN_EXPORT int
pixman_version (void)
{
    return PIXMAN_VERSION;
}

/**
 * pixman_version_string:
 *
 * Returns the version of the pixman library as a human-readable string
 * of the form "X.Y.Z".
 *
 * See also pixman_version() as well as the compile-time equivalents
 * %PIXMAN_VERSION_STRING and %PIXMAN_VERSION.
 *
 * Return value: a string containing the version.
 **/
PIXMAN_EXPORT const char*
pixman_version_string (void)
{
    return PIXMAN_VERSION_STRING;
}

/**
 * pixman_format_supported_source:
 * @format: A pixman_format_code_t format
 *
 * Return value: whether the provided format code is a supported
 * format for a pixman surface used as a source in
 * rendering.
 *
 * Currently, all pixman_format_code_t values are supported.
 **/
PIXMAN_EXPORT pixman_bool_t
pixman_format_supported_source (pixman_format_code_t format)
{
    switch (format)
    {
    /* 32 bpp formats */
    case PIXMAN_a2b10g10r10:
    case PIXMAN_x2b10g10r10:
    case PIXMAN_a2r10g10b10:
    case PIXMAN_x2r10g10b10:
    case PIXMAN_a8r8g8b8:
    case PIXMAN_a8r8g8b8_sRGB:
    case PIXMAN_x8r8g8b8:
    case PIXMAN_a8b8g8r8:
    case PIXMAN_x8b8g8r8:
    case PIXMAN_b8g8r8a8:
    case PIXMAN_b8g8r8x8:
    case PIXMAN_r8g8b8a8:
    case PIXMAN_r8g8b8x8:
    case PIXMAN_r8g8b8:
    case PIXMAN_b8g8r8:
    case PIXMAN_r5g6b5:
    case PIXMAN_b5g6r5:
    case PIXMAN_x14r6g6b6:
    /* 16 bpp formats */
    case PIXMAN_a1r5g5b5:
    case PIXMAN_x1r5g5b5:
    case PIXMAN_a1b5g5r5:
    case PIXMAN_x1b5g5r5:
    case PIXMAN_a4r4g4b4:
    case PIXMAN_x4r4g4b4:
    case PIXMAN_a4b4g4r4:
    case PIXMAN_x4b4g4r4:
    /* 8bpp formats */
    case PIXMAN_a8:
    case PIXMAN_r3g3b2:
    case PIXMAN_b2g3r3:
    case PIXMAN_a2r2g2b2:
    case PIXMAN_a2b2g2r2:
    case PIXMAN_c8:
    case PIXMAN_g8:
    case PIXMAN_x4a4:
    /* Collides with PIXMAN_c8
       case PIXMAN_x4c4:
     */
    /* Collides with PIXMAN_g8
       case PIXMAN_x4g4:
     */
    /* 4bpp formats */
    case PIXMAN_a4:
    case PIXMAN_r1g2b1:
    case PIXMAN_b1g2r1:
    case PIXMAN_a1r1g1b1:
    case PIXMAN_a1b1g1r1:
    case PIXMAN_c4:
    case PIXMAN_g4:
    /* 1bpp formats */
    case PIXMAN_a1:
    case PIXMAN_g1:
    /* YUV formats */
    case PIXMAN_yuy2:
    case PIXMAN_yv12:
	return TRUE;

    default:
	return FALSE;
    }
}

/**
 * pixman_format_supported_destination:
 * @format: A pixman_format_code_t format
 *
 * Return value: whether the provided format code is a supported
 * format for a pixman surface used as a destination in
 * rendering.
 *
 * Currently, all pixman_format_code_t values are supported
 * except for the YUV formats.
 **/
PIXMAN_EXPORT pixman_bool_t
pixman_format_supported_destination (pixman_format_code_t format)
{
    /* YUV formats cannot be written to at the moment */
    if (format == PIXMAN_yuy2 || format == PIXMAN_yv12)
	return FALSE;

    return pixman_format_supported_source (format);
}

PIXMAN_EXPORT pixman_bool_t
pixman_compute_composite_region (pixman_region16_t * region,
                                 pixman_image_t *    src_image,
                                 pixman_image_t *    mask_image,
                                 pixman_image_t *    dest_image,
                                 int16_t             src_x,
                                 int16_t             src_y,
                                 int16_t             mask_x,
                                 int16_t             mask_y,
                                 int16_t             dest_x,
                                 int16_t             dest_y,
                                 uint16_t            width,
                                 uint16_t            height)
{
    pixman_region32_t r32;
    pixman_bool_t retval;

    pixman_region32_init (&r32);

    retval = _pixman_compute_composite_region32 (
	&r32, src_image, mask_image, dest_image,
	src_x, src_y, mask_x, mask_y, dest_x, dest_y,
	width, height);

    if (retval)
    {
	if (!pixman_region16_copy_from_region32 (region, &r32))
	    retval = FALSE;
    }

    pixman_region32_fini (&r32);
    return retval;
}