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
34namespace AAT {
35
36using namespace OT;
37
38
39/*
40 * Lookup Table
41 */
42
43template <typename T> struct Lookup;
44
45template <typename T>
46struct 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
77template <typename T>
78struct 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 HBGlyphID last; /* Last GlyphID in this segment */
97 HBGlyphID 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
103template <typename T>
104struct 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
136template <typename T>
137struct 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 ...Ts>
157 bool sanitize (hb_sanitize_context_t *c, const void *base, Ts&&... ds) const
158 {
159 TRACE_SANITIZE (this);
160 return_trace (c->check_struct (this) &&
161 first <= last &&
162 valuesZ.sanitize (c, base, last - first + 1, hb_forward<Ts> (ds)...));
163 }
164
165 HBGlyphID last; /* Last GlyphID in this segment */
166 HBGlyphID 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
174template <typename T>
175struct 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
207template <typename T>
208struct 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 HBGlyphID glyph; /* Last GlyphID */
226 T value; /* The lookup value (only one) */
227 public:
228 DEFINE_SIZE_STATIC (2 + T::static_size);
229};
230
231template <typename T>
232struct 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
262template <typename T>
263struct 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 HBGlyphID 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
297template <typename T>
298struct 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 HBGlyphID 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
339template <typename T>
340struct 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<> :(. */
420extern HB_INTERNAL const unsigned char _hb_Null_AAT_Lookup[2];
421template <typename T>
422struct Null<AAT::Lookup<T>> {
423 static AAT::Lookup<T> const & get_null ()
424 { return *reinterpret_cast<const AAT::Lookup<T> *> (_hb_Null_AAT_Lookup); }
425};
426namespace AAT {
427
428enum { DELETED_GLYPH = 0xFFFF };
429
430/*
431 * (Extended) State Table
432 */
433
434template <typename T>
435struct Entry
436{
437 bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
438 {
439 TRACE_SANITIZE (this);
440 /* Note, we don't recurse-sanitize data because we don't access it.
441 * That said, in our DEFINE_SIZE_STATIC we access T::static_size,
442 * which ensures that data has a simple sanitize(). To be determined
443 * if I need to remove that as well.
444 *
445 * HOWEVER! Because we are a template, our DEFINE_SIZE_STATIC
446 * assertion wouldn't be checked, hence the line below. */
447 static_assert (T::static_size, "");
448
449 return_trace (c->check_struct (this));
450 }
451
452 public:
453 HBUINT16 newState; /* Byte offset from beginning of state table
454 * to the new state. Really?!?! Or just state
455 * number? The latter in morx for sure. */
456 HBUINT16 flags; /* Table specific. */
457 T data; /* Optional offsets to per-glyph tables. */
458 public:
459 DEFINE_SIZE_STATIC (4 + T::static_size);
460};
461
462template <>
463struct Entry<void>
464{
465 bool sanitize (hb_sanitize_context_t *c, unsigned int count /*XXX Unused?*/) const
466 {
467 TRACE_SANITIZE (this);
468 return_trace (c->check_struct (this));
469 }
470
471 public:
472 HBUINT16 newState; /* Byte offset from beginning of state table to the new state. */
473 HBUINT16 flags; /* Table specific. */
474 public:
475 DEFINE_SIZE_STATIC (4);
476};
477
478template <typename Types, typename Extra>
479struct StateTable
480{
481 typedef typename Types::HBUINT HBUINT;
482 typedef typename Types::HBUSHORT HBUSHORT;
483 typedef typename Types::ClassTypeNarrow ClassType;
484
485 enum State
486 {
487 STATE_START_OF_TEXT = 0,
488 STATE_START_OF_LINE = 1,
489 };
490 enum Class
491 {
492 CLASS_END_OF_TEXT = 0,
493 CLASS_OUT_OF_BOUNDS = 1,
494 CLASS_DELETED_GLYPH = 2,
495 CLASS_END_OF_LINE = 3,
496 };
497
498 int new_state (unsigned int newState) const
499 { return Types::extended ? newState : ((int) newState - (int) stateArrayTable) / (int) nClasses; }
500
501 unsigned int get_class (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
502 {
503 if (unlikely (glyph_id == DELETED_GLYPH)) return CLASS_DELETED_GLYPH;
504 return (this+classTable).get_class (glyph_id, num_glyphs, 1);
505 }
506
507 const Entry<Extra> *get_entries () const
508 { return (this+entryTable).arrayZ; }
509
510 const Entry<Extra> &get_entry (int state, unsigned int klass) const
511 {
512 if (unlikely (klass >= nClasses))
513 klass = StateTable<Types, Entry<Extra>>::CLASS_OUT_OF_BOUNDS;
514
515 const HBUSHORT *states = (this+stateArrayTable).arrayZ;
516 const Entry<Extra> *entries = (this+entryTable).arrayZ;
517
518 unsigned int entry = states[state * nClasses + klass];
519 DEBUG_MSG (APPLY, nullptr, "e%u", entry);
520
521 return entries[entry];
522 }
523
524 bool sanitize (hb_sanitize_context_t *c,
525 unsigned int *num_entries_out = nullptr) const
526 {
527 TRACE_SANITIZE (this);
528 if (unlikely (!(c->check_struct (this) &&
529 nClasses >= 4 /* Ensure pre-defined classes fit. */ &&
530 classTable.sanitize (c, this)))) return_trace (false);
531
532 const HBUSHORT *states = (this+stateArrayTable).arrayZ;
533 const Entry<Extra> *entries = (this+entryTable).arrayZ;
534
535 unsigned int num_classes = nClasses;
536 if (unlikely (hb_unsigned_mul_overflows (num_classes, states[0].static_size)))
537 return_trace (false);
538 unsigned int row_stride = num_classes * states[0].static_size;
539
540 /* Apple 'kern' table has this peculiarity:
541 *
542 * "Because the stateTableOffset in the state table header is (strictly
543 * speaking) redundant, some 'kern' tables use it to record an initial
544 * state where that should not be StartOfText. To determine if this is
545 * done, calculate what the stateTableOffset should be. If it's different
546 * from the actual stateTableOffset, use it as the initial state."
547 *
548 * We implement this by calling the initial state zero, but allow *negative*
549 * states if the start state indeed was not the first state. Since the code
550 * is shared, this will also apply to 'mort' table. The 'kerx' / 'morx'
551 * tables are not affected since those address states by index, not offset.
552 */
553
554 int min_state = 0;
555 int max_state = 0;
556 unsigned int num_entries = 0;
557
558 int state_pos = 0;
559 int state_neg = 0;
560 unsigned int entry = 0;
561 while (min_state < state_neg || state_pos <= max_state)
562 {
563 if (min_state < state_neg)
564 {
565 /* Negative states. */
566 if (unlikely (hb_unsigned_mul_overflows (min_state, num_classes)))
567 return_trace (false);
568 if (unlikely (!c->check_range (&states[min_state * num_classes],
569 -min_state,
570 row_stride)))
571 return_trace (false);
572 if ((c->max_ops -= state_neg - min_state) <= 0)
573 return_trace (false);
574 { /* Sweep new states. */
575 const HBUSHORT *stop = &states[min_state * num_classes];
576 if (unlikely (stop > states))
577 return_trace (false);
578 for (const HBUSHORT *p = states; stop < p; p--)
579 num_entries = hb_max (num_entries, *(p - 1) + 1);
580 state_neg = min_state;
581 }
582 }
583
584 if (state_pos <= max_state)
585 {
586 /* Positive states. */
587 if (unlikely (!c->check_range (states,
588 max_state + 1,
589 row_stride)))
590 return_trace (false);
591 if ((c->max_ops -= max_state - state_pos + 1) <= 0)
592 return_trace (false);
593 { /* Sweep new states. */
594 if (unlikely (hb_unsigned_mul_overflows ((max_state + 1), num_classes)))
595 return_trace (false);
596 const HBUSHORT *stop = &states[(max_state + 1) * num_classes];
597 if (unlikely (stop < states))
598 return_trace (false);
599 for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++)
600 num_entries = hb_max (num_entries, *p + 1);
601 state_pos = max_state + 1;
602 }
603 }
604
605 if (unlikely (!c->check_array (entries, num_entries)))
606 return_trace (false);
607 if ((c->max_ops -= num_entries - entry) <= 0)
608 return_trace (false);
609 { /* Sweep new entries. */
610 const Entry<Extra> *stop = &entries[num_entries];
611 for (const Entry<Extra> *p = &entries[entry]; p < stop; p++)
612 {
613 int newState = new_state (p->newState);
614 min_state = hb_min (min_state, newState);
615 max_state = hb_max (max_state, newState);
616 }
617 entry = num_entries;
618 }
619 }
620
621 if (num_entries_out)
622 *num_entries_out = num_entries;
623
624 return_trace (true);
625 }
626
627 protected:
628 HBUINT nClasses; /* Number of classes, which is the number of indices
629 * in a single line in the state array. */
630 NNOffsetTo<ClassType, HBUINT>
631 classTable; /* Offset to the class table. */
632 NNOffsetTo<UnsizedArrayOf<HBUSHORT>, HBUINT>
633 stateArrayTable;/* Offset to the state array. */
634 NNOffsetTo<UnsizedArrayOf<Entry<Extra>>, HBUINT>
635 entryTable; /* Offset to the entry array. */
636
637 public:
638 DEFINE_SIZE_STATIC (4 * sizeof (HBUINT));
639};
640
641template <typename HBUCHAR>
642struct ClassTable
643{
644 unsigned int get_class (hb_codepoint_t glyph_id, unsigned int outOfRange) const
645 {
646 unsigned int i = glyph_id - firstGlyph;
647 return i >= classArray.len ? outOfRange : classArray.arrayZ[i];
648 }
649 unsigned int get_class (hb_codepoint_t glyph_id,
650 unsigned int num_glyphs HB_UNUSED,
651 unsigned int outOfRange) const
652 {
653 return get_class (glyph_id, outOfRange);
654 }
655 bool sanitize (hb_sanitize_context_t *c) const
656 {
657 TRACE_SANITIZE (this);
658 return_trace (c->check_struct (this) && classArray.sanitize (c));
659 }
660 protected:
661 HBGlyphID firstGlyph; /* First glyph index included in the trimmed array. */
662 ArrayOf<HBUCHAR> classArray; /* The class codes (indexed by glyph index minus
663 * firstGlyph). */
664 public:
665 DEFINE_SIZE_ARRAY (4, classArray);
666};
667
668struct ObsoleteTypes
669{
670 static constexpr bool extended = false;
671 typedef HBUINT16 HBUINT;
672 typedef HBUINT8 HBUSHORT;
673 typedef ClassTable<HBUINT8> ClassTypeNarrow;
674 typedef ClassTable<HBUINT16> ClassTypeWide;
675
676 template <typename T>
677 static unsigned int offsetToIndex (unsigned int offset,
678 const void *base,
679 const T *array)
680 {
681 return (offset - ((const char *) array - (const char *) base)) / T::static_size;
682 }
683 template <typename T>
684 static unsigned int byteOffsetToIndex (unsigned int offset,
685 const void *base,
686 const T *array)
687 {
688 return offsetToIndex (offset, base, array);
689 }
690 template <typename T>
691 static unsigned int wordOffsetToIndex (unsigned int offset,
692 const void *base,
693 const T *array)
694 {
695 return offsetToIndex (2 * offset, base, array);
696 }
697};
698struct ExtendedTypes
699{
700 static constexpr bool extended = true;
701 typedef HBUINT32 HBUINT;
702 typedef HBUINT16 HBUSHORT;
703 typedef Lookup<HBUINT16> ClassTypeNarrow;
704 typedef Lookup<HBUINT16> ClassTypeWide;
705
706 template <typename T>
707 static unsigned int offsetToIndex (unsigned int offset,
708 const void *base HB_UNUSED,
709 const T *array HB_UNUSED)
710 {
711 return offset;
712 }
713 template <typename T>
714 static unsigned int byteOffsetToIndex (unsigned int offset,
715 const void *base HB_UNUSED,
716 const T *array HB_UNUSED)
717 {
718 return offset / 2;
719 }
720 template <typename T>
721 static unsigned int wordOffsetToIndex (unsigned int offset,
722 const void *base HB_UNUSED,
723 const T *array HB_UNUSED)
724 {
725 return offset;
726 }
727};
728
729template <typename Types, typename EntryData>
730struct StateTableDriver
731{
732 StateTableDriver (const StateTable<Types, EntryData> &machine_,
733 hb_buffer_t *buffer_,
734 hb_face_t *face_) :
735 machine (machine_),
736 buffer (buffer_),
737 num_glyphs (face_->get_num_glyphs ()) {}
738
739 template <typename context_t>
740 void drive (context_t *c)
741 {
742 if (!c->in_place)
743 buffer->clear_output ();
744
745 int state = StateTable<Types, EntryData>::STATE_START_OF_TEXT;
746 for (buffer->idx = 0; buffer->successful;)
747 {
748 unsigned int klass = buffer->idx < buffer->len ?
749 machine.get_class (buffer->info[buffer->idx].codepoint, num_glyphs) :
750 (unsigned) StateTable<Types, EntryData>::CLASS_END_OF_TEXT;
751 DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx);
752 const Entry<EntryData> &entry = machine.get_entry (state, klass);
753
754 /* Unsafe-to-break before this if not in state 0, as things might
755 * go differently if we start from state 0 here.
756 *
757 * Ugh. The indexing here is ugly... */
758 if (state && buffer->backtrack_len () && buffer->idx < buffer->len)
759 {
760 /* If there's no action and we're just epsilon-transitioning to state 0,
761 * safe to break. */
762 if (c->is_actionable (this, entry) ||
763 !(entry.newState == StateTable<Types, EntryData>::STATE_START_OF_TEXT &&
764 entry.flags == context_t::DontAdvance))
765 buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1);
766 }
767
768 /* Unsafe-to-break if end-of-text would kick in here. */
769 if (buffer->idx + 2 <= buffer->len)
770 {
771 const Entry<EntryData> &end_entry = machine.get_entry (state, StateTable<Types, EntryData>::CLASS_END_OF_TEXT);
772 if (c->is_actionable (this, end_entry))
773 buffer->unsafe_to_break (buffer->idx, buffer->idx + 2);
774 }
775
776 c->transition (this, entry);
777
778 state = machine.new_state (entry.newState);
779 DEBUG_MSG (APPLY, nullptr, "s%d", state);
780
781 if (buffer->idx == buffer->len)
782 break;
783
784 if (!(entry.flags & context_t::DontAdvance) || buffer->max_ops-- <= 0)
785 buffer->next_glyph ();
786 }
787
788 if (!c->in_place)
789 {
790 for (; buffer->successful && buffer->idx < buffer->len;)
791 buffer->next_glyph ();
792 buffer->swap_buffers ();
793 }
794 }
795
796 public:
797 const StateTable<Types, EntryData> &machine;
798 hb_buffer_t *buffer;
799 unsigned int num_glyphs;
800};
801
802
803struct ankr;
804
805struct hb_aat_apply_context_t :
806 hb_dispatch_context_t<hb_aat_apply_context_t, bool, HB_DEBUG_APPLY>
807{
808 const char *get_name () { return "APPLY"; }
809 template <typename T>
810 return_t dispatch (const T &obj) { return obj.apply (this); }
811 static return_t default_return_value () { return false; }
812 bool stop_sublookup_iteration (return_t r) const { return r; }
813
814 const hb_ot_shape_plan_t *plan;
815 hb_font_t *font;
816 hb_face_t *face;
817 hb_buffer_t *buffer;
818 hb_sanitize_context_t sanitizer;
819 const ankr *ankr_table;
820
821 /* Unused. For debug tracing only. */
822 unsigned int lookup_index;
823
824 HB_INTERNAL hb_aat_apply_context_t (const hb_ot_shape_plan_t *plan_,
825 hb_font_t *font_,
826 hb_buffer_t *buffer_,
827 hb_blob_t *blob = const_cast<hb_blob_t *> (&Null (hb_blob_t)));
828
829 HB_INTERNAL ~hb_aat_apply_context_t ();
830
831 HB_INTERNAL void set_ankr_table (const AAT::ankr *ankr_table_);
832
833 void set_lookup_index (unsigned int i) { lookup_index = i; }
834};
835
836
837} /* namespace AAT */
838
839
840#endif /* HB_AAT_LAYOUT_COMMON_HH */
841