Visualization Library 2.0.0-b5

A lightweight C++ OpenGL middleware for 2D/3D graphics

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ttpload.c
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1 /***************************************************************************/
2 /* */
3 /* ttpload.c */
4 /* */
5 /* TrueType-specific tables loader (body). */
6 /* */
7 /* Copyright 1996-2002, 2004-2013 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
9 /* */
10 /* This file is part of the FreeType project, and may only be used, */
11 /* modified, and distributed under the terms of the FreeType project */
12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13 /* this file you indicate that you have read the license and */
14 /* understand and accept it fully. */
15 /* */
16 /***************************************************************************/
17 
18 
19 #include <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_OBJECTS_H
22 #include FT_INTERNAL_STREAM_H
23 #include FT_TRUETYPE_TAGS_H
24 
25 #include "ttpload.h"
26 
27 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
28 #include "ttgxvar.h"
29 #endif
30 
31 #include "tterrors.h"
32 
33 
34  /*************************************************************************/
35  /* */
36  /* The macro FT_COMPONENT is used in trace mode. It is an implicit */
37  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
38  /* messages during execution. */
39  /* */
40 #undef FT_COMPONENT
41 #define FT_COMPONENT trace_ttpload
42 
43 
44  /*************************************************************************/
45  /* */
46  /* <Function> */
47  /* tt_face_load_loca */
48  /* */
49  /* <Description> */
50  /* Load the locations table. */
51  /* */
52  /* <InOut> */
53  /* face :: A handle to the target face object. */
54  /* */
55  /* <Input> */
56  /* stream :: The input stream. */
57  /* */
58  /* <Return> */
59  /* FreeType error code. 0 means success. */
60  /* */
61  FT_LOCAL_DEF( FT_Error )
62  tt_face_load_loca( TT_Face face,
63  FT_Stream stream )
64  {
65  FT_Error error;
66  FT_ULong table_len;
67  FT_Int shift;
68 
69 
70  /* we need the size of the `glyf' table for malformed `loca' tables */
71  error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
72 
73  /* it is possible that a font doesn't have a glyf table at all */
74  /* or its size is zero */
75  if ( FT_ERR_EQ( error, Table_Missing ) )
76  face->glyf_len = 0;
77  else if ( error )
78  goto Exit;
79 
80  FT_TRACE2(( "Locations " ));
81  error = face->goto_table( face, TTAG_loca, stream, &table_len );
82  if ( error )
83  {
84  error = FT_THROW( Locations_Missing );
85  goto Exit;
86  }
87 
88  if ( face->header.Index_To_Loc_Format != 0 )
89  {
90  shift = 2;
91 
92  if ( table_len >= 0x40000L )
93  {
94  FT_TRACE2(( "table too large\n" ));
95  error = FT_THROW( Invalid_Table );
96  goto Exit;
97  }
98  face->num_locations = table_len >> shift;
99  }
100  else
101  {
102  shift = 1;
103 
104  if ( table_len >= 0x20000L )
105  {
106  FT_TRACE2(( "table too large\n" ));
107  error = FT_THROW( Invalid_Table );
108  goto Exit;
109  }
110  face->num_locations = table_len >> shift;
111  }
112 
113  if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 )
114  {
115  FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n",
116  face->num_locations - 1, face->root.num_glyphs ));
117 
118  /* we only handle the case where `maxp' gives a larger value */
119  if ( face->num_locations <= (FT_ULong)face->root.num_glyphs )
120  {
121  FT_Long new_loca_len =
122  ( (FT_Long)( face->root.num_glyphs ) + 1 ) << shift;
123 
124  TT_Table entry = face->dir_tables;
125  TT_Table limit = entry + face->num_tables;
126 
127  FT_Long pos = FT_Stream_Pos( stream );
128  FT_Long dist = 0x7FFFFFFFL;
129 
130 
131  /* compute the distance to next table in font file */
132  for ( ; entry < limit; entry++ )
133  {
134  FT_Long diff = entry->Offset - pos;
135 
136 
137  if ( diff > 0 && diff < dist )
138  dist = diff;
139  }
140 
141  if ( entry == limit )
142  {
143  /* `loca' is the last table */
144  dist = stream->size - pos;
145  }
146 
147  if ( new_loca_len <= dist )
148  {
149  face->num_locations = face->root.num_glyphs + 1;
150  table_len = new_loca_len;
151 
152  FT_TRACE2(( "adjusting num_locations to %d\n",
153  face->num_locations ));
154  }
155  }
156  }
157 
158  /*
159  * Extract the frame. We don't need to decompress it since
160  * we are able to parse it directly.
161  */
162  if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) )
163  goto Exit;
164 
165  FT_TRACE2(( "loaded\n" ));
166 
167  Exit:
168  return error;
169  }
170 
171 
172  FT_LOCAL_DEF( FT_ULong )
173  tt_face_get_location( TT_Face face,
174  FT_UInt gindex,
175  FT_UInt *asize )
176  {
177  FT_ULong pos1, pos2;
178  FT_Byte* p;
179  FT_Byte* p_limit;
180 
181 
182  pos1 = pos2 = 0;
183 
184  if ( gindex < face->num_locations )
185  {
186  if ( face->header.Index_To_Loc_Format != 0 )
187  {
188  p = face->glyph_locations + gindex * 4;
189  p_limit = face->glyph_locations + face->num_locations * 4;
190 
191  pos1 = FT_NEXT_ULONG( p );
192  pos2 = pos1;
193 
194  if ( p + 4 <= p_limit )
195  pos2 = FT_NEXT_ULONG( p );
196  }
197  else
198  {
199  p = face->glyph_locations + gindex * 2;
200  p_limit = face->glyph_locations + face->num_locations * 2;
201 
202  pos1 = FT_NEXT_USHORT( p );
203  pos2 = pos1;
204 
205  if ( p + 2 <= p_limit )
206  pos2 = FT_NEXT_USHORT( p );
207 
208  pos1 <<= 1;
209  pos2 <<= 1;
210  }
211  }
212 
213  /* Check broken location data */
214  if ( pos1 > face->glyf_len )
215  {
216  FT_TRACE1(( "tt_face_get_location:"
217  " too large offset=0x%08lx found for gid=0x%04lx,"
218  " exceeding the end of glyf table (0x%08lx)\n",
219  pos1, gindex, face->glyf_len ));
220  *asize = 0;
221  return 0;
222  }
223 
224  if ( pos2 > face->glyf_len )
225  {
226  FT_TRACE1(( "tt_face_get_location:"
227  " too large offset=0x%08lx found for gid=0x%04lx,"
228  " truncate at the end of glyf table (0x%08lx)\n",
229  pos2, gindex + 1, face->glyf_len ));
230  pos2 = face->glyf_len;
231  }
232 
233  /* The `loca' table must be ordered; it refers to the length of */
234  /* an entry as the difference between the current and the next */
235  /* position. However, there do exist (malformed) fonts which */
236  /* don't obey this rule, so we are only able to provide an */
237  /* upper bound for the size. */
238  /* */
239  /* We get (intentionally) a wrong, non-zero result in case the */
240  /* `glyf' table is missing. */
241  if ( pos2 >= pos1 )
242  *asize = (FT_UInt)( pos2 - pos1 );
243  else
244  *asize = (FT_UInt)( face->glyf_len - pos1 );
245 
246  return pos1;
247  }
248 
249 
250  FT_LOCAL_DEF( void )
251  tt_face_done_loca( TT_Face face )
252  {
253  FT_Stream stream = face->root.stream;
254 
255 
256  FT_FRAME_RELEASE( face->glyph_locations );
257  face->num_locations = 0;
258  }
259 
260 
261 
262  /*************************************************************************/
263  /* */
264  /* <Function> */
265  /* tt_face_load_cvt */
266  /* */
267  /* <Description> */
268  /* Load the control value table into a face object. */
269  /* */
270  /* <InOut> */
271  /* face :: A handle to the target face object. */
272  /* */
273  /* <Input> */
274  /* stream :: A handle to the input stream. */
275  /* */
276  /* <Return> */
277  /* FreeType error code. 0 means success. */
278  /* */
279  FT_LOCAL_DEF( FT_Error )
280  tt_face_load_cvt( TT_Face face,
281  FT_Stream stream )
282  {
283 #ifdef TT_USE_BYTECODE_INTERPRETER
284 
285  FT_Error error;
286  FT_Memory memory = stream->memory;
287  FT_ULong table_len;
288 
289 
290  FT_TRACE2(( "CVT " ));
291 
292  error = face->goto_table( face, TTAG_cvt, stream, &table_len );
293  if ( error )
294  {
295  FT_TRACE2(( "is missing\n" ));
296 
297  face->cvt_size = 0;
298  face->cvt = NULL;
299  error = FT_Err_Ok;
300 
301  goto Exit;
302  }
303 
304  face->cvt_size = table_len / 2;
305 
306  if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) )
307  goto Exit;
308 
309  if ( FT_FRAME_ENTER( face->cvt_size * 2L ) )
310  goto Exit;
311 
312  {
313  FT_Short* cur = face->cvt;
314  FT_Short* limit = cur + face->cvt_size;
315 
316 
317  for ( ; cur < limit; cur++ )
318  *cur = FT_GET_SHORT();
319  }
320 
321  FT_FRAME_EXIT();
322  FT_TRACE2(( "loaded\n" ));
323 
324 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
325  if ( face->doblend )
326  error = tt_face_vary_cvt( face, stream );
327 #endif
328 
329  Exit:
330  return error;
331 
332 #else /* !TT_USE_BYTECODE_INTERPRETER */
333 
334  FT_UNUSED( face );
335  FT_UNUSED( stream );
336 
337  return FT_Err_Ok;
338 
339 #endif
340  }
341 
342 
343  /*************************************************************************/
344  /* */
345  /* <Function> */
346  /* tt_face_load_fpgm */
347  /* */
348  /* <Description> */
349  /* Load the font program. */
350  /* */
351  /* <InOut> */
352  /* face :: A handle to the target face object. */
353  /* */
354  /* <Input> */
355  /* stream :: A handle to the input stream. */
356  /* */
357  /* <Return> */
358  /* FreeType error code. 0 means success. */
359  /* */
360  FT_LOCAL_DEF( FT_Error )
361  tt_face_load_fpgm( TT_Face face,
362  FT_Stream stream )
363  {
364 #ifdef TT_USE_BYTECODE_INTERPRETER
365 
366  FT_Error error;
367  FT_ULong table_len;
368 
369 
370  FT_TRACE2(( "Font program " ));
371 
372  /* The font program is optional */
373  error = face->goto_table( face, TTAG_fpgm, stream, &table_len );
374  if ( error )
375  {
376  face->font_program = NULL;
377  face->font_program_size = 0;
378  error = FT_Err_Ok;
379 
380  FT_TRACE2(( "is missing\n" ));
381  }
382  else
383  {
384  face->font_program_size = table_len;
385  if ( FT_FRAME_EXTRACT( table_len, face->font_program ) )
386  goto Exit;
387 
388  FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size ));
389  }
390 
391  Exit:
392  return error;
393 
394 #else /* !TT_USE_BYTECODE_INTERPRETER */
395 
396  FT_UNUSED( face );
397  FT_UNUSED( stream );
398 
399  return FT_Err_Ok;
400 
401 #endif
402  }
403 
404 
405  /*************************************************************************/
406  /* */
407  /* <Function> */
408  /* tt_face_load_prep */
409  /* */
410  /* <Description> */
411  /* Load the cvt program. */
412  /* */
413  /* <InOut> */
414  /* face :: A handle to the target face object. */
415  /* */
416  /* <Input> */
417  /* stream :: A handle to the input stream. */
418  /* */
419  /* <Return> */
420  /* FreeType error code. 0 means success. */
421  /* */
422  FT_LOCAL_DEF( FT_Error )
423  tt_face_load_prep( TT_Face face,
424  FT_Stream stream )
425  {
426 #ifdef TT_USE_BYTECODE_INTERPRETER
427 
428  FT_Error error;
429  FT_ULong table_len;
430 
431 
432  FT_TRACE2(( "Prep program " ));
433 
434  error = face->goto_table( face, TTAG_prep, stream, &table_len );
435  if ( error )
436  {
437  face->cvt_program = NULL;
438  face->cvt_program_size = 0;
439  error = FT_Err_Ok;
440 
441  FT_TRACE2(( "is missing\n" ));
442  }
443  else
444  {
445  face->cvt_program_size = table_len;
446  if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) )
447  goto Exit;
448 
449  FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size ));
450  }
451 
452  Exit:
453  return error;
454 
455 #else /* !TT_USE_BYTECODE_INTERPRETER */
456 
457  FT_UNUSED( face );
458  FT_UNUSED( stream );
459 
460  return FT_Err_Ok;
461 
462 #endif
463  }
464 
465 
466  /*************************************************************************/
467  /* */
468  /* <Function> */
469  /* tt_face_load_hdmx */
470  /* */
471  /* <Description> */
472  /* Load the `hdmx' table into the face object. */
473  /* */
474  /* <Input> */
475  /* face :: A handle to the target face object. */
476  /* */
477  /* stream :: A handle to the input stream. */
478  /* */
479  /* <Return> */
480  /* FreeType error code. 0 means success. */
481  /* */
482 
483  FT_LOCAL_DEF( FT_Error )
484  tt_face_load_hdmx( TT_Face face,
485  FT_Stream stream )
486  {
487  FT_Error error;
488  FT_Memory memory = stream->memory;
489  FT_UInt version, nn, num_records;
490  FT_ULong table_size, record_size;
491  FT_Byte* p;
492  FT_Byte* limit;
493 
494 
495  /* this table is optional */
496  error = face->goto_table( face, TTAG_hdmx, stream, &table_size );
497  if ( error || table_size < 8 )
498  return FT_Err_Ok;
499 
500  if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) )
501  goto Exit;
502 
503  p = face->hdmx_table;
504  limit = p + table_size;
505 
506  version = FT_NEXT_USHORT( p );
507  num_records = FT_NEXT_USHORT( p );
508  record_size = FT_NEXT_ULONG( p );
509 
510  /* The maximum number of bytes in an hdmx device record is the */
511  /* maximum number of glyphs + 2; this is 0xFFFF + 2; this is */
512  /* the reason why `record_size' is a long (which we read as */
513  /* unsigned long for convenience). In practice, two bytes */
514  /* sufficient to hold the size value. */
515  /* */
516  /* There are at least two fonts, HANNOM-A and HANNOM-B version */
517  /* 2.0 (2005), which get this wrong: The upper two bytes of */
518  /* the size value are set to 0xFF instead of 0x00. We catch */
519  /* and fix this. */
520 
521  if ( record_size >= 0xFFFF0000UL )
522  record_size &= 0xFFFFU;
523 
524  /* The limit for `num_records' is a heuristic value. */
525 
526  if ( version != 0 || num_records > 255 || record_size > 0x10001L )
527  {
528  error = FT_THROW( Invalid_File_Format );
529  goto Fail;
530  }
531 
532  if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) )
533  goto Fail;
534 
535  for ( nn = 0; nn < num_records; nn++ )
536  {
537  if ( p + record_size > limit )
538  break;
539 
540  face->hdmx_record_sizes[nn] = p[0];
541  p += record_size;
542  }
543 
544  face->hdmx_record_count = nn;
545  face->hdmx_table_size = table_size;
546  face->hdmx_record_size = record_size;
547 
548  Exit:
549  return error;
550 
551  Fail:
552  FT_FRAME_RELEASE( face->hdmx_table );
553  face->hdmx_table_size = 0;
554  goto Exit;
555  }
556 
557 
558  FT_LOCAL_DEF( void )
559  tt_face_free_hdmx( TT_Face face )
560  {
561  FT_Stream stream = face->root.stream;
562  FT_Memory memory = stream->memory;
563 
564 
565  FT_FREE( face->hdmx_record_sizes );
566  FT_FRAME_RELEASE( face->hdmx_table );
567  }
568 
569 
570  /*************************************************************************/
571  /* */
572  /* Return the advance width table for a given pixel size if it is found */
573  /* in the font's `hdmx' table (if any). */
574  /* */
575  FT_LOCAL_DEF( FT_Byte* )
576  tt_face_get_device_metrics( TT_Face face,
577  FT_UInt ppem,
578  FT_UInt gindex )
579  {
580  FT_UInt nn;
581  FT_Byte* result = NULL;
582  FT_ULong record_size = face->hdmx_record_size;
583  FT_Byte* record = face->hdmx_table + 8;
584 
585 
586  for ( nn = 0; nn < face->hdmx_record_count; nn++ )
587  if ( face->hdmx_record_sizes[nn] == ppem )
588  {
589  gindex += 2;
590  if ( gindex < record_size )
591  result = record + nn * record_size + gindex;
592  break;
593  }
594 
595  return result;
596  }
597 
598 
599 /* END */
FT_Error
int FT_Error
Definition: fttypes.h:296
stream
GLuint GLuint stream
Definition: khronos_glext.h:7516
TTAG_hdmx
#define TTAG_hdmx
Definition: tttags.h:62
FT_Long
signed long FT_Long
Definition: fttypes.h:238
FT_ULong
unsigned long FT_ULong
Definition: fttypes.h:249
p
GLfloat GLfloat p
Definition: khronos_glext.h:8896
TTAG_glyf
#define TTAG_glyf
Definition: tttags.h:58
NULL
#define NULL
Definition: ftobjs.h:61
FT_Int
signed int FT_Int
Definition: fttypes.h:216
TT_TableRec_::Offset
FT_ULong Offset
Definition: tttypes.h:134
FT_THROW
return FT_THROW(Missing_Property)
tt_face_load_loca
tt_face_load_loca(TT_Face face, FT_Stream stream)
Definition: ttpload.c:62
FT_UNUSED
#define FT_UNUSED(arg)
Definition: ftconfig.h:76
FT_Stream_Pos
FT_Stream_Pos(FT_Stream stream)
Definition: ftstream.c:103
FT_Err_Ok
return FT_Err_Ok
Definition: ftbbox.c:645
tt_face_get_device_metrics
tt_face_get_device_metrics(TT_Face face, FT_UInt ppem, FT_UInt gindex)
Definition: ttpload.c:576
tt_face_load_cvt
tt_face_load_cvt(TT_Face face, FT_Stream stream)
Definition: ttpload.c:280
FT_TRACE1
#define FT_TRACE1(varformat)
Definition: ftdebug.h:158
face
GLenum GLuint GLint GLenum face
Definition: khronos_glext.h:7019
tt_face_free_hdmx
tt_face_free_hdmx(TT_Face face)
Definition: ttpload.c:559
FT_Byte
unsigned char FT_Byte
Definition: fttypes.h:150
FT_StreamRec_::memory
FT_Memory memory
Definition: ftsystem.h:332
FT_FREE
#define FT_FREE(ptr)
Definition: ftmemory.h:286
tt_face_load_hdmx
tt_face_load_hdmx(TT_Face face, FT_Stream stream)
Definition: ttpload.c:484
TTAG_fpgm
#define TTAG_fpgm
Definition: tttags.h:54
error
FT_Error error
Definition: cffdrivr.c:411
FT_TRACE2
#define FT_TRACE2(varformat)
Definition: ftdebug.h:159
TT_TableRec_
Definition: tttypes.h:130
FT_ERR_EQ
#define FT_ERR_EQ(x, e)
Definition: fttypes.h:587
version
int const char * version
Definition: zlib.h:813
TTAG_loca
#define TTAG_loca
Definition: tttags.h:70
tt_face_vary_cvt
tt_face_vary_cvt(TT_Face face, FT_Stream stream)
FT_Short
signed short FT_Short
Definition: fttypes.h:194
FT_Memory
typedefFT_BEGIN_HEADER struct FT_MemoryRec_ * FT_Memory
Definition: ftsystem.h:66
FT_FRAME_EXIT
#define FT_FRAME_EXIT()
Definition: ftstream.h:514
FT_NEW_ARRAY
#define FT_NEW_ARRAY(ptr, count)
Definition: ftmemory.h:290
FT_NEXT_USHORT
#define FT_NEXT_USHORT(buffer)
Definition: ftstream.h:226
FT_FRAME_RELEASE
#define FT_FRAME_RELEASE(bytes)
Definition: ftstream.h:522
TTAG_cvt
#define TTAG_cvt
Definition: tttags.h:47
result
GLuint64EXT * result
Definition: khronos_glext.h:11298
FT_UInt
unsigned int FT_UInt
Definition: fttypes.h:227
tt_face_load_prep
tt_face_load_prep(TT_Face face, FT_Stream stream)
Definition: ttpload.c:423
FT_NEXT_ULONG
#define FT_NEXT_ULONG(buffer)
Definition: ftstream.h:238
FT_FRAME_EXTRACT
#define FT_FRAME_EXTRACT(size, bytes)
Definition: ftstream.h:517
FT_GET_SHORT
#define FT_GET_SHORT()
Definition: ftstream.h:288
FT_FRAME_ENTER
#define FT_FRAME_ENTER(size)
Definition: ftstream.h:510
tt_face_load_fpgm
tt_face_load_fpgm(TT_Face face, FT_Stream stream)
Definition: ttpload.c:361
FT_StreamRec_
Definition: ftsystem.h:321
TT_FaceRec_
Definition: tttypes.h:1258
limit
GLint limit
Definition: khronos_glext.h:10320
tt_face_get_location
tt_face_get_location(TT_Face face, FT_UInt gindex, FT_UInt *asize)
Definition: ttpload.c:173
FT_LOCAL_DEF
#define FT_LOCAL_DEF(x)
Definition: ftconfig.h:236
tt_face_done_loca
tt_face_done_loca(TT_Face face)
Definition: ttpload.c:251
TTAG_prep
#define TTAG_prep
Definition: tttags.h:87

Visualization Library 2.0.0-b5 Reference Documentation

Updated on Mon Feb 10 2020 02:44:44.

© Copyright Michele Bosi. All rights reserved.