aboutsummaryrefslogtreecommitdiff
path: root/mesalib/src/mesa/main/ff_fragment_shader.cpp
blob: bc6fdbdd8918051e0fdd7f1ed77a8dbaf6c3cccd (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
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
/**************************************************************************
 * 
 * Copyright 2007 VMware, Inc.
 * All Rights Reserved.
 * Copyright 2009 VMware, Inc.  All Rights Reserved.
 * Copyright © 2010-2011 Intel Corporation
 * 
 * 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, sub license, 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 (including the
 * next paragraph) 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
 * 
 **************************************************************************/

#include "glheader.h"
#include "imports.h"
#include "mtypes.h"
#include "main/context.h"
#include "main/macros.h"
#include "main/samplerobj.h"
#include "main/texenvprogram.h"
#include "main/texobj.h"
#include "main/uniforms.h"
#include "program/program.h"
#include "program/prog_parameter.h"
#include "program/prog_cache.h"
#include "program/prog_instruction.h"
#include "program/prog_print.h"
#include "program/prog_statevars.h"
#include "program/programopt.h"
#include "../glsl/glsl_types.h"
#include "../glsl/ir.h"
#include "../glsl/ir_builder.h"
#include "../glsl/glsl_symbol_table.h"
#include "../glsl/glsl_parser_extras.h"
#include "../glsl/ir_optimization.h"
#include "../program/ir_to_mesa.h"

using namespace ir_builder;

/*
 * Note on texture units:
 *
 * The number of texture units supported by fixed-function fragment
 * processing is MAX_TEXTURE_COORD_UNITS, not MAX_TEXTURE_IMAGE_UNITS.
 * That's because there's a one-to-one correspondence between texture
 * coordinates and samplers in fixed-function processing.
 *
 * Since fixed-function vertex processing is limited to MAX_TEXTURE_COORD_UNITS
 * sets of texcoords, so is fixed-function fragment processing.
 *
 * We can safely use ctx->Const.MaxTextureUnits for loop bounds.
 */


struct texenvprog_cache_item
{
   GLuint hash;
   void *key;
   struct gl_shader_program *data;
   struct texenvprog_cache_item *next;
};

static GLboolean
texenv_doing_secondary_color(struct gl_context *ctx)
{
   if (ctx->Light.Enabled &&
       (ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR))
      return GL_TRUE;

   if (ctx->Fog.ColorSumEnabled)
      return GL_TRUE;

   return GL_FALSE;
}

struct mode_opt {
#ifdef __GNUC__
   __extension__ GLubyte Source:4;  /**< SRC_x */
   __extension__ GLubyte Operand:3; /**< OPR_x */
#else
   GLubyte Source;  /**< SRC_x */
   GLubyte Operand; /**< OPR_x */
#endif
};

struct state_key {
   GLuint nr_enabled_units:8;
   GLuint enabled_units:8;
   GLuint separate_specular:1;
   GLuint fog_enabled:1;
   GLuint fog_mode:2;          /**< FOG_x */
   GLuint inputs_available:12;
   GLuint num_draw_buffers:4;

   /* NOTE: This array of structs must be last! (see "keySize" below) */
   struct {
      GLuint enabled:1;
      GLuint source_index:4;   /**< TEXTURE_x_INDEX */
      GLuint shadow:1;
      GLuint ScaleShiftRGB:2;
      GLuint ScaleShiftA:2;

      GLuint NumArgsRGB:3;  /**< up to MAX_COMBINER_TERMS */
      GLuint ModeRGB:5;     /**< MODE_x */

      GLuint NumArgsA:3;  /**< up to MAX_COMBINER_TERMS */
      GLuint ModeA:5;     /**< MODE_x */

      struct mode_opt OptRGB[MAX_COMBINER_TERMS];
      struct mode_opt OptA[MAX_COMBINER_TERMS];
   } unit[MAX_TEXTURE_UNITS];
};

#define FOG_LINEAR  0
#define FOG_EXP     1
#define FOG_EXP2    2
#define FOG_UNKNOWN 3

static GLuint translate_fog_mode( GLenum mode )
{
   switch (mode) {
   case GL_LINEAR: return FOG_LINEAR;
   case GL_EXP: return FOG_EXP;
   case GL_EXP2: return FOG_EXP2;
   default: return FOG_UNKNOWN;
   }
}

#define OPR_SRC_COLOR           0
#define OPR_ONE_MINUS_SRC_COLOR 1
#define OPR_SRC_ALPHA           2
#define OPR_ONE_MINUS_SRC_ALPHA	3
#define OPR_ZERO                4
#define OPR_ONE                 5
#define OPR_UNKNOWN             7

static GLuint translate_operand( GLenum operand )
{
   switch (operand) {
   case GL_SRC_COLOR: return OPR_SRC_COLOR;
   case GL_ONE_MINUS_SRC_COLOR: return OPR_ONE_MINUS_SRC_COLOR;
   case GL_SRC_ALPHA: return OPR_SRC_ALPHA;
   case GL_ONE_MINUS_SRC_ALPHA: return OPR_ONE_MINUS_SRC_ALPHA;
   case GL_ZERO: return OPR_ZERO;
   case GL_ONE: return OPR_ONE;
   default:
      assert(0);
      return OPR_UNKNOWN;
   }
}

#define SRC_TEXTURE  0
#define SRC_TEXTURE0 1
#define SRC_TEXTURE1 2
#define SRC_TEXTURE2 3
#define SRC_TEXTURE3 4
#define SRC_TEXTURE4 5
#define SRC_TEXTURE5 6
#define SRC_TEXTURE6 7
#define SRC_TEXTURE7 8
#define SRC_CONSTANT 9
#define SRC_PRIMARY_COLOR 10
#define SRC_PREVIOUS 11
#define SRC_ZERO     12
#define SRC_UNKNOWN  15

static GLuint translate_source( GLenum src )
{
   switch (src) {
   case GL_TEXTURE: return SRC_TEXTURE;
   case GL_TEXTURE0:
   case GL_TEXTURE1:
   case GL_TEXTURE2:
   case GL_TEXTURE3:
   case GL_TEXTURE4:
   case GL_TEXTURE5:
   case GL_TEXTURE6:
   case GL_TEXTURE7: return SRC_TEXTURE0 + (src - GL_TEXTURE0);
   case GL_CONSTANT: return SRC_CONSTANT;
   case GL_PRIMARY_COLOR: return SRC_PRIMARY_COLOR;
   case GL_PREVIOUS: return SRC_PREVIOUS;
   case GL_ZERO:
      return SRC_ZERO;
   default:
      assert(0);
      return SRC_UNKNOWN;
   }
}

#define MODE_REPLACE                     0  /* r = a0 */
#define MODE_MODULATE                    1  /* r = a0 * a1 */
#define MODE_ADD                         2  /* r = a0 + a1 */
#define MODE_ADD_SIGNED                  3  /* r = a0 + a1 - 0.5 */
#define MODE_INTERPOLATE                 4  /* r = a0 * a2 + a1 * (1 - a2) */
#define MODE_SUBTRACT                    5  /* r = a0 - a1 */
#define MODE_DOT3_RGB                    6  /* r = a0 . a1 */
#define MODE_DOT3_RGB_EXT                7  /* r = a0 . a1 */
#define MODE_DOT3_RGBA                   8  /* r = a0 . a1 */
#define MODE_DOT3_RGBA_EXT               9  /* r = a0 . a1 */
#define MODE_MODULATE_ADD_ATI           10  /* r = a0 * a2 + a1 */
#define MODE_MODULATE_SIGNED_ADD_ATI    11  /* r = a0 * a2 + a1 - 0.5 */
#define MODE_MODULATE_SUBTRACT_ATI      12  /* r = a0 * a2 - a1 */
#define MODE_ADD_PRODUCTS               13  /* r = a0 * a1 + a2 * a3 */
#define MODE_ADD_PRODUCTS_SIGNED        14  /* r = a0 * a1 + a2 * a3 - 0.5 */
#define MODE_UNKNOWN                    16

/**
 * Translate GL combiner state into a MODE_x value
 */
static GLuint translate_mode( GLenum envMode, GLenum mode )
{
   switch (mode) {
   case GL_REPLACE: return MODE_REPLACE;
   case GL_MODULATE: return MODE_MODULATE;
   case GL_ADD:
      if (envMode == GL_COMBINE4_NV)
         return MODE_ADD_PRODUCTS;
      else
         return MODE_ADD;
   case GL_ADD_SIGNED:
      if (envMode == GL_COMBINE4_NV)
         return MODE_ADD_PRODUCTS_SIGNED;
      else
         return MODE_ADD_SIGNED;
   case GL_INTERPOLATE: return MODE_INTERPOLATE;
   case GL_SUBTRACT: return MODE_SUBTRACT;
   case GL_DOT3_RGB: return MODE_DOT3_RGB;
   case GL_DOT3_RGB_EXT: return MODE_DOT3_RGB_EXT;
   case GL_DOT3_RGBA: return MODE_DOT3_RGBA;
   case GL_DOT3_RGBA_EXT: return MODE_DOT3_RGBA_EXT;
   case GL_MODULATE_ADD_ATI: return MODE_MODULATE_ADD_ATI;
   case GL_MODULATE_SIGNED_ADD_ATI: return MODE_MODULATE_SIGNED_ADD_ATI;
   case GL_MODULATE_SUBTRACT_ATI: return MODE_MODULATE_SUBTRACT_ATI;
   default:
      assert(0);
      return MODE_UNKNOWN;
   }
}


/**
 * Do we need to clamp the results of the given texture env/combine mode?
 * If the inputs to the mode are in [0,1] we don't always have to clamp
 * the results.
 */
static GLboolean
need_saturate( GLuint mode )
{
   switch (mode) {
   case MODE_REPLACE:
   case MODE_MODULATE:
   case MODE_INTERPOLATE:
      return GL_FALSE;
   case MODE_ADD:
   case MODE_ADD_SIGNED:
   case MODE_SUBTRACT:
   case MODE_DOT3_RGB:
   case MODE_DOT3_RGB_EXT:
   case MODE_DOT3_RGBA:
   case MODE_DOT3_RGBA_EXT:
   case MODE_MODULATE_ADD_ATI:
   case MODE_MODULATE_SIGNED_ADD_ATI:
   case MODE_MODULATE_SUBTRACT_ATI:
   case MODE_ADD_PRODUCTS:
   case MODE_ADD_PRODUCTS_SIGNED:
      return GL_TRUE;
   default:
      assert(0);
      return GL_FALSE;
   }
}

#define VERT_BIT_TEX_ANY    (0xff << VERT_ATTRIB_TEX0)

/**
 * Identify all possible varying inputs.  The fragment program will
 * never reference non-varying inputs, but will track them via state
 * constants instead.
 *
 * This function figures out all the inputs that the fragment program
 * has access to.  The bitmask is later reduced to just those which
 * are actually referenced.
 */
static GLbitfield get_fp_input_mask( struct gl_context *ctx )
{
   /* _NEW_PROGRAM */
   const GLboolean vertexShader =
      (ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX] &&
       ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX]->LinkStatus &&
       ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX]->_LinkedShaders[MESA_SHADER_VERTEX]);
   const GLboolean vertexProgram = ctx->VertexProgram._Enabled;
   GLbitfield fp_inputs = 0x0;

   if (ctx->VertexProgram._Overriden) {
      /* Somebody's messing with the vertex program and we don't have
       * a clue what's happening.  Assume that it could be producing
       * all possible outputs.
       */
      fp_inputs = ~0;
   }
   else if (ctx->RenderMode == GL_FEEDBACK) {
      /* _NEW_RENDERMODE */
      fp_inputs = (VARYING_BIT_COL0 | VARYING_BIT_TEX0);
   }
   else if (!(vertexProgram || vertexShader)) {
      /* Fixed function vertex logic */
      /* _NEW_VARYING_VP_INPUTS */
      GLbitfield64 varying_inputs = ctx->varying_vp_inputs;

      /* These get generated in the setup routine regardless of the
       * vertex program:
       */
      /* _NEW_POINT */
      if (ctx->Point.PointSprite)
         varying_inputs |= VARYING_BITS_TEX_ANY;

      /* First look at what values may be computed by the generated
       * vertex program:
       */
      /* _NEW_LIGHT */
      if (ctx->Light.Enabled) {
         fp_inputs |= VARYING_BIT_COL0;

         if (texenv_doing_secondary_color(ctx))
            fp_inputs |= VARYING_BIT_COL1;
      }

      /* _NEW_TEXTURE */
      fp_inputs |= (ctx->Texture._TexGenEnabled |
                    ctx->Texture._TexMatEnabled) << VARYING_SLOT_TEX0;

      /* Then look at what might be varying as a result of enabled
       * arrays, etc:
       */
      if (varying_inputs & VERT_BIT_COLOR0)
         fp_inputs |= VARYING_BIT_COL0;
      if (varying_inputs & VERT_BIT_COLOR1)
         fp_inputs |= VARYING_BIT_COL1;

      fp_inputs |= (((varying_inputs & VERT_BIT_TEX_ANY) >> VERT_ATTRIB_TEX0) 
                    << VARYING_SLOT_TEX0);

   }
   else {
      /* calculate from vp->outputs */
      struct gl_program *vprog;
      GLbitfield64 vp_outputs;

      /* Choose GLSL vertex shader over ARB vertex program.  Need this
       * since vertex shader state validation comes after fragment state
       * validation (see additional comments in state.c).
       */
      if (vertexShader)
         vprog = ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX]->_LinkedShaders[MESA_SHADER_VERTEX]->Program;
      else
         vprog = &ctx->VertexProgram.Current->Base;

      vp_outputs = vprog->OutputsWritten;

      /* These get generated in the setup routine regardless of the
       * vertex program:
       */
      /* _NEW_POINT */
      if (ctx->Point.PointSprite)
         vp_outputs |= VARYING_BITS_TEX_ANY;

      if (vp_outputs & (1 << VARYING_SLOT_COL0))
         fp_inputs |= VARYING_BIT_COL0;
      if (vp_outputs & (1 << VARYING_SLOT_COL1))
         fp_inputs |= VARYING_BIT_COL1;

      fp_inputs |= (((vp_outputs & VARYING_BITS_TEX_ANY) >> VARYING_SLOT_TEX0) 
                    << VARYING_SLOT_TEX0);
   }
   
   return fp_inputs;
}


/**
 * Examine current texture environment state and generate a unique
 * key to identify it.
 */
static GLuint make_state_key( struct gl_context *ctx,  struct state_key *key )
{
   GLuint i, j;
   GLbitfield inputs_referenced = VARYING_BIT_COL0;
   const GLbitfield inputs_available = get_fp_input_mask( ctx );
   GLuint keySize;

   memset(key, 0, sizeof(*key));

   /* _NEW_TEXTURE */
   for (i = 0; i < ctx->Const.MaxTextureUnits; i++) {
      const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[i];
      const struct gl_texture_object *texObj = texUnit->_Current;
      const struct gl_tex_env_combine_state *comb = texUnit->_CurrentCombine;
      const struct gl_sampler_object *samp;
      GLenum format;

      if (!texUnit->_Current || !texUnit->Enabled)
         continue;

      samp = _mesa_get_samplerobj(ctx, i);
      format = texObj->Image[0][texObj->BaseLevel]->_BaseFormat;

      key->unit[i].enabled = 1;
      key->enabled_units |= (1<<i);
      key->nr_enabled_units = i + 1;
      inputs_referenced |= VARYING_BIT_TEX(i);

      key->unit[i].source_index = _mesa_tex_target_to_index(ctx,
                                                            texObj->Target);

      key->unit[i].shadow =
         ((samp->CompareMode == GL_COMPARE_R_TO_TEXTURE) &&
          ((format == GL_DEPTH_COMPONENT) || 
           (format == GL_DEPTH_STENCIL_EXT)));

      key->unit[i].NumArgsRGB = comb->_NumArgsRGB;
      key->unit[i].NumArgsA = comb->_NumArgsA;

      key->unit[i].ModeRGB =
	 translate_mode(texUnit->EnvMode, comb->ModeRGB);
      key->unit[i].ModeA =
	 translate_mode(texUnit->EnvMode, comb->ModeA);

      key->unit[i].ScaleShiftRGB = comb->ScaleShiftRGB;
      key->unit[i].ScaleShiftA = comb->ScaleShiftA;

      for (j = 0; j < MAX_COMBINER_TERMS; j++) {
         key->unit[i].OptRGB[j].Operand = translate_operand(comb->OperandRGB[j]);
         key->unit[i].OptA[j].Operand = translate_operand(comb->OperandA[j]);
         key->unit[i].OptRGB[j].Source = translate_source(comb->SourceRGB[j]);
         key->unit[i].OptA[j].Source = translate_source(comb->SourceA[j]);
      }
   }

   /* _NEW_LIGHT | _NEW_FOG */
   if (texenv_doing_secondary_color(ctx)) {
      key->separate_specular = 1;
      inputs_referenced |= VARYING_BIT_COL1;
   }

   /* _NEW_FOG */
   if (ctx->Fog.Enabled) {
      key->fog_enabled = 1;
      key->fog_mode = translate_fog_mode(ctx->Fog.Mode);
      inputs_referenced |= VARYING_BIT_FOGC; /* maybe */
   }

   /* _NEW_BUFFERS */
   key->num_draw_buffers = ctx->DrawBuffer->_NumColorDrawBuffers;

   /* _NEW_COLOR */
   if (ctx->Color.AlphaEnabled && key->num_draw_buffers == 0) {
      /* if alpha test is enabled we need to emit at least one color */
      key->num_draw_buffers = 1;
   }

   key->inputs_available = (inputs_available & inputs_referenced);

   /* compute size of state key, ignoring unused texture units */
   keySize = sizeof(*key) - sizeof(key->unit)
      + key->nr_enabled_units * sizeof(key->unit[0]);

   return keySize;
}


/** State used to build the fragment program:
 */
class texenv_fragment_program : public ir_factory {
public:
   struct gl_shader_program *shader_program;
   struct gl_shader *shader;
   exec_list *top_instructions;
   struct state_key *state;

   ir_variable *src_texture[MAX_TEXTURE_COORD_UNITS];
   /* Reg containing each texture unit's sampled texture color,
    * else undef.
    */

   /* Texcoord override from bumpmapping. */
   ir_variable *texcoord_tex[MAX_TEXTURE_COORD_UNITS];

   /* Reg containing texcoord for a texture unit,
    * needed for bump mapping, else undef.
    */

   ir_rvalue *src_previous;	/**< Reg containing color from previous
				 * stage.  May need to be decl'd.
				 */
};

static ir_rvalue *
get_current_attrib(texenv_fragment_program *p, GLuint attrib)
{
   ir_variable *current;
   ir_rvalue *val;

   current = p->shader->symbols->get_variable("gl_CurrentAttribFragMESA");
   assert(current);
   current->data.max_array_access = MAX2(current->data.max_array_access, attrib);
   val = new(p->mem_ctx) ir_dereference_variable(current);
   ir_rvalue *index = new(p->mem_ctx) ir_constant(attrib);
   return new(p->mem_ctx) ir_dereference_array(val, index);
}

static ir_rvalue *
get_gl_Color(texenv_fragment_program *p)
{
   if (p->state->inputs_available & VARYING_BIT_COL0) {
      ir_variable *var = p->shader->symbols->get_variable("gl_Color");
      assert(var);
      return new(p->mem_ctx) ir_dereference_variable(var);
   } else {
      return get_current_attrib(p, VERT_ATTRIB_COLOR0);
   }
}

static ir_rvalue *
get_source(texenv_fragment_program *p,
	   GLuint src, GLuint unit)
{
   ir_variable *var;
   ir_dereference *deref;

   switch (src) {
   case SRC_TEXTURE: 
      return new(p->mem_ctx) ir_dereference_variable(p->src_texture[unit]);

   case SRC_TEXTURE0:
   case SRC_TEXTURE1:
   case SRC_TEXTURE2:
   case SRC_TEXTURE3:
   case SRC_TEXTURE4:
   case SRC_TEXTURE5:
   case SRC_TEXTURE6:
   case SRC_TEXTURE7: 
      return new(p->mem_ctx)
	 ir_dereference_variable(p->src_texture[src - SRC_TEXTURE0]);

   case SRC_CONSTANT:
      var = p->shader->symbols->get_variable("gl_TextureEnvColor");
      assert(var);
      deref = new(p->mem_ctx) ir_dereference_variable(var);
      var->data.max_array_access = MAX2(var->data.max_array_access, unit);
      return new(p->mem_ctx) ir_dereference_array(deref,
						  new(p->mem_ctx) ir_constant(unit));

   case SRC_PRIMARY_COLOR:
      var = p->shader->symbols->get_variable("gl_Color");
      assert(var);
      return new(p->mem_ctx) ir_dereference_variable(var);

   case SRC_ZERO:
      return new(p->mem_ctx) ir_constant(0.0f);

   case SRC_PREVIOUS:
      if (!p->src_previous) {
	 return get_gl_Color(p);
      } else {
	 return p->src_previous->clone(p->mem_ctx, NULL);
      }

   default:
      assert(0);
      return NULL;
   }
}

static ir_rvalue *
emit_combine_source(texenv_fragment_program *p,
		    GLuint unit,
		    GLuint source,
		    GLuint operand)
{
   ir_rvalue *src;

   src = get_source(p, source, unit);

   switch (operand) {
   case OPR_ONE_MINUS_SRC_COLOR: 
      return sub(new(p->mem_ctx) ir_constant(1.0f), src);

   case OPR_SRC_ALPHA:
      return src->type->is_scalar() ? src : swizzle_w(src);

   case OPR_ONE_MINUS_SRC_ALPHA: {
      ir_rvalue *const scalar = src->type->is_scalar() ? src : swizzle_w(src);

      return sub(new(p->mem_ctx) ir_constant(1.0f), scalar);
   }

   case OPR_ZERO:
      return new(p->mem_ctx) ir_constant(0.0f);
   case OPR_ONE:
      return new(p->mem_ctx) ir_constant(1.0f);
   case OPR_SRC_COLOR: 
      return src;
   default:
      assert(0);
      return src;
   }
}

/**
 * Check if the RGB and Alpha sources and operands match for the given
 * texture unit's combinder state.  When the RGB and A sources and
 * operands match, we can emit fewer instructions.
 */
static GLboolean args_match( const struct state_key *key, GLuint unit )
{
   GLuint i, numArgs = key->unit[unit].NumArgsRGB;

   for (i = 0; i < numArgs; i++) {
      if (key->unit[unit].OptA[i].Source != key->unit[unit].OptRGB[i].Source) 
	 return GL_FALSE;

      switch (key->unit[unit].OptA[i].Operand) {
      case OPR_SRC_ALPHA: 
	 switch (key->unit[unit].OptRGB[i].Operand) {
	 case OPR_SRC_COLOR: 
	 case OPR_SRC_ALPHA: 
	    break;
	 default:
	    return GL_FALSE;
	 }
	 break;
      case OPR_ONE_MINUS_SRC_ALPHA: 
	 switch (key->unit[unit].OptRGB[i].Operand) {
	 case OPR_ONE_MINUS_SRC_COLOR: 
	 case OPR_ONE_MINUS_SRC_ALPHA: 
	    break;
	 default:
	    return GL_FALSE;
	 }
	 break;
      default: 
	 return GL_FALSE;	/* impossible */
      }
   }

   return GL_TRUE;
}

static ir_rvalue *
smear(ir_rvalue *val)
{
   if (!val->type->is_scalar())
      return val;

   return swizzle_xxxx(val);
}

static ir_rvalue *
emit_combine(texenv_fragment_program *p,
	     GLuint unit,
	     GLuint nr,
	     GLuint mode,
	     const struct mode_opt *opt)
{
   ir_rvalue *src[MAX_COMBINER_TERMS];
   ir_rvalue *tmp0, *tmp1;
   GLuint i;

   assert(nr <= MAX_COMBINER_TERMS);

   for (i = 0; i < nr; i++)
      src[i] = emit_combine_source( p, unit, opt[i].Source, opt[i].Operand );

   switch (mode) {
   case MODE_REPLACE: 
      return src[0];

   case MODE_MODULATE: 
      return mul(src[0], src[1]);

   case MODE_ADD: 
      return add(src[0], src[1]);

   case MODE_ADD_SIGNED:
      return add(add(src[0], src[1]), new(p->mem_ctx) ir_constant(-0.5f));

   case MODE_INTERPOLATE: 
      /* Arg0 * (Arg2) + Arg1 * (1-Arg2) */
      tmp0 = mul(src[0], src[2]);
      tmp1 = mul(src[1], sub(new(p->mem_ctx) ir_constant(1.0f),
			     src[2]->clone(p->mem_ctx, NULL)));
      return add(tmp0, tmp1);

   case MODE_SUBTRACT: 
      return sub(src[0], src[1]);

   case MODE_DOT3_RGBA:
   case MODE_DOT3_RGBA_EXT: 
   case MODE_DOT3_RGB_EXT:
   case MODE_DOT3_RGB: {
      tmp0 = mul(src[0], new(p->mem_ctx) ir_constant(2.0f));
      tmp0 = add(tmp0, new(p->mem_ctx) ir_constant(-1.0f));

      tmp1 = mul(src[1], new(p->mem_ctx) ir_constant(2.0f));
      tmp1 = add(tmp1, new(p->mem_ctx) ir_constant(-1.0f));

      return dot(swizzle_xyz(smear(tmp0)), swizzle_xyz(smear(tmp1)));
   }
   case MODE_MODULATE_ADD_ATI:
      return add(mul(src[0], src[2]), src[1]);

   case MODE_MODULATE_SIGNED_ADD_ATI:
      return add(add(mul(src[0], src[2]), src[1]),
		 new(p->mem_ctx) ir_constant(-0.5f));

   case MODE_MODULATE_SUBTRACT_ATI:
      return sub(mul(src[0], src[2]), src[1]);

   case MODE_ADD_PRODUCTS:
      return add(mul(src[0], src[1]), mul(src[2], src[3]));

   case MODE_ADD_PRODUCTS_SIGNED:
      return add(add(mul(src[0], src[1]), mul(src[2], src[3])),
		 new(p->mem_ctx) ir_constant(-0.5f));
   default: 
      assert(0);
      return src[0];
   }
}

/**
 * Generate instructions for one texture unit's env/combiner mode.
 */
static ir_rvalue *
emit_texenv(texenv_fragment_program *p, GLuint unit)
{
   const struct state_key *key = p->state;
   GLboolean rgb_saturate, alpha_saturate;
   GLuint rgb_shift, alpha_shift;

   if (!key->unit[unit].enabled) {
      return get_source(p, SRC_PREVIOUS, 0);
   }
   
   switch (key->unit[unit].ModeRGB) {
   case MODE_DOT3_RGB_EXT:
      alpha_shift = key->unit[unit].ScaleShiftA;
      rgb_shift = 0;
      break;
   case MODE_DOT3_RGBA_EXT:
      alpha_shift = 0;
      rgb_shift = 0;
      break;
   default:
      rgb_shift = key->unit[unit].ScaleShiftRGB;
      alpha_shift = key->unit[unit].ScaleShiftA;
      break;
   }
   
   /* If we'll do rgb/alpha shifting don't saturate in emit_combine().
    * We don't want to clamp twice.
    */
   if (rgb_shift)
      rgb_saturate = GL_FALSE;  /* saturate after rgb shift */
   else if (need_saturate(key->unit[unit].ModeRGB))
      rgb_saturate = GL_TRUE;
   else
      rgb_saturate = GL_FALSE;

   if (alpha_shift)
      alpha_saturate = GL_FALSE;  /* saturate after alpha shift */
   else if (need_saturate(key->unit[unit].ModeA))
      alpha_saturate = GL_TRUE;
   else
      alpha_saturate = GL_FALSE;

   ir_variable *temp_var = p->make_temp(glsl_type::vec4_type, "texenv_combine");
   ir_dereference *deref;
   ir_rvalue *val;

   /* Emit the RGB and A combine ops
    */
   if (key->unit[unit].ModeRGB == key->unit[unit].ModeA &&
       args_match(key, unit)) {
      val = emit_combine(p, unit,
			 key->unit[unit].NumArgsRGB,
			 key->unit[unit].ModeRGB,
			 key->unit[unit].OptRGB);
      val = smear(val);
      if (rgb_saturate)
	 val = saturate(val);

      p->emit(assign(temp_var, val));
   }
   else if (key->unit[unit].ModeRGB == MODE_DOT3_RGBA_EXT ||
	    key->unit[unit].ModeRGB == MODE_DOT3_RGBA) {
      ir_rvalue *val = emit_combine(p, unit,
				    key->unit[unit].NumArgsRGB,
				    key->unit[unit].ModeRGB,
				    key->unit[unit].OptRGB);
      val = smear(val);
      if (rgb_saturate)
	 val = saturate(val);
      p->emit(assign(temp_var, val));
   }
   else {
      /* Need to do something to stop from re-emitting identical
       * argument calculations here:
       */
      val = emit_combine(p, unit,
			 key->unit[unit].NumArgsRGB,
			 key->unit[unit].ModeRGB,
			 key->unit[unit].OptRGB);
      val = swizzle_xyz(smear(val));
      if (rgb_saturate)
	 val = saturate(val);
      p->emit(assign(temp_var, val, WRITEMASK_XYZ));

      val = emit_combine(p, unit,
			 key->unit[unit].NumArgsA,
			 key->unit[unit].ModeA,
			 key->unit[unit].OptA);
      val = swizzle_w(smear(val));
      if (alpha_saturate)
	 val = saturate(val);
      p->emit(assign(temp_var, val, WRITEMASK_W));
   }

   deref = new(p->mem_ctx) ir_dereference_variable(temp_var);

   /* Deal with the final shift:
    */
   if (alpha_shift || rgb_shift) {
      ir_constant *shift;

      if (rgb_shift == alpha_shift) {
	 shift = new(p->mem_ctx) ir_constant((float)(1 << rgb_shift));
      }
      else {
         ir_constant_data const_data;

         const_data.f[0] = float(1 << rgb_shift);
         const_data.f[1] = float(1 << rgb_shift);
         const_data.f[2] = float(1 << rgb_shift);
         const_data.f[3] = float(1 << alpha_shift);

         shift = new(p->mem_ctx) ir_constant(glsl_type::vec4_type,
                                             &const_data);
      }

      return saturate(mul(deref, shift));
   }
   else
      return deref;
}


/**
 * Generate instruction for getting a texture source term.
 */
static void load_texture( texenv_fragment_program *p, GLuint unit )
{
   ir_dereference *deref;

   if (p->src_texture[unit])
      return;

   const GLuint texTarget = p->state->unit[unit].source_index;
   ir_rvalue *texcoord;

   if (!(p->state->inputs_available & (VARYING_BIT_TEX0 << unit))) {
      texcoord = get_current_attrib(p, VERT_ATTRIB_TEX0 + unit);
   } else if (p->texcoord_tex[unit]) {
      texcoord = new(p->mem_ctx) ir_dereference_variable(p->texcoord_tex[unit]);
   } else {
      ir_variable *tc_array = p->shader->symbols->get_variable("gl_TexCoord");
      assert(tc_array);
      texcoord = new(p->mem_ctx) ir_dereference_variable(tc_array);
      ir_rvalue *index = new(p->mem_ctx) ir_constant(unit);
      texcoord = new(p->mem_ctx) ir_dereference_array(texcoord, index);
      tc_array->data.max_array_access = MAX2(tc_array->data.max_array_access, unit);
   }

   if (!p->state->unit[unit].enabled) {
      p->src_texture[unit] = p->make_temp(glsl_type::vec4_type,
					  "dummy_tex");
      p->emit(p->src_texture[unit]);

      p->emit(assign(p->src_texture[unit], new(p->mem_ctx) ir_constant(0.0f)));
      return ;
   }

   const glsl_type *sampler_type = NULL;
   int coords = 0;

   switch (texTarget) {
   case TEXTURE_1D_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::sampler1DShadow_type;
      else
	 sampler_type = glsl_type::sampler1D_type;
      coords = 1;
      break;
   case TEXTURE_1D_ARRAY_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::sampler1DArrayShadow_type;
      else
	 sampler_type = glsl_type::sampler1DArray_type;
      coords = 2;
      break;
   case TEXTURE_2D_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::sampler2DShadow_type;
      else
	 sampler_type = glsl_type::sampler2D_type;
      coords = 2;
      break;
   case TEXTURE_2D_ARRAY_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::sampler2DArrayShadow_type;
      else
	 sampler_type = glsl_type::sampler2DArray_type;
      coords = 3;
      break;
   case TEXTURE_RECT_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::sampler2DRectShadow_type;
      else
	 sampler_type = glsl_type::sampler2DRect_type;
      coords = 2;
      break;
   case TEXTURE_3D_INDEX:
      assert(!p->state->unit[unit].shadow);
      sampler_type = glsl_type::sampler3D_type;
      coords = 3;
      break;
   case TEXTURE_CUBE_INDEX:
      if (p->state->unit[unit].shadow)
	 sampler_type = glsl_type::samplerCubeShadow_type;
      else
	 sampler_type = glsl_type::samplerCube_type;
      coords = 3;
      break;
   case TEXTURE_EXTERNAL_INDEX:
      assert(!p->state->unit[unit].shadow);
      sampler_type = glsl_type::samplerExternalOES_type;
      coords = 2;
      break;
   }

   p->src_texture[unit] = p->make_temp(glsl_type::vec4_type,
				       "tex");

   ir_texture *tex = new(p->mem_ctx) ir_texture(ir_tex);


   char *sampler_name = ralloc_asprintf(p->mem_ctx, "sampler_%d", unit);
   ir_variable *sampler = new(p->mem_ctx) ir_variable(sampler_type,
						      sampler_name,
						      ir_var_uniform);
   p->top_instructions->push_head(sampler);

   /* Set the texture unit for this sampler.  The linker will pick this value
    * up and do-the-right-thing.
    *
    * NOTE: The cast to int is important.  Without it, the constant will have
    * type uint, and things later on may get confused.
    */
   sampler->constant_value = new(p->mem_ctx) ir_constant(int(unit));

   deref = new(p->mem_ctx) ir_dereference_variable(sampler);
   tex->set_sampler(deref, glsl_type::vec4_type);

   tex->coordinate = new(p->mem_ctx) ir_swizzle(texcoord, 0, 1, 2, 3, coords);

   if (p->state->unit[unit].shadow) {
      texcoord = texcoord->clone(p->mem_ctx, NULL);
      tex->shadow_comparitor = new(p->mem_ctx) ir_swizzle(texcoord,
							  coords, 0, 0, 0,
							  1);
      coords++;
   }

   texcoord = texcoord->clone(p->mem_ctx, NULL);
   tex->projector = swizzle_w(texcoord);

   p->emit(assign(p->src_texture[unit], tex));
}

static void
load_texenv_source(texenv_fragment_program *p,
		   GLuint src, GLuint unit)
{
   switch (src) {
   case SRC_TEXTURE:
      load_texture(p, unit);
      break;

   case SRC_TEXTURE0:
   case SRC_TEXTURE1:
   case SRC_TEXTURE2:
   case SRC_TEXTURE3:
   case SRC_TEXTURE4:
   case SRC_TEXTURE5:
   case SRC_TEXTURE6:
   case SRC_TEXTURE7:       
      load_texture(p, src - SRC_TEXTURE0);
      break;
      
   default:
      /* not a texture src - do nothing */
      break;
   }
}


/**
 * Generate instructions for loading all texture source terms.
 */
static GLboolean
load_texunit_sources( texenv_fragment_program *p, GLuint unit )
{
   const struct state_key *key = p->state;
   GLuint i;

   for (i = 0; i < key->unit[unit].NumArgsRGB; i++) {
      load_texenv_source( p, key->unit[unit].OptRGB[i].Source, unit );
   }

   for (i = 0; i < key->unit[unit].NumArgsA; i++) {
      load_texenv_source( p, key->unit[unit].OptA[i].Source, unit );
   }

   return GL_TRUE;
}

/**
 * Applies the fog calculations.
 *
 * This is basically like the ARB_fragment_prorgam fog options.  Note
 * that ffvertex_prog.c produces fogcoord for us when
 * GL_FOG_COORDINATE_EXT is set to GL_FRAGMENT_DEPTH_EXT.
 */
static ir_rvalue *
emit_fog_instructions(texenv_fragment_program *p,
		      ir_rvalue *fragcolor)
{
   struct state_key *key = p->state;
   ir_rvalue *f, *temp;
   ir_variable *params, *oparams;
   ir_variable *fogcoord;

   /* Temporary storage for the whole fog result.  Fog calculations
    * only affect rgb so we're hanging on to the .a value of fragcolor
    * this way.
    */
   ir_variable *fog_result = p->make_temp(glsl_type::vec4_type, "fog_result");
   p->emit(assign(fog_result, fragcolor));

   fragcolor = swizzle_xyz(fog_result);

   oparams = p->shader->symbols->get_variable("gl_FogParamsOptimizedMESA");
   assert(oparams);
   fogcoord = p->shader->symbols->get_variable("gl_FogFragCoord");
   assert(fogcoord);
   params = p->shader->symbols->get_variable("gl_Fog");
   assert(params);
   f = new(p->mem_ctx) ir_dereference_variable(fogcoord);

   ir_variable *f_var = p->make_temp(glsl_type::float_type, "fog_factor");

   switch (key->fog_mode) {
   case FOG_LINEAR:
      /* f = (end - z) / (end - start)
       *
       * gl_MesaFogParamsOptimized gives us (-1 / (end - start)) and
       * (end / (end - start)) so we can generate a single MAD.
       */
      f = add(mul(f, swizzle_x(oparams)), swizzle_y(oparams));
      break;
   case FOG_EXP:
      /* f = e^(-(density * fogcoord))
       *
       * gl_MesaFogParamsOptimized gives us density/ln(2) so we can
       * use EXP2 which is generally the native instruction without
       * having to do any further math on the fog density uniform.
       */
      f = mul(f, swizzle_z(oparams));
      f = new(p->mem_ctx) ir_expression(ir_unop_neg, f);
      f = new(p->mem_ctx) ir_expression(ir_unop_exp2, f);
      break;
   case FOG_EXP2:
      /* f = e^(-(density * fogcoord)^2)
       *
       * gl_MesaFogParamsOptimized gives us density/sqrt(ln(2)) so we
       * can do this like FOG_EXP but with a squaring after the
       * multiply by density.
       */
      ir_variable *temp_var = p->make_temp(glsl_type::float_type, "fog_temp");
      p->emit(assign(temp_var, mul(f, swizzle_w(oparams))));

      f = mul(temp_var, temp_var);
      f = new(p->mem_ctx) ir_expression(ir_unop_neg, f);
      f = new(p->mem_ctx) ir_expression(ir_unop_exp2, f);
      break;
   }

   p->emit(assign(f_var, saturate(f)));

   f = sub(new(p->mem_ctx) ir_constant(1.0f), f_var);
   temp = new(p->mem_ctx) ir_dereference_variable(params);
   temp = new(p->mem_ctx) ir_dereference_record(temp, "color");
   temp = mul(swizzle_xyz(temp), f);

   p->emit(assign(fog_result, add(temp, mul(fragcolor, f_var)), WRITEMASK_XYZ));

   return new(p->mem_ctx) ir_dereference_variable(fog_result);
}

static void
emit_instructions(texenv_fragment_program *p)
{
   struct state_key *key = p->state;
   GLuint unit;

   if (key->enabled_units) {
      /* First pass - to support texture_env_crossbar, first identify
       * all referenced texture sources and emit texld instructions
       * for each:
       */
      for (unit = 0; unit < key->nr_enabled_units; unit++)
	 if (key->unit[unit].enabled) {
	    load_texunit_sources(p, unit);
	 }

      /* Second pass - emit combine instructions to build final color:
       */
      for (unit = 0; unit < key->nr_enabled_units; unit++) {
	 if (key->unit[unit].enabled) {
	    p->src_previous = emit_texenv(p, unit);
	 }
      }
   }

   ir_rvalue *cf = get_source(p, SRC_PREVIOUS, 0);

   if (key->separate_specular) {
      ir_variable *spec_result = p->make_temp(glsl_type::vec4_type,
					      "specular_add");
      p->emit(assign(spec_result, cf));

      ir_rvalue *secondary;
      if (p->state->inputs_available & VARYING_BIT_COL1) {
	 ir_variable *var =
	    p->shader->symbols->get_variable("gl_SecondaryColor");
	 assert(var);
	 secondary = swizzle_xyz(var);
      } else {
	 secondary = swizzle_xyz(get_current_attrib(p, VERT_ATTRIB_COLOR1));
      }

      p->emit(assign(spec_result, add(swizzle_xyz(spec_result), secondary),
		     WRITEMASK_XYZ));

      cf = new(p->mem_ctx) ir_dereference_variable(spec_result);
   }

   if (key->fog_enabled) {
      cf = emit_fog_instructions(p, cf);
   }

   ir_variable *frag_color = p->shader->symbols->get_variable("gl_FragColor");
   assert(frag_color);
   p->emit(assign(frag_color, cf));
}

/**
 * Generate a new fragment program which implements the context's
 * current texture env/combine mode.
 */
static struct gl_shader_program *
create_new_program(struct gl_context *ctx, struct state_key *key)
{
   texenv_fragment_program p;
   unsigned int unit;
   _mesa_glsl_parse_state *state;

   p.mem_ctx = ralloc_context(NULL);
   p.shader = ctx->Driver.NewShader(ctx, 0, GL_FRAGMENT_SHADER);
   p.shader->ir = new(p.shader) exec_list;
   state = new(p.shader) _mesa_glsl_parse_state(ctx, MESA_SHADER_FRAGMENT,
						p.shader);
   p.shader->symbols = state->symbols;
   p.top_instructions = p.shader->ir;
   p.instructions = p.shader->ir;
   p.state = key;
   p.shader_program = ctx->Driver.NewShaderProgram(0);

   /* Tell the linker to ignore the fact that we're building a
    * separate shader, in case we're in a GLES2 context that would
    * normally reject that.  The real problem is that we're building a
    * fixed function program in a GLES2 context at all, but that's a
    * big mess to clean up.
    */
   p.shader_program->SeparateShader = GL_TRUE;

   state->language_version = 130;
   state->es_shader = false;
   if (_mesa_is_gles(ctx) && ctx->Extensions.OES_EGL_image_external)
      state->OES_EGL_image_external_enable = true;
   _mesa_glsl_initialize_types(state);
   _mesa_glsl_initialize_variables(p.instructions, state);

   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
      p.src_texture[unit] = NULL;
      p.texcoord_tex[unit] = NULL;
   }

   p.src_previous = NULL;

   ir_function *main_f = new(p.mem_ctx) ir_function("main");
   p.emit(main_f);
   state->symbols->add_function(main_f);

   ir_function_signature *main_sig =
      new(p.mem_ctx) ir_function_signature(glsl_type::void_type);
   main_sig->is_defined = true;
   main_f->add_signature(main_sig);

   p.instructions = &main_sig->body;
   if (key->num_draw_buffers)
      emit_instructions(&p);

   validate_ir_tree(p.shader->ir);

   const struct gl_shader_compiler_options *options =
      &ctx->Const.ShaderCompilerOptions[MESA_SHADER_FRAGMENT];

   while (do_common_optimization(p.shader->ir, false, false, options,
                                 ctx->Const.NativeIntegers))
      ;
   reparent_ir(p.shader->ir, p.shader->ir);

   p.shader->CompileStatus = true;
   p.shader->Version = state->language_version;
   p.shader->uses_builtin_functions = state->uses_builtin_functions;
   p.shader_program->Shaders =
      (gl_shader **)malloc(sizeof(*p.shader_program->Shaders));
   p.shader_program->Shaders[0] = p.shader;
   p.shader_program->NumShaders = 1;

   _mesa_glsl_link_shader(ctx, p.shader_program);

   if (!p.shader_program->LinkStatus)
      _mesa_problem(ctx, "Failed to link fixed function fragment shader: %s\n",
		    p.shader_program->InfoLog);

   ralloc_free(p.mem_ctx);
   return p.shader_program;
}

extern "C" {

/**
 * Return a fragment program which implements the current
 * fixed-function texture, fog and color-sum operations.
 */
struct gl_shader_program *
_mesa_get_fixed_func_fragment_program(struct gl_context *ctx)
{
   struct gl_shader_program *shader_program;
   struct state_key key;
   GLuint keySize;

   keySize = make_state_key(ctx, &key);

   shader_program = (struct gl_shader_program *)
      _mesa_search_program_cache(ctx->FragmentProgram.Cache,
                                 &key, keySize);

   if (!shader_program) {
      shader_program = create_new_program(ctx, &key);

      _mesa_shader_cache_insert(ctx, ctx->FragmentProgram.Cache,
				&key, keySize, shader_program);
   }

   return shader_program;
}

}