1 /*
2 * Copyright © 2017 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): Behdad Esfahbod
25 */
26
27 #ifndef HB_AAT_LAYOUT_COMMON_HH
28 #define HB_AAT_LAYOUT_COMMON_HH
29
30 #include "hb-aat-layout.hh"
31 #include "hb-open-type.hh"
32
33
34 namespace AAT {
35
36 using namespace OT;
37
38
39 /*
40 * Lookup Table
41 */
42
43 template <typename T> struct Lookup;
44
45 template <typename T>
46 struct LookupFormat0
47 {
48 friend struct Lookup<T>;
49
50 private:
51 const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
52 {
53 if (unlikely (glyph_id >= num_glyphs)) return nullptr;
54 return &arrayZ[glyph_id];
55 }
56
57 bool sanitize (hb_sanitize_context_t *c) const
58 {
59 TRACE_SANITIZE (this);
60 return_trace (arrayZ.sanitize (c, c->get_num_glyphs ()));
61 }
62 bool sanitize (hb_sanitize_context_t *c, const void *base) const
63 {
64 TRACE_SANITIZE (this);
65 return_trace (arrayZ.sanitize (c, c->get_num_glyphs (), base));
66 }
67
68 protected:
69 HBUINT16 format; /* Format identifier--format = 0 */
70 UnsizedArrayOf<T>
71 arrayZ; /* Array of lookup values, indexed by glyph index. */
72 public:
73 DEFINE_SIZE_UNBOUNDED (2);
74 };
75
76
77 template <typename T>
78 struct LookupSegmentSingle
79 {
80 static constexpr unsigned TerminationWordCount = 2u;
81
82 int cmp (hb_codepoint_t g) const
83 { return g < first ? -1 : g <= last ? 0 : +1 ; }
84
85 bool sanitize (hb_sanitize_context_t *c) const
86 {
87 TRACE_SANITIZE (this);
88 return_trace (c->check_struct (this) && value.sanitize (c));
89 }
90 bool sanitize (hb_sanitize_context_t *c, const void *base) const
91 {
92 TRACE_SANITIZE (this);
93 return_trace (c->check_struct (this) && value.sanitize (c, base));
94 }
95
96 GlyphID last; /* Last GlyphID in this segment */
97 GlyphID first; /* First GlyphID in this segment */
98 T value; /* The lookup value (only one) */
99 public:
100 DEFINE_SIZE_STATIC (4 + T::static_size);
101 };
102
103 template <typename T>
104 struct LookupFormat2
105 {
106 friend struct Lookup<T>;
107
108 private:
109 const T* get_value (hb_codepoint_t glyph_id) const
110 {
111 const LookupSegmentSingle<T> *v = segments.bsearch (glyph_id);
112 return v ? &v->value : nullptr;
113 }
114
115 bool sanitize (hb_sanitize_context_t *c) const
116 {
117 TRACE_SANITIZE (this);
118 return_trace (segments.sanitize (c));
119 }
120 bool sanitize (hb_sanitize_context_t *c, const void *base) const
121 {
122 TRACE_SANITIZE (this);
123 return_trace (segments.sanitize (c, base));
124 }
125
126 protected:
127 HBUINT16 format; /* Format identifier--format = 2 */
128 VarSizedBinSearchArrayOf<LookupSegmentSingle<T> >
129 segments; /* The actual segments. These must already be sorted,
130 * according to the first word in each one (the last
131 * glyph in each segment). */
132 public:
133 DEFINE_SIZE_ARRAY (8, segments);
134 };
135
136 template <typename T>
137 struct LookupSegmentArray
138 {
139 static constexpr unsigned TerminationWordCount = 2u;
140
141 const T* get_value (hb_codepoint_t glyph_id, const void *base) const
142 {
143 return first <= glyph_id && glyph_id <= last ? &(base+valuesZ)[glyph_id - first] : nullptr;
144 }
145
146 int cmp (hb_codepoint_t g) const
147 { return g < first ? -1 : g <= last ? 0 : +1; }
148
149 bool sanitize (hb_sanitize_context_t *c, const void *base) const
150 {
151 TRACE_SANITIZE (this);
152 return_trace (c->check_struct (this) &&
153 first <= last &&
154 valuesZ.sanitize (c, base, last - first + 1));
155 }
156 template <typename T2>
157 bool sanitize (hb_sanitize_context_t *c, const void *base, T2 user_data) const
158 {
159 TRACE_SANITIZE (this);
160 return_trace (c->check_struct (this) &&
161 first <= last &&
162 valuesZ.sanitize (c, base, last - first + 1, user_data));
163 }
164
165 GlyphID last; /* Last GlyphID in this segment */
166 GlyphID first; /* First GlyphID in this segment */
167 NNOffsetTo<UnsizedArrayOf<T> >
168 valuesZ; /* A 16-bit offset from the start of
169 * the table to the data. */
170 public:
171 DEFINE_SIZE_STATIC (6);
172 };
173
174 template <typename T>
175 struct LookupFormat4
176 {
177 friend struct Lookup<T>;
178
179 private:
180 const T* get_value (hb_codepoint_t glyph_id) const
181 {
182 const LookupSegmentArray<T> *v = segments.bsearch (glyph_id);
183 return v ? v->get_value (glyph_id, this) : nullptr;
184 }
185
186 bool sanitize (hb_sanitize_context_t *c) const
187 {
188 TRACE_SANITIZE (this);
189 return_trace (segments.sanitize (c, this));
190 }
191 bool sanitize (hb_sanitize_context_t *c, const void *base) const
192 {
193 TRACE_SANITIZE (this);
194 return_trace (segments.sanitize (c, this, base));
195 }
196
197 protected:
198 HBUINT16 format; /* Format identifier--format = 4 */
199 VarSizedBinSearchArrayOf<LookupSegmentArray<T> >
200 segments; /* The actual segments. These must already be sorted,
201 * according to the first word in each one (the last
202 * glyph in each segment). */
203 public:
204 DEFINE_SIZE_ARRAY (8, segments);
205 };
206
207 template <typename T>
208 struct LookupSingle
209 {
210 static constexpr unsigned TerminationWordCount = 1u;
211
212 int cmp (hb_codepoint_t g) const { return glyph.cmp (g); }
213
214 bool sanitize (hb_sanitize_context_t *c) const
215 {
216 TRACE_SANITIZE (this);
217 return_trace (c->check_struct (this) && value.sanitize (c));
218 }
219 bool sanitize (hb_sanitize_context_t *c, const void *base) const
220 {
221 TRACE_SANITIZE (this);
222 return_trace (c->check_struct (this) && value.sanitize (c, base));
223 }
224
225 GlyphID glyph; /* Last GlyphID */
226 T value; /* The lookup value (only one) */
227 public:
228 DEFINE_SIZE_STATIC (2 + T::static_size);
229 };
230
231 template <typename T>
232 struct LookupFormat6
233 {
234 friend struct Lookup<T>;
235
236 private:
237 const T* get_value (hb_codepoint_t glyph_id) const
238 {
239 const LookupSingle<T> *v = entries.bsearch (glyph_id);
240 return v ? &v->value : nullptr;
241 }
242
243 bool sanitize (hb_sanitize_context_t *c) const
244 {
245 TRACE_SANITIZE (this);
246 return_trace (entries.sanitize (c));
247 }
248 bool sanitize (hb_sanitize_context_t *c, const void *base) const
249 {
250 TRACE_SANITIZE (this);
251 return_trace (entries.sanitize (c, base));
252 }
253
254 protected:
255 HBUINT16 format; /* Format identifier--format = 6 */
256 VarSizedBinSearchArrayOf<LookupSingle<T> >
257 entries; /* The actual entries, sorted by glyph index. */
258 public:
259 DEFINE_SIZE_ARRAY (8, entries);
260 };
261
262 template <typename T>
263 struct LookupFormat8
264 {
265 friend struct Lookup<T>;
266
267 private:
268 const T* get_value (hb_codepoint_t glyph_id) const
269 {
270 return firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount ?
271 &valueArrayZ[glyph_id - firstGlyph] : nullptr;
272 }
273
274 bool sanitize (hb_sanitize_context_t *c) const
275 {
276 TRACE_SANITIZE (this);
277 return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount));
278 }
279 bool sanitize (hb_sanitize_context_t *c, const void *base) const
280 {
281 TRACE_SANITIZE (this);
282 return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount, base));
283 }
284
285 protected:
286 HBUINT16 format; /* Format identifier--format = 8 */
287 GlyphID firstGlyph; /* First glyph index included in the trimmed array. */
288 HBUINT16 glyphCount; /* Total number of glyphs (equivalent to the last
289 * glyph minus the value of firstGlyph plus 1). */
290 UnsizedArrayOf<T>
291 valueArrayZ; /* The lookup values (indexed by the glyph index
292 * minus the value of firstGlyph). */
293 public:
294 DEFINE_SIZE_ARRAY (6, valueArrayZ);
295 };
296
297 template <typename T>
298 struct LookupFormat10
299 {
300 friend struct Lookup<T>;
301
302 private:
303 const typename T::type get_value_or_null (hb_codepoint_t glyph_id) const
304 {
305 if (!(firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount))
306 return Null(T);
307
308 const HBUINT8 *p = &valueArrayZ[(glyph_id - firstGlyph) * valueSize];
309
310 unsigned int v = 0;
311 unsigned int count = valueSize;
312 for (unsigned int i = 0; i < count; i++)
313 v = (v << 8) | *p++;
314
315 return v;
316 }
317
318 bool sanitize (hb_sanitize_context_t *c) const
319 {
320 TRACE_SANITIZE (this);
321 return_trace (c->check_struct (this) &&
322 valueSize <= 4 &&
323 valueArrayZ.sanitize (c, glyphCount * valueSize));
324 }
325
326 protected:
327 HBUINT16 format; /* Format identifier--format = 8 */
328 HBUINT16 valueSize; /* Byte size of each value. */
329 GlyphID firstGlyph; /* First glyph index included in the trimmed array. */
330 HBUINT16 glyphCount; /* Total number of glyphs (equivalent to the last
331 * glyph minus the value of firstGlyph plus 1). */
332 UnsizedArrayOf<HBUINT8>
333 valueArrayZ; /* The lookup values (indexed by the glyph index
334 * minus the value of firstGlyph). */
335 public:
336 DEFINE_SIZE_ARRAY (8, valueArrayZ);
337 };
338
339 template <typename T>
340 struct Lookup
341 {
342 const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
343 {
344 switch (u.format) {
345 case 0: return u.format0.get_value (glyph_id, num_glyphs);
346 case 2: return u.format2.get_value (glyph_id);
347 case 4: return u.format4.get_value (glyph_id);
348 case 6: return u.format6.get_value (glyph_id);
349 case 8: return u.format8.get_value (glyph_id);
350 default:return nullptr;
351 }
352 }
353
354 const typename T::type get_value_or_null (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
355 {
356 switch (u.format) {
357 /* Format 10 cannot return a pointer. */
358 case 10: return u.format10.get_value_or_null (glyph_id);
359 default:
360 const T *v = get_value (glyph_id, num_glyphs);
361 return v ? *v : Null(T);
362 }
363 }
364
365 typename T::type get_class (hb_codepoint_t glyph_id,
366 unsigned int num_glyphs,
367 unsigned int outOfRange) const
368 {
369 const T *v = get_value (glyph_id, num_glyphs);
370 return v ? *v : outOfRange;
371 }
372
373 bool sanitize (hb_sanitize_context_t *c) const
374 {
375 TRACE_SANITIZE (this);
376 if (!u.format.sanitize (c)) return_trace (false);
377 switch (u.format) {
378 case 0: return_trace (u.format0.sanitize (c));
379 case 2: return_trace (u.format2.sanitize (c));
380 case 4: return_trace (u.format4.sanitize (c));
381 case 6: return_trace (u.format6.sanitize (c));
382 case 8: return_trace (u.format8.sanitize (c));
383 case 10: return_trace (u.format10.sanitize (c));
384 default:return_trace (true);
385 }
386 }
387 bool sanitize (hb_sanitize_context_t *c, const void *base) const
388 {
389 TRACE_SANITIZE (this);
390 if (!u.format.sanitize (c)) return_trace (false);
391 switch (u.format) {
392 case 0: return_trace (u.format0.sanitize (c, base));
393 case 2: return_trace (u.format2.sanitize (c, base));
394 case 4: return_trace (u.format4.sanitize (c, base));
395 case 6: return_trace (u.format6.sanitize (c, base));
396 case 8: return_trace (u.format8.sanitize (c, base));
397 case 10: return_trace (false); /* We don't support format10 here currently. */
398 default:return_trace (true);
399 }
400 }
401
402 protected:
403 union {
404 HBUINT16 format; /* Format identifier */
405 LookupFormat0<T> format0;
406 LookupFormat2<T> format2;
407 LookupFormat4<T> format4;
408 LookupFormat6<T> format6;
409 LookupFormat8<T> format8;
410 LookupFormat10<T> format10;
411 } u;
412 public:
413 DEFINE_SIZE_UNION (2, format);
414 };
415 /* Lookup 0 has unbounded size (dependant on num_glyphs). So we need to defined
416 * special NULL objects for Lookup<> objects, but since it's template our macros
417 * don't work. So we have to hand-code them here. UGLY. */
418 } /* Close namespace. */
419 /* Ugly hand-coded null objects for template Lookup<> :(. */
420 extern HB_INTERNAL const unsigned char _hb_Null_AAT_Lookup[2];
421 template <>
422 /*static*/ inline const AAT::Lookup<OT::HBUINT16>& Null<AAT::Lookup<OT::HBUINT16> > ()
423 { return *reinterpret_cast<const AAT::Lookup<OT::HBUINT16> *> (_hb_Null_AAT_Lookup); }
424 template <>
425 /*static*/ inline const AAT::Lookup<OT::HBUINT32>& Null<AAT::Lookup<OT::HBUINT32> > ()
426 { return *reinterpret_cast<const AAT::Lookup<OT::HBUINT32> *> (_hb_Null_AAT_Lookup); }
427 template <>
428 /*static*/ inline const AAT::Lookup<OT::Offset<OT::HBUINT16, false> >& Null<AAT::Lookup<OT::Offset<OT::HBUINT16, false> > > ()
429 { return *reinterpret_cast<const AAT::Lookup<OT::Offset<OT::HBUINT16, false> > *> (_hb_Null_AAT_Lookup); }
430 namespace AAT {
431
432 enum { DELETED_GLYPH = 0xFFFF };
433
434 /*
435 * (Extended) State Table
436 */
437
438 template <typename T>
439 struct Entry
440 {
441 bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
442 {
443 TRACE_SANITIZE (this);
444 /* Note, we don't recurse-sanitize data because we don't access it.
445 * That said, in our DEFINE_SIZE_STATIC we access T::static_size,
446 * which ensures that data has a simple sanitize(). To be determined
447 * if I need to remove that as well.
448 *
449 * HOWEVER! Because we are a template, our DEFINE_SIZE_STATIC
450 * assertion wouldn't be checked, hence the line below. */
451 static_assert (T::static_size, "");
452
453 return_trace (c->check_struct (this));
454 }
455
456 public:
457 HBUINT16 newState; /* Byte offset from beginning of state table
458 * to the new state. Really?!?! Or just state
459 * number? The latter in morx for sure. */
460 HBUINT16 flags; /* Table specific. */
461 T data; /* Optional offsets to per-glyph tables. */
462 public:
463 DEFINE_SIZE_STATIC (4 + T::static_size);
464 };
465
466 template <>
467 struct Entry<void>
468 {
469 bool sanitize (hb_sanitize_context_t *c, unsigned int count /*XXX Unused?*/) const
470 {
471 TRACE_SANITIZE (this);
472 return_trace (c->check_struct (this));
473 }
474
475 public:
476 HBUINT16 newState; /* Byte offset from beginning of state table to the new state. */
477 HBUINT16 flags; /* Table specific. */
478 public:
479 DEFINE_SIZE_STATIC (4);
480 };
481
482 template <typename Types, typename Extra>
483 struct StateTable
484 {
485 typedef typename Types::HBUINT HBUINT;
486 typedef typename Types::HBUSHORT HBUSHORT;
487 typedef typename Types::ClassTypeNarrow ClassType;
488
489 enum State
490 {
491 STATE_START_OF_TEXT = 0,
492 STATE_START_OF_LINE = 1,
493 };
494 enum Class
495 {
496 CLASS_END_OF_TEXT = 0,
497 CLASS_OUT_OF_BOUNDS = 1,
498 CLASS_DELETED_GLYPH = 2,
499 CLASS_END_OF_LINE = 3,
500 };
501
502 int new_state (unsigned int newState) const
503 { return Types::extended ? newState : ((int) newState - (int) stateArrayTable) / (int) nClasses; }
504
505 unsigned int get_class (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
506 {
507 if (unlikely (glyph_id == DELETED_GLYPH)) return CLASS_DELETED_GLYPH;
508 return (this+classTable).get_class (glyph_id, num_glyphs, 1);
509 }
510
511 const Entry<Extra> *get_entries () const
512 { return (this+entryTable).arrayZ; }
513
514 const Entry<Extra> &get_entry (int state, unsigned int klass) const
515 {
516 if (unlikely (klass >= nClasses))
517 klass = StateTable<Types, Entry<Extra> >::CLASS_OUT_OF_BOUNDS;
518
519 const HBUSHORT *states = (this+stateArrayTable).arrayZ;
520 const Entry<Extra> *entries = (this+entryTable).arrayZ;
521
522 unsigned int entry = states[state * nClasses + klass];
523 DEBUG_MSG (APPLY, nullptr, "e%u", entry);
524
525 return entries[entry];
526 }
527
528 bool sanitize (hb_sanitize_context_t *c,
529 unsigned int *num_entries_out = nullptr) const
530 {
531 TRACE_SANITIZE (this);
532 if (unlikely (!(c->check_struct (this) &&
533 nClasses >= 4 /* Ensure pre-defined classes fit. */ &&
534 classTable.sanitize (c, this)))) return_trace (false);
535
536 const HBUSHORT *states = (this+stateArrayTable).arrayZ;
537 const Entry<Extra> *entries = (this+entryTable).arrayZ;
538
539 unsigned int num_classes = nClasses;
540 if (unlikely (hb_unsigned_mul_overflows (num_classes, states[0].static_size)))
541 return_trace (false);
542 unsigned int row_stride = num_classes * states[0].static_size;
543
544 /* Apple 'kern' table has this peculiarity:
545 *
546 * "Because the stateTableOffset in the state table header is (strictly
547 * speaking) redundant, some 'kern' tables use it to record an initial
548 * state where that should not be StartOfText. To determine if this is
549 * done, calculate what the stateTableOffset should be. If it's different
550 * from the actual stateTableOffset, use it as the initial state."
551 *
552 * We implement this by calling the initial state zero, but allow *negative*
553 * states if the start state indeed was not the first state. Since the code
554 * is shared, this will also apply to 'mort' table. The 'kerx' / 'morx'
555 * tables are not affected since those address states by index, not offset.
556 */
557
558 int min_state = 0;
559 int max_state = 0;
560 unsigned int num_entries = 0;
561
562 int state_pos = 0;
563 int state_neg = 0;
564 unsigned int entry = 0;
565 while (min_state < state_neg || state_pos <= max_state)
566 {
567 if (min_state < state_neg)
568 {
569 /* Negative states. */
570 if (unlikely (hb_unsigned_mul_overflows (min_state, num_classes)))
571 return_trace (false);
572 if (unlikely (!c->check_range (&states[min_state * num_classes],
573 -min_state,
574 row_stride)))
575 return_trace (false);
576 if ((c->max_ops -= state_neg - min_state) <= 0)
577 return_trace (false);
578 { /* Sweep new states. */
579 const HBUSHORT *stop = &states[min_state * num_classes];
580 if (unlikely (stop > states))
581 return_trace (false);
582 for (const HBUSHORT *p = states; stop < p; p--)
583 num_entries = MAX<unsigned int> (num_entries, *(p - 1) + 1);
584 state_neg = min_state;
585 }
586 }
587
588 if (state_pos <= max_state)
589 {
590 /* Positive states. */
591 if (unlikely (!c->check_range (states,
592 max_state + 1,
593 row_stride)))
594 return_trace (false);
595 if ((c->max_ops -= max_state - state_pos + 1) <= 0)
596 return_trace (false);
597 { /* Sweep new states. */
598 if (unlikely (hb_unsigned_mul_overflows ((max_state + 1), num_classes)))
599 return_trace (false);
600 const HBUSHORT *stop = &states[(max_state + 1) * num_classes];
601 if (unlikely (stop < states))
602 return_trace (false);
603 for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++)
604 num_entries = MAX<unsigned int> (num_entries, *p + 1);
605 state_pos = max_state + 1;
606 }
607 }
608
609 if (unlikely (!c->check_array (entries, num_entries)))
610 return_trace (false);
611 if ((c->max_ops -= num_entries - entry) <= 0)
612 return_trace (false);
613 { /* Sweep new entries. */
614 const Entry<Extra> *stop = &entries[num_entries];
615 for (const Entry<Extra> *p = &entries[entry]; p < stop; p++)
616 {
617 int newState = new_state (p->newState);
618 min_state = MIN (min_state, newState);
619 max_state = MAX (max_state, newState);
620 }
621 entry = num_entries;
622 }
623 }
624
625 if (num_entries_out)
626 *num_entries_out = num_entries;
627
628 return_trace (true);
629 }
630
631 protected:
632 HBUINT nClasses; /* Number of classes, which is the number of indices
633 * in a single line in the state array. */
634 NNOffsetTo<ClassType, HBUINT>
635 classTable; /* Offset to the class table. */
636 NNOffsetTo<UnsizedArrayOf<HBUSHORT>, HBUINT>
637 stateArrayTable;/* Offset to the state array. */
638 NNOffsetTo<UnsizedArrayOf<Entry<Extra> >, HBUINT>
639 entryTable; /* Offset to the entry array. */
640
641 public:
642 DEFINE_SIZE_STATIC (4 * sizeof (HBUINT));
643 };
644
645 template <typename HBUCHAR>
646 struct ClassTable
647 {
648 unsigned int get_class (hb_codepoint_t glyph_id, unsigned int outOfRange) const
649 {
650 unsigned int i = glyph_id - firstGlyph;
651 return i >= classArray.len ? outOfRange : classArray.arrayZ[i];
652 }
653 unsigned int get_class (hb_codepoint_t glyph_id,
654 unsigned int num_glyphs HB_UNUSED,
655 unsigned int outOfRange) const
656 {
657 return get_class (glyph_id, outOfRange);
658 }
659 bool sanitize (hb_sanitize_context_t *c) const
660 {
661 TRACE_SANITIZE (this);
662 return_trace (c->check_struct (this) && classArray.sanitize (c));
663 }
664 protected:
665 GlyphID firstGlyph; /* First glyph index included in the trimmed array. */
666 ArrayOf<HBUCHAR> classArray; /* The class codes (indexed by glyph index minus
667 * firstGlyph). */
668 public:
669 DEFINE_SIZE_ARRAY (4, classArray);
670 };
671
672 struct ObsoleteTypes
673 {
674 static constexpr bool extended = false;
675 typedef HBUINT16 HBUINT;
676 typedef HBUINT8 HBUSHORT;
677 typedef ClassTable<HBUINT8> ClassTypeNarrow;
678 typedef ClassTable<HBUINT16> ClassTypeWide;
679
680 template <typename T>
681 static unsigned int offsetToIndex (unsigned int offset,
682 const void *base,
683 const T *array)
684 {
685 return (offset - ((const char *) array - (const char *) base)) / sizeof (T);
686 }
687 template <typename T>
688 static unsigned int byteOffsetToIndex (unsigned int offset,
689 const void *base,
690 const T *array)
691 {
692 return offsetToIndex (offset, base, array);
693 }
694 template <typename T>
695 static unsigned int wordOffsetToIndex (unsigned int offset,
696 const void *base,
697 const T *array)
698 {
699 return offsetToIndex (2 * offset, base, array);
700 }
701 };
702 struct ExtendedTypes
703 {
704 static constexpr bool extended = true;
705 typedef HBUINT32 HBUINT;
706 typedef HBUINT16 HBUSHORT;
707 typedef Lookup<HBUINT16> ClassTypeNarrow;
708 typedef Lookup<HBUINT16> ClassTypeWide;
709
710 template <typename T>
711 static unsigned int offsetToIndex (unsigned int offset,
712 const void *base HB_UNUSED,
713 const T *array HB_UNUSED)
714 {
715 return offset;
716 }
717 template <typename T>
718 static unsigned int byteOffsetToIndex (unsigned int offset,
719 const void *base HB_UNUSED,
720 const T *array HB_UNUSED)
721 {
722 return offset / 2;
723 }
724 template <typename T>
725 static unsigned int wordOffsetToIndex (unsigned int offset,
726 const void *base HB_UNUSED,
727 const T *array HB_UNUSED)
728 {
729 return offset;
730 }
731 };
732
733 template <typename Types, typename EntryData>
734 struct StateTableDriver
735 {
736 StateTableDriver (const StateTable<Types, EntryData> &machine_,
737 hb_buffer_t *buffer_,
738 hb_face_t *face_) :
739 machine (machine_),
740 buffer (buffer_),
741 num_glyphs (face_->get_num_glyphs ()) {}
742
743 template <typename context_t>
744 void drive (context_t *c)
745 {
746 if (!c->in_place)
747 buffer->clear_output ();
748
749 int state = StateTable<Types, EntryData>::STATE_START_OF_TEXT;
750 for (buffer->idx = 0; buffer->successful;)
751 {
752 unsigned int klass = buffer->idx < buffer->len ?
753 machine.get_class (buffer->info[buffer->idx].codepoint, num_glyphs) :
754 (unsigned) StateTable<Types, EntryData>::CLASS_END_OF_TEXT;
755 DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx);
756 const Entry<EntryData> &entry = machine.get_entry (state, klass);
757
758 /* Unsafe-to-break before this if not in state 0, as things might
759 * go differently if we start from state 0 here.
760 *
761 * Ugh. The indexing here is ugly... */
762 if (state && buffer->backtrack_len () && buffer->idx < buffer->len)
763 {
764 /* If there's no action and we're just epsilon-transitioning to state 0,
765 * safe to break. */
766 if (c->is_actionable (this, entry) ||
767 !(entry.newState == StateTable<Types, EntryData>::STATE_START_OF_TEXT &&
768 entry.flags == context_t::DontAdvance))
769 buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1);
770 }
771
772 /* Unsafe-to-break if end-of-text would kick in here. */
773 if (buffer->idx + 2 <= buffer->len)
774 {
775 const Entry<EntryData> &end_entry = machine.get_entry (state, StateTable<Types, EntryData>::CLASS_END_OF_TEXT);
776 if (c->is_actionable (this, end_entry))
777 buffer->unsafe_to_break (buffer->idx, buffer->idx + 2);
778 }
779
780 c->transition (this, entry);
781
782 state = machine.new_state (entry.newState);
783 DEBUG_MSG (APPLY, nullptr, "s%d", state);
784
785 if (buffer->idx == buffer->len)
786 break;
787
788 if (!(entry.flags & context_t::DontAdvance) || buffer->max_ops-- <= 0)
789 buffer->next_glyph ();
790 }
791
792 if (!c->in_place)
793 {
794 for (; buffer->successful && buffer->idx < buffer->len;)
795 buffer->next_glyph ();
796 buffer->swap_buffers ();
797 }
798 }
799
800 public:
801 const StateTable<Types, EntryData> &machine;
802 hb_buffer_t *buffer;
803 unsigned int num_glyphs;
804 };
805
806
807 struct ankr;
808
809 struct hb_aat_apply_context_t :
810 hb_dispatch_context_t<hb_aat_apply_context_t, bool, HB_DEBUG_APPLY>
811 {
812 const char *get_name () { return "APPLY"; }
813 template <typename T>
814 return_t dispatch (const T &obj) { return obj.apply (this); }
815 static return_t default_return_value () { return false; }
816 bool stop_sublookup_iteration (return_t r) const { return r; }
817
818 const hb_ot_shape_plan_t *plan;
819 hb_font_t *font;
820 hb_face_t *face;
821 hb_buffer_t *buffer;
822 hb_sanitize_context_t sanitizer;
823 const ankr *ankr_table;
824
825 /* Unused. For debug tracing only. */
826 unsigned int lookup_index;
827 unsigned int debug_depth;
828
829 HB_INTERNAL hb_aat_apply_context_t (const hb_ot_shape_plan_t *plan_,
830 hb_font_t *font_,
831 hb_buffer_t *buffer_,
832 hb_blob_t *blob = const_cast<hb_blob_t *> (&Null(hb_blob_t)));
833
834 HB_INTERNAL ~hb_aat_apply_context_t ();
835
836 HB_INTERNAL void set_ankr_table (const AAT::ankr *ankr_table_);
837
838 void set_lookup_index (unsigned int i) { lookup_index = i; }
839 };
840
841
842 } /* namespace AAT */
843
844
845 #endif /* HB_AAT_LAYOUT_COMMON_HH */