aboutsummaryrefslogtreecommitdiff
path: root/freetype/src/truetype/ttgxvar.c
blob: 7899d3671dc8f07c7b2d065f3e47910aa308482b (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
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
/***************************************************************************/
/*                                                                         */
/*  ttgxvar.c                                                              */
/*                                                                         */
/*    TrueType GX Font Variation loader                                    */
/*                                                                         */
/*  Copyright 2004-2013 by                                                 */
/*  David Turner, Robert Wilhelm, Werner Lemberg, and George Williams.     */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* Apple documents the `fvar', `gvar', `cvar', and `avar' tables at      */
  /*                                                                       */
  /*   http://developer.apple.com/fonts/TTRefMan/RM06/Chap6[fgca]var.html  */
  /*                                                                       */
  /* The documentation for `fvar' is inconsistent.  At one point it says   */
  /* that `countSizePairs' should be 3, at another point 2.  It should     */
  /* be 2.                                                                 */
  /*                                                                       */
  /* The documentation for `gvar' is not intelligible; `cvar' refers you   */
  /* to `gvar' and is thus also incomprehensible.                          */
  /*                                                                       */
  /* The documentation for `avar' appears correct, but Apple has no fonts  */
  /* with an `avar' table, so it is hard to test.                          */
  /*                                                                       */
  /* Many thanks to John Jenkins (at Apple) in figuring this out.          */
  /*                                                                       */
  /*                                                                       */
  /* Apple's `kern' table has some references to tuple indices, but as     */
  /* there is no indication where these indices are defined, nor how to    */
  /* interpolate the kerning values (different tuples have different       */
  /* classes) this issue is ignored.                                       */
  /*                                                                       */
  /*************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_CONFIG_CONFIG_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_TAGS_H
#include FT_MULTIPLE_MASTERS_H

#include "ttpload.h"
#include "ttgxvar.h"

#include "tterrors.h"


#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT


#define FT_Stream_FTell( stream )  \
          (FT_ULong)( (stream)->cursor - (stream)->base )
#define FT_Stream_SeekSet( stream, off ) \
          ( (stream)->cursor = (stream)->base + (off) )


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttgxvar


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       Internal Routines                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* The macro ALL_POINTS is used in `ft_var_readpackedpoints'.  It        */
  /* indicates that there is a delta for every point without needing to    */
  /* enumerate all of them.                                                */
  /*                                                                       */

  /* ensure that value `0' has the same width as a pointer */
#define ALL_POINTS  (FT_UShort*)~(FT_PtrDist)0


#define GX_PT_POINTS_ARE_WORDS      0x80
#define GX_PT_POINT_RUN_COUNT_MASK  0x7F


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_readpackedpoints                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Read a set of points to which the following deltas will apply.     */
  /*    Points are packed with a run length encoding.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream    :: The data stream.                                      */
  /*                                                                       */
  /* <Output>                                                              */
  /*    point_cnt :: The number of points read.  A zero value means that   */
  /*                 all points in the glyph will be affected, without     */
  /*                 enumerating them individually.                        */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An array of FT_UShort containing the affected points or the        */
  /*    special value ALL_POINTS.                                          */
  /*                                                                       */
  static FT_UShort*
  ft_var_readpackedpoints( FT_Stream  stream,
                           FT_UInt   *point_cnt )
  {
    FT_UShort *points = NULL;
    FT_Int     n;
    FT_Int     runcnt;
    FT_Int     i;
    FT_Int     j;
    FT_Int     first;
    FT_Memory  memory = stream->memory;
    FT_Error   error  = FT_Err_Ok;

    FT_UNUSED( error );


    *point_cnt = n = FT_GET_BYTE();
    if ( n == 0 )
      return ALL_POINTS;

    if ( n & GX_PT_POINTS_ARE_WORDS )
      n = FT_GET_BYTE() | ( ( n & GX_PT_POINT_RUN_COUNT_MASK ) << 8 );

    if ( FT_NEW_ARRAY( points, n ) )
      return NULL;

    i = 0;
    while ( i < n )
    {
      runcnt = FT_GET_BYTE();
      if ( runcnt & GX_PT_POINTS_ARE_WORDS )
      {
        runcnt = runcnt & GX_PT_POINT_RUN_COUNT_MASK;
        first  = points[i++] = FT_GET_USHORT();

        if ( runcnt < 1 || i + runcnt >= n )
          goto Exit;

        /* first point not included in runcount */
        for ( j = 0; j < runcnt; ++j )
          points[i++] = (FT_UShort)( first += FT_GET_USHORT() );
      }
      else
      {
        first = points[i++] = FT_GET_BYTE();

        if ( runcnt < 1 || i + runcnt >= n )
          goto Exit;

        for ( j = 0; j < runcnt; ++j )
          points[i++] = (FT_UShort)( first += FT_GET_BYTE() );
      }
    }

  Exit:
    return points;
  }


  enum
  {
    GX_DT_DELTAS_ARE_ZERO      = 0x80,
    GX_DT_DELTAS_ARE_WORDS     = 0x40,
    GX_DT_DELTA_RUN_COUNT_MASK = 0x3F
  };


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_readpackeddeltas                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Read a set of deltas.  These are packed slightly differently than  */
  /*    points.  In particular there is no overall count.                  */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream    :: The data stream.                                      */
  /*                                                                       */
  /*    delta_cnt :: The number of to be read.                             */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An array of FT_Short containing the deltas for the affected        */
  /*    points.  (This only gets the deltas for one dimension.  It will    */
  /*    generally be called twice, once for x, once for y.  When used in   */
  /*    cvt table, it will only be called once.)                           */
  /*                                                                       */
  static FT_Short*
  ft_var_readpackeddeltas( FT_Stream  stream,
                           FT_Offset  delta_cnt )
  {
    FT_Short  *deltas = NULL;
    FT_UInt    runcnt;
    FT_Offset  i;
    FT_UInt    j;
    FT_Memory  memory = stream->memory;
    FT_Error   error  = FT_Err_Ok;

    FT_UNUSED( error );


    if ( FT_NEW_ARRAY( deltas, delta_cnt ) )
      return NULL;

    i = 0;
    while ( i < delta_cnt )
    {
      runcnt = FT_GET_BYTE();
      if ( runcnt & GX_DT_DELTAS_ARE_ZERO )
      {
        /* runcnt zeroes get added */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = 0;
      }
      else if ( runcnt & GX_DT_DELTAS_ARE_WORDS )
      {
        /* runcnt shorts from the stack */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = FT_GET_SHORT();
      }
      else
      {
        /* runcnt signed bytes from the stack */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = FT_GET_CHAR();
      }

      if ( j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) )
      {
        /* Bad format */
        FT_FREE( deltas );
        return NULL;
      }
    }

    return deltas;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_load_avar                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parse the `avar' table if present.  It need not be, so we return   */
  /*    nothing.                                                           */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face :: The font face.                                             */
  /*                                                                       */
  static void
  ft_var_load_avar( TT_Face  face )
  {
    FT_Stream       stream = FT_FACE_STREAM(face);
    FT_Memory       memory = stream->memory;
    GX_Blend        blend  = face->blend;
    GX_AVarSegment  segment;
    FT_Error        error = FT_Err_Ok;
    FT_ULong        version;
    FT_Long         axisCount;
    FT_Int          i, j;
    FT_ULong        table_len;

    FT_UNUSED( error );


    blend->avar_checked = TRUE;
    if ( (error = face->goto_table( face, TTAG_avar, stream, &table_len )) != 0 )
      return;

    if ( FT_FRAME_ENTER( table_len ) )
      return;

    version   = FT_GET_LONG();
    axisCount = FT_GET_LONG();

    if ( version != 0x00010000L                       ||
         axisCount != (FT_Long)blend->mmvar->num_axis )
      goto Exit;

    if ( FT_NEW_ARRAY( blend->avar_segment, axisCount ) )
      goto Exit;

    segment = &blend->avar_segment[0];
    for ( i = 0; i < axisCount; ++i, ++segment )
    {
      segment->pairCount = FT_GET_USHORT();
      if ( FT_NEW_ARRAY( segment->correspondence, segment->pairCount ) )
      {
        /* Failure.  Free everything we have done so far.  We must do */
        /* it right now since loading the `avar' table is optional.   */

        for ( j = i - 1; j >= 0; --j )
          FT_FREE( blend->avar_segment[j].correspondence );

        FT_FREE( blend->avar_segment );
        blend->avar_segment = NULL;
        goto Exit;
      }

      for ( j = 0; j < segment->pairCount; ++j )
      {
        segment->correspondence[j].fromCoord =
          FT_GET_SHORT() << 2;    /* convert to Fixed */
        segment->correspondence[j].toCoord =
          FT_GET_SHORT()<<2;    /* convert to Fixed */
      }
    }

  Exit:
    FT_FRAME_EXIT();
  }


  typedef struct  GX_GVar_Head_
  {
    FT_Long    version;
    FT_UShort  axisCount;
    FT_UShort  globalCoordCount;
    FT_ULong   offsetToCoord;
    FT_UShort  glyphCount;
    FT_UShort  flags;
    FT_ULong   offsetToData;

  } GX_GVar_Head;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_load_gvar                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parses the `gvar' table if present.  If `fvar' is there, `gvar'    */
  /*    had better be there too.                                           */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face :: The font face.                                             */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  static FT_Error
  ft_var_load_gvar( TT_Face  face )
  {
    FT_Stream     stream = FT_FACE_STREAM(face);
    FT_Memory     memory = stream->memory;
    GX_Blend      blend  = face->blend;
    FT_Error      error;
    FT_UInt       i, j;
    FT_ULong      table_len;
    FT_ULong      gvar_start;
    FT_ULong      offsetToData;
    GX_GVar_Head  gvar_head;

    static const FT_Frame_Field  gvar_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_GVar_Head

      FT_FRAME_START( 20 ),
        FT_FRAME_LONG  ( version ),
        FT_FRAME_USHORT( axisCount ),
        FT_FRAME_USHORT( globalCoordCount ),
        FT_FRAME_ULONG ( offsetToCoord ),
        FT_FRAME_USHORT( glyphCount ),
        FT_FRAME_USHORT( flags ),
        FT_FRAME_ULONG ( offsetToData ),
      FT_FRAME_END
    };

    if ( (error = face->goto_table( face, TTAG_gvar, stream, &table_len )) != 0 )
      goto Exit;

    gvar_start = FT_STREAM_POS( );
    if ( FT_STREAM_READ_FIELDS( gvar_fields, &gvar_head ) )
      goto Exit;

    blend->tuplecount  = gvar_head.globalCoordCount;
    blend->gv_glyphcnt = gvar_head.glyphCount;
    offsetToData       = gvar_start + gvar_head.offsetToData;

    if ( gvar_head.version   != (FT_Long)0x00010000L              ||
         gvar_head.axisCount != (FT_UShort)blend->mmvar->num_axis )
    {
      error = FT_THROW( Invalid_Table );
      goto Exit;
    }

    if ( FT_NEW_ARRAY( blend->glyphoffsets, blend->gv_glyphcnt + 1 ) )
      goto Exit;

    if ( gvar_head.flags & 1 )
    {
      /* long offsets (one more offset than glyphs, to mark size of last) */
      if ( FT_FRAME_ENTER( ( blend->gv_glyphcnt + 1 ) * 4L ) )
        goto Exit;

      for ( i = 0; i <= blend->gv_glyphcnt; ++i )
        blend->glyphoffsets[i] = offsetToData + FT_GET_LONG();

      FT_FRAME_EXIT();
    }
    else
    {
      /* short offsets (one more offset than glyphs, to mark size of last) */
      if ( FT_FRAME_ENTER( ( blend->gv_glyphcnt + 1 ) * 2L ) )
        goto Exit;

      for ( i = 0; i <= blend->gv_glyphcnt; ++i )
        blend->glyphoffsets[i] = offsetToData + FT_GET_USHORT() * 2;
                                              /* XXX: Undocumented: `*2'! */

      FT_FRAME_EXIT();
    }

    if ( blend->tuplecount != 0 )
    {
      if ( FT_NEW_ARRAY( blend->tuplecoords,
                         gvar_head.axisCount * blend->tuplecount ) )
        goto Exit;

      if ( FT_STREAM_SEEK( gvar_start + gvar_head.offsetToCoord )       ||
           FT_FRAME_ENTER( blend->tuplecount * gvar_head.axisCount * 2L )                   )
        goto Exit;

      for ( i = 0; i < blend->tuplecount; ++i )
        for ( j = 0 ; j < (FT_UInt)gvar_head.axisCount; ++j )
          blend->tuplecoords[i * gvar_head.axisCount + j] =
            FT_GET_SHORT() << 2;                /* convert to FT_Fixed */

      FT_FRAME_EXIT();
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_apply_tuple                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Figure out whether a given tuple (design) applies to the current   */
  /*    blend, and if so, what is the scaling factor.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    blend           :: The current blend of the font.                  */
  /*                                                                       */
  /*    tupleIndex      :: A flag saying whether this is an intermediate   */
  /*                       tuple or not.                                   */
  /*                                                                       */
  /*    tuple_coords    :: The coordinates of the tuple in normalized axis */
  /*                       units.                                          */
  /*                                                                       */
  /*    im_start_coords :: The initial coordinates where this tuple starts */
  /*                       to apply (for intermediate coordinates).        */
  /*                                                                       */
  /*    im_end_coords   :: The final coordinates after which this tuple no */
  /*                       longer applies (for intermediate coordinates).  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An FT_Fixed value containing the scaling factor.                   */
  /*                                                                       */
  static FT_Fixed
  ft_var_apply_tuple( GX_Blend   blend,
                      FT_UShort  tupleIndex,
                      FT_Fixed*  tuple_coords,
                      FT_Fixed*  im_start_coords,
                      FT_Fixed*  im_end_coords )
  {
    FT_UInt   i;
    FT_Fixed  apply = 0x10000L;


    for ( i = 0; i < blend->num_axis; ++i )
    {
      if ( tuple_coords[i] == 0 )
        /* It's not clear why (for intermediate tuples) we don't need     */
        /* to check against start/end -- the documentation says we don't. */
        /* Similarly, it's unclear why we don't need to scale along the   */
        /* axis.                                                          */
        continue;

      else if ( blend->normalizedcoords[i] == 0                           ||
                ( blend->normalizedcoords[i] < 0 && tuple_coords[i] > 0 ) ||
                ( blend->normalizedcoords[i] > 0 && tuple_coords[i] < 0 ) )
      {
        apply = 0;
        break;
      }

      else if ( !( tupleIndex & GX_TI_INTERMEDIATE_TUPLE ) )
        /* not an intermediate tuple */
        apply = FT_MulFix( apply,
                           blend->normalizedcoords[i] > 0
                             ? blend->normalizedcoords[i]
                             : -blend->normalizedcoords[i] );

      else if ( blend->normalizedcoords[i] <= im_start_coords[i] ||
                blend->normalizedcoords[i] >= im_end_coords[i]   )
      {
        apply = 0;
        break;
      }

      else if ( blend->normalizedcoords[i] < tuple_coords[i] )
        apply = FT_MulDiv( apply,
                           blend->normalizedcoords[i] - im_start_coords[i],
                           tuple_coords[i] - im_start_coords[i] );

      else
        apply = FT_MulDiv( apply,
                           im_end_coords[i] - blend->normalizedcoords[i],
                           im_end_coords[i] - tuple_coords[i] );
    }

    return apply;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****               MULTIPLE MASTERS SERVICE FUNCTIONS              *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  typedef struct  GX_FVar_Head_
  {
    FT_Long    version;
    FT_UShort  offsetToData;
    FT_UShort  countSizePairs;
    FT_UShort  axisCount;
    FT_UShort  axisSize;
    FT_UShort  instanceCount;
    FT_UShort  instanceSize;

  } GX_FVar_Head;


  typedef struct  fvar_axis_
  {
    FT_ULong   axisTag;
    FT_ULong   minValue;
    FT_ULong   defaultValue;
    FT_ULong   maxValue;
    FT_UShort  flags;
    FT_UShort  nameID;

  } GX_FVar_Axis;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Get_MM_Var                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Check that the font's `fvar' table is valid, parse it, and return  */
  /*    those data.                                                        */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face   :: The font face.                                           */
  /*              TT_Get_MM_Var initializes the blend structure.           */
  /*                                                                       */
  /* <Output>                                                              */
  /*    master :: The `fvar' data (must be freed by caller).               */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Get_MM_Var( TT_Face      face,
                 FT_MM_Var*  *master )
  {
    FT_Stream            stream = face->root.stream;
    FT_Memory            memory = face->root.memory;
    FT_ULong             table_len;
    FT_Error             error  = FT_Err_Ok;
    FT_ULong             fvar_start;
    FT_Int               i, j;
    FT_MM_Var*           mmvar = NULL;
    FT_Fixed*            next_coords;
    FT_String*           next_name;
    FT_Var_Axis*         a;
    FT_Var_Named_Style*  ns;
    GX_FVar_Head         fvar_head;

    static const FT_Frame_Field  fvar_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_FVar_Head

      FT_FRAME_START( 16 ),
        FT_FRAME_LONG  ( version ),
        FT_FRAME_USHORT( offsetToData ),
        FT_FRAME_USHORT( countSizePairs ),
        FT_FRAME_USHORT( axisCount ),
        FT_FRAME_USHORT( axisSize ),
        FT_FRAME_USHORT( instanceCount ),
        FT_FRAME_USHORT( instanceSize ),
      FT_FRAME_END
    };

    static const FT_Frame_Field  fvaraxis_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_FVar_Axis

      FT_FRAME_START( 20 ),
        FT_FRAME_ULONG ( axisTag ),
        FT_FRAME_ULONG ( minValue ),
        FT_FRAME_ULONG ( defaultValue ),
        FT_FRAME_ULONG ( maxValue ),
        FT_FRAME_USHORT( flags ),
        FT_FRAME_USHORT( nameID ),
      FT_FRAME_END
    };


    if ( face->blend == NULL )
    {
      /* both `fvar' and `gvar' must be present */
      if ( (error = face->goto_table( face, TTAG_gvar,
                                      stream, &table_len )) != 0 )
        goto Exit;

      if ( (error = face->goto_table( face, TTAG_fvar,
                                      stream, &table_len )) != 0 )
        goto Exit;

      fvar_start = FT_STREAM_POS( );

      if ( FT_STREAM_READ_FIELDS( fvar_fields, &fvar_head ) )
        goto Exit;

      if ( fvar_head.version != (FT_Long)0x00010000L                      ||
           fvar_head.countSizePairs != 2                                  ||
           fvar_head.axisSize != 20                                       ||
           /* axisCount limit implied by 16-bit instanceSize */
           fvar_head.axisCount > 0x3FFE                                   ||
           fvar_head.instanceSize != 4 + 4 * fvar_head.axisCount          ||
           /* instanceCount limit implied by limited range of name IDs */
           fvar_head.instanceCount > 0x7EFF                               ||
           fvar_head.offsetToData + fvar_head.axisCount * 20U +
             fvar_head.instanceCount * fvar_head.instanceSize > table_len )
      {
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }

      if ( FT_NEW( face->blend ) )
        goto Exit;

      /* cannot overflow 32-bit arithmetic because of limits above */
      face->blend->mmvar_len =
        sizeof ( FT_MM_Var ) +
        fvar_head.axisCount * sizeof ( FT_Var_Axis ) +
        fvar_head.instanceCount * sizeof ( FT_Var_Named_Style ) +
        fvar_head.instanceCount * fvar_head.axisCount * sizeof ( FT_Fixed ) +
        5 * fvar_head.axisCount;

      if ( FT_ALLOC( mmvar, face->blend->mmvar_len ) )
        goto Exit;
      face->blend->mmvar = mmvar;

      mmvar->num_axis =
        fvar_head.axisCount;
      mmvar->num_designs =
        ~0U;                   /* meaningless in this context; each glyph */
                               /* may have a different number of designs  */
                               /* (or tuples, as called by Apple)         */
      mmvar->num_namedstyles =
        fvar_head.instanceCount;
      mmvar->axis =
        (FT_Var_Axis*)&(mmvar[1]);
      mmvar->namedstyle =
        (FT_Var_Named_Style*)&(mmvar->axis[fvar_head.axisCount]);

      next_coords =
        (FT_Fixed*)&(mmvar->namedstyle[fvar_head.instanceCount]);
      for ( i = 0; i < fvar_head.instanceCount; ++i )
      {
        mmvar->namedstyle[i].coords  = next_coords;
        next_coords                 += fvar_head.axisCount;
      }

      next_name = (FT_String*)next_coords;
      for ( i = 0; i < fvar_head.axisCount; ++i )
      {
        mmvar->axis[i].name  = next_name;
        next_name           += 5;
      }

      if ( FT_STREAM_SEEK( fvar_start + fvar_head.offsetToData ) )
        goto Exit;

      a = mmvar->axis;
      for ( i = 0; i < fvar_head.axisCount; ++i )
      {
        GX_FVar_Axis  axis_rec;


        if ( FT_STREAM_READ_FIELDS( fvaraxis_fields, &axis_rec ) )
          goto Exit;
        a->tag     = axis_rec.axisTag;
        a->minimum = axis_rec.minValue;     /* A Fixed */
        a->def     = axis_rec.defaultValue; /* A Fixed */
        a->maximum = axis_rec.maxValue;     /* A Fixed */
        a->strid   = axis_rec.nameID;

        a->name[0] = (FT_String)(   a->tag >> 24 );
        a->name[1] = (FT_String)( ( a->tag >> 16 ) & 0xFF );
        a->name[2] = (FT_String)( ( a->tag >>  8 ) & 0xFF );
        a->name[3] = (FT_String)( ( a->tag       ) & 0xFF );
        a->name[4] = 0;

        ++a;
      }

      ns = mmvar->namedstyle;
      for ( i = 0; i < fvar_head.instanceCount; ++i, ++ns )
      {
        if ( FT_FRAME_ENTER( 4L + 4L * fvar_head.axisCount ) )
          goto Exit;

        ns->strid       =    FT_GET_USHORT();
        (void) /* flags = */ FT_GET_USHORT();

        for ( j = 0; j < fvar_head.axisCount; ++j )
          ns->coords[j] = FT_GET_ULONG();     /* A Fixed */

        FT_FRAME_EXIT();
      }
    }

    if ( master != NULL )
    {
      FT_UInt  n;


      if ( FT_ALLOC( mmvar, face->blend->mmvar_len ) )
        goto Exit;
      FT_MEM_COPY( mmvar, face->blend->mmvar, face->blend->mmvar_len );

      mmvar->axis =
        (FT_Var_Axis*)&(mmvar[1]);
      mmvar->namedstyle =
        (FT_Var_Named_Style*)&(mmvar->axis[mmvar->num_axis]);
      next_coords =
        (FT_Fixed*)&(mmvar->namedstyle[mmvar->num_namedstyles]);

      for ( n = 0; n < mmvar->num_namedstyles; ++n )
      {
        mmvar->namedstyle[n].coords  = next_coords;
        next_coords                 += mmvar->num_axis;
      }

      a = mmvar->axis;
      next_name = (FT_String*)next_coords;
      for ( n = 0; n < mmvar->num_axis; ++n )
      {
        a->name = next_name;

        /* standard PostScript names for some standard apple tags */
        if ( a->tag == TTAG_wght )
          a->name = (char *)"Weight";
        else if ( a->tag == TTAG_wdth )
          a->name = (char *)"Width";
        else if ( a->tag == TTAG_opsz )
          a->name = (char *)"OpticalSize";
        else if ( a->tag == TTAG_slnt )
          a->name = (char *)"Slant";

        next_name += 5;
        ++a;
      }

      *master = mmvar;
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Set_MM_Blend                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Set the blend (normalized) coordinates for this instance of the    */
  /*    font.  Check that the `gvar' table is reasonable and does some     */
  /*    initial preparation.                                               */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face       :: The font.                                            */
  /*                  Initialize the blend structure with `gvar' data.     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    num_coords :: Must be the axis count of the font.                  */
  /*                                                                       */
  /*    coords     :: An array of num_coords, each between [-1,1].         */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Set_MM_Blend( TT_Face    face,
                   FT_UInt    num_coords,
                   FT_Fixed*  coords )
  {
    FT_Error    error = FT_Err_Ok;
    GX_Blend    blend;
    FT_MM_Var*  mmvar;
    FT_UInt     i;
    FT_Memory   memory = face->root.memory;

    enum
    {
      mcvt_retain,
      mcvt_modify,
      mcvt_load

    } manageCvt;


    face->doblend = FALSE;

    if ( face->blend == NULL )
    {
      if ( (error = TT_Get_MM_Var( face, NULL)) != 0 )
        goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if ( num_coords != mmvar->num_axis )
    {
      error = FT_THROW( Invalid_Argument );
      goto Exit;
    }

    for ( i = 0; i < num_coords; ++i )
      if ( coords[i] < -0x00010000L || coords[i] > 0x00010000L )
      {
        error = FT_THROW( Invalid_Argument );
        goto Exit;
      }

    if ( blend->glyphoffsets == NULL )
      if ( (error = ft_var_load_gvar( face )) != 0 )
        goto Exit;

    if ( blend->normalizedcoords == NULL )
    {
      if ( FT_NEW_ARRAY( blend->normalizedcoords, num_coords ) )
        goto Exit;

      manageCvt = mcvt_modify;

      /* If we have not set the blend coordinates before this, then the  */
      /* cvt table will still be what we read from the `cvt ' table and  */
      /* we don't need to reload it.  We may need to change it though... */
    }
    else
    {
      manageCvt = mcvt_retain;
      for ( i = 0; i < num_coords; ++i )
      {
        if ( blend->normalizedcoords[i] != coords[i] )
        {
          manageCvt = mcvt_load;
          break;
        }
      }

      /* If we don't change the blend coords then we don't need to do  */
      /* anything to the cvt table.  It will be correct.  Otherwise we */
      /* no longer have the original cvt (it was modified when we set  */
      /* the blend last time), so we must reload and then modify it.   */
    }

    blend->num_axis = num_coords;
    FT_MEM_COPY( blend->normalizedcoords,
                 coords,
                 num_coords * sizeof ( FT_Fixed ) );

    face->doblend = TRUE;

    if ( face->cvt != NULL )
    {
      switch ( manageCvt )
      {
      case mcvt_load:
        /* The cvt table has been loaded already; every time we change the */
        /* blend we may need to reload and remodify the cvt table.         */
        FT_FREE( face->cvt );
        face->cvt = NULL;

        tt_face_load_cvt( face, face->root.stream );
        break;

      case mcvt_modify:
        /* The original cvt table is in memory.  All we need to do is */
        /* apply the `cvar' table (if any).                           */
        tt_face_vary_cvt( face, face->root.stream );
        break;

      case mcvt_retain:
        /* The cvt table is correct for this set of coordinates. */
        break;
      }
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Set_Var_Design                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Set the coordinates for the instance, measured in the user         */
  /*    coordinate system.  Parse the `avar' table (if present) to convert */
  /*    from user to normalized coordinates.                               */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face       :: The font face.                                       */
  /*                  Initialize the blend struct with `gvar' data.        */
  /*                                                                       */
  /* <Input>                                                               */
  /*    num_coords :: This must be the axis count of the font.             */
  /*                                                                       */
  /*    coords     :: A coordinate array with `num_coords' elements.       */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Set_Var_Design( TT_Face    face,
                     FT_UInt    num_coords,
                     FT_Fixed*  coords )
  {
    FT_Error        error      = FT_Err_Ok;
    FT_Fixed*       normalized = NULL;
    GX_Blend        blend;
    FT_MM_Var*      mmvar;
    FT_UInt         i, j;
    FT_Var_Axis*    a;
    GX_AVarSegment  av;
    FT_Memory       memory = face->root.memory;


    if ( face->blend == NULL )
    {
      if ( (error = TT_Get_MM_Var( face, NULL )) != 0 )
        goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if ( num_coords != mmvar->num_axis )
    {
      error = FT_THROW( Invalid_Argument );
      goto Exit;
    }

    /* Axis normalization is a two stage process.  First we normalize */
    /* based on the [min,def,max] values for the axis to be [-1,0,1]. */
    /* Then, if there's an `avar' table, we renormalize this range.   */

    if ( FT_NEW_ARRAY( normalized, mmvar->num_axis ) )
      goto Exit;

    a = mmvar->axis;
    for ( i = 0; i < mmvar->num_axis; ++i, ++a )
    {
      if ( coords[i] > a->maximum || coords[i] < a->minimum )
      {
        error = FT_THROW( Invalid_Argument );
        goto Exit;
      }

      if ( coords[i] < a->def )
        normalized[i] = -FT_DivFix( coords[i] - a->def, a->minimum - a->def );
      else if ( a->maximum == a->def )
        normalized[i] = 0;
      else
        normalized[i] = FT_DivFix( coords[i] - a->def, a->maximum - a->def );
    }

    if ( !blend->avar_checked )
      ft_var_load_avar( face );

    if ( blend->avar_segment != NULL )
    {
      av = blend->avar_segment;
      for ( i = 0; i < mmvar->num_axis; ++i, ++av )
      {
        for ( j = 1; j < (FT_UInt)av->pairCount; ++j )
          if ( normalized[i] < av->correspondence[j].fromCoord )
          {
            normalized[i] =
              FT_MulDiv( normalized[i] - av->correspondence[j - 1].fromCoord,
                         av->correspondence[j].toCoord -
                           av->correspondence[j - 1].toCoord,
                         av->correspondence[j].fromCoord -
                           av->correspondence[j - 1].fromCoord ) +
              av->correspondence[j - 1].toCoord;
            break;
          }
      }
    }

    error = TT_Set_MM_Blend( face, num_coords, normalized );

  Exit:
    FT_FREE( normalized );
    return error;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                     GX VAR PARSING ROUTINES                   *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_vary_cvt                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Modify the loaded cvt table according to the `cvar' table and the  */
  /*    font's blend.                                                      */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face   :: A handle to the target face object.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream :: A handle to the input stream.                            */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /*    Most errors are ignored.  It is perfectly valid not to have a      */
  /*    `cvar' table even if there is a `gvar' and `fvar' table.           */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_face_vary_cvt( TT_Face    face,
                    FT_Stream  stream )
  {
    FT_Error    error;
    FT_Memory   memory = stream->memory;
    FT_ULong    table_start;
    FT_ULong    table_len;
    FT_UInt     tupleCount;
    FT_ULong    offsetToData;
    FT_ULong    here;
    FT_UInt     i, j;
    FT_Fixed*   tuple_coords    = NULL;
    FT_Fixed*   im_start_coords = NULL;
    FT_Fixed*   im_end_coords   = NULL;
    GX_Blend    blend           = face->blend;
    FT_UInt     point_count;
    FT_UShort*  localpoints;
    FT_Short*   deltas;


    FT_TRACE2(( "CVAR " ));

    if ( blend == NULL )
    {
      FT_TRACE2(( "tt_face_vary_cvt: no blend specified\n" ));

      error = FT_Err_Ok;
      goto Exit;
    }

    if ( face->cvt == NULL )
    {
      FT_TRACE2(( "tt_face_vary_cvt: no `cvt ' table\n" ));

      error = FT_Err_Ok;
      goto Exit;
    }

    error = face->goto_table( face, TTAG_cvar, stream, &table_len );
    if ( error )
    {
      FT_TRACE2(( "is missing\n" ));

      error = FT_Err_Ok;
      goto Exit;
    }

    if ( FT_FRAME_ENTER( table_len ) )
    {
      error = FT_Err_Ok;
      goto Exit;
    }

    table_start = FT_Stream_FTell( stream );
    if ( FT_GET_LONG() != 0x00010000L )
    {
      FT_TRACE2(( "bad table version\n" ));

      error = FT_Err_Ok;
      goto FExit;
    }

    if ( FT_NEW_ARRAY( tuple_coords, blend->num_axis )    ||
         FT_NEW_ARRAY( im_start_coords, blend->num_axis ) ||
         FT_NEW_ARRAY( im_end_coords, blend->num_axis )   )
      goto FExit;

    tupleCount   = FT_GET_USHORT();
    offsetToData = table_start + FT_GET_USHORT();

    /* The documentation implies there are flags packed into the        */
    /* tuplecount, but John Jenkins says that shared points don't apply */
    /* to `cvar', and no other flags are defined.                       */

    for ( i = 0; i < ( tupleCount & 0xFFF ); ++i )
    {
      FT_UInt   tupleDataSize;
      FT_UInt   tupleIndex;
      FT_Fixed  apply;


      tupleDataSize = FT_GET_USHORT();
      tupleIndex    = FT_GET_USHORT();

      /* There is no provision here for a global tuple coordinate section, */
      /* so John says.  There are no tuple indices, just embedded tuples.  */

      if ( tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          tuple_coords[j] = FT_GET_SHORT() << 2; /* convert from        */
                                                 /* short frac to fixed */
      }
      else
      {
        /* skip this tuple; it makes no sense */

        if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
          for ( j = 0; j < 2 * blend->num_axis; ++j )
            (void)FT_GET_SHORT();

        offsetToData += tupleDataSize;
        continue;
      }

      if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          im_start_coords[j] = FT_GET_SHORT() << 2;
        for ( j = 0; j < blend->num_axis; ++j )
          im_end_coords[j] = FT_GET_SHORT() << 2;
      }

      apply = ft_var_apply_tuple( blend,
                                  (FT_UShort)tupleIndex,
                                  tuple_coords,
                                  im_start_coords,
                                  im_end_coords );
      if ( /* tuple isn't active for our blend */
           apply == 0                                    ||
           /* global points not allowed,           */
           /* if they aren't local, makes no sense */
           !( tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS ) )
      {
        offsetToData += tupleDataSize;
        continue;
      }

      here = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, offsetToData );

      localpoints = ft_var_readpackedpoints( stream, &point_count );
      deltas      = ft_var_readpackeddeltas( stream,
                                             point_count == 0 ? face->cvt_size
                                                              : point_count );
      if ( localpoints == NULL || deltas == NULL )
        /* failure, ignore it */;

      else if ( localpoints == ALL_POINTS )
      {
        /* this means that there are deltas for every entry in cvt */
        for ( j = 0; j < face->cvt_size; ++j )
          face->cvt[j] = (FT_Short)( face->cvt[j] +
                                     FT_MulFix( deltas[j], apply ) );
      }

      else
      {
        for ( j = 0; j < point_count; ++j )
        {
          int  pindex = localpoints[j];

          face->cvt[pindex] = (FT_Short)( face->cvt[pindex] +
                                          FT_MulFix( deltas[j], apply ) );
        }
      }

      if ( localpoints != ALL_POINTS )
        FT_FREE( localpoints );
      FT_FREE( deltas );

      offsetToData += tupleDataSize;

      FT_Stream_SeekSet( stream, here );
    }

  FExit:
    FT_FRAME_EXIT();

  Exit:
    FT_FREE( tuple_coords );
    FT_FREE( im_start_coords );
    FT_FREE( im_end_coords );

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Vary_Get_Glyph_Deltas                                           */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Load the appropriate deltas for the current glyph.                 */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face        :: A handle to the target face object.                 */
  /*                                                                       */
  /*    glyph_index :: The index of the glyph being modified.              */
  /*                                                                       */
  /*    n_points    :: The number of the points in the glyph, including    */
  /*                   phantom points.                                     */
  /*                                                                       */
  /* <Output>                                                              */
  /*    deltas      :: The array of points to change.                      */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Vary_Get_Glyph_Deltas( TT_Face      face,
                            FT_UInt      glyph_index,
                            FT_Vector*  *deltas,
                            FT_UInt      n_points )
  {
    FT_Stream   stream = face->root.stream;
    FT_Memory   memory = stream->memory;
    GX_Blend    blend  = face->blend;
    FT_Vector*  delta_xy = NULL;

    FT_Error    error;
    FT_ULong    glyph_start;
    FT_UInt     tupleCount;
    FT_ULong    offsetToData;
    FT_ULong    here;
    FT_UInt     i, j;
    FT_Fixed*   tuple_coords    = NULL;
    FT_Fixed*   im_start_coords = NULL;
    FT_Fixed*   im_end_coords   = NULL;
    FT_UInt     point_count, spoint_count = 0;
    FT_UShort*  sharedpoints = NULL;
    FT_UShort*  localpoints  = NULL;
    FT_UShort*  points;
    FT_Short    *deltas_x, *deltas_y;


    if ( !face->doblend || blend == NULL )
      return FT_THROW( Invalid_Argument );

    /* to be freed by the caller */
    if ( FT_NEW_ARRAY( delta_xy, n_points ) )
      goto Exit;
    *deltas = delta_xy;

    if ( glyph_index >= blend->gv_glyphcnt      ||
         blend->glyphoffsets[glyph_index] ==
           blend->glyphoffsets[glyph_index + 1] )
      return FT_Err_Ok;               /* no variation data for this glyph */

    if ( FT_STREAM_SEEK( blend->glyphoffsets[glyph_index] )   ||
         FT_FRAME_ENTER( blend->glyphoffsets[glyph_index + 1] -
                           blend->glyphoffsets[glyph_index] ) )
      goto Fail1;

    glyph_start = FT_Stream_FTell( stream );

    /* each set of glyph variation data is formatted similarly to `cvar' */
    /* (except we get shared points and global tuples)                   */

    if ( FT_NEW_ARRAY( tuple_coords, blend->num_axis )    ||
         FT_NEW_ARRAY( im_start_coords, blend->num_axis ) ||
         FT_NEW_ARRAY( im_end_coords, blend->num_axis )   )
      goto Fail2;

    tupleCount   = FT_GET_USHORT();
    offsetToData = glyph_start + FT_GET_USHORT();

    if ( tupleCount & GX_TC_TUPLES_SHARE_POINT_NUMBERS )
    {
      here = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, offsetToData );

      sharedpoints = ft_var_readpackedpoints( stream, &spoint_count );
      offsetToData = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, here );
    }

    for ( i = 0; i < ( tupleCount & GX_TC_TUPLE_COUNT_MASK ); ++i )
    {
      FT_UInt   tupleDataSize;
      FT_UInt   tupleIndex;
      FT_Fixed  apply;


      tupleDataSize = FT_GET_USHORT();
      tupleIndex    = FT_GET_USHORT();

      if ( tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          tuple_coords[j] = FT_GET_SHORT() << 2;  /* convert from        */
                                                  /* short frac to fixed */
      }
      else if ( ( tupleIndex & GX_TI_TUPLE_INDEX_MASK ) >= blend->tuplecount )
      {
        error = FT_THROW( Invalid_Table );
        goto Fail3;
      }
      else
      {
        FT_MEM_COPY(
          tuple_coords,
          &blend->tuplecoords[(tupleIndex & 0xFFF) * blend->num_axis],
          blend->num_axis * sizeof ( FT_Fixed ) );
      }

      if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          im_start_coords[j] = FT_GET_SHORT() << 2;
        for ( j = 0; j < blend->num_axis; ++j )
          im_end_coords[j] = FT_GET_SHORT() << 2;
      }

      apply = ft_var_apply_tuple( blend,
                                  (FT_UShort)tupleIndex,
                                  tuple_coords,
                                  im_start_coords,
                                  im_end_coords );

      if ( apply == 0 )              /* tuple isn't active for our blend */
      {
        offsetToData += tupleDataSize;
        continue;
      }

      here = FT_Stream_FTell( stream );

      if ( tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS )
      {
        FT_Stream_SeekSet( stream, offsetToData );

        localpoints = ft_var_readpackedpoints( stream, &point_count );
        points      = localpoints;
      }
      else
      {
        points      = sharedpoints;
        point_count = spoint_count;
      }

      deltas_x = ft_var_readpackeddeltas( stream,
                                          point_count == 0 ? n_points
                                                           : point_count );
      deltas_y = ft_var_readpackeddeltas( stream,
                                          point_count == 0 ? n_points
                                                           : point_count );

      if ( points == NULL || deltas_y == NULL || deltas_x == NULL )
        ; /* failure, ignore it */

      else if ( points == ALL_POINTS )
      {
        /* this means that there are deltas for every point in the glyph */
        for ( j = 0; j < n_points; ++j )
        {
          delta_xy[j].x += FT_MulFix( deltas_x[j], apply );
          delta_xy[j].y += FT_MulFix( deltas_y[j], apply );
        }
      }

      else
      {
        for ( j = 0; j < point_count; ++j )
        {
          if ( localpoints[j] >= n_points )
            continue;

          delta_xy[localpoints[j]].x += FT_MulFix( deltas_x[j], apply );
          delta_xy[localpoints[j]].y += FT_MulFix( deltas_y[j], apply );
        }
      }

      if ( localpoints != ALL_POINTS )
        FT_FREE( localpoints );
      FT_FREE( deltas_x );
      FT_FREE( deltas_y );

      offsetToData += tupleDataSize;

      FT_Stream_SeekSet( stream, here );
    }

  Fail3:
    FT_FREE( tuple_coords );
    FT_FREE( im_start_coords );
    FT_FREE( im_end_coords );

  Fail2:
    FT_FRAME_EXIT();

  Fail1:
    if ( error )
    {
      FT_FREE( delta_xy );
      *deltas = NULL;
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_done_blend                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Frees the blend internal data structure.                           */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_done_blend( FT_Memory  memory,
                 GX_Blend   blend )
  {
    if ( blend != NULL )
    {
      FT_UInt  i;


      FT_FREE( blend->normalizedcoords );
      FT_FREE( blend->mmvar );

      if ( blend->avar_segment != NULL )
      {
        for ( i = 0; i < blend->num_axis; ++i )
          FT_FREE( blend->avar_segment[i].correspondence );
        FT_FREE( blend->avar_segment );
      }

      FT_FREE( blend->tuplecoords );
      FT_FREE( blend->glyphoffsets );
      FT_FREE( blend );
    }
  }

#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */


/* END */