aboutsummaryrefslogtreecommitdiff
path: root/xorg-server/dix/gc.c
blob: 64901659539f3ed4e9a41f917cbf02f3969abc24 (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
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
/***********************************************************

Copyright 1987, 1998  The Open Group

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.

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.


Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
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 Digital not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.  

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL 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.

******************************************************************/


#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <X11/X.h>
#include <X11/Xmd.h>
#include <X11/Xproto.h>
#include "misc.h"
#include "resource.h"
#include "gcstruct.h"
#include "pixmapstr.h"
#include "dixfontstr.h"
#include "scrnintstr.h"
#include "region.h"

#include "privates.h"
#include "dix.h"
#include "xace.h"
#include <assert.h>

extern XID clientErrorValue;
extern FontPtr defaultFont;

static Bool CreateDefaultTile(GCPtr pGC);

static unsigned char DefaultDash[2] = {4, 4};

void
ValidateGC(DrawablePtr pDraw, GC *pGC)
{
    (*pGC->funcs->ValidateGC) (pGC, pGC->stateChanges, pDraw);
    pGC->stateChanges = 0;
    pGC->serialNumber = pDraw->serialNumber;
}


/* dixChangeGC(client, pGC, mask, pC32, pUnion)
 * 
 * This function was created as part of the Security extension
 * implementation.  The client performing the gc change must be passed so
 * that access checks can be performed on any tiles, stipples, or fonts
 * that are specified.  ddxen can call this too; they should normally
 * pass NullClient for the client since any access checking should have
 * already been done at a higher level.
 * 
 * Since we had to create a new function anyway, we decided to change the
 * way the list of gc values is passed to eliminate the compiler warnings
 * caused by the DoChangeGC interface.  You can pass the values via pC32
 * or pUnion, but not both; one of them must be NULL.  If you don't need
 * to pass any pointers, you can use either one:
 * 
 *     example calling dixChangeGC using pC32 parameter
 *
 *     CARD32 v[2];
 *     v[0] = foreground;
 *     v[1] = background;
 *     dixChangeGC(client, pGC, GCForeground|GCBackground, v, NULL);
 * 
 *     example calling dixChangeGC using pUnion parameter;
 *     same effect as above
 *
 *     ChangeGCVal v[2];
 *     v[0].val = foreground;
 *     v[1].val = background;
 *     dixChangeGC(client, pGC, GCForeground|GCBackground, NULL, v);
 * 
 * However, if you need to pass a pointer to a pixmap or font, you MUST
 * use the pUnion parameter.
 * 
 *     example calling dixChangeGC passing pointers in the value list
 *     v[1].ptr is a pointer to a pixmap
 *
 *     ChangeGCVal v[2];
 *     v[0].val = FillTiled;
 *     v[1].ptr = pPixmap;
 *     dixChangeGC(client, pGC, GCFillStyle|GCTile, NULL, v);
 * 
 * Note: we could have gotten by with just the pUnion parameter, but on
 * 64 bit machines that would have forced us to copy the value list that
 * comes in the ChangeGC request.
 * 
 * Ideally, we'd change all the DoChangeGC calls to dixChangeGC, but this
 * is far too many changes to consider at this time, so we've only
 * changed the ones that caused compiler warnings.  New code should use
 * dixChangeGC.
 * 
 * dpw
 */

#define NEXTVAL(_type, _var) { \
      if (pC32) _var = (_type)*pC32++; \
      else { \
	_var = (_type)(pUnion->val); pUnion++; \
      } \
    }

#define NEXT_PTR(_type, _var) { \
    assert(pUnion); _var = (_type)pUnion->ptr; pUnion++; }

int
dixChangeGC(ClientPtr client, GC *pGC, BITS32 mask, CARD32 *pC32, ChangeGCValPtr pUnion)
{
    BITS32 	index2;
    int 	rc, error = 0;
    PixmapPtr 	pPixmap;
    BITS32	maskQ;

    assert( (pC32 && !pUnion) || (!pC32 && pUnion) );
    pGC->serialNumber |= GC_CHANGE_SERIAL_BIT;

    maskQ = mask;	/* save these for when we walk the GCque */
    while (mask && !error) 
    {
	index2 = (BITS32) lowbit (mask);
	mask &= ~index2;
	pGC->stateChanges |= index2;
	switch (index2)
	{
	    case GCFunction:
	    {
		CARD8 newalu;
		NEXTVAL(CARD8, newalu);
		if (newalu <= GXset)
		    pGC->alu = newalu;
		else
		{
		    clientErrorValue = newalu;
		    error = BadValue;
		}
		break;
	    }
	    case GCPlaneMask:
		NEXTVAL(unsigned long, pGC->planemask);
		break;
	    case GCForeground:
		NEXTVAL(unsigned long, pGC->fgPixel);
		/*
		 * this is for CreateGC
		 */
		if (!pGC->tileIsPixel && !pGC->tile.pixmap)
		{
		    pGC->tileIsPixel = TRUE;
		    pGC->tile.pixel = pGC->fgPixel;
		}
		break;
	    case GCBackground:
		NEXTVAL(unsigned long, pGC->bgPixel);
		break;
	    case GCLineWidth:		/* ??? line width is a CARD16 */
		 NEXTVAL(CARD16, pGC->lineWidth);
		break;
	    case GCLineStyle:
	    {
		unsigned int newlinestyle;
		NEXTVAL(unsigned int, newlinestyle);
		if (newlinestyle <= LineDoubleDash)
		    pGC->lineStyle = newlinestyle;
		else
		{
		    clientErrorValue = newlinestyle;
		    error = BadValue;
		}
		break;
	    }
	    case GCCapStyle:
	    {
		unsigned int newcapstyle;
		NEXTVAL(unsigned int, newcapstyle);
		if (newcapstyle <= CapProjecting)
		    pGC->capStyle = newcapstyle;
		else
		{
		    clientErrorValue = newcapstyle;
		    error = BadValue;
		}
		break;
	    }
	    case GCJoinStyle:
	    {
		unsigned int newjoinstyle;
		NEXTVAL(unsigned int, newjoinstyle);
		if (newjoinstyle <= JoinBevel)
		    pGC->joinStyle = newjoinstyle;
		else
		{
		    clientErrorValue = newjoinstyle;
		    error = BadValue;
		}
		break;
	    }
	    case GCFillStyle:
	    {
		unsigned int newfillstyle;
		NEXTVAL(unsigned int, newfillstyle);
		if (newfillstyle <= FillOpaqueStippled)
		    pGC->fillStyle = newfillstyle;
		else
		{
		    clientErrorValue = newfillstyle;
		    error = BadValue;
		}
		break;
	    }
	    case GCFillRule:
	    {
		unsigned int newfillrule;
		NEXTVAL(unsigned int, newfillrule);
		if (newfillrule <= WindingRule)
		    pGC->fillRule = newfillrule;
		else
		{
		    clientErrorValue = newfillrule;
		    error = BadValue;
		}
		break;
	    }
	    case GCTile:
	    {
		XID newpix = 0;
		if (pUnion)
		{
		    NEXT_PTR(PixmapPtr, pPixmap);
		    rc = Success;
		}
		else
		{
		    NEXTVAL(XID, newpix);
		    rc = dixLookupResourceByType((pointer *)&pPixmap, newpix,
					   RT_PIXMAP, client, DixReadAccess);
		}
		if (rc == Success)
		{
		    if ((pPixmap->drawable.depth != pGC->depth) ||
			(pPixmap->drawable.pScreen != pGC->pScreen))
		    {
			error = BadMatch;
		    }
		    else
		    {
			pPixmap->refcnt++;
			if (!pGC->tileIsPixel)
			    (* pGC->pScreen->DestroyPixmap)(pGC->tile.pixmap);
			pGC->tileIsPixel = FALSE;
			pGC->tile.pixmap = pPixmap;
		    }
		}
		else
		{
		    clientErrorValue = newpix;
		    error = (rc == BadValue) ? BadPixmap : rc;
		}
		break;
	    }
	    case GCStipple:
	    {
		XID newstipple = 0;
		if (pUnion)
		{
		    NEXT_PTR(PixmapPtr, pPixmap);
		    rc = Success;
		}
		else
		{
		    NEXTVAL(XID, newstipple)
		    rc = dixLookupResourceByType((pointer *)&pPixmap, newstipple,
					   RT_PIXMAP, client, DixReadAccess);
		}
		if (rc == Success)
		{
		    if ((pPixmap->drawable.depth != 1) ||
			(pPixmap->drawable.pScreen != pGC->pScreen))
		    {
			error = BadMatch;
		    }
		    else
		    {
			pPixmap->refcnt++;
			if (pGC->stipple)
			    (* pGC->pScreen->DestroyPixmap)(pGC->stipple);
			pGC->stipple = pPixmap;
		    }
		}
		else
		{
		    clientErrorValue = newstipple;
		    error = (rc == BadValue) ? BadPixmap : rc;
		}
		break;
	    }
	    case GCTileStipXOrigin:
		NEXTVAL(INT16, pGC->patOrg.x);
		break;
	    case GCTileStipYOrigin:
		NEXTVAL(INT16, pGC->patOrg.y);
		break;
	    case GCFont:
    	    {
		FontPtr	pFont;
		XID newfont = 0;
		if (pUnion)
		{
		    NEXT_PTR(FontPtr, pFont);
		    rc = Success;
		}
		else
		{
		    NEXTVAL(XID, newfont)
		    rc = dixLookupResourceByType((pointer *)&pFont, newfont,
					   RT_FONT, client, DixUseAccess);
		}
		if (rc == Success)
		{
		    pFont->refcnt++;
		    if (pGC->font)
    		        CloseFont(pGC->font, (Font)0);
		    pGC->font = pFont;
		 }
		else
		{
		    clientErrorValue = newfont;
		    error = (rc == BadValue) ? BadFont : rc;
		}
		break;
	    }
	    case GCSubwindowMode:
	    {
		unsigned int newclipmode;
		NEXTVAL(unsigned int, newclipmode);
		if (newclipmode <= IncludeInferiors)
		    pGC->subWindowMode = newclipmode;
		else
		{
		    clientErrorValue = newclipmode;
		    error = BadValue;
		}
		break;
	    }
	    case GCGraphicsExposures:
    	    {
		unsigned int newge;
		NEXTVAL(unsigned int, newge);
		if (newge <= xTrue)
		    pGC->graphicsExposures = newge;
		else
		{
		    clientErrorValue = newge;
		    error = BadValue;
		}
		break;
	    }
	    case GCClipXOrigin:
		NEXTVAL(INT16, pGC->clipOrg.x);
		break;
	    case GCClipYOrigin:
		NEXTVAL(INT16, pGC->clipOrg.y);
		break;
	    case GCClipMask:
	    {
		Pixmap pid = 0;
		int    clipType = 0;

		if (pUnion)
		{
		    NEXT_PTR(PixmapPtr, pPixmap);
		}
		else
		{
		    NEXTVAL(Pixmap, pid)
		    if (pid == None)
		    {
			clipType = CT_NONE;
			pPixmap = NullPixmap;
		    }
		    else {
			rc = dixLookupResourceByType((pointer *)&pPixmap, pid,
					       RT_PIXMAP, client,
					       DixReadAccess);
			if (rc != Success) {
			    clientErrorValue = pid;
			    error = (rc == BadValue) ? BadPixmap : rc;
			}
		    }
		}

		if (pPixmap)
		{
		    if ((pPixmap->drawable.depth != 1) ||
			(pPixmap->drawable.pScreen != pGC->pScreen))
		    {
			error = BadMatch;
		    }
		    else
		    {
			clipType = CT_PIXMAP;
			pPixmap->refcnt++;
		    }
		}
		if(error == Success)
		{
		    (*pGC->funcs->ChangeClip)(pGC, clipType,
					      (pointer)pPixmap, 0);
		}
		break;
	    }
	    case GCDashOffset:
		NEXTVAL(INT16, pGC->dashOffset);
		break;
	    case GCDashList:
	    {
		CARD8 newdash;
		NEXTVAL(CARD8, newdash);
		if (newdash == 4)
		{
		    if (pGC->dash != DefaultDash)
		    {
			xfree(pGC->dash);
			pGC->numInDashList = 2;
			pGC->dash = DefaultDash;
		    }
		}
		else if (newdash != 0)
 		{
		    unsigned char *dash;

		    dash = xalloc(2 * sizeof(unsigned char));
		    if (dash)
		    {
			if (pGC->dash != DefaultDash)
			    xfree(pGC->dash);
			pGC->numInDashList = 2;
			pGC->dash = dash;
			dash[0] = newdash;
			dash[1] = newdash;
		    }
		    else
			error = BadAlloc;
		}
 		else
		{
		   clientErrorValue = newdash;
		   error = BadValue;
		}
		break;
	    }
	    case GCArcMode:
	    {
		unsigned int newarcmode;
		NEXTVAL(unsigned int, newarcmode);
		if (newarcmode <= ArcPieSlice)
		    pGC->arcMode = newarcmode;
		else
		{
		    clientErrorValue = newarcmode;
		    error = BadValue;
		}
		break;
	    }
	    default:
		clientErrorValue = maskQ;
		error = BadValue;
		break;
	}
    } /* end while mask && !error */

    if (pGC->fillStyle == FillTiled && pGC->tileIsPixel)
    {
	if (!CreateDefaultTile (pGC))
	{
	    pGC->fillStyle = FillSolid;
	    error = BadAlloc;
	}
    }
    (*pGC->funcs->ChangeGC)(pGC, maskQ);
    return error;
}

#undef NEXTVAL
#undef NEXT_PTR

/* Publically defined entry to ChangeGC.  Just calls dixChangeGC and tells
 * it that all of the entries are constants or IDs */
int
ChangeGC(GC *pGC, BITS32 mask, XID *pval)
{
    return (dixChangeGC(NullClient, pGC, mask, pval, NULL));
}

/* DoChangeGC(pGC, mask, pval, fPointer)
   mask is a set of bits indicating which values to change.
   pval contains an appropriate value for each mask.
   fPointer is true if the values for tiles, stipples, fonts or clipmasks
   are pointers instead of IDs.  Note: if you are passing pointers you
   MUST declare the array of values as type pointer!  Other data types
   may not be large enough to hold pointers on some machines.  Yes,
   this means you have to cast to (XID *) when you pass the array to
   DoChangeGC.  Similarly, if you are not passing pointers (fPointer = 0) you
   MUST declare the array as type XID (not unsigned long!), or again the wrong
   size data type may be used.  To avoid this cruftiness, use dixChangeGC
   above.

   if there is an error, the value is marked as changed 
   anyway, which is probably wrong, but infrequent.

NOTE:
	all values sent over the protocol for ChangeGC requests are
32 bits long
*/
int
DoChangeGC(GC *pGC, BITS32 mask, XID *pval, int fPointer)
{
    if (fPointer)
    /* XXX might be a problem on 64 bit big-endian servers */
	return dixChangeGC(NullClient, pGC, mask, NULL, (ChangeGCValPtr)pval);
    else
	return dixChangeGC(NullClient, pGC, mask, pval, NULL);
}


/* CreateGC(pDrawable, mask, pval, pStatus)
   creates a default GC for the given drawable, using mask to fill
   in any non-default values.
   Returns a pointer to the new GC on success, NULL otherwise.
   returns status of non-default fields in pStatus
BUG:
   should check for failure to create default tile

*/
GCPtr
CreateGC(DrawablePtr pDrawable, BITS32 mask, XID *pval, int *pStatus,
	 XID gcid, ClientPtr client)
{
    GCPtr pGC;

    pGC = xalloc(sizeof(GC));
    if (!pGC)
    {
	*pStatus = BadAlloc;
	return (GCPtr)NULL;
    }

    pGC->pScreen = pDrawable->pScreen;
    pGC->depth = pDrawable->depth;
    pGC->alu = GXcopy; /* dst <- src */
    pGC->planemask = ~0;
    pGC->serialNumber = GC_CHANGE_SERIAL_BIT;
    pGC->funcs = 0;
    pGC->devPrivates = NULL;
    pGC->fgPixel = 0;
    pGC->bgPixel = 1;
    pGC->lineWidth = 0;
    pGC->lineStyle = LineSolid;
    pGC->capStyle = CapButt;
    pGC->joinStyle = JoinMiter;
    pGC->fillStyle = FillSolid;
    pGC->fillRule = EvenOddRule;
    pGC->arcMode = ArcPieSlice;
    pGC->tile.pixel = 0;
    pGC->tile.pixmap = NullPixmap;
    if (mask & GCForeground)
    {
	/*
	 * magic special case -- ChangeGC checks for this condition
	 * and snags the Foreground value to create a pseudo default-tile
	 */
	pGC->tileIsPixel = FALSE;
    }
    else
    {
	pGC->tileIsPixel = TRUE;
    }

    pGC->patOrg.x = 0;
    pGC->patOrg.y = 0;
    pGC->subWindowMode = ClipByChildren;
    pGC->graphicsExposures = TRUE;
    pGC->clipOrg.x = 0;
    pGC->clipOrg.y = 0;
    pGC->clientClipType = CT_NONE;
    pGC->clientClip = (pointer)NULL;
    pGC->numInDashList = 2;
    pGC->dash = DefaultDash;
    pGC->dashOffset = 0;
    pGC->lastWinOrg.x = 0;
    pGC->lastWinOrg.y = 0;

    /* use the default font and stipple */
    pGC->font = defaultFont;
    defaultFont->refcnt++;
    pGC->stipple = pGC->pScreen->PixmapPerDepth[0];
    pGC->stipple->refcnt++;

    /* security creation/labeling check */
    *pStatus = XaceHook(XACE_RESOURCE_ACCESS, client, gcid, RT_GC, pGC,
			RT_NONE, NULL, DixCreateAccess|DixSetAttrAccess);
    if (*pStatus != Success)
	goto out;

    pGC->stateChanges = (1 << (GCLastBit+1)) - 1;
    if (!(*pGC->pScreen->CreateGC)(pGC))
	*pStatus = BadAlloc;
    else if (mask)
        *pStatus = ChangeGC(pGC, mask, pval);
    else
	*pStatus = Success;

out:
    if (*pStatus != Success)
    {
	if (!pGC->tileIsPixel && !pGC->tile.pixmap)
	    pGC->tileIsPixel = TRUE; /* undo special case */
	FreeGC(pGC, (XID)0);
	pGC = (GCPtr)NULL;
    }

    return (pGC);
}

static Bool
CreateDefaultTile (GCPtr pGC)
{
    XID		tmpval[3];
    PixmapPtr 	pTile;
    GCPtr	pgcScratch;
    xRectangle	rect;
    CARD16	w, h;

    w = 1;
    h = 1;
    (*pGC->pScreen->QueryBestSize)(TileShape, &w, &h, pGC->pScreen);
    pTile = (PixmapPtr)
	    (*pGC->pScreen->CreatePixmap)(pGC->pScreen,
					  w, h, pGC->depth, 0);
    pgcScratch = GetScratchGC(pGC->depth, pGC->pScreen);
    if (!pTile || !pgcScratch)
    {
	if (pTile)
	    (*pTile->drawable.pScreen->DestroyPixmap)(pTile);
	if (pgcScratch)
	    FreeScratchGC(pgcScratch);
	return FALSE;
    }
    tmpval[0] = GXcopy;
    tmpval[1] = pGC->tile.pixel;
    tmpval[2] = FillSolid;
    (void)ChangeGC(pgcScratch, GCFunction | GCForeground | GCFillStyle, 
		   tmpval);
    ValidateGC((DrawablePtr)pTile, pgcScratch);
    rect.x = 0;
    rect.y = 0;
    rect.width = w;
    rect.height = h;
    (*pgcScratch->ops->PolyFillRect)((DrawablePtr)pTile, pgcScratch, 1, &rect);
    /* Always remember to free the scratch graphics context after use. */
    FreeScratchGC(pgcScratch);

    pGC->tileIsPixel = FALSE;
    pGC->tile.pixmap = pTile;
    return TRUE;
}

int
CopyGC(GC *pgcSrc, GC *pgcDst, BITS32 mask)
{
    BITS32	index2;
    BITS32	maskQ;
    int 	error = 0;

    if (pgcSrc == pgcDst)
	return Success;
    pgcDst->serialNumber |= GC_CHANGE_SERIAL_BIT;
    pgcDst->stateChanges |= mask;
    maskQ = mask;
    while (mask)
    {
	index2 = (BITS32) lowbit (mask);
	mask &= ~index2;
	switch (index2)
	{
	    case GCFunction:
		pgcDst->alu = pgcSrc->alu;
		break;
	    case GCPlaneMask:
		pgcDst->planemask = pgcSrc->planemask;
		break;
	    case GCForeground:
		pgcDst->fgPixel = pgcSrc->fgPixel;
		break;
	    case GCBackground:
		pgcDst->bgPixel = pgcSrc->bgPixel;
		break;
	    case GCLineWidth:
		pgcDst->lineWidth = pgcSrc->lineWidth;
		break;
	    case GCLineStyle:
		pgcDst->lineStyle = pgcSrc->lineStyle;
		break;
	    case GCCapStyle:
		pgcDst->capStyle = pgcSrc->capStyle;
		break;
	    case GCJoinStyle:
		pgcDst->joinStyle = pgcSrc->joinStyle;
		break;
	    case GCFillStyle:
		pgcDst->fillStyle = pgcSrc->fillStyle;
		break;
	    case GCFillRule:
		pgcDst->fillRule = pgcSrc->fillRule;
		break;
	    case GCTile:
		{
		    if (EqualPixUnion(pgcDst->tileIsPixel,
				      pgcDst->tile,
				      pgcSrc->tileIsPixel,
				      pgcSrc->tile))
		    {
			break;
		    }
		    if (!pgcDst->tileIsPixel)
			(* pgcDst->pScreen->DestroyPixmap)(pgcDst->tile.pixmap);
		    pgcDst->tileIsPixel = pgcSrc->tileIsPixel;
		    pgcDst->tile = pgcSrc->tile;
		    if (!pgcDst->tileIsPixel)
		       pgcDst->tile.pixmap->refcnt++;
		    break;
		}
	    case GCStipple:
		{
		    if (pgcDst->stipple == pgcSrc->stipple)
			break;
		    if (pgcDst->stipple)
			(* pgcDst->pScreen->DestroyPixmap)(pgcDst->stipple);
		    pgcDst->stipple = pgcSrc->stipple;
		    if (pgcDst->stipple)
			pgcDst->stipple->refcnt ++;
		    break;
		}
	    case GCTileStipXOrigin:
		pgcDst->patOrg.x = pgcSrc->patOrg.x;
		break;
	    case GCTileStipYOrigin:
		pgcDst->patOrg.y = pgcSrc->patOrg.y;
		break;
	    case GCFont:
		if (pgcDst->font == pgcSrc->font)
		    break;
		if (pgcDst->font)
		    CloseFont(pgcDst->font, (Font)0);
		if ((pgcDst->font = pgcSrc->font) != NullFont)
		    (pgcDst->font)->refcnt++;
		break;
	    case GCSubwindowMode:
		pgcDst->subWindowMode = pgcSrc->subWindowMode;
		break;
	    case GCGraphicsExposures:
		pgcDst->graphicsExposures = pgcSrc->graphicsExposures;
		break;
	    case GCClipXOrigin:
		pgcDst->clipOrg.x = pgcSrc->clipOrg.x;
		break;
	    case GCClipYOrigin:
		pgcDst->clipOrg.y = pgcSrc->clipOrg.y;
		break;
	    case GCClipMask:
		(* pgcDst->funcs->CopyClip)(pgcDst, pgcSrc);
		break;
	    case GCDashOffset:
		pgcDst->dashOffset = pgcSrc->dashOffset;
		break;
	    case GCDashList:
		if (pgcSrc->dash == DefaultDash)
		{
		    if (pgcDst->dash != DefaultDash)
		    {
			xfree(pgcDst->dash);
			pgcDst->numInDashList = pgcSrc->numInDashList;
			pgcDst->dash = pgcSrc->dash;
		    }
		}
		else
		{
		    unsigned char *dash;
		    unsigned int i;

		    dash = xalloc(pgcSrc->numInDashList * sizeof(unsigned char));
		    if (dash)
		    {
			if (pgcDst->dash != DefaultDash)
			    xfree(pgcDst->dash);
			pgcDst->numInDashList = pgcSrc->numInDashList;
			pgcDst->dash = dash;
			for (i=0; i<pgcSrc->numInDashList; i++)
			    dash[i] = pgcSrc->dash[i];
		    }
		    else
			error = BadAlloc;
		}
		break;
	    case GCArcMode:
		pgcDst->arcMode = pgcSrc->arcMode;
		break;
	    default:
		clientErrorValue = maskQ;
		error = BadValue;
		break;
	}
    }
    if (pgcDst->fillStyle == FillTiled && pgcDst->tileIsPixel)
    {
	if (!CreateDefaultTile (pgcDst))
	{
	    pgcDst->fillStyle = FillSolid;
	    error = BadAlloc;
	}
    }
    (*pgcDst->funcs->CopyGC) (pgcSrc, maskQ, pgcDst);
    return error;
}

/**
 * does the diX part of freeing the characteristics in the GC.
 *
 *  \param value  must conform to DeleteType
 */
int
FreeGC(pointer value, XID gid)
{
    GCPtr pGC = (GCPtr)value;

    CloseFont(pGC->font, (Font)0);
    (* pGC->funcs->DestroyClip)(pGC);

    if (!pGC->tileIsPixel)
	(* pGC->pScreen->DestroyPixmap)(pGC->tile.pixmap);
    if (pGC->stipple)
	(* pGC->pScreen->DestroyPixmap)(pGC->stipple);

    (*pGC->funcs->DestroyGC) (pGC);
    if (pGC->dash != DefaultDash)
	xfree(pGC->dash);
    dixFreePrivates(pGC->devPrivates);
    xfree(pGC);
    return(Success);
}

/* CreateScratchGC(pScreen, depth)
    like CreateGC, but doesn't do the default tile or stipple,
since we can't create them without already having a GC.  any code
using the tile or stipple has to set them explicitly anyway,
since the state of the scratch gc is unknown.  This is OK
because ChangeGC() has to be able to deal with NULL tiles and
stipples anyway (in case the CreateGC() call has provided a 
value for them -- we can't set the default tile until the
client-supplied attributes are installed, since the fgPixel
is what fills the default tile.  (maybe this comment should
go with CreateGC() or ChangeGC().)
*/

GCPtr
CreateScratchGC(ScreenPtr pScreen, unsigned depth)
{
    GCPtr pGC;

    pGC = xalloc(sizeof(GC));
    if (!pGC)
	return (GCPtr)NULL;

    pGC->pScreen = pScreen;
    pGC->depth = depth;
    pGC->alu = GXcopy; /* dst <- src */
    pGC->planemask = ~0;
    pGC->serialNumber = 0;
    pGC->devPrivates = NULL;
    pGC->fgPixel = 0;
    pGC->bgPixel = 1;
    pGC->lineWidth = 0;
    pGC->lineStyle = LineSolid;
    pGC->capStyle = CapButt;
    pGC->joinStyle = JoinMiter;
    pGC->fillStyle = FillSolid;
    pGC->fillRule = EvenOddRule;
    pGC->arcMode = ArcPieSlice;
    pGC->font = defaultFont;
    if ( pGC->font)  /* necessary, because open of default font could fail */
	pGC->font->refcnt++;
    pGC->tileIsPixel = TRUE;
    pGC->tile.pixel = 0;
    pGC->tile.pixmap = NullPixmap;
    pGC->stipple = NullPixmap;
    pGC->patOrg.x = 0;
    pGC->patOrg.y = 0;
    pGC->subWindowMode = ClipByChildren;
    pGC->graphicsExposures = TRUE;
    pGC->clipOrg.x = 0;
    pGC->clipOrg.y = 0;
    pGC->clientClipType = CT_NONE;
    pGC->dashOffset = 0;
    pGC->numInDashList = 2;
    pGC->dash = DefaultDash;
    pGC->lastWinOrg.x = 0;
    pGC->lastWinOrg.y = 0;

    pGC->stateChanges = (1 << (GCLastBit+1)) - 1;
    if (!(*pScreen->CreateGC)(pGC))
    {
	FreeGC(pGC, (XID)0);
	pGC = (GCPtr)NULL;
    }
    return pGC;
}

void
FreeGCperDepth(int screenNum)
{
    int i;
    ScreenPtr pScreen;
    GCPtr *ppGC;

    pScreen = screenInfo.screens[screenNum];
    ppGC = pScreen->GCperDepth;

    for (i = 0; i <= pScreen->numDepths; i++)
	(void)FreeGC(ppGC[i], (XID)0);
    pScreen->rgf = ~0L;
}


Bool
CreateGCperDepth(int screenNum)
{
    int i;
    ScreenPtr pScreen;
    DepthPtr pDepth;
    GCPtr *ppGC;

    pScreen = screenInfo.screens[screenNum];
    pScreen->rgf = 0;
    ppGC = pScreen->GCperDepth;
    /* do depth 1 separately because it's not included in list */
    if (!(ppGC[0] = CreateScratchGC(pScreen, 1)))
	return FALSE;
    ppGC[0]->graphicsExposures = FALSE;
    /* Make sure we don't overflow GCperDepth[] */
    if( pScreen->numDepths > MAXFORMATS )
	    return FALSE;

    pDepth = pScreen->allowedDepths;
    for (i=0; i<pScreen->numDepths; i++, pDepth++)
    {
	if (!(ppGC[i+1] = CreateScratchGC(pScreen, pDepth->depth)))
	{
	    for (; i >= 0; i--)
		(void)FreeGC(ppGC[i], (XID)0);
	    return FALSE;
	}
	ppGC[i+1]->graphicsExposures = FALSE;
    }
    return TRUE;
}

Bool
CreateDefaultStipple(int screenNum)
{
    ScreenPtr pScreen;
    XID tmpval[3];
    xRectangle rect;
    CARD16 w, h;
    GCPtr pgcScratch;

    pScreen = screenInfo.screens[screenNum];

    w = 16;
    h = 16;
    (* pScreen->QueryBestSize)(StippleShape, &w, &h, pScreen);
    if (!(pScreen->PixmapPerDepth[0] =
			(*pScreen->CreatePixmap)(pScreen, w, h, 1, 0)))
	return FALSE;
    /* fill stipple with 1 */
    tmpval[0] = GXcopy; tmpval[1] = 1; tmpval[2] = FillSolid;
    pgcScratch = GetScratchGC(1, pScreen);
    if (!pgcScratch)
    {
	(*pScreen->DestroyPixmap)(pScreen->PixmapPerDepth[0]);
	return FALSE;
    }
    (void)ChangeGC(pgcScratch, GCFunction|GCForeground|GCFillStyle, tmpval);
    ValidateGC((DrawablePtr)pScreen->PixmapPerDepth[0], pgcScratch);
    rect.x = 0;
    rect.y = 0;
    rect.width = w;
    rect.height = h;
    (*pgcScratch->ops->PolyFillRect)((DrawablePtr)pScreen->PixmapPerDepth[0], 
				     pgcScratch, 1, &rect);
    FreeScratchGC(pgcScratch);
    return TRUE;
}

void
FreeDefaultStipple(int screenNum)
{
    ScreenPtr pScreen = screenInfo.screens[screenNum];
    (*pScreen->DestroyPixmap)(pScreen->PixmapPerDepth[0]);
}

int
SetDashes(GCPtr pGC, unsigned offset, unsigned ndash, unsigned char *pdash)
{
    long i;
    unsigned char *p, *indash;
    BITS32 maskQ = 0;

    i = ndash;
    p = pdash;
    while (i--)
    {
	if (!*p++)
	{
	    /* dash segment must be > 0 */
	    clientErrorValue = 0;
	    return BadValue;
	}
    }

    if (ndash & 1)
	p = xalloc(2 * ndash * sizeof(unsigned char));
    else
	p = xalloc(ndash * sizeof(unsigned char));
    if (!p)
	return BadAlloc;

    pGC->serialNumber |= GC_CHANGE_SERIAL_BIT;
    if (offset != pGC->dashOffset)
    {
	pGC->dashOffset = offset;
	pGC->stateChanges |= GCDashOffset;
	maskQ |= GCDashOffset;
    }

    if (pGC->dash != DefaultDash)
	xfree(pGC->dash);
    pGC->numInDashList = ndash;
    pGC->dash = p;
    if (ndash & 1)
    {
	pGC->numInDashList += ndash;
	indash = pdash;
	i = ndash;
	while (i--)
	    *p++ = *indash++;
    }
    while(ndash--)
	*p++ = *pdash++;
    pGC->stateChanges |= GCDashList;
    maskQ |= GCDashList;

    if (pGC->funcs->ChangeGC)
	(*pGC->funcs->ChangeGC) (pGC, maskQ);
    return Success;
}

int
VerifyRectOrder(int nrects, xRectangle *prects, int ordering)
{
    xRectangle	*prectP, *prectN;
    int	i;

    switch(ordering)
    {
      case Unsorted:
	  return CT_UNSORTED;
      case YSorted:
	  if(nrects > 1)
	  {
	      for(i = 1, prectP = prects, prectN = prects + 1;
		  i < nrects;
		  i++, prectP++, prectN++)
		  if(prectN->y < prectP->y)
		      return -1;
	  }
	  return CT_YSORTED;
      case YXSorted:
	  if(nrects > 1)
	  {
	      for(i = 1, prectP = prects, prectN = prects + 1;
		  i < nrects;
		  i++, prectP++, prectN++)
		  if((prectN->y < prectP->y) ||
		      ( (prectN->y == prectP->y) &&
		        (prectN->x < prectP->x) ) )
		      return -1;
	  }
	  return CT_YXSORTED;
      case YXBanded:
	  if(nrects > 1)
	  {
	      for(i = 1, prectP = prects, prectN = prects + 1;
		  i < nrects;
		  i++, prectP++, prectN++)
		  if((prectN->y != prectP->y &&
 		      prectN->y < prectP->y + (int) prectP->height) ||
		     ((prectN->y == prectP->y) &&
		      (prectN->height != prectP->height ||
		       prectN->x < prectP->x + (int) prectP->width)))
		      return -1;
	  }
	  return CT_YXBANDED;
    }
    return -1;
}

int
SetClipRects(GCPtr pGC, int xOrigin, int yOrigin, int nrects, 
             xRectangle *prects, int ordering)
{
    int			newct, size;
    xRectangle 		*prectsNew;

    newct = VerifyRectOrder(nrects, prects, ordering);
    if (newct < 0)
	return(BadMatch);
    size = nrects * sizeof(xRectangle);
    prectsNew = xalloc(size);
    if (!prectsNew && size)
	return BadAlloc;

    pGC->serialNumber |= GC_CHANGE_SERIAL_BIT;
    pGC->clipOrg.x = xOrigin;
    pGC->stateChanges |= GCClipXOrigin;
		 
    pGC->clipOrg.y = yOrigin;
    pGC->stateChanges |= GCClipYOrigin;

    if (size)
	memmove((char *)prectsNew, (char *)prects, size);
    (*pGC->funcs->ChangeClip)(pGC, newct, (pointer)prectsNew, nrects);
    if (pGC->funcs->ChangeGC)
	(*pGC->funcs->ChangeGC) (pGC, GCClipXOrigin|GCClipYOrigin|GCClipMask);
    return Success;
}


/*
   sets reasonable defaults 
   if we can get a pre-allocated one, use it and mark it as used.
   if we can't, create one out of whole cloth (The Velveteen GC -- if
   you use it often enough it will become real.)
*/
GCPtr
GetScratchGC(unsigned depth, ScreenPtr pScreen)
{
    int i;
    GCPtr pGC;

    for (i=0; i<=pScreen->numDepths; i++)
        if ( pScreen->GCperDepth[i]->depth == depth &&
	     !(pScreen->rgf & (1L << (i+1)))
	   )
	{
	    pScreen->rgf |= (1L << (i+1));
            pGC = (pScreen->GCperDepth[i]);

	    pGC->alu = GXcopy;
	    pGC->planemask = ~0;
	    pGC->serialNumber = 0;
	    pGC->fgPixel = 0;
	    pGC->bgPixel = 1;
	    pGC->lineWidth = 0;
	    pGC->lineStyle = LineSolid;
	    pGC->capStyle = CapButt;
	    pGC->joinStyle = JoinMiter;
	    pGC->fillStyle = FillSolid;
	    pGC->fillRule = EvenOddRule;
	    pGC->arcMode = ArcChord;
	    pGC->patOrg.x = 0;
	    pGC->patOrg.y = 0;
	    pGC->subWindowMode = ClipByChildren;
	    pGC->graphicsExposures = FALSE;
	    pGC->clipOrg.x = 0;
	    pGC->clipOrg.y = 0;
	    if (pGC->clientClipType != CT_NONE)
		(*pGC->funcs->ChangeClip) (pGC, CT_NONE, NULL, 0);
	    pGC->stateChanges = (1 << (GCLastBit+1)) - 1;
	    return pGC;
	}
    /* if we make it this far, need to roll our own */
    pGC = CreateScratchGC(pScreen, depth);
    if (pGC)
	pGC->graphicsExposures = FALSE;
    return pGC;
}

/*
   if the gc to free is in the table of pre-existing ones,
mark it as available.
   if not, free it for real
*/
void
FreeScratchGC(GCPtr pGC)
{
    ScreenPtr pScreen = pGC->pScreen;
    int i;

    for (i=0; i<=pScreen->numDepths; i++)
    {
        if ( pScreen->GCperDepth[i] == pGC)
	{
	    pScreen->rgf &= ~(1L << (i+1));
	    return;
	}
    }
    (void)FreeGC(pGC, (GContext)0);
}