1 /*
2 * Copyright © 2007,2008,2009 Red Hat, Inc.
3 * Copyright © 2012 Google, Inc.
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29 #ifndef HB_OPEN_FILE_HH
30 #define HB_OPEN_FILE_HH
31
32 #include "hb-open-type.hh"
33 #include "hb-ot-head-table.hh"
34
35
36 namespace OT {
37
38
39 /*
40 *
41 * The OpenType Font File
42 *
43 */
44
45
46 /*
47 * Organization of an OpenType Font
48 */
49
50 struct OpenTypeFontFile;
51 struct OffsetTable;
52 struct TTCHeader;
53
54
55 typedef struct TableRecord
56 {
57 int cmp (Tag t) const { return -t.cmp (tag); }
58
59 static int cmp (const void *pa, const void *pb)
60 {
61 const TableRecord *a = (const TableRecord *) pa;
62 const TableRecord *b = (const TableRecord *) pb;
63 return b->cmp (a->tag);
64 }
65
66 bool sanitize (hb_sanitize_context_t *c) const
67 {
68 TRACE_SANITIZE (this);
69 return_trace (c->check_struct (this));
70 }
71
72 Tag tag; /* 4-byte identifier. */
73 CheckSum checkSum; /* CheckSum for this table. */
74 Offset32 offset; /* Offset from beginning of TrueType font
75 * file. */
76 HBUINT32 length; /* Length of this table. */
77 public:
78 DEFINE_SIZE_STATIC (16);
79 } OpenTypeTable;
80
81 typedef struct OffsetTable
82 {
83 friend struct OpenTypeFontFile;
84
85 unsigned int get_table_count () const { return tables.len; }
86 const TableRecord& get_table (unsigned int i) const
87 { return tables[i]; }
88 unsigned int get_table_tags (unsigned int start_offset,
89 unsigned int *table_count, /* IN/OUT */
90 hb_tag_t *table_tags /* OUT */) const
91 {
92 if (table_count)
93 {
94 if (start_offset >= tables.len)
95 *table_count = 0;
96 else
97 *table_count = MIN<unsigned int> (*table_count, tables.len - start_offset);
98
99 const TableRecord *sub_tables = tables.arrayZ + start_offset;
100 unsigned int count = *table_count;
101 for (unsigned int i = 0; i < count; i++)
102 table_tags[i] = sub_tables[i].tag;
103 }
104 return tables.len;
105 }
106 bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
107 {
108 Tag t;
109 t.set (tag);
110 return tables.bfind (t, table_index, HB_BFIND_NOT_FOUND_STORE, Index::NOT_FOUND_INDEX);
111 }
112 const TableRecord& get_table_by_tag (hb_tag_t tag) const
113 {
114 unsigned int table_index;
115 find_table_index (tag, &table_index);
116 return get_table (table_index);
117 }
118
119 public:
120
121 template <typename item_t>
122 bool serialize (hb_serialize_context_t *c,
123 hb_tag_t sfnt_tag,
124 hb_array_t<item_t> items)
125 {
126 TRACE_SERIALIZE (this);
127 /* Alloc 12 for the OTHeader. */
128 if (unlikely (!c->extend_min (*this))) return_trace (false);
129 /* Write sfntVersion (bytes 0..3). */
130 sfnt_version.set (sfnt_tag);
131 /* Take space for numTables, searchRange, entrySelector, RangeShift
132 * and the TableRecords themselves. */
133 if (unlikely (!tables.serialize (c, items.length))) return_trace (false);
134
135 const char *dir_end = (const char *) c->head;
136 HBUINT32 *checksum_adjustment = nullptr;
137
138 /* Write OffsetTables, alloc for and write actual table blobs. */
139 for (unsigned int i = 0; i < tables.len; i++)
140 {
141 TableRecord &rec = tables.arrayZ[i];
142 hb_blob_t *blob = items[i].blob;
143 rec.tag.set (items[i].tag);
144 rec.length.set (hb_blob_get_length (blob));
145 rec.offset.serialize (c, this);
146
147 /* Allocate room for the table and copy it. */
148 char *start = (char *) c->allocate_size<void> (rec.length);
149 if (unlikely (!start)) {return false;}
150
151 memcpy (start, hb_blob_get_data (blob, nullptr), rec.length);
152
153 /* 4-byte alignment. */
154 c->align (4);
155 const char *end = (const char *) c->head;
156
157 if (items[i].tag == HB_OT_TAG_head &&
158 (unsigned) (end - start) >= head::static_size)
159 {
160 head *h = (head *) start;
161 checksum_adjustment = &h->checkSumAdjustment;
162 checksum_adjustment->set (0);
163 }
164
165 rec.checkSum.set_for_data (start, end - start);
166 }
167
168 tables.qsort ();
169
170 if (checksum_adjustment)
171 {
172 CheckSum checksum;
173
174 /* The following line is a slower version of the following block. */
175 //checksum.set_for_data (this, (const char *) c->head - (const char *) this);
176 checksum.set_for_data (this, dir_end - (const char *) this);
177 for (unsigned int i = 0; i < items.length; i++)
178 {
179 TableRecord &rec = tables.arrayZ[i];
180 checksum.set (checksum + rec.checkSum);
181 }
182
183 checksum_adjustment->set (0xB1B0AFBAu - checksum);
184 }
185
186 return_trace (true);
187 }
188
189 bool sanitize (hb_sanitize_context_t *c) const
190 {
191 TRACE_SANITIZE (this);
192 return_trace (c->check_struct (this) && tables.sanitize (c));
193 }
194
195 protected:
196 Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
197 BinSearchArrayOf<TableRecord>
198 tables;
199 public:
200 DEFINE_SIZE_ARRAY (12, tables);
201 } OpenTypeFontFace;
202
203
204 /*
205 * TrueType Collections
206 */
207
208 struct TTCHeaderVersion1
209 {
210 friend struct TTCHeader;
211
212 unsigned int get_face_count () const { return table.len; }
213 const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }
214
215 bool sanitize (hb_sanitize_context_t *c) const
216 {
217 TRACE_SANITIZE (this);
218 return_trace (table.sanitize (c, this));
219 }
220
221 protected:
222 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
223 FixedVersion<>version; /* Version of the TTC Header (1.0),
224 * 0x00010000u */
225 LArrayOf<LOffsetTo<OffsetTable> >
226 table; /* Array of offsets to the OffsetTable for each font
227 * from the beginning of the file */
228 public:
229 DEFINE_SIZE_ARRAY (12, table);
230 };
231
232 struct TTCHeader
233 {
234 friend struct OpenTypeFontFile;
235
236 private:
237
238 unsigned int get_face_count () const
239 {
240 switch (u.header.version.major) {
241 case 2: /* version 2 is compatible with version 1 */
242 case 1: return u.version1.get_face_count ();
243 default:return 0;
244 }
245 }
246 const OpenTypeFontFace& get_face (unsigned int i) const
247 {
248 switch (u.header.version.major) {
249 case 2: /* version 2 is compatible with version 1 */
250 case 1: return u.version1.get_face (i);
251 default:return Null(OpenTypeFontFace);
252 }
253 }
254
255 bool sanitize (hb_sanitize_context_t *c) const
256 {
257 TRACE_SANITIZE (this);
258 if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
259 switch (u.header.version.major) {
260 case 2: /* version 2 is compatible with version 1 */
261 case 1: return_trace (u.version1.sanitize (c));
262 default:return_trace (true);
263 }
264 }
265
266 protected:
267 union {
268 struct {
269 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
270 FixedVersion<>version; /* Version of the TTC Header (1.0 or 2.0),
271 * 0x00010000u or 0x00020000u */
272 } header;
273 TTCHeaderVersion1 version1;
274 } u;
275 };
276
277 /*
278 * Mac Resource Fork
279 *
280 * http://mirror.informatimago.com/next/developer.apple.com/documentation/mac/MoreToolbox/MoreToolbox-99.html
281 */
282
283 struct ResourceRecord
284 {
285 const OpenTypeFontFace & get_face (const void *data_base) const
286 { return CastR<OpenTypeFontFace> ((data_base+offset).arrayZ); }
287
288 bool sanitize (hb_sanitize_context_t *c,
289 const void *data_base) const
290 {
291 TRACE_SANITIZE (this);
292 return_trace (c->check_struct (this) &&
293 offset.sanitize (c, data_base) &&
294 get_face (data_base).sanitize (c));
295 }
296
297 protected:
298 HBUINT16 id; /* Resource ID. */
299 HBINT16 nameOffset; /* Offset from beginning of resource name list
300 * to resource name, -1 means there is none. */
301 HBUINT8 attrs; /* Resource attributes */
302 NNOffsetTo<LArrayOf<HBUINT8>, HBUINT24>
303 offset; /* Offset from beginning of data block to
304 * data for this resource */
305 HBUINT32 reserved; /* Reserved for handle to resource */
306 public:
307 DEFINE_SIZE_STATIC (12);
308 };
309
310 #define HB_TAG_sfnt HB_TAG ('s','f','n','t')
311
312 struct ResourceTypeRecord
313 {
314 unsigned int get_resource_count () const
315 { return tag == HB_TAG_sfnt ? resCountM1 + 1 : 0; }
316
317 bool is_sfnt () const { return tag == HB_TAG_sfnt; }
318
319 const ResourceRecord& get_resource_record (unsigned int i,
320 const void *type_base) const
321 { return (type_base+resourcesZ).as_array (get_resource_count ())[i]; }
322
323 bool sanitize (hb_sanitize_context_t *c,
324 const void *type_base,
325 const void *data_base) const
326 {
327 TRACE_SANITIZE (this);
328 return_trace (c->check_struct (this) &&
329 resourcesZ.sanitize (c, type_base,
330 get_resource_count (),
331 data_base));
332 }
333
334 protected:
335 Tag tag; /* Resource type. */
336 HBUINT16 resCountM1; /* Number of resources minus 1. */
337 NNOffsetTo<UnsizedArrayOf<ResourceRecord> >
338 resourcesZ; /* Offset from beginning of resource type list
339 * to reference item list for this type. */
340 public:
341 DEFINE_SIZE_STATIC (8);
342 };
343
344 struct ResourceMap
345 {
346 unsigned int get_face_count () const
347 {
348 unsigned int count = get_type_count ();
349 for (unsigned int i = 0; i < count; i++)
350 {
351 const ResourceTypeRecord& type = get_type_record (i);
352 if (type.is_sfnt ())
353 return type.get_resource_count ();
354 }
355 return 0;
356 }
357
358 const OpenTypeFontFace& get_face (unsigned int idx,
359 const void *data_base) const
360 {
361 unsigned int count = get_type_count ();
362 for (unsigned int i = 0; i < count; i++)
363 {
364 const ResourceTypeRecord& type = get_type_record (i);
365 /* The check for idx < count is here because ResourceRecord is NOT null-safe.
366 * Because an offset of 0 there does NOT mean null. */
367 if (type.is_sfnt () && idx < type.get_resource_count ())
368 return type.get_resource_record (idx, &(this+typeList)).get_face (data_base);
369 }
370 return Null (OpenTypeFontFace);
371 }
372
373 bool sanitize (hb_sanitize_context_t *c, const void *data_base) const
374 {
375 TRACE_SANITIZE (this);
376 return_trace (c->check_struct (this) &&
377 typeList.sanitize (c, this,
378 &(this+typeList),
379 data_base));
380 }
381
382 private:
383 unsigned int get_type_count () const { return (this+typeList).lenM1 + 1; }
384
385 const ResourceTypeRecord& get_type_record (unsigned int i) const
386 { return (this+typeList)[i]; }
387
388 protected:
389 HBUINT8 reserved0[16]; /* Reserved for copy of resource header */
390 HBUINT32 reserved1; /* Reserved for handle to next resource map */
391 HBUINT16 resreved2; /* Reserved for file reference number */
392 HBUINT16 attrs; /* Resource fork attribute */
393 NNOffsetTo<ArrayOfM1<ResourceTypeRecord> >
394 typeList; /* Offset from beginning of map to
395 * resource type list */
396 Offset16 nameList; /* Offset from beginning of map to
397 * resource name list */
398 public:
399 DEFINE_SIZE_STATIC (28);
400 };
401
402 struct ResourceForkHeader
403 {
404 unsigned int get_face_count () const
405 { return (this+map).get_face_count (); }
406
407 const OpenTypeFontFace& get_face (unsigned int idx,
408 unsigned int *base_offset = nullptr) const
409 {
410 const OpenTypeFontFace &face = (this+map).get_face (idx, &(this+data));
411 if (base_offset)
412 *base_offset = (const char *) &face - (const char *) this;
413 return face;
414 }
415
416 bool sanitize (hb_sanitize_context_t *c) const
417 {
418 TRACE_SANITIZE (this);
419 return_trace (c->check_struct (this) &&
420 data.sanitize (c, this, dataLen) &&
421 map.sanitize (c, this, &(this+data)));
422 }
423
424 protected:
425 LNNOffsetTo<UnsizedArrayOf<HBUINT8> >
426 data; /* Offset from beginning of resource fork
427 * to resource data */
428 LNNOffsetTo<ResourceMap >
429 map; /* Offset from beginning of resource fork
430 * to resource map */
431 HBUINT32 dataLen; /* Length of resource data */
432 HBUINT32 mapLen; /* Length of resource map */
433 public:
434 DEFINE_SIZE_STATIC (16);
435 };
436
437 /*
438 * OpenType Font File
439 */
440
441 struct OpenTypeFontFile
442 {
443 enum {
444 CFFTag = HB_TAG ('O','T','T','O'), /* OpenType with Postscript outlines */
445 TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ), /* OpenType with TrueType outlines */
446 TTCTag = HB_TAG ('t','t','c','f'), /* TrueType Collection */
447 DFontTag = HB_TAG ( 0 , 0 , 1 , 0 ), /* DFont Mac Resource Fork */
448 TrueTag = HB_TAG ('t','r','u','e'), /* Obsolete Apple TrueType */
449 Typ1Tag = HB_TAG ('t','y','p','1') /* Obsolete Apple Type1 font in SFNT container */
450 };
451
452 hb_tag_t get_tag () const { return u.tag; }
453
454 unsigned int get_face_count () const
455 {
456 switch (u.tag) {
457 case CFFTag: /* All the non-collection tags */
458 case TrueTag:
459 case Typ1Tag:
460 case TrueTypeTag: return 1;
461 case TTCTag: return u.ttcHeader.get_face_count ();
462 case DFontTag: return u.rfHeader.get_face_count ();
463 default: return 0;
464 }
465 }
466 const OpenTypeFontFace& get_face (unsigned int i, unsigned int *base_offset = nullptr) const
467 {
468 if (base_offset)
469 *base_offset = 0;
470 switch (u.tag) {
471 /* Note: for non-collection SFNT data we ignore index. This is because
472 * Apple dfont container is a container of SFNT's. So each SFNT is a
473 * non-TTC, but the index is more than zero. */
474 case CFFTag: /* All the non-collection tags */
475 case TrueTag:
476 case Typ1Tag:
477 case TrueTypeTag: return u.fontFace;
478 case TTCTag: return u.ttcHeader.get_face (i);
479 case DFontTag: return u.rfHeader.get_face (i, base_offset);
480 default: return Null(OpenTypeFontFace);
481 }
482 }
483
484 template <typename item_t>
485 bool serialize_single (hb_serialize_context_t *c,
486 hb_tag_t sfnt_tag,
487 hb_array_t<item_t> items)
488 {
489 TRACE_SERIALIZE (this);
490 assert (sfnt_tag != TTCTag);
491 if (unlikely (!c->extend_min (*this))) return_trace (false);
492 return_trace (u.fontFace.serialize (c, sfnt_tag, items));
493 }
494
495 bool sanitize (hb_sanitize_context_t *c) const
496 {
497 TRACE_SANITIZE (this);
498 if (unlikely (!u.tag.sanitize (c))) return_trace (false);
499 switch (u.tag) {
500 case CFFTag: /* All the non-collection tags */
501 case TrueTag:
502 case Typ1Tag:
503 case TrueTypeTag: return_trace (u.fontFace.sanitize (c));
504 case TTCTag: return_trace (u.ttcHeader.sanitize (c));
505 case DFontTag: return_trace (u.rfHeader.sanitize (c));
506 default: return_trace (true);
507 }
508 }
509
510 protected:
511 union {
512 Tag tag; /* 4-byte identifier. */
513 OpenTypeFontFace fontFace;
514 TTCHeader ttcHeader;
515 ResourceForkHeader rfHeader;
516 } u;
517 public:
518 DEFINE_SIZE_UNION (4, tag);
519 };
520
521
522 } /* namespace OT */
523
524
525 #endif /* HB_OPEN_FILE_HH */