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
36namespace OT {
37
38
39/*
40 *
41 * The OpenType Font File
42 *
43 */
44
45
46/*
47 * Organization of an OpenType Font
48 */
49
50struct OpenTypeFontFile;
51struct OffsetTable;
52struct TTCHeader;
53
54
55typedef struct TableRecord
56{
57 int cmp (Tag t) const { return -t.cmp (tag); }
58
59 HB_INTERNAL 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
81typedef 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 = hb_min (*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 = 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 = 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 = items[i].tag;
144 rec.length = blob->length;
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 if (likely (rec.length))
152 memcpy (start, blob->data, rec.length);
153
154 /* 4-byte alignment. */
155 c->align (4);
156 const char *end = (const char *) c->head;
157
158 if (items[i].tag == HB_OT_TAG_head &&
159 (unsigned) (end - start) >= head::static_size)
160 {
161 head *h = (head *) start;
162 checksum_adjustment = &h->checkSumAdjustment;
163 *checksum_adjustment = 0;
164 }
165
166 rec.checkSum.set_for_data (start, end - start);
167 }
168
169 tables.qsort ();
170
171 if (checksum_adjustment)
172 {
173 CheckSum checksum;
174
175 /* The following line is a slower version of the following block. */
176 //checksum.set_for_data (this, (const char *) c->head - (const char *) this);
177 checksum.set_for_data (this, dir_end - (const char *) this);
178 for (unsigned int i = 0; i < items.length; i++)
179 {
180 TableRecord &rec = tables.arrayZ[i];
181 checksum = checksum + rec.checkSum;
182 }
183
184 *checksum_adjustment = 0xB1B0AFBAu - checksum;
185 }
186
187 return_trace (true);
188 }
189
190 bool sanitize (hb_sanitize_context_t *c) const
191 {
192 TRACE_SANITIZE (this);
193 return_trace (c->check_struct (this) && tables.sanitize (c));
194 }
195
196 protected:
197 Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
198 BinSearchArrayOf<TableRecord>
199 tables;
200 public:
201 DEFINE_SIZE_ARRAY (12, tables);
202} OpenTypeFontFace;
203
204
205/*
206 * TrueType Collections
207 */
208
209struct TTCHeaderVersion1
210{
211 friend struct TTCHeader;
212
213 unsigned int get_face_count () const { return table.len; }
214 const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }
215
216 bool sanitize (hb_sanitize_context_t *c) const
217 {
218 TRACE_SANITIZE (this);
219 return_trace (table.sanitize (c, this));
220 }
221
222 protected:
223 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
224 FixedVersion<>version; /* Version of the TTC Header (1.0),
225 * 0x00010000u */
226 LArrayOf<LOffsetTo<OffsetTable>>
227 table; /* Array of offsets to the OffsetTable for each font
228 * from the beginning of the file */
229 public:
230 DEFINE_SIZE_ARRAY (12, table);
231};
232
233struct TTCHeader
234{
235 friend struct OpenTypeFontFile;
236
237 private:
238
239 unsigned int get_face_count () const
240 {
241 switch (u.header.version.major) {
242 case 2: /* version 2 is compatible with version 1 */
243 case 1: return u.version1.get_face_count ();
244 default:return 0;
245 }
246 }
247 const OpenTypeFontFace& get_face (unsigned int i) const
248 {
249 switch (u.header.version.major) {
250 case 2: /* version 2 is compatible with version 1 */
251 case 1: return u.version1.get_face (i);
252 default:return Null(OpenTypeFontFace);
253 }
254 }
255
256 bool sanitize (hb_sanitize_context_t *c) const
257 {
258 TRACE_SANITIZE (this);
259 if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
260 switch (u.header.version.major) {
261 case 2: /* version 2 is compatible with version 1 */
262 case 1: return_trace (u.version1.sanitize (c));
263 default:return_trace (true);
264 }
265 }
266
267 protected:
268 union {
269 struct {
270 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
271 FixedVersion<>version; /* Version of the TTC Header (1.0 or 2.0),
272 * 0x00010000u or 0x00020000u */
273 } header;
274 TTCHeaderVersion1 version1;
275 } u;
276};
277
278/*
279 * Mac Resource Fork
280 *
281 * http://mirror.informatimago.com/next/developer.apple.com/documentation/mac/MoreToolbox/MoreToolbox-99.html
282 */
283
284struct ResourceRecord
285{
286 const OpenTypeFontFace & get_face (const void *data_base) const
287 { return CastR<OpenTypeFontFace> ((data_base+offset).arrayZ); }
288
289 bool sanitize (hb_sanitize_context_t *c,
290 const void *data_base) const
291 {
292 TRACE_SANITIZE (this);
293 return_trace (c->check_struct (this) &&
294 offset.sanitize (c, data_base) &&
295 get_face (data_base).sanitize (c));
296 }
297
298 protected:
299 HBUINT16 id; /* Resource ID. */
300 HBINT16 nameOffset; /* Offset from beginning of resource name list
301 * to resource name, -1 means there is none. */
302 HBUINT8 attrs; /* Resource attributes */
303 NNOffsetTo<LArrayOf<HBUINT8>, HBUINT24>
304 offset; /* Offset from beginning of data block to
305 * data for this resource */
306 HBUINT32 reserved; /* Reserved for handle to resource */
307 public:
308 DEFINE_SIZE_STATIC (12);
309};
310
311#define HB_TAG_sfnt HB_TAG ('s','f','n','t')
312
313struct ResourceTypeRecord
314{
315 unsigned int get_resource_count () const
316 { return tag == HB_TAG_sfnt ? resCountM1 + 1 : 0; }
317
318 bool is_sfnt () const { return tag == HB_TAG_sfnt; }
319
320 const ResourceRecord& get_resource_record (unsigned int i,
321 const void *type_base) const
322 { return (type_base+resourcesZ).as_array (get_resource_count ())[i]; }
323
324 bool sanitize (hb_sanitize_context_t *c,
325 const void *type_base,
326 const void *data_base) const
327 {
328 TRACE_SANITIZE (this);
329 return_trace (c->check_struct (this) &&
330 resourcesZ.sanitize (c, type_base,
331 get_resource_count (),
332 data_base));
333 }
334
335 protected:
336 Tag tag; /* Resource type. */
337 HBUINT16 resCountM1; /* Number of resources minus 1. */
338 NNOffsetTo<UnsizedArrayOf<ResourceRecord>>
339 resourcesZ; /* Offset from beginning of resource type list
340 * to reference item list for this type. */
341 public:
342 DEFINE_SIZE_STATIC (8);
343};
344
345struct ResourceMap
346{
347 unsigned int get_face_count () const
348 {
349 unsigned int count = get_type_count ();
350 for (unsigned int i = 0; i < count; i++)
351 {
352 const ResourceTypeRecord& type = get_type_record (i);
353 if (type.is_sfnt ())
354 return type.get_resource_count ();
355 }
356 return 0;
357 }
358
359 const OpenTypeFontFace& get_face (unsigned int idx,
360 const void *data_base) const
361 {
362 unsigned int count = get_type_count ();
363 for (unsigned int i = 0; i < count; i++)
364 {
365 const ResourceTypeRecord& type = get_type_record (i);
366 /* The check for idx < count is here because ResourceRecord is NOT null-safe.
367 * Because an offset of 0 there does NOT mean null. */
368 if (type.is_sfnt () && idx < type.get_resource_count ())
369 return type.get_resource_record (idx, &(this+typeList)).get_face (data_base);
370 }
371 return Null (OpenTypeFontFace);
372 }
373
374 bool sanitize (hb_sanitize_context_t *c, const void *data_base) const
375 {
376 TRACE_SANITIZE (this);
377 return_trace (c->check_struct (this) &&
378 typeList.sanitize (c, this,
379 &(this+typeList),
380 data_base));
381 }
382
383 private:
384 unsigned int get_type_count () const { return (this+typeList).lenM1 + 1; }
385
386 const ResourceTypeRecord& get_type_record (unsigned int i) const
387 { return (this+typeList)[i]; }
388
389 protected:
390 HBUINT8 reserved0[16]; /* Reserved for copy of resource header */
391 HBUINT32 reserved1; /* Reserved for handle to next resource map */
392 HBUINT16 resreved2; /* Reserved for file reference number */
393 HBUINT16 attrs; /* Resource fork attribute */
394 NNOffsetTo<ArrayOfM1<ResourceTypeRecord>>
395 typeList; /* Offset from beginning of map to
396 * resource type list */
397 Offset16 nameList; /* Offset from beginning of map to
398 * resource name list */
399 public:
400 DEFINE_SIZE_STATIC (28);
401};
402
403struct ResourceForkHeader
404{
405 unsigned int get_face_count () const
406 { return (this+map).get_face_count (); }
407
408 const OpenTypeFontFace& get_face (unsigned int idx,
409 unsigned int *base_offset = nullptr) const
410 {
411 const OpenTypeFontFace &face = (this+map).get_face (idx, &(this+data));
412 if (base_offset)
413 *base_offset = (const char *) &face - (const char *) this;
414 return face;
415 }
416
417 bool sanitize (hb_sanitize_context_t *c) const
418 {
419 TRACE_SANITIZE (this);
420 return_trace (c->check_struct (this) &&
421 data.sanitize (c, this, dataLen) &&
422 map.sanitize (c, this, &(this+data)));
423 }
424
425 protected:
426 LNNOffsetTo<UnsizedArrayOf<HBUINT8>>
427 data; /* Offset from beginning of resource fork
428 * to resource data */
429 LNNOffsetTo<ResourceMap >
430 map; /* Offset from beginning of resource fork
431 * to resource map */
432 HBUINT32 dataLen; /* Length of resource data */
433 HBUINT32 mapLen; /* Length of resource map */
434 public:
435 DEFINE_SIZE_STATIC (16);
436};
437
438/*
439 * OpenType Font File
440 */
441
442struct OpenTypeFontFile
443{
444 enum {
445 CFFTag = HB_TAG ('O','T','T','O'), /* OpenType with Postscript outlines */
446 TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ), /* OpenType with TrueType outlines */
447 TTCTag = HB_TAG ('t','t','c','f'), /* TrueType Collection */
448 DFontTag = HB_TAG ( 0 , 0 , 1 , 0 ), /* DFont Mac Resource Fork */
449 TrueTag = HB_TAG ('t','r','u','e'), /* Obsolete Apple TrueType */
450 Typ1Tag = HB_TAG ('t','y','p','1') /* Obsolete Apple Type1 font in SFNT container */
451 };
452
453 hb_tag_t get_tag () const { return u.tag; }
454
455 unsigned int get_face_count () const
456 {
457 switch (u.tag) {
458 case CFFTag: /* All the non-collection tags */
459 case TrueTag:
460 case Typ1Tag:
461 case TrueTypeTag: return 1;
462 case TTCTag: return u.ttcHeader.get_face_count ();
463 case DFontTag: return u.rfHeader.get_face_count ();
464 default: return 0;
465 }
466 }
467 const OpenTypeFontFace& get_face (unsigned int i, unsigned int *base_offset = nullptr) const
468 {
469 if (base_offset)
470 *base_offset = 0;
471 switch (u.tag) {
472 /* Note: for non-collection SFNT data we ignore index. This is because
473 * Apple dfont container is a container of SFNT's. So each SFNT is a
474 * non-TTC, but the index is more than zero. */
475 case CFFTag: /* All the non-collection tags */
476 case TrueTag:
477 case Typ1Tag:
478 case TrueTypeTag: return u.fontFace;
479 case TTCTag: return u.ttcHeader.get_face (i);
480 case DFontTag: return u.rfHeader.get_face (i, base_offset);
481 default: return Null(OpenTypeFontFace);
482 }
483 }
484
485 template <typename item_t>
486 bool serialize_single (hb_serialize_context_t *c,
487 hb_tag_t sfnt_tag,
488 hb_array_t<item_t> items)
489 {
490 TRACE_SERIALIZE (this);
491 assert (sfnt_tag != TTCTag);
492 if (unlikely (!c->extend_min (*this))) return_trace (false);
493 return_trace (u.fontFace.serialize (c, sfnt_tag, items));
494 }
495
496 bool sanitize (hb_sanitize_context_t *c) const
497 {
498 TRACE_SANITIZE (this);
499 if (unlikely (!u.tag.sanitize (c))) return_trace (false);
500 switch (u.tag) {
501 case CFFTag: /* All the non-collection tags */
502 case TrueTag:
503 case Typ1Tag:
504 case TrueTypeTag: return_trace (u.fontFace.sanitize (c));
505 case TTCTag: return_trace (u.ttcHeader.sanitize (c));
506 case DFontTag: return_trace (u.rfHeader.sanitize (c));
507 default: return_trace (true);
508 }
509 }
510
511 protected:
512 union {
513 Tag tag; /* 4-byte identifier. */
514 OpenTypeFontFace fontFace;
515 TTCHeader ttcHeader;
516 ResourceForkHeader rfHeader;
517 } u;
518 public:
519 DEFINE_SIZE_UNION (4, tag);
520};
521
522
523} /* namespace OT */
524
525
526#endif /* HB_OPEN_FILE_HH */
527