summaryrefslogtreecommitdiff
path: root/src/mesa/drivers/x11/xm_dd.c
blob: 465a40ac8dde27cb6a98902eb9126651defd5061 (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
/*
 * Mesa 3-D graphics library
 * Version:  6.5.2
 *
 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * 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
 * BRIAN PAUL 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.
 */


/**
 * \file xm_dd.h
 * General device driver functions for Xlib driver.
 */

#include "glxheader.h"
#include "main/bufferobj.h"
#include "main/buffers.h"
#include "main/context.h"
#include "main/colormac.h"
#include "main/depth.h"
#include "main/drawpix.h"
#include "main/extensions.h"
#include "main/framebuffer.h"
#include "main/macros.h"
#include "main/image.h"
#include "main/imports.h"
#include "main/mtypes.h"
#include "main/state.h"
#include "main/texobj.h"
#include "main/teximage.h"
#include "main/texstore.h"
#include "main/texformat.h"
#include "swrast/swrast.h"
#include "swrast/s_context.h"
#include "swrast_setup/swrast_setup.h"
#include "tnl/tnl.h"
#include "tnl/t_context.h"
#include "drivers/common/meta.h"
#include "xmesaP.h"



/*
 * Dithering kernels and lookup tables.
 */

const int xmesa_kernel8[DITH_DY * DITH_DX] = {
    0 * MAXC,  8 * MAXC,  2 * MAXC, 10 * MAXC,
   12 * MAXC,  4 * MAXC, 14 * MAXC,  6 * MAXC,
    3 * MAXC, 11 * MAXC,  1 * MAXC,  9 * MAXC,
   15 * MAXC,  7 * MAXC, 13 * MAXC,  5 * MAXC,
};

const short xmesa_HPCR_DRGB[3][2][16] = {
   {
      { 16, -4,  1,-11, 14, -6,  3, -9, 15, -5,  2,-10, 13, -7,  4, -8},
      {-15,  5,  0, 12,-13,  7, -2, 10,-14,  6, -1, 11,-12,  8, -3,  9}
   },
   {
      {-11, 15, -7,  3, -8, 14, -4,  2,-10, 16, -6,  4, -9, 13, -5,  1},
      { 12,-14,  8, -2,  9,-13,  5, -1, 11,-15,  7, -3, 10,-12,  6,  0}
   },
   {
      {  6,-18, 26,-14,  2,-22, 30,-10,  8,-16, 28,-12,  4,-20, 32, -8},
      { -4, 20,-24, 16,  0, 24,-28, 12, -6, 18,-26, 14, -2, 22,-30, 10}
   }
};

const int xmesa_kernel1[16] = {
   0*47,  9*47,  4*47, 12*47,     /* 47 = (255*3)/16 */
   6*47,  2*47, 14*47,  8*47,
  10*47,  1*47,  5*47, 11*47,
   7*47, 13*47,  3*47, 15*47
};


static void
finish_or_flush( GLcontext *ctx )
{
#ifdef XFree86Server
      /* NOT_NEEDED */
#else
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   if (xmesa) {
      _glthread_LOCK_MUTEX(_xmesa_lock);
      XSync( xmesa->display, False );
      _glthread_UNLOCK_MUTEX(_xmesa_lock);
   }
#endif
}


static void
clear_index( GLcontext *ctx, GLuint index )
{
   if (ctx->DrawBuffer->Name == 0) {
      const XMesaContext xmesa = XMESA_CONTEXT(ctx);
      XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
      xmesa->clearpixel = (unsigned long) index;
      XMesaSetForeground( xmesa->display, xmbuf->cleargc, (unsigned long) index );
   }
}


static void
clear_color( GLcontext *ctx, const GLfloat color[4] )
{
   if (ctx->DrawBuffer->Name == 0) {
      const XMesaContext xmesa = XMESA_CONTEXT(ctx);
      XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);

      CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[0], color[0]);
      CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[1], color[1]);
      CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[2], color[2]);
      CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[3], color[3]);
      xmesa->clearpixel = xmesa_color_to_pixel( ctx,
                                                xmesa->clearcolor[0],
                                                xmesa->clearcolor[1],
                                                xmesa->clearcolor[2],
                                                xmesa->clearcolor[3],
                                                xmesa->xm_visual->undithered_pf );
      _glthread_LOCK_MUTEX(_xmesa_lock);
      XMesaSetForeground( xmesa->display, xmbuf->cleargc,
                          xmesa->clearpixel );
      _glthread_UNLOCK_MUTEX(_xmesa_lock);
   }
}



/* Set index mask ala glIndexMask */
static void
index_mask( GLcontext *ctx, GLuint mask )
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
   /* not sure this conditional is really needed */
   if (xmbuf->backxrb && xmbuf->backxrb->pixmap) {
      unsigned long m;
      if (mask==0xffffffff) {
	 m = ((unsigned long)~0L);
      }
      else {
         m = (unsigned long) mask;
      }
      XMesaSetPlaneMask( xmesa->display, xmbuf->cleargc, m );
   }
}


/* Implements glColorMask() */
static void
color_mask(GLcontext *ctx,
           GLboolean rmask, GLboolean gmask, GLboolean bmask, GLboolean amask)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   XMesaBuffer xmbuf;
   const int xclass = xmesa->xm_visual->mesa_visual.visualType;
   (void) amask;

   if (ctx->DrawBuffer->Name != 0)
      return;

   xmbuf = XMESA_BUFFER(ctx->DrawBuffer);

   if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
      unsigned long m;
      if (rmask && gmask && bmask) {
         m = ((unsigned long)~0L);
      }
      else {
         m = 0;
         if (rmask)   m |= GET_REDMASK(xmesa->xm_visual);
         if (gmask)   m |= GET_GREENMASK(xmesa->xm_visual);
         if (bmask)   m |= GET_BLUEMASK(xmesa->xm_visual);
      }
      XMesaSetPlaneMask( xmesa->display, xmbuf->cleargc, m );
   }
}



/**********************************************************************/
/*** glClear implementations                                        ***/
/**********************************************************************/


/**
 * Clear the front or back color buffer, if it's implemented with a pixmap.
 */
static void
clear_pixmap(GLcontext *ctx, struct xmesa_renderbuffer *xrb,
             GLint x, GLint y, GLint width, GLint height)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);

   assert(xmbuf);
   assert(xrb->pixmap);
   assert(xmesa);
   assert(xmesa->display);
   assert(xrb->pixmap);
   assert(xmbuf->cleargc);

   XMesaFillRectangle( xmesa->display, xrb->pixmap, xmbuf->cleargc,
                       x, xrb->Base.Height - y - height,
                       width, height );
}


static void
clear_8bit_ximage( GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                   GLint x, GLint y, GLint width, GLint height )
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   GLint i;
   for (i = 0; i < height; i++) {
      GLubyte *ptr = PIXEL_ADDR1(xrb, x, y + i);
      MEMSET( ptr, xmesa->clearpixel, width );
   }
}


static void
clear_HPCR_ximage( GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                   GLint x, GLint y, GLint width, GLint height )
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   GLint i;
   for (i = y; i < y + height; i++) {
      GLubyte *ptr = PIXEL_ADDR1( xrb, x, i );
      int j;
      const GLubyte *sptr = xmesa->xm_visual->hpcr_clear_ximage_pattern[0];
      if (i & 1) {
         sptr += 16;
      }
      for (j = x; j < x + width; j++) {
         *ptr = sptr[j&15];
         ptr++;
      }
   }
}


static void
clear_16bit_ximage( GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                    GLint x, GLint y, GLint width, GLint height)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   GLuint pixel = (GLuint) xmesa->clearpixel;
   GLint i, j;

   if (xmesa->swapbytes) {
      pixel = ((pixel >> 8) & 0x00ff) | ((pixel << 8) & 0xff00);
   }

   for (j = 0; j < height; j++) {
      GLushort *ptr2 = PIXEL_ADDR2(xrb, x, y + j);
      for (i = 0; i < width; i++) {
         ptr2[i] = pixel;
      }
   }
}


/* Optimized code provided by Nozomi Ytow <noz@xfree86.org> */
static void
clear_24bit_ximage(GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                   GLint x, GLint y, GLint width, GLint height)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   const GLubyte r = xmesa->clearcolor[0];
   const GLubyte g = xmesa->clearcolor[1];
   const GLubyte b = xmesa->clearcolor[2];

   if (r == g && g == b) {
      /* same value for all three components (gray) */
      GLint j;
      for (j = 0; j < height; j++) {
         bgr_t *ptr3 = PIXEL_ADDR3(xrb, x, y + j);
         MEMSET(ptr3, r, 3 * width);
      }
   }
   else {
      /* non-gray clear color */
      GLint i, j;
      for (j = 0; j < height; j++) {
         bgr_t *ptr3 = PIXEL_ADDR3(xrb, x, y + j);
         for (i = 0; i < width; i++) {
            ptr3->r = r;
            ptr3->g = g;
            ptr3->b = b;
            ptr3++;
         }
      }
   }
}


static void
clear_32bit_ximage(GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                   GLint x, GLint y, GLint width, GLint height)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   register GLuint pixel = (GLuint) xmesa->clearpixel;

   if (!xrb->ximage)
      return;

   if (xmesa->swapbytes) {
      pixel = ((pixel >> 24) & 0x000000ff)
            | ((pixel >> 8)  & 0x0000ff00)
            | ((pixel << 8)  & 0x00ff0000)
            | ((pixel << 24) & 0xff000000);
   }

   if (width == xrb->Base.Width && height == xrb->Base.Height) {
      /* clearing whole buffer */
      const GLuint n = xrb->Base.Width * xrb->Base.Height;
      GLuint *ptr4 = (GLuint *) xrb->ximage->data;
      if (pixel == 0) {
         /* common case */
         _mesa_memset(ptr4, pixel, 4 * n);
      }
      else {
         GLuint i;
         for (i = 0; i < n; i++)
            ptr4[i] = pixel;
      }
   }
   else {
      /* clearing scissored region */
      GLint i, j;
      for (j = 0; j < height; j++) {
         GLuint *ptr4 = PIXEL_ADDR4(xrb, x, y + j);
         for (i = 0; i < width; i++) {
            ptr4[i] = pixel;
         }
      }
   }
}


static void
clear_nbit_ximage(GLcontext *ctx, struct xmesa_renderbuffer *xrb,
                  GLint x, GLint y, GLint width, GLint height)
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);
   XMesaImage *img = xrb->ximage;
   GLint i, j;

   /* TODO: optimize this */
   y = YFLIP(xrb, y);
   for (j = 0; j < height; j++) {
      for (i = 0; i < width; i++) {
         XMesaPutPixel(img, x+i, y-j, xmesa->clearpixel);
      }
   }
}



static void
clear_buffers(GLcontext *ctx, GLbitfield buffers)
{
   if (ctx->DrawBuffer->Name == 0) {
      /* this is a window system framebuffer */
      const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
      XMesaBuffer b = XMESA_BUFFER(ctx->DrawBuffer);
      const GLint x = ctx->DrawBuffer->_Xmin;
      const GLint y = ctx->DrawBuffer->_Ymin;
      const GLint width = ctx->DrawBuffer->_Xmax - x;
      const GLint height = ctx->DrawBuffer->_Ymax - y;

      /* we can't handle color or index masking */
      if (*colorMask == 0xffffffff && ctx->Color.IndexMask == 0xffffffff) {
         if (buffers & BUFFER_BIT_FRONT_LEFT) {
            /* clear front color buffer */
            struct gl_renderbuffer *frontRb
               = ctx->DrawBuffer->Attachment[BUFFER_FRONT_LEFT].Renderbuffer;
            if (b->frontxrb == xmesa_renderbuffer(frontRb)) {
               /* renderbuffer is not wrapped - great! */
               b->frontxrb->clearFunc(ctx, b->frontxrb, x, y, width, height);
               buffers &= ~BUFFER_BIT_FRONT_LEFT;
            }
            else {
               /* we can't directly clear an alpha-wrapped color buffer */
            }
         }
         if (buffers & BUFFER_BIT_BACK_LEFT) {
            /* clear back color buffer */
            struct gl_renderbuffer *backRb
               = ctx->DrawBuffer->Attachment[BUFFER_BACK_LEFT].Renderbuffer;
            if (b->backxrb == xmesa_renderbuffer(backRb)) {
               /* renderbuffer is not wrapped - great! */
               b->backxrb->clearFunc(ctx, b->backxrb, x, y, width, height);
               buffers &= ~BUFFER_BIT_BACK_LEFT;
            }
         }
      }
   }
   if (buffers)
      _swrast_Clear(ctx, buffers);
}


#ifndef XFree86Server
/* XXX these functions haven't been tested in the Xserver environment */


/**
 * Check if we can do an optimized glDrawPixels into an 8R8G8B visual.
 */
static GLboolean
can_do_DrawPixels_8R8G8B(GLcontext *ctx, GLenum format, GLenum type)
{
   if (format == GL_BGRA &&
       type == GL_UNSIGNED_BYTE &&
       ctx->DrawBuffer &&
       ctx->DrawBuffer->Name == 0 &&
       ctx->Pixel.ZoomX == 1.0 &&        /* no zooming */
       ctx->Pixel.ZoomY == 1.0 &&
       ctx->_ImageTransferState == 0 /* no color tables, scale/bias, etc */) {
      const SWcontext *swrast = SWRAST_CONTEXT(ctx);

      if (swrast->NewState)
         _swrast_validate_derived( ctx );
      
      if ((swrast->_RasterMask & ~CLIP_BIT) == 0) /* no blend, z-test, etc */ {
         struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
         if (rb) {
            struct xmesa_renderbuffer *xrb = xmesa_renderbuffer(rb->Wrapped);
            if (xrb &&
                xrb->pixmap && /* drawing to pixmap or window */
                xrb->Base.AlphaBits == 0) {
               return GL_TRUE;
            }
         }
      }
   }
   return GL_FALSE;
}


/**
 * This function implements glDrawPixels() with an XPutImage call when
 * drawing to the front buffer (X Window drawable).
 * The image format must be GL_BGRA to match the PF_8R8G8B pixel format.
 */
static void
xmesa_DrawPixels_8R8G8B( GLcontext *ctx,
                         GLint x, GLint y, GLsizei width, GLsizei height,
                         GLenum format, GLenum type,
                         const struct gl_pixelstore_attrib *unpack,
                         const GLvoid *pixels )
{
   if (can_do_DrawPixels_8R8G8B(ctx, format, type)) {
      const SWcontext *swrast = SWRAST_CONTEXT( ctx );
      struct gl_pixelstore_attrib clippedUnpack = *unpack;
      int dstX = x;
      int dstY = y;
      int w = width;
      int h = height;

      if (swrast->NewState)
         _swrast_validate_derived( ctx );

      if (unpack->BufferObj->Name) {
         /* unpack from PBO */
         GLubyte *buf;
         if (!_mesa_validate_pbo_access(2, unpack, width, height, 1,
                                        format, type, pixels)) {
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glDrawPixels(invalid PBO access)");
            return;
         }
         buf = (GLubyte *) ctx->Driver.MapBuffer(ctx,
                                                 GL_PIXEL_UNPACK_BUFFER_EXT,
                                                 GL_READ_ONLY_ARB,
                                                 unpack->BufferObj);
         if (!buf) {
            /* buffer is already mapped - that's an error */
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glDrawPixels(PBO is mapped)");
            return;
         }
         pixels = ADD_POINTERS(buf, pixels);
      }

      if (_mesa_clip_drawpixels(ctx, &dstX, &dstY, &w, &h, &clippedUnpack)) {
         const XMesaContext xmesa = XMESA_CONTEXT(ctx);
         XMesaDisplay *dpy = xmesa->xm_visual->display;
         XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
         const XMesaGC gc = xmbuf->cleargc;  /* effected by glColorMask */
         struct xmesa_renderbuffer *xrb
            = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
         const int srcX = clippedUnpack.SkipPixels;
         const int srcY = clippedUnpack.SkipRows;
         const int rowLength = clippedUnpack.RowLength;
         XMesaImage ximage;

         ASSERT(xmesa->xm_visual->dithered_pf == PF_8R8G8B);
         ASSERT(xmesa->xm_visual->undithered_pf == PF_8R8G8B);
         ASSERT(dpy);
         ASSERT(gc);

         /* This is a little tricky since all coordinates up to now have
          * been in the OpenGL bottom-to-top orientation.  X is top-to-bottom
          * so we have to carefully compute the Y coordinates/addresses here.
          */
         MEMSET(&ximage, 0, sizeof(XMesaImage));
         ximage.width = width;
         ximage.height = height;
         ximage.format = ZPixmap;
         ximage.data = (char *) pixels
            + ((srcY + h - 1) * rowLength + srcX) * 4;
         ximage.byte_order = LSBFirst;
         ximage.bitmap_unit = 32;
         ximage.bitmap_bit_order = LSBFirst;
         ximage.bitmap_pad = 32;
         ximage.depth = 32;
         ximage.bits_per_pixel = 32;
         ximage.bytes_per_line = -rowLength * 4; /* negative to flip image */
         /* it seems we don't need to set the ximage.red/green/blue_mask fields */
         /* flip Y axis for dest position */
         dstY = YFLIP(xrb, dstY) - h + 1;
         XPutImage(dpy, xrb->pixmap, gc, &ximage, 0, 0, dstX, dstY, w, h);
      }

      if (unpack->BufferObj->Name) {
         ctx->Driver.UnmapBuffer(ctx, GL_PIXEL_UNPACK_BUFFER_EXT,
                                 unpack->BufferObj);
      }
   }
   else {
      /* software fallback */
      _swrast_DrawPixels(ctx, x, y, width, height,
                         format, type, unpack, pixels);
   }
}



/**
 * Check if we can do an optimized glDrawPixels into an 5R6G5B visual.
 */
static GLboolean
can_do_DrawPixels_5R6G5B(GLcontext *ctx, GLenum format, GLenum type)
{
   if (format == GL_RGB &&
       type == GL_UNSIGNED_SHORT_5_6_5 &&
       !ctx->Color.DitherFlag &&  /* no dithering */
       ctx->DrawBuffer &&
       ctx->DrawBuffer->Name == 0 &&
       ctx->Pixel.ZoomX == 1.0 &&        /* no zooming */
       ctx->Pixel.ZoomY == 1.0 &&
       ctx->_ImageTransferState == 0 /* no color tables, scale/bias, etc */) {
      const SWcontext *swrast = SWRAST_CONTEXT(ctx);

      if (swrast->NewState)
         _swrast_validate_derived( ctx );
      
      if ((swrast->_RasterMask & ~CLIP_BIT) == 0) /* no blend, z-test, etc */ {
         struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
         if (rb) {
            struct xmesa_renderbuffer *xrb = xmesa_renderbuffer(rb->Wrapped);
            if (xrb &&
                xrb->pixmap && /* drawing to pixmap or window */
                xrb->Base.AlphaBits == 0) {
               return GL_TRUE;
            }
         }
      }
   }
   return GL_FALSE;
}


/**
 * This function implements glDrawPixels() with an XPutImage call when
 * drawing to the front buffer (X Window drawable).  The image format
 * must be GL_RGB and image type must be GL_UNSIGNED_SHORT_5_6_5 to
 * match the PF_5R6G5B pixel format.
 */
static void
xmesa_DrawPixels_5R6G5B( GLcontext *ctx,
                         GLint x, GLint y, GLsizei width, GLsizei height,
                         GLenum format, GLenum type,
                         const struct gl_pixelstore_attrib *unpack,
                         const GLvoid *pixels )
{
   if (can_do_DrawPixels_5R6G5B(ctx, format, type)) {
      const SWcontext *swrast = SWRAST_CONTEXT( ctx );
      struct gl_pixelstore_attrib clippedUnpack = *unpack;
      int dstX = x;
      int dstY = y;
      int w = width;
      int h = height;

      if (swrast->NewState)
         _swrast_validate_derived( ctx );
      
      if (unpack->BufferObj->Name) {
         /* unpack from PBO */
         GLubyte *buf;
         if (!_mesa_validate_pbo_access(2, unpack, width, height, 1,
                                        format, type, pixels)) {
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glDrawPixels(invalid PBO access)");
            return;
         }
         buf = (GLubyte *) ctx->Driver.MapBuffer(ctx,
                                                 GL_PIXEL_UNPACK_BUFFER_EXT,
                                                 GL_READ_ONLY_ARB,
                                                 unpack->BufferObj);
         if (!buf) {
            /* buffer is already mapped - that's an error */
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glDrawPixels(PBO is mapped)");
            return;
         }
         pixels = ADD_POINTERS(buf, pixels);
      }

      if (_mesa_clip_drawpixels(ctx, &dstX, &dstY, &w, &h, &clippedUnpack)) {
         const XMesaContext xmesa = XMESA_CONTEXT(ctx);
         XMesaDisplay *dpy = xmesa->xm_visual->display;
         XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
         const XMesaGC gc = xmbuf->cleargc;  /* effected by glColorMask */
         struct xmesa_renderbuffer *xrb
            = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
         const int srcX = clippedUnpack.SkipPixels;
         const int srcY = clippedUnpack.SkipRows;
         const int rowLength = clippedUnpack.RowLength;
         XMesaImage ximage;

         ASSERT(xmesa->xm_visual->undithered_pf == PF_5R6G5B);
         ASSERT(dpy);
         ASSERT(gc);

         /* This is a little tricky since all coordinates up to now have
          * been in the OpenGL bottom-to-top orientation.  X is top-to-bottom
          * so we have to carefully compute the Y coordinates/addresses here.
          */
         MEMSET(&ximage, 0, sizeof(XMesaImage));
         ximage.width = width;
         ximage.height = height;
         ximage.format = ZPixmap;
         ximage.data = (char *) pixels
            + ((srcY + h - 1) * rowLength + srcX) * 2;
         ximage.byte_order = LSBFirst;
         ximage.bitmap_unit = 16;
         ximage.bitmap_bit_order = LSBFirst;
         ximage.bitmap_pad = 16;
         ximage.depth = 16;
         ximage.bits_per_pixel = 16;
         ximage.bytes_per_line = -rowLength * 2; /* negative to flip image */
         /* it seems we don't need to set the ximage.red/green/blue_mask fields */
         /* flip Y axis for dest position */
         dstY = YFLIP(xrb, dstY) - h + 1;
         XPutImage(dpy, xrb->pixmap, gc, &ximage, 0, 0, dstX, dstY, w, h);
      }

      if (unpack->BufferObj->Name) {
         ctx->Driver.UnmapBuffer(ctx, GL_PIXEL_UNPACK_BUFFER_EXT,
                                 unpack->BufferObj);
      }
   }
   else {
      /* software fallback */
      _swrast_DrawPixels(ctx, x, y, width, height,
                         format, type, unpack, pixels);
   }
}


/**
 * Determine if we can do an optimized glCopyPixels.
 */
static GLboolean
can_do_CopyPixels(GLcontext *ctx, GLenum type)
{
   if (type == GL_COLOR &&
       ctx->_ImageTransferState == 0 &&  /* no color tables, scale/bias, etc */
       ctx->Pixel.ZoomX == 1.0 &&        /* no zooming */
       ctx->Pixel.ZoomY == 1.0 &&
       ctx->Color.DrawBuffer[0] == GL_FRONT &&  /* copy to front buf */
       ctx->Pixel.ReadBuffer == GL_FRONT &&    /* copy from front buf */
       ctx->ReadBuffer->_ColorReadBuffer &&
       ctx->DrawBuffer->_ColorDrawBuffers[0]) {
      const SWcontext *swrast = SWRAST_CONTEXT( ctx );

      if (swrast->NewState)
         _swrast_validate_derived( ctx );

      if ((swrast->_RasterMask & ~CLIP_BIT) == 0x0 &&
          ctx->ReadBuffer &&
          ctx->ReadBuffer->_ColorReadBuffer &&
          ctx->DrawBuffer &&
          ctx->DrawBuffer->_ColorDrawBuffers[0]) {
         struct xmesa_renderbuffer *srcXrb
            = xmesa_renderbuffer(ctx->ReadBuffer->_ColorReadBuffer->Wrapped);
         struct xmesa_renderbuffer *dstXrb
            = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
         if (srcXrb->pixmap && dstXrb->pixmap) {
            return GL_TRUE;
         }
      }
   }
   return GL_FALSE;
}


/**
 * Implement glCopyPixels for the front color buffer (or back buffer Pixmap)
 * for the color buffer.  Don't support zooming, pixel transfer, etc.
 * We do support copying from one window to another, ala glXMakeCurrentRead.
 */
static void
xmesa_CopyPixels( GLcontext *ctx,
                  GLint srcx, GLint srcy, GLsizei width, GLsizei height,
                  GLint destx, GLint desty, GLenum type )
{
   if (can_do_CopyPixels(ctx, type)) {
      const XMesaContext xmesa = XMESA_CONTEXT(ctx);
      XMesaDisplay *dpy = xmesa->xm_visual->display;
      XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
      const XMesaGC gc = xmbuf->cleargc;  /* effected by glColorMask */
      struct xmesa_renderbuffer *srcXrb
         = xmesa_renderbuffer(ctx->ReadBuffer->_ColorReadBuffer->Wrapped);
      struct xmesa_renderbuffer *dstXrb
         = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);

      ASSERT(dpy);
      ASSERT(gc);

      /* Note: we don't do any special clipping work here.  We could,
       * but X will do it for us.
       */
      srcy = YFLIP(srcXrb, srcy) - height + 1;
      desty = YFLIP(dstXrb, desty) - height + 1;
      XCopyArea(dpy, srcXrb->pixmap, dstXrb->pixmap, gc,
                srcx, srcy, width, height, destx, desty);
   }
   else {
      _swrast_CopyPixels(ctx, srcx, srcy, width, height, destx, desty, type );
   }
}

#endif /* XFree86Server */



/*
 * Every driver should implement a GetString function in order to
 * return a meaningful GL_RENDERER string.
 */
static const GLubyte *
get_string( GLcontext *ctx, GLenum name )
{
   (void) ctx;
   switch (name) {
      case GL_RENDERER:
#ifdef XFree86Server
         return (const GLubyte *) "Mesa GLX Indirect";
#else
         return (const GLubyte *) "Mesa X11";
#endif
      case GL_VENDOR:
#ifdef XFree86Server
         return (const GLubyte *) "Mesa project: www.mesa3d.org";
#else
         return NULL;
#endif
      default:
         return NULL;
   }
}


/*
 * We implement the glEnable function only because we care about
 * dither enable/disable.
 */
static void
enable( GLcontext *ctx, GLenum pname, GLboolean state )
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);

   switch (pname) {
      case GL_DITHER:
         if (state)
            xmesa->pixelformat = xmesa->xm_visual->dithered_pf;
         else
            xmesa->pixelformat = xmesa->xm_visual->undithered_pf;
         break;
      default:
         ;  /* silence compiler warning */
   }
}


static void
clear_color_HPCR_ximage( GLcontext *ctx, const GLfloat color[4] )
{
   int i;
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);

   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[0], color[0]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[1], color[1]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[2], color[2]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[3], color[3]);

   if (color[0] == 0.0 && color[1] == 0.0 && color[2] == 0.0) {
      /* black is black */
      MEMSET( xmesa->xm_visual->hpcr_clear_ximage_pattern, 0x0 ,
              sizeof(xmesa->xm_visual->hpcr_clear_ximage_pattern));
   }
   else {
      /* build clear pattern */
      for (i=0; i<16; i++) {
         xmesa->xm_visual->hpcr_clear_ximage_pattern[0][i] =
            DITHER_HPCR(i, 0,
                        xmesa->clearcolor[0],
                        xmesa->clearcolor[1],
                        xmesa->clearcolor[2]);
         xmesa->xm_visual->hpcr_clear_ximage_pattern[1][i]    =
            DITHER_HPCR(i, 1,
                        xmesa->clearcolor[0],
                        xmesa->clearcolor[1],
                        xmesa->clearcolor[2]);
      }
   }
}


static void
clear_color_HPCR_pixmap( GLcontext *ctx, const GLfloat color[4] )
{
   int i;
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);

   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[0], color[0]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[1], color[1]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[2], color[2]);
   CLAMPED_FLOAT_TO_UBYTE(xmesa->clearcolor[3], color[3]);

   if (color[0] == 0.0 && color[1] == 0.0 && color[2] == 0.0) {
      /* black is black */
      for (i=0; i<16; i++) {
         XMesaPutPixel(xmesa->xm_visual->hpcr_clear_ximage, i, 0, 0);
         XMesaPutPixel(xmesa->xm_visual->hpcr_clear_ximage, i, 1, 0);
      }
   }
   else {
      for (i=0; i<16; i++) {
         XMesaPutPixel(xmesa->xm_visual->hpcr_clear_ximage, i, 0,
                       DITHER_HPCR(i, 0,
                                   xmesa->clearcolor[0],
                                   xmesa->clearcolor[1],
                                   xmesa->clearcolor[2]));
         XMesaPutPixel(xmesa->xm_visual->hpcr_clear_ximage, i, 1,
                       DITHER_HPCR(i, 1,
                                   xmesa->clearcolor[0],
                                   xmesa->clearcolor[1],
                                   xmesa->clearcolor[2]));
      }
   }
   /* change tile pixmap content */
   XMesaPutImage(xmesa->display,
		 (XMesaDrawable)xmesa->xm_visual->hpcr_clear_pixmap,
		 XMESA_BUFFER(ctx->DrawBuffer)->cleargc,
		 xmesa->xm_visual->hpcr_clear_ximage, 0, 0, 0, 0, 16, 2);
}


/**
 * Called when the driver should update its state, based on the new_state
 * flags.
 */
void
xmesa_update_state( GLcontext *ctx, GLbitfield new_state )
{
   const XMesaContext xmesa = XMESA_CONTEXT(ctx);

   /* Propagate statechange information to swrast and swrast_setup
    * modules.  The X11 driver has no internal GL-dependent state.
    */
   _swrast_InvalidateState( ctx, new_state );
   _tnl_InvalidateState( ctx, new_state );
   _vbo_InvalidateState( ctx, new_state );
   _swsetup_InvalidateState( ctx, new_state );

   if (ctx->DrawBuffer->Name != 0)
      return;

   /*
    * GL_DITHER, GL_READ/DRAW_BUFFER, buffer binding state, etc. effect
    * renderbuffer span/clear funcs.
    * Check _NEW_COLOR to detect dither enable/disable.
    */
   if (new_state & (_NEW_COLOR | _NEW_BUFFERS)) {
      XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
      struct xmesa_renderbuffer *front_xrb, *back_xrb;

      front_xrb = xmbuf->frontxrb;
      if (front_xrb) {
         xmesa_set_renderbuffer_funcs(front_xrb, xmesa->pixelformat,
                                      xmesa->xm_visual->BitsPerPixel);
         front_xrb->clearFunc = clear_pixmap;
      }

      back_xrb = xmbuf->backxrb;
      if (back_xrb) {
         xmesa_set_renderbuffer_funcs(back_xrb, xmesa->pixelformat,
                                      xmesa->xm_visual->BitsPerPixel);
         if (xmbuf->backxrb->pixmap) {
            back_xrb->clearFunc = clear_pixmap;
         }
         else {
            switch (xmesa->xm_visual->BitsPerPixel) {
            case 8:
               if (xmesa->xm_visual->hpcr_clear_flag) {
                  back_xrb->clearFunc = clear_HPCR_ximage;
               }
               else {
                  back_xrb->clearFunc = clear_8bit_ximage;
               }
               break;
            case 16:
               back_xrb->clearFunc = clear_16bit_ximage;
               break;
            case 24:
               back_xrb->clearFunc = clear_24bit_ximage;
               break;
            case 32:
               back_xrb->clearFunc = clear_32bit_ximage;
               break;
            default:
               back_xrb->clearFunc = clear_nbit_ximage;
               break;
            }
         }
      }
   }

   if (xmesa->xm_visual->hpcr_clear_flag) {
      /* this depends on whether we're drawing to the front or back buffer */
      /* XXX FIX THIS! */
#if 0
      if (pixmap) {
         ctx->Driver.ClearColor = clear_color_HPCR_pixmap;
      }
      else {
         ctx->Driver.ClearColor = clear_color_HPCR_ximage;
      }
#else
      (void) clear_color_HPCR_pixmap;
      (void) clear_color_HPCR_ximage;
#endif
   }
}



/**
 * Called via ctx->Driver.TestProxyTeximage().  Normally, we'd just use
 * the _mesa_test_proxy_teximage() fallback function, but we're going to
 * special-case the 3D texture case to allow textures up to 512x512x32
 * texels.
 */
static GLboolean
test_proxy_teximage(GLcontext *ctx, GLenum target, GLint level,
                    GLint internalFormat, GLenum format, GLenum type,
                    GLint width, GLint height, GLint depth, GLint border)
{
   if (target == GL_PROXY_TEXTURE_3D) {
      /* special case for 3D textures */
      if (width * height * depth > 512 * 512 * 64 ||
          width  < 2 * border ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(width  - 2 * border) != 1) ||
          height < 2 * border ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(height - 2 * border) != 1) ||
          depth  < 2 * border ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(depth  - 2 * border) != 1)) {
         /* Bad size, or too many texels */
         return GL_FALSE;
      }
      return GL_TRUE;
   }
   else {
      /* use the fallback routine for 1D, 2D, cube and rect targets */
      return _mesa_test_proxy_teximage(ctx, target, level, internalFormat,
                                       format, type, width, height, depth,
                                       border);
   }
}


/**
 * In SW, we don't really compress GL_COMPRESSED_RGB[A] textures!
 */
static const struct gl_texture_format *
choose_tex_format( GLcontext *ctx, GLint internalFormat,
                   GLenum format, GLenum type )
{
   switch (internalFormat) {
      case GL_COMPRESSED_RGB_ARB:
         return &_mesa_texformat_rgb;
      case GL_COMPRESSED_RGBA_ARB:
         return &_mesa_texformat_rgba;
      default:
         return _mesa_choose_tex_format(ctx, internalFormat, format, type);
   }
}


/**
 * Called by glViewport.
 * This is a good time for us to poll the current X window size and adjust
 * our renderbuffers to match the current window size.
 * Remember, we have no opportunity to respond to conventional
 * X Resize/StructureNotify events since the X driver has no event loop.
 * Thus, we poll.
 * Note that this trick isn't fool-proof.  If the application never calls
 * glViewport, our notion of the current window size may be incorrect.
 * That problem led to the GLX_MESA_resize_buffers extension.
 */
static void
xmesa_viewport(GLcontext *ctx, GLint x, GLint y, GLsizei w, GLsizei h)
{
   XMesaContext xmctx = XMESA_CONTEXT(ctx);
   XMesaBuffer xmdrawbuf = XMESA_BUFFER(ctx->WinSysDrawBuffer);
   XMesaBuffer xmreadbuf = XMESA_BUFFER(ctx->WinSysReadBuffer);
   xmesa_check_and_update_buffer_size(xmctx, xmdrawbuf);
   xmesa_check_and_update_buffer_size(xmctx, xmreadbuf);
   (void) x;
   (void) y;
   (void) w;
   (void) h;
}


#if ENABLE_EXT_timer_query

/*
 * The GL_EXT_timer_query extension is not enabled for the XServer
 * indirect renderer.  Not sure about how/if wrapping of gettimeofday()
 * is done, etc.
 */

struct xmesa_query_object
{
   struct gl_query_object Base;
   struct timeval StartTime;
};


static struct gl_query_object *
xmesa_new_query_object(GLcontext *ctx, GLuint id)
{
   struct xmesa_query_object *q = CALLOC_STRUCT(xmesa_query_object);
   if (q) {
      q->Base.Id = id;
      q->Base.Ready = GL_TRUE;
   }
   return &q->Base;
}


static void
xmesa_begin_query(GLcontext *ctx, struct gl_query_object *q)
{
   if (q->Target == GL_TIME_ELAPSED_EXT) {
      struct xmesa_query_object *xq = (struct xmesa_query_object *) q;
      (void) gettimeofday(&xq->StartTime, NULL);
   }
}


/**
 * Return the difference between the two given times in microseconds.
 */
#ifdef __VMS
#define suseconds_t unsigned int
#endif
static GLuint64EXT
time_diff(const struct timeval *t0, const struct timeval *t1)
{
   GLuint64EXT seconds0 = t0->tv_sec & 0xff;  /* 0 .. 255 seconds */
   GLuint64EXT seconds1 = t1->tv_sec & 0xff;  /* 0 .. 255 seconds */
   GLuint64EXT nanosec0 = (seconds0 * 1000000 + t0->tv_usec) * 1000;
   GLuint64EXT nanosec1 = (seconds1 * 1000000 + t1->tv_usec) * 1000;
   return nanosec1 - nanosec0;
}


static void
xmesa_end_query(GLcontext *ctx, struct gl_query_object *q)
{
   if (q->Target == GL_TIME_ELAPSED_EXT) {
      struct xmesa_query_object *xq = (struct xmesa_query_object *) q;
      struct timeval endTime;
      (void) gettimeofday(&endTime, NULL);
      /* result is in nanoseconds! */
      q->Result = time_diff(&xq->StartTime, &endTime);
   }
   q->Ready = GL_TRUE;
}

#endif /* ENABLE_timer_query */


/**
 * Initialize the device driver function table with the functions
 * we implement in this driver.
 */
void
xmesa_init_driver_functions( XMesaVisual xmvisual,
                             struct dd_function_table *driver )
{
   driver->GetString = get_string;
   driver->UpdateState = xmesa_update_state;
   driver->GetBufferSize = NULL; /* OBSOLETE */
   driver->Flush = finish_or_flush;
   driver->Finish = finish_or_flush;
   driver->ClearIndex = clear_index;
   driver->ClearColor = clear_color;
   driver->IndexMask = index_mask;
   driver->ColorMask = color_mask;
   driver->Enable = enable;
   driver->Viewport = xmesa_viewport;
   if (TEST_META_FUNCS) {
      driver->Clear = _mesa_meta_clear;
      driver->CopyPixels = _mesa_meta_copy_pixels;
      driver->BlitFramebuffer = _mesa_meta_blit_framebuffer;
      driver->DrawPixels = _mesa_meta_draw_pixels;
   }
   else {
      driver->Clear = clear_buffers;
#ifndef XFree86Server
      driver->CopyPixels = xmesa_CopyPixels;
      if (xmvisual->undithered_pf == PF_8R8G8B &&
          xmvisual->dithered_pf == PF_8R8G8B &&
          xmvisual->BitsPerPixel == 32) {
         driver->DrawPixels = xmesa_DrawPixels_8R8G8B;
      }
      else if (xmvisual->undithered_pf == PF_5R6G5B) {
         driver->DrawPixels = xmesa_DrawPixels_5R6G5B;
      }
   }
#endif
   driver->TestProxyTexImage = test_proxy_teximage;
#if ENABLE_EXT_texure_compression_s3tc
   driver->ChooseTextureFormat = choose_tex_format;
#else
   (void) choose_tex_format;
#endif

#if ENABLE_EXT_timer_query
   driver->NewQueryObject = xmesa_new_query_object;
   driver->BeginQuery = xmesa_begin_query;
   driver->EndQuery = xmesa_end_query;
#endif
}


#define XMESA_NEW_POINT  (_NEW_POINT | \
                          _NEW_RENDERMODE | \
                          _SWRAST_NEW_RASTERMASK)

#define XMESA_NEW_LINE   (_NEW_LINE | \
                          _NEW_TEXTURE | \
                          _NEW_LIGHT | \
                          _NEW_DEPTH | \
                          _NEW_RENDERMODE | \
                          _SWRAST_NEW_RASTERMASK)

#define XMESA_NEW_TRIANGLE (_NEW_POLYGON | \
                            _NEW_TEXTURE | \
                            _NEW_LIGHT | \
                            _NEW_DEPTH | \
                            _NEW_RENDERMODE | \
                            _SWRAST_NEW_RASTERMASK)


/**
 * Extend the software rasterizer with our line/point/triangle
 * functions.
 * Called during context creation only.
 */
void xmesa_register_swrast_functions( GLcontext *ctx )
{
   SWcontext *swrast = SWRAST_CONTEXT( ctx );

   swrast->choose_point = xmesa_choose_point;
   swrast->choose_line = xmesa_choose_line;
   swrast->choose_triangle = xmesa_choose_triangle;

   /* XXX these lines have no net effect.  Remove??? */
   swrast->InvalidatePointMask |= XMESA_NEW_POINT;
   swrast->InvalidateLineMask |= XMESA_NEW_LINE;
   swrast->InvalidateTriangleMask |= XMESA_NEW_TRIANGLE;
}