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
|
/***************************************************************************/
/* */
/* ttpload.c */
/* */
/* TrueType-specific tables loader (body). */
/* */
/* Copyright 1996-2002, 2004-2013 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* 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. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include <internal/ftdebug.h>
#include <internal/ftobjs.h>
#include <internal/ftstream.h>
#include FT_TRUETYPE_TAGS_H
#include "ttpload.h"
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include "ttgxvar.h"
#endif
#include "tterrors.h"
/*************************************************************************/
/* */
/* 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_ttpload
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_loca */
/* */
/* <Description> */
/* Load the locations table. */
/* */
/* <InOut> */
/* face :: A handle to the target face object. */
/* */
/* <Input> */
/* stream :: The input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_loca( TT_Face face,
FT_Stream stream )
{
FT_Error error;
FT_ULong table_len;
FT_Int shift;
/* we need the size of the `glyf' table for malformed `loca' tables */
error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
/* it is possible that a font doesn't have a glyf table at all */
/* or its size is zero */
if ( FT_ERR_EQ( error, Table_Missing ) )
face->glyf_len = 0;
else if ( error )
goto Exit;
FT_TRACE2(( "Locations " ));
error = face->goto_table( face, TTAG_loca, stream, &table_len );
if ( error )
{
error = FT_THROW( Locations_Missing );
goto Exit;
}
if ( face->header.Index_To_Loc_Format != 0 )
{
shift = 2;
if ( table_len >= 0x40000L )
{
FT_TRACE2(( "table too large\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
face->num_locations = table_len >> shift;
}
else
{
shift = 1;
if ( table_len >= 0x20000L )
{
FT_TRACE2(( "table too large\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
face->num_locations = table_len >> shift;
}
if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 )
{
FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n",
face->num_locations - 1, face->root.num_glyphs ));
/* we only handle the case where `maxp' gives a larger value */
if ( face->num_locations <= (FT_ULong)face->root.num_glyphs )
{
FT_Long new_loca_len =
( (FT_Long)( face->root.num_glyphs ) + 1 ) << shift;
TT_Table entry = face->dir_tables;
TT_Table limit = entry + face->num_tables;
FT_Long pos = FT_Stream_Pos( stream );
FT_Long dist = 0x7FFFFFFFL;
/* compute the distance to next table in font file */
for ( ; entry < limit; entry++ )
{
FT_Long diff = entry->Offset - pos;
if ( diff > 0 && diff < dist )
dist = diff;
}
if ( entry == limit )
{
/* `loca' is the last table */
dist = stream->size - pos;
}
if ( new_loca_len <= dist )
{
face->num_locations = face->root.num_glyphs + 1;
table_len = new_loca_len;
FT_TRACE2(( "adjusting num_locations to %d\n",
face->num_locations ));
}
}
}
/*
* Extract the frame. We don't need to decompress it since
* we are able to parse it directly.
*/
if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) )
goto Exit;
FT_TRACE2(( "loaded\n" ));
Exit:
return error;
}
FT_LOCAL_DEF( FT_ULong )
tt_face_get_location( TT_Face face,
FT_UInt gindex,
FT_UInt *asize )
{
FT_ULong pos1, pos2;
FT_Byte* p;
FT_Byte* p_limit;
pos1 = pos2 = 0;
if ( gindex < face->num_locations )
{
if ( face->header.Index_To_Loc_Format != 0 )
{
p = face->glyph_locations + gindex * 4;
p_limit = face->glyph_locations + face->num_locations * 4;
pos1 = FT_NEXT_ULONG( p );
pos2 = pos1;
if ( p + 4 <= p_limit )
pos2 = FT_NEXT_ULONG( p );
}
else
{
p = face->glyph_locations + gindex * 2;
p_limit = face->glyph_locations + face->num_locations * 2;
pos1 = FT_NEXT_USHORT( p );
pos2 = pos1;
if ( p + 2 <= p_limit )
pos2 = FT_NEXT_USHORT( p );
pos1 <<= 1;
pos2 <<= 1;
}
}
/* Check broken location data */
if ( pos1 > face->glyf_len )
{
FT_TRACE1(( "tt_face_get_location:"
" too large offset=0x%08lx found for gid=0x%04lx,"
" exceeding the end of glyf table (0x%08lx)\n",
pos1, gindex, face->glyf_len ));
*asize = 0;
return 0;
}
if ( pos2 > face->glyf_len )
{
FT_TRACE1(( "tt_face_get_location:"
" too large offset=0x%08lx found for gid=0x%04lx,"
" truncate at the end of glyf table (0x%08lx)\n",
pos2, gindex + 1, face->glyf_len ));
pos2 = face->glyf_len;
}
/* The `loca' table must be ordered; it refers to the length of */
/* an entry as the difference between the current and the next */
/* position. However, there do exist (malformed) fonts which */
/* don't obey this rule, so we are only able to provide an */
/* upper bound for the size. */
/* */
/* We get (intentionally) a wrong, non-zero result in case the */
/* `glyf' table is missing. */
if ( pos2 >= pos1 )
*asize = (FT_UInt)( pos2 - pos1 );
else
*asize = (FT_UInt)( face->glyf_len - pos1 );
return pos1;
}
FT_LOCAL_DEF( void )
tt_face_done_loca( TT_Face face )
{
FT_Stream stream = face->root.stream;
FT_FRAME_RELEASE( face->glyph_locations );
face->num_locations = 0;
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_cvt */
/* */
/* <Description> */
/* Load the control value table into a face object. */
/* */
/* <InOut> */
/* face :: A handle to the target face object. */
/* */
/* <Input> */
/* stream :: A handle to the input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_cvt( TT_Face face,
FT_Stream stream )
{
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_Error error;
FT_Memory memory = stream->memory;
FT_ULong table_len;
FT_TRACE2(( "CVT " ));
error = face->goto_table( face, TTAG_cvt, stream, &table_len );
if ( error )
{
FT_TRACE2(( "is missing\n" ));
face->cvt_size = 0;
face->cvt = NULL;
error = FT_Err_Ok;
goto Exit;
}
face->cvt_size = table_len / 2;
if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) )
goto Exit;
if ( FT_FRAME_ENTER( face->cvt_size * 2L ) )
goto Exit;
{
FT_Short* cur = face->cvt;
FT_Short* limit = cur + face->cvt_size;
for ( ; cur < limit; cur++ )
*cur = FT_GET_SHORT();
}
FT_FRAME_EXIT();
FT_TRACE2(( "loaded\n" ));
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
if ( face->doblend )
error = tt_face_vary_cvt( face, stream );
#endif
Exit:
return error;
#else /* !TT_USE_BYTECODE_INTERPRETER */
FT_UNUSED( face );
FT_UNUSED( stream );
return FT_Err_Ok;
#endif
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_fpgm */
/* */
/* <Description> */
/* Load the font program. */
/* */
/* <InOut> */
/* face :: A handle to the target face object. */
/* */
/* <Input> */
/* stream :: A handle to the input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_fpgm( TT_Face face,
FT_Stream stream )
{
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_Error error;
FT_ULong table_len;
FT_TRACE2(( "Font program " ));
/* The font program is optional */
error = face->goto_table( face, TTAG_fpgm, stream, &table_len );
if ( error )
{
face->font_program = NULL;
face->font_program_size = 0;
error = FT_Err_Ok;
FT_TRACE2(( "is missing\n" ));
}
else
{
face->font_program_size = table_len;
if ( FT_FRAME_EXTRACT( table_len, face->font_program ) )
goto Exit;
FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size ));
}
Exit:
return error;
#else /* !TT_USE_BYTECODE_INTERPRETER */
FT_UNUSED( face );
FT_UNUSED( stream );
return FT_Err_Ok;
#endif
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_prep */
/* */
/* <Description> */
/* Load the cvt program. */
/* */
/* <InOut> */
/* face :: A handle to the target face object. */
/* */
/* <Input> */
/* stream :: A handle to the input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_prep( TT_Face face,
FT_Stream stream )
{
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_Error error;
FT_ULong table_len;
FT_TRACE2(( "Prep program " ));
error = face->goto_table( face, TTAG_prep, stream, &table_len );
if ( error )
{
face->cvt_program = NULL;
face->cvt_program_size = 0;
error = FT_Err_Ok;
FT_TRACE2(( "is missing\n" ));
}
else
{
face->cvt_program_size = table_len;
if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) )
goto Exit;
FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size ));
}
Exit:
return error;
#else /* !TT_USE_BYTECODE_INTERPRETER */
FT_UNUSED( face );
FT_UNUSED( stream );
return FT_Err_Ok;
#endif
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_hdmx */
/* */
/* <Description> */
/* Load the `hdmx' table into the face object. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
/* stream :: A handle to the input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_hdmx( TT_Face face,
FT_Stream stream )
{
FT_Error error;
FT_Memory memory = stream->memory;
FT_UInt version, nn, num_records;
FT_ULong table_size, record_size;
FT_Byte* p;
FT_Byte* limit;
/* this table is optional */
error = face->goto_table( face, TTAG_hdmx, stream, &table_size );
if ( error || table_size < 8 )
return FT_Err_Ok;
if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) )
goto Exit;
p = face->hdmx_table;
limit = p + table_size;
version = FT_NEXT_USHORT( p );
num_records = FT_NEXT_USHORT( p );
record_size = FT_NEXT_ULONG( p );
/* The maximum number of bytes in an hdmx device record is the */
/* maximum number of glyphs + 2; this is 0xFFFF + 2, thus */
/* explaining why `record_size' is a long (which we read as */
/* unsigned long for convenience). In practice, two bytes are */
/* sufficient to hold the size value. */
/* */
/* There are at least two fonts, HANNOM-A and HANNOM-B version */
/* 2.0 (2005), which get this wrong: The upper two bytes of */
/* the size value are set to 0xFF instead of 0x00. We catch */
/* and fix this. */
if ( record_size >= 0xFFFF0000UL )
record_size &= 0xFFFFU;
/* The limit for `num_records' is a heuristic value. */
if ( version != 0 ||
num_records > 255 ||
record_size > 0x10001L ||
record_size < 4 )
{
error = FT_THROW( Invalid_File_Format );
goto Fail;
}
if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) )
goto Fail;
for ( nn = 0; nn < num_records; nn++ )
{
if ( p + record_size > limit )
break;
face->hdmx_record_sizes[nn] = p[0];
p += record_size;
}
face->hdmx_record_count = nn;
face->hdmx_table_size = table_size;
face->hdmx_record_size = record_size;
Exit:
return error;
Fail:
FT_FRAME_RELEASE( face->hdmx_table );
face->hdmx_table_size = 0;
goto Exit;
}
FT_LOCAL_DEF( void )
tt_face_free_hdmx( TT_Face face )
{
FT_Stream stream = face->root.stream;
FT_Memory memory = stream->memory;
FT_FREE( face->hdmx_record_sizes );
FT_FRAME_RELEASE( face->hdmx_table );
}
/*************************************************************************/
/* */
/* Return the advance width table for a given pixel size if it is found */
/* in the font's `hdmx' table (if any). */
/* */
FT_LOCAL_DEF( FT_Byte* )
tt_face_get_device_metrics( TT_Face face,
FT_UInt ppem,
FT_UInt gindex )
{
FT_UInt nn;
FT_Byte* result = NULL;
FT_ULong record_size = face->hdmx_record_size;
FT_Byte* record = face->hdmx_table + 8;
for ( nn = 0; nn < face->hdmx_record_count; nn++ )
if ( face->hdmx_record_sizes[nn] == ppem )
{
gindex += 2;
if ( gindex < record_size )
result = record + nn * record_size + gindex;
break;
}
return result;
}
/* END */
|
