1 /*
2 * Copyright © 2016 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Seigo Nonaka, Calder Kitagawa
25 */
26
27 #ifndef HB_OT_COLOR_CBDT_TABLE_HH
28 #define HB_OT_COLOR_CBDT_TABLE_HH
29
30 #include "hb-open-type.hh"
31
32 /*
33 * CBLC -- Color Bitmap Location
34 * https://docs.microsoft.com/en-us/typography/opentype/spec/cblc
35 * https://docs.microsoft.com/en-us/typography/opentype/spec/eblc
36 * CBDT -- Color Bitmap Data
37 * https://docs.microsoft.com/en-us/typography/opentype/spec/cbdt
38 * https://docs.microsoft.com/en-us/typography/opentype/spec/ebdt
39 */
40 #define HB_OT_TAG_CBLC HB_TAG('C','B','L','C')
41 #define HB_OT_TAG_CBDT HB_TAG('C','B','D','T')
42
43
44 namespace OT {
45
46 struct cblc_bitmap_size_subset_context_t
47 {
48 const char *cbdt;
49 unsigned int cbdt_length;
50 hb_vector_t<char> *cbdt_prime;
51 unsigned int size; /* INOUT
52 * Input: old size of IndexSubtable
53 * Output: new size of IndexSubtable
54 */
55 unsigned int num_tables; /* INOUT
56 * Input: old number of subtables.
57 * Output: new number of subtables.
58 */
59 hb_codepoint_t start_glyph; /* OUT */
60 hb_codepoint_t end_glyph; /* OUT */
61 };
62
63 static inline bool
_copy_data_to_cbdt(hb_vector_t<char> * cbdt_prime,const void * data,unsigned length)64 _copy_data_to_cbdt (hb_vector_t<char> *cbdt_prime,
65 const void *data,
66 unsigned length)
67 {
68 unsigned int new_len = cbdt_prime->length + length;
69 if (unlikely (!cbdt_prime->alloc (new_len))) return false;
70 memcpy (cbdt_prime->arrayZ + cbdt_prime->length, data, length);
71 cbdt_prime->length = new_len;
72 return true;
73 }
74
75 struct SmallGlyphMetrics
76 {
sanitizeOT::SmallGlyphMetrics77 bool sanitize (hb_sanitize_context_t *c) const
78 {
79 TRACE_SANITIZE (this);
80 return_trace (c->check_struct (this));
81 }
82
get_extentsOT::SmallGlyphMetrics83 void get_extents (hb_font_t *font, hb_glyph_extents_t *extents) const
84 {
85 extents->x_bearing = font->em_scale_x (bearingX);
86 extents->y_bearing = font->em_scale_y (bearingY);
87 extents->width = font->em_scale_x (width);
88 extents->height = font->em_scale_y (-static_cast<int>(height));
89 }
90
91 HBUINT8 height;
92 HBUINT8 width;
93 HBINT8 bearingX;
94 HBINT8 bearingY;
95 HBUINT8 advance;
96 public:
97 DEFINE_SIZE_STATIC (5);
98 };
99
100 struct BigGlyphMetrics : SmallGlyphMetrics
101 {
102 HBINT8 vertBearingX;
103 HBINT8 vertBearingY;
104 HBUINT8 vertAdvance;
105 public:
106 DEFINE_SIZE_STATIC (8);
107 };
108
109 struct SBitLineMetrics
110 {
sanitizeOT::SBitLineMetrics111 bool sanitize (hb_sanitize_context_t *c) const
112 {
113 TRACE_SANITIZE (this);
114 return_trace (c->check_struct (this));
115 }
116
117 HBINT8 ascender;
118 HBINT8 decender;
119 HBUINT8 widthMax;
120 HBINT8 caretSlopeNumerator;
121 HBINT8 caretSlopeDenominator;
122 HBINT8 caretOffset;
123 HBINT8 minOriginSB;
124 HBINT8 minAdvanceSB;
125 HBINT8 maxBeforeBL;
126 HBINT8 minAfterBL;
127 HBINT8 padding1;
128 HBINT8 padding2;
129 public:
130 DEFINE_SIZE_STATIC (12);
131 };
132
133
134 /*
135 * Index Subtables.
136 */
137
138 struct IndexSubtableHeader
139 {
sanitizeOT::IndexSubtableHeader140 bool sanitize (hb_sanitize_context_t *c) const
141 {
142 TRACE_SANITIZE (this);
143 return_trace (c->check_struct (this));
144 }
145
146 HBUINT16 indexFormat;
147 HBUINT16 imageFormat;
148 HBUINT32 imageDataOffset;
149 public:
150 DEFINE_SIZE_STATIC (8);
151 };
152
153 template <typename OffsetType>
154 struct IndexSubtableFormat1Or3
155 {
sanitizeOT::IndexSubtableFormat1Or3156 bool sanitize (hb_sanitize_context_t *c, unsigned int glyph_count) const
157 {
158 TRACE_SANITIZE (this);
159 return_trace (c->check_struct (this) &&
160 offsetArrayZ.sanitize (c, glyph_count + 1));
161 }
162
get_image_dataOT::IndexSubtableFormat1Or3163 bool get_image_data (unsigned int idx,
164 unsigned int *offset,
165 unsigned int *length) const
166 {
167 if (unlikely (offsetArrayZ[idx + 1] <= offsetArrayZ[idx]))
168 return false;
169
170 *offset = header.imageDataOffset + offsetArrayZ[idx];
171 *length = offsetArrayZ[idx + 1] - offsetArrayZ[idx];
172 return true;
173 }
174
add_offsetOT::IndexSubtableFormat1Or3175 bool add_offset (hb_serialize_context_t *c,
176 unsigned int offset,
177 unsigned int *size /* OUT (accumulated) */)
178 {
179 TRACE_SERIALIZE (this);
180 Offset<OffsetType> embedded_offset;
181 embedded_offset = offset;
182 *size += sizeof (OffsetType);
183 auto *o = c->embed (embedded_offset);
184 return_trace ((bool) o);
185 }
186
187 IndexSubtableHeader header;
188 UnsizedArrayOf<Offset<OffsetType>>
189 offsetArrayZ;
190 public:
191 DEFINE_SIZE_ARRAY (8, offsetArrayZ);
192 };
193
194 struct IndexSubtableFormat1 : IndexSubtableFormat1Or3<HBUINT32> {};
195 struct IndexSubtableFormat3 : IndexSubtableFormat1Or3<HBUINT16> {};
196
197 struct IndexSubtable
198 {
sanitizeOT::IndexSubtable199 bool sanitize (hb_sanitize_context_t *c, unsigned int glyph_count) const
200 {
201 TRACE_SANITIZE (this);
202 if (!u.header.sanitize (c)) return_trace (false);
203 switch (u.header.indexFormat)
204 {
205 case 1: return_trace (u.format1.sanitize (c, glyph_count));
206 case 3: return_trace (u.format3.sanitize (c, glyph_count));
207 default:return_trace (true);
208 }
209 }
210
211 bool
finish_subtableOT::IndexSubtable212 finish_subtable (hb_serialize_context_t *c,
213 unsigned int cbdt_prime_len,
214 unsigned int num_glyphs,
215 unsigned int *size /* OUT (accumulated) */)
216 {
217 TRACE_SERIALIZE (this);
218
219 unsigned int local_offset = cbdt_prime_len - u.header.imageDataOffset;
220 switch (u.header.indexFormat)
221 {
222 case 1: return_trace (u.format1.add_offset (c, local_offset, size));
223 case 3: {
224 if (!u.format3.add_offset (c, local_offset, size))
225 return_trace (false);
226 if (!(num_glyphs & 0x01)) // Pad to 32-bit alignment if needed.
227 return_trace (u.format3.add_offset (c, 0, size));
228 return_trace (true);
229 }
230 // TODO: implement 2, 4, 5.
231 case 2: case 4: // No-op.
232 case 5: // Pad to 32-bit aligned.
233 default: return_trace (false);
234 }
235 }
236
237 bool
fill_missing_glyphsOT::IndexSubtable238 fill_missing_glyphs (hb_serialize_context_t *c,
239 unsigned int cbdt_prime_len,
240 unsigned int num_missing,
241 unsigned int *size /* OUT (accumulated) */,
242 unsigned int *num_glyphs /* OUT (accumulated) */)
243 {
244 TRACE_SERIALIZE (this);
245
246 unsigned int local_offset = cbdt_prime_len - u.header.imageDataOffset;
247 switch (u.header.indexFormat)
248 {
249 case 1: {
250 for (unsigned int i = 0; i < num_missing; i++)
251 {
252 if (unlikely (!u.format1.add_offset (c, local_offset, size)))
253 return_trace (false);
254 *num_glyphs += 1;
255 }
256 return_trace (true);
257 }
258 case 3: {
259 for (unsigned int i = 0; i < num_missing; i++)
260 {
261 if (unlikely (!u.format3.add_offset (c, local_offset, size)))
262 return_trace (false);
263 *num_glyphs += 1;
264 }
265 return_trace (true);
266 }
267 // TODO: implement 2, 4, 5.
268 case 2: // Add empty space in cbdt_prime?.
269 case 4: case 5: // No-op as sparse is supported.
270 default: return_trace (false);
271 }
272 }
273
274 bool
copy_glyph_at_idxOT::IndexSubtable275 copy_glyph_at_idx (hb_serialize_context_t *c, unsigned int idx,
276 const char *cbdt, unsigned int cbdt_length,
277 hb_vector_t<char> *cbdt_prime /* INOUT */,
278 IndexSubtable *subtable_prime /* INOUT */,
279 unsigned int *size /* OUT (accumulated) */) const
280 {
281 TRACE_SERIALIZE (this);
282
283 unsigned int offset, length, format;
284 if (unlikely (!get_image_data (idx, &offset, &length, &format))) return_trace (false);
285 if (unlikely (offset > cbdt_length || cbdt_length - offset < length)) return_trace (false);
286
287 auto *header_prime = subtable_prime->get_header ();
288 unsigned int new_local_offset = cbdt_prime->length - (unsigned int) header_prime->imageDataOffset;
289 if (unlikely (!_copy_data_to_cbdt (cbdt_prime, cbdt + offset, length))) return_trace (false);
290
291 return_trace (subtable_prime->add_offset (c, new_local_offset, size));
292 }
293
294 bool
add_offsetOT::IndexSubtable295 add_offset (hb_serialize_context_t *c, unsigned int local_offset,
296 unsigned int *size /* OUT (accumulated) */)
297 {
298 TRACE_SERIALIZE (this);
299 switch (u.header.indexFormat)
300 {
301 case 1: return_trace (u.format1.add_offset (c, local_offset, size));
302 case 3: return_trace (u.format3.add_offset (c, local_offset, size));
303 // TODO: Implement tables 2, 4, 5
304 case 2: // Should be a no-op.
305 case 4: case 5: // Handle sparse cases.
306 default: return_trace (false);
307 }
308 }
309
get_extentsOT::IndexSubtable310 bool get_extents (hb_glyph_extents_t *extents HB_UNUSED) const
311 {
312 switch (u.header.indexFormat)
313 {
314 case 2: case 5: /* TODO */
315 case 1: case 3: case 4: /* Variable-metrics formats do not have metrics here. */
316 default:return (false);
317 }
318 }
319
320 bool
get_image_dataOT::IndexSubtable321 get_image_data (unsigned int idx, unsigned int *offset,
322 unsigned int *length, unsigned int *format) const
323 {
324 *format = u.header.imageFormat;
325 switch (u.header.indexFormat)
326 {
327 case 1: return u.format1.get_image_data (idx, offset, length);
328 case 3: return u.format3.get_image_data (idx, offset, length);
329 default: return false;
330 }
331 }
332
get_headerOT::IndexSubtable333 const IndexSubtableHeader* get_header () const { return &u.header; }
334
populate_headerOT::IndexSubtable335 void populate_header (unsigned index_format,
336 unsigned image_format,
337 unsigned int image_data_offset,
338 unsigned int *size)
339 {
340 u.header.indexFormat = index_format;
341 u.header.imageFormat = image_format;
342 u.header.imageDataOffset = image_data_offset;
343 switch (u.header.indexFormat)
344 {
345 case 1: *size += IndexSubtableFormat1::min_size; break;
346 case 3: *size += IndexSubtableFormat3::min_size; break;
347 }
348 }
349
350 protected:
351 union {
352 IndexSubtableHeader header;
353 IndexSubtableFormat1 format1;
354 IndexSubtableFormat3 format3;
355 /* TODO: Format 2, 4, 5. */
356 } u;
357 public:
358 DEFINE_SIZE_UNION (8, header);
359 };
360
361 struct IndexSubtableRecord
362 {
sanitizeOT::IndexSubtableRecord363 bool sanitize (hb_sanitize_context_t *c, const void *base) const
364 {
365 TRACE_SANITIZE (this);
366 return_trace (c->check_struct (this) &&
367 firstGlyphIndex <= lastGlyphIndex &&
368 offsetToSubtable.sanitize (c, base, lastGlyphIndex - firstGlyphIndex + 1));
369 }
370
get_subtableOT::IndexSubtableRecord371 const IndexSubtable* get_subtable (const void *base) const
372 {
373 return &(base+offsetToSubtable);
374 }
375
add_new_subtableOT::IndexSubtableRecord376 bool add_new_subtable (hb_subset_context_t* c,
377 cblc_bitmap_size_subset_context_t *bitmap_size_context,
378 IndexSubtableRecord *record,
379 const hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> *lookup, /* IN */
380 const void *base,
381 unsigned int *start /* INOUT */) const
382 {
383 TRACE_SERIALIZE (this);
384
385 auto *subtable = c->serializer->start_embed<IndexSubtable> ();
386 if (unlikely (!subtable)) return_trace (false);
387 if (unlikely (!c->serializer->extend_min (subtable))) return_trace (false);
388
389 auto *old_subtable = get_subtable (base);
390 auto *old_header = old_subtable->get_header ();
391
392 subtable->populate_header (old_header->indexFormat,
393 old_header->imageFormat,
394 bitmap_size_context->cbdt_prime->length,
395 &bitmap_size_context->size);
396
397 unsigned int num_glyphs = 0;
398 bool early_exit = false;
399 for (unsigned int i = *start; i < lookup->length; i++)
400 {
401 hb_codepoint_t new_gid = (*lookup)[i].first;
402 const IndexSubtableRecord *next_record = (*lookup)[i].second;
403 const IndexSubtable *next_subtable = next_record->get_subtable (base);
404 auto *next_header = next_subtable->get_header ();
405 if (next_header != old_header)
406 {
407 *start = i;
408 early_exit = true;
409 break;
410 }
411 unsigned int num_missing = record->add_glyph_for_subset (new_gid);
412 if (unlikely (!subtable->fill_missing_glyphs (c->serializer,
413 bitmap_size_context->cbdt_prime->length,
414 num_missing,
415 &bitmap_size_context->size,
416 &num_glyphs)))
417 return_trace (false);
418
419 hb_codepoint_t old_gid = 0;
420 c->plan->old_gid_for_new_gid (new_gid, &old_gid);
421 if (old_gid < next_record->firstGlyphIndex)
422 return_trace (false);
423
424 unsigned int old_idx = (unsigned int) old_gid - next_record->firstGlyphIndex;
425 if (unlikely (!next_subtable->copy_glyph_at_idx (c->serializer,
426 old_idx,
427 bitmap_size_context->cbdt,
428 bitmap_size_context->cbdt_length,
429 bitmap_size_context->cbdt_prime,
430 subtable,
431 &bitmap_size_context->size)))
432 return_trace (false);
433 num_glyphs += 1;
434 }
435 if (!early_exit)
436 *start = lookup->length;
437 if (unlikely (!subtable->finish_subtable (c->serializer,
438 bitmap_size_context->cbdt_prime->length,
439 num_glyphs,
440 &bitmap_size_context->size)))
441 return_trace (false);
442 return_trace (true);
443 }
444
add_new_recordOT::IndexSubtableRecord445 bool add_new_record (hb_subset_context_t *c,
446 cblc_bitmap_size_subset_context_t *bitmap_size_context,
447 const hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> *lookup, /* IN */
448 const void *base,
449 unsigned int *start, /* INOUT */
450 hb_vector_t<IndexSubtableRecord>* records /* INOUT */) const
451 {
452 TRACE_SERIALIZE (this);
453 auto snap = c->serializer->snapshot ();
454 unsigned int old_size = bitmap_size_context->size;
455 unsigned int old_cbdt_prime_length = bitmap_size_context->cbdt_prime->length;
456
457 // Set to invalid state to indicate filling glyphs is not yet started.
458 if (unlikely (!c->serializer->check_success (records->resize (records->length + 1))))
459 return_trace (false);
460
461 (*records)[records->length - 1].firstGlyphIndex = 1;
462 (*records)[records->length - 1].lastGlyphIndex = 0;
463 bitmap_size_context->size += IndexSubtableRecord::min_size;
464
465 c->serializer->push ();
466
467 if (unlikely (!add_new_subtable (c, bitmap_size_context, &((*records)[records->length - 1]), lookup, base, start)))
468 {
469 c->serializer->pop_discard ();
470 c->serializer->revert (snap);
471 bitmap_size_context->cbdt_prime->shrink (old_cbdt_prime_length);
472 bitmap_size_context->size = old_size;
473 records->resize (records->length - 1);
474 return_trace (false);
475 }
476
477 bitmap_size_context->num_tables += 1;
478 return_trace (true);
479 }
480
add_glyph_for_subsetOT::IndexSubtableRecord481 unsigned int add_glyph_for_subset (hb_codepoint_t gid)
482 {
483 if (firstGlyphIndex > lastGlyphIndex)
484 {
485 firstGlyphIndex = gid;
486 lastGlyphIndex = gid;
487 return 0;
488 }
489 // TODO maybe assert? this shouldn't occur.
490 if (lastGlyphIndex > gid)
491 return 0;
492 unsigned int num_missing = (unsigned int) (gid - lastGlyphIndex - 1);
493 lastGlyphIndex = gid;
494 return num_missing;
495 }
496
get_extentsOT::IndexSubtableRecord497 bool get_extents (hb_glyph_extents_t *extents, const void *base) const
498 { return (base+offsetToSubtable).get_extents (extents); }
499
get_image_dataOT::IndexSubtableRecord500 bool get_image_data (unsigned int gid,
501 const void *base,
502 unsigned int *offset,
503 unsigned int *length,
504 unsigned int *format) const
505 {
506 if (gid < firstGlyphIndex || gid > lastGlyphIndex) return false;
507 return (base+offsetToSubtable).get_image_data (gid - firstGlyphIndex,
508 offset, length, format);
509 }
510
511 HBGlyphID firstGlyphIndex;
512 HBGlyphID lastGlyphIndex;
513 Offset32To<IndexSubtable> offsetToSubtable;
514 public:
515 DEFINE_SIZE_STATIC (8);
516 };
517
518 struct IndexSubtableArray
519 {
520 friend struct CBDT;
521
sanitizeOT::IndexSubtableArray522 bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
523 {
524 TRACE_SANITIZE (this);
525 return_trace (indexSubtablesZ.sanitize (c, count, this));
526 }
527
528 void
build_lookupOT::IndexSubtableArray529 build_lookup (hb_subset_context_t *c, cblc_bitmap_size_subset_context_t *bitmap_size_context,
530 hb_vector_t<hb_pair_t<hb_codepoint_t,
531 const IndexSubtableRecord*>> *lookup /* OUT */) const
532 {
533 bool start_glyph_is_set = false;
534 for (hb_codepoint_t new_gid = 0; new_gid < c->plan->num_output_glyphs (); new_gid++)
535 {
536 hb_codepoint_t old_gid;
537 if (unlikely (!c->plan->old_gid_for_new_gid (new_gid, &old_gid))) continue;
538
539 const IndexSubtableRecord* record = find_table (old_gid, bitmap_size_context->num_tables);
540 if (unlikely (!record)) continue;
541
542 // Don't add gaps to the lookup. The best way to determine if a glyph is a
543 // gap is that it has no image data.
544 unsigned int offset, length, format;
545 if (unlikely (!record->get_image_data (old_gid, this, &offset, &length, &format))) continue;
546
547 lookup->push (hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*> (new_gid, record));
548
549 if (!start_glyph_is_set)
550 {
551 bitmap_size_context->start_glyph = new_gid;
552 start_glyph_is_set = true;
553 }
554
555 bitmap_size_context->end_glyph = new_gid;
556 }
557 }
558
559 bool
subsetOT::IndexSubtableArray560 subset (hb_subset_context_t *c,
561 cblc_bitmap_size_subset_context_t *bitmap_size_context) const
562 {
563 TRACE_SUBSET (this);
564
565 auto *dst = c->serializer->start_embed<IndexSubtableArray> ();
566 if (unlikely (!dst)) return_trace (false);
567
568 hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> lookup;
569 build_lookup (c, bitmap_size_context, &lookup);
570 if (unlikely (!c->serializer->propagate_error (lookup)))
571 return false;
572
573 bitmap_size_context->size = 0;
574 bitmap_size_context->num_tables = 0;
575 hb_vector_t<IndexSubtableRecord> records;
576 for (unsigned int start = 0; start < lookup.length;)
577 {
578 if (unlikely (!lookup[start].second->add_new_record (c, bitmap_size_context, &lookup, this, &start, &records)))
579 {
580 // Discard any leftover pushes to the serializer from successful records.
581 for (unsigned int i = 0; i < records.length; i++)
582 c->serializer->pop_discard ();
583 return_trace (false);
584 }
585 }
586
587 /* Workaround to ensure offset ordering is from least to greatest when
588 * resolving links. */
589 hb_vector_t<hb_serialize_context_t::objidx_t> objidxs;
590 for (unsigned int i = 0; i < records.length; i++)
591 objidxs.push (c->serializer->pop_pack ());
592 for (unsigned int i = 0; i < records.length; i++)
593 {
594 IndexSubtableRecord* record = c->serializer->embed (records[i]);
595 if (unlikely (!record)) return_trace (false);
596 c->serializer->add_link (record->offsetToSubtable, objidxs[records.length - 1 - i]);
597 }
598 return_trace (true);
599 }
600
601 public:
find_tableOT::IndexSubtableArray602 const IndexSubtableRecord* find_table (hb_codepoint_t glyph, unsigned int numTables) const
603 {
604 for (unsigned int i = 0; i < numTables; ++i)
605 {
606 unsigned int firstGlyphIndex = indexSubtablesZ[i].firstGlyphIndex;
607 unsigned int lastGlyphIndex = indexSubtablesZ[i].lastGlyphIndex;
608 if (firstGlyphIndex <= glyph && glyph <= lastGlyphIndex)
609 return &indexSubtablesZ[i];
610 }
611 return nullptr;
612 }
613
614 protected:
615 UnsizedArrayOf<IndexSubtableRecord> indexSubtablesZ;
616 };
617
618 struct BitmapSizeTable
619 {
620 friend struct CBLC;
621 friend struct CBDT;
622
sanitizeOT::BitmapSizeTable623 bool sanitize (hb_sanitize_context_t *c, const void *base) const
624 {
625 TRACE_SANITIZE (this);
626 return_trace (c->check_struct (this) &&
627 indexSubtableArrayOffset.sanitize (c, base, numberOfIndexSubtables) &&
628 horizontal.sanitize (c) &&
629 vertical.sanitize (c));
630 }
631
632 const IndexSubtableRecord *
find_tableOT::BitmapSizeTable633 find_table (hb_codepoint_t glyph, const void *base, const void **out_base) const
634 {
635 *out_base = &(base+indexSubtableArrayOffset);
636 return (base+indexSubtableArrayOffset).find_table (glyph, numberOfIndexSubtables);
637 }
638
639 bool
subsetOT::BitmapSizeTable640 subset (hb_subset_context_t *c, const void *base,
641 const char *cbdt, unsigned int cbdt_length,
642 hb_vector_t<char> *cbdt_prime /* INOUT */) const
643 {
644 TRACE_SUBSET (this);
645 auto *out_table = c->serializer->embed (this);
646 if (unlikely (!out_table)) return_trace (false);
647
648 cblc_bitmap_size_subset_context_t bitmap_size_context;
649 bitmap_size_context.cbdt = cbdt;
650 bitmap_size_context.cbdt_length = cbdt_length;
651 bitmap_size_context.cbdt_prime = cbdt_prime;
652 bitmap_size_context.size = indexTablesSize;
653 bitmap_size_context.num_tables = numberOfIndexSubtables;
654 bitmap_size_context.start_glyph = 1;
655 bitmap_size_context.end_glyph = 0;
656
657 if (!out_table->indexSubtableArrayOffset.serialize_subset (c,
658 indexSubtableArrayOffset,
659 base,
660 &bitmap_size_context))
661 return_trace (false);
662 if (!bitmap_size_context.size ||
663 !bitmap_size_context.num_tables ||
664 bitmap_size_context.start_glyph > bitmap_size_context.end_glyph)
665 return_trace (false);
666
667 out_table->indexTablesSize = bitmap_size_context.size;
668 out_table->numberOfIndexSubtables = bitmap_size_context.num_tables;
669 out_table->startGlyphIndex = bitmap_size_context.start_glyph;
670 out_table->endGlyphIndex = bitmap_size_context.end_glyph;
671 return_trace (true);
672 }
673
674 protected:
675 NNOffset32To<IndexSubtableArray>
676 indexSubtableArrayOffset;
677 HBUINT32 indexTablesSize;
678 HBUINT32 numberOfIndexSubtables;
679 HBUINT32 colorRef;
680 SBitLineMetrics horizontal;
681 SBitLineMetrics vertical;
682 HBGlyphID startGlyphIndex;
683 HBGlyphID endGlyphIndex;
684 HBUINT8 ppemX;
685 HBUINT8 ppemY;
686 HBUINT8 bitDepth;
687 HBINT8 flags;
688 public:
689 DEFINE_SIZE_STATIC (48);
690 };
691
692
693 /*
694 * Glyph Bitmap Data Formats.
695 */
696
697 struct GlyphBitmapDataFormat17
698 {
699 SmallGlyphMetrics glyphMetrics;
700 Array32Of<HBUINT8> data;
701 public:
702 DEFINE_SIZE_ARRAY (9, data);
703 };
704
705 struct GlyphBitmapDataFormat18
706 {
707 BigGlyphMetrics glyphMetrics;
708 Array32Of<HBUINT8> data;
709 public:
710 DEFINE_SIZE_ARRAY (12, data);
711 };
712
713 struct GlyphBitmapDataFormat19
714 {
715 Array32Of<HBUINT8> data;
716 public:
717 DEFINE_SIZE_ARRAY (4, data);
718 };
719
720 struct CBLC
721 {
722 friend struct CBDT;
723
724 static constexpr hb_tag_t tableTag = HB_OT_TAG_CBLC;
725
sanitizeOT::CBLC726 bool sanitize (hb_sanitize_context_t *c) const
727 {
728 TRACE_SANITIZE (this);
729 return_trace (c->check_struct (this) &&
730 likely (version.major == 2 || version.major == 3) &&
731 sizeTables.sanitize (c, this));
732 }
733
734 static bool
sink_cbdtOT::CBLC735 sink_cbdt (hb_subset_context_t *c, hb_vector_t<char>* cbdt_prime)
736 {
737 hb_blob_t *cbdt_prime_blob = hb_blob_create (cbdt_prime->arrayZ,
738 cbdt_prime->length,
739 HB_MEMORY_MODE_WRITABLE,
740 cbdt_prime->arrayZ,
741 free);
742 cbdt_prime->init (); // Leak arrayZ to the blob.
743 bool ret = c->plan->add_table (HB_OT_TAG_CBDT, cbdt_prime_blob);
744 hb_blob_destroy (cbdt_prime_blob);
745 return ret;
746 }
747
748 bool
subset_size_tableOT::CBLC749 subset_size_table (hb_subset_context_t *c, const BitmapSizeTable& table,
750 const char *cbdt /* IN */, unsigned int cbdt_length,
751 CBLC *cblc_prime /* INOUT */, hb_vector_t<char> *cbdt_prime /* INOUT */) const
752 {
753 TRACE_SUBSET (this);
754 cblc_prime->sizeTables.len++;
755
756 auto snap = c->serializer->snapshot ();
757 auto cbdt_prime_len = cbdt_prime->length;
758
759 if (!table.subset (c, this, cbdt, cbdt_length, cbdt_prime))
760 {
761 cblc_prime->sizeTables.len--;
762 c->serializer->revert (snap);
763 cbdt_prime->shrink (cbdt_prime_len);
764 return_trace (false);
765 }
766 return_trace (true);
767 }
768
769 // Implemented in cc file as it depends on definition of CBDT.
770 HB_INTERNAL bool subset (hb_subset_context_t *c) const;
771
772 protected:
choose_strikeOT::CBLC773 const BitmapSizeTable &choose_strike (hb_font_t *font) const
774 {
775 unsigned count = sizeTables.len;
776 if (unlikely (!count))
777 return Null (BitmapSizeTable);
778
779 unsigned int requested_ppem = hb_max (font->x_ppem, font->y_ppem);
780 if (!requested_ppem)
781 requested_ppem = 1<<30; /* Choose largest strike. */
782 unsigned int best_i = 0;
783 unsigned int best_ppem = hb_max (sizeTables[0].ppemX, sizeTables[0].ppemY);
784
785 for (unsigned int i = 1; i < count; i++)
786 {
787 unsigned int ppem = hb_max (sizeTables[i].ppemX, sizeTables[i].ppemY);
788 if ((requested_ppem <= ppem && ppem < best_ppem) ||
789 (requested_ppem > best_ppem && ppem > best_ppem))
790 {
791 best_i = i;
792 best_ppem = ppem;
793 }
794 }
795
796 return sizeTables[best_i];
797 }
798
799 protected:
800 FixedVersion<> version;
801 Array32Of<BitmapSizeTable> sizeTables;
802 public:
803 DEFINE_SIZE_ARRAY (8, sizeTables);
804 };
805
806 struct CBDT
807 {
808 static constexpr hb_tag_t tableTag = HB_OT_TAG_CBDT;
809
810 struct accelerator_t
811 {
initOT::CBDT::accelerator_t812 void init (hb_face_t *face)
813 {
814 cblc = hb_sanitize_context_t ().reference_table<CBLC> (face);
815 cbdt = hb_sanitize_context_t ().reference_table<CBDT> (face);
816
817 upem = hb_face_get_upem (face);
818 }
819
finiOT::CBDT::accelerator_t820 void fini ()
821 {
822 this->cblc.destroy ();
823 this->cbdt.destroy ();
824 }
825
826 bool
get_extentsOT::CBDT::accelerator_t827 get_extents (hb_font_t *font, hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
828 {
829 const void *base;
830 const BitmapSizeTable &strike = this->cblc->choose_strike (font);
831 const IndexSubtableRecord *subtable_record = strike.find_table (glyph, cblc, &base);
832 if (!subtable_record || !strike.ppemX || !strike.ppemY)
833 return false;
834
835 if (subtable_record->get_extents (extents, base))
836 return true;
837
838 unsigned int image_offset = 0, image_length = 0, image_format = 0;
839 if (!subtable_record->get_image_data (glyph, base, &image_offset, &image_length, &image_format))
840 return false;
841
842 unsigned int cbdt_len = cbdt.get_length ();
843 if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
844 return false;
845
846 switch (image_format)
847 {
848 case 17: {
849 if (unlikely (image_length < GlyphBitmapDataFormat17::min_size))
850 return false;
851 auto &glyphFormat17 = StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
852 glyphFormat17.glyphMetrics.get_extents (font, extents);
853 break;
854 }
855 case 18: {
856 if (unlikely (image_length < GlyphBitmapDataFormat18::min_size))
857 return false;
858 auto &glyphFormat18 = StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
859 glyphFormat18.glyphMetrics.get_extents (font, extents);
860 break;
861 }
862 default: return false; /* TODO: Support other image formats. */
863 }
864
865 /* Convert to font units. */
866 float x_scale = upem / (float) strike.ppemX;
867 float y_scale = upem / (float) strike.ppemY;
868 extents->x_bearing = roundf (extents->x_bearing * x_scale);
869 extents->y_bearing = roundf (extents->y_bearing * y_scale);
870 extents->width = roundf (extents->width * x_scale);
871 extents->height = roundf (extents->height * y_scale);
872
873 return true;
874 }
875
876 hb_blob_t*
reference_pngOT::CBDT::accelerator_t877 reference_png (hb_font_t *font, hb_codepoint_t glyph) const
878 {
879 const void *base;
880 const BitmapSizeTable &strike = this->cblc->choose_strike (font);
881 const IndexSubtableRecord *subtable_record = strike.find_table (glyph, cblc, &base);
882 if (!subtable_record || !strike.ppemX || !strike.ppemY)
883 return hb_blob_get_empty ();
884
885 unsigned int image_offset = 0, image_length = 0, image_format = 0;
886 if (!subtable_record->get_image_data (glyph, base, &image_offset, &image_length, &image_format))
887 return hb_blob_get_empty ();
888
889 unsigned int cbdt_len = cbdt.get_length ();
890 if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
891 return hb_blob_get_empty ();
892
893 switch (image_format)
894 {
895 case 17:
896 {
897 if (unlikely (image_length < GlyphBitmapDataFormat17::min_size))
898 return hb_blob_get_empty ();
899 auto &glyphFormat17 = StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
900 return hb_blob_create_sub_blob (cbdt.get_blob (),
901 image_offset + GlyphBitmapDataFormat17::min_size,
902 glyphFormat17.data.len);
903 }
904 case 18:
905 {
906 if (unlikely (image_length < GlyphBitmapDataFormat18::min_size))
907 return hb_blob_get_empty ();
908 auto &glyphFormat18 = StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
909 return hb_blob_create_sub_blob (cbdt.get_blob (),
910 image_offset + GlyphBitmapDataFormat18::min_size,
911 glyphFormat18.data.len);
912 }
913 case 19:
914 {
915 if (unlikely (image_length < GlyphBitmapDataFormat19::min_size))
916 return hb_blob_get_empty ();
917 auto &glyphFormat19 = StructAtOffset<GlyphBitmapDataFormat19> (this->cbdt, image_offset);
918 return hb_blob_create_sub_blob (cbdt.get_blob (),
919 image_offset + GlyphBitmapDataFormat19::min_size,
920 glyphFormat19.data.len);
921 }
922 default: return hb_blob_get_empty (); /* TODO: Support other image formats. */
923 }
924 }
925
has_dataOT::CBDT::accelerator_t926 bool has_data () const { return cbdt.get_length (); }
927
928 private:
929 hb_blob_ptr_t<CBLC> cblc;
930 hb_blob_ptr_t<CBDT> cbdt;
931
932 unsigned int upem;
933 };
934
sanitizeOT::CBDT935 bool sanitize (hb_sanitize_context_t *c) const
936 {
937 TRACE_SANITIZE (this);
938 return_trace (c->check_struct (this) &&
939 likely (version.major == 2 || version.major == 3));
940 }
941
942 protected:
943 FixedVersion<> version;
944 UnsizedArrayOf<HBUINT8> dataZ;
945 public:
946 DEFINE_SIZE_ARRAY (4, dataZ);
947 };
948
949 inline bool
subset(hb_subset_context_t * c) const950 CBLC::subset (hb_subset_context_t *c) const
951 {
952 TRACE_SUBSET (this);
953
954 auto *cblc_prime = c->serializer->start_embed<CBLC> ();
955
956 // Use a vector as a secondary buffer as the tables need to be built in parallel.
957 hb_vector_t<char> cbdt_prime;
958
959 if (unlikely (!cblc_prime)) return_trace (false);
960 if (unlikely (!c->serializer->extend_min (cblc_prime))) return_trace (false);
961 cblc_prime->version = version;
962
963 hb_blob_t* cbdt_blob = hb_sanitize_context_t ().reference_table<CBDT> (c->plan->source);
964 unsigned int cbdt_length;
965 CBDT* cbdt = (CBDT *) hb_blob_get_data (cbdt_blob, &cbdt_length);
966 if (unlikely (cbdt_length < CBDT::min_size))
967 {
968 hb_blob_destroy (cbdt_blob);
969 return_trace (false);
970 }
971 _copy_data_to_cbdt (&cbdt_prime, cbdt, CBDT::min_size);
972
973 for (const BitmapSizeTable& table : + sizeTables.iter ())
974 subset_size_table (c, table, (const char *) cbdt, cbdt_length, cblc_prime, &cbdt_prime);
975
976 hb_blob_destroy (cbdt_blob);
977
978 return_trace (CBLC::sink_cbdt (c, &cbdt_prime));
979 }
980
981 struct CBDT_accelerator_t : CBDT::accelerator_t {};
982
983 } /* namespace OT */
984
985 #endif /* HB_OT_COLOR_CBDT_TABLE_HH */
986