1 /*
2 * Copyright © 2007,2008,2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2012,2013 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_OT_LAYOUT_GPOS_TABLE_HH
30 #define HB_OT_LAYOUT_GPOS_TABLE_HH
31
32 #include "hb-ot-layout-gsubgpos-private.hh"
33
34
35 namespace OT {
36
37
38 /* buffer **position** var allocations */
39 #define attach_chain() var.i16[0] /* glyph to which this attaches to, relative to current glyphs; negative for going back, positive for forward. */
40 #define attach_type() var.u8[2] /* attachment type */
41 /* Note! if attach_chain() is zero, the value of attach_type() is irrelevant. */
42
43 enum attach_type_t {
44 ATTACH_TYPE_NONE = 0X00,
45
46 /* Each attachment should be either a mark or a cursive; can't be both. */
47 ATTACH_TYPE_MARK = 0X01,
48 ATTACH_TYPE_CURSIVE = 0X02,
49 };
50
51
52 /* Shared Tables: ValueRecord, Anchor Table, and MarkArray */
53
54 typedef USHORT Value;
55
56 typedef Value ValueRecord[VAR];
57
58 struct ValueFormat : USHORT
59 {
60 enum Flags {
61 xPlacement = 0x0001u, /* Includes horizontal adjustment for placement */
62 yPlacement = 0x0002u, /* Includes vertical adjustment for placement */
63 xAdvance = 0x0004u, /* Includes horizontal adjustment for advance */
64 yAdvance = 0x0008u, /* Includes vertical adjustment for advance */
65 xPlaDevice = 0x0010u, /* Includes horizontal Device table for placement */
66 yPlaDevice = 0x0020u, /* Includes vertical Device table for placement */
67 xAdvDevice = 0x0040u, /* Includes horizontal Device table for advance */
68 yAdvDevice = 0x0080u, /* Includes vertical Device table for advance */
69 ignored = 0x0F00u, /* Was used in TrueType Open for MM fonts */
70 reserved = 0xF000u, /* For future use */
71
72 devices = 0x00F0u /* Mask for having any Device table */
73 };
74
75 /* All fields are options. Only those available advance the value pointer. */
76 #if 0
77 SHORT xPlacement; /* Horizontal adjustment for
78 * placement--in design units */
79 SHORT yPlacement; /* Vertical adjustment for
80 * placement--in design units */
81 SHORT xAdvance; /* Horizontal adjustment for
82 * advance--in design units (only used
83 * for horizontal writing) */
84 SHORT yAdvance; /* Vertical adjustment for advance--in
85 * design units (only used for vertical
86 * writing) */
87 Offset xPlaDevice; /* Offset to Device table for
88 * horizontal placement--measured from
89 * beginning of PosTable (may be NULL) */
90 Offset yPlaDevice; /* Offset to Device table for vertical
91 * placement--measured from beginning
92 * of PosTable (may be NULL) */
93 Offset xAdvDevice; /* Offset to Device table for
94 * horizontal advance--measured from
95 * beginning of PosTable (may be NULL) */
96 Offset yAdvDevice; /* Offset to Device table for vertical
97 * advance--measured from beginning of
98 * PosTable (may be NULL) */
99 #endif
100
101 inline unsigned int get_len (void) const
102 { return _hb_popcount32 ((unsigned int) *this); }
103 inline unsigned int get_size (void) const
104 { return get_len () * Value::static_size; }
105
106 void apply_value (hb_apply_context_t *c,
107 const void *base,
108 const Value *values,
109 hb_glyph_position_t &glyph_pos) const
110 {
111 unsigned int format = *this;
112 if (!format) return;
113
114 hb_font_t *font = c->font;
115 hb_bool_t horizontal = HB_DIRECTION_IS_HORIZONTAL (c->direction);
116
117 if (format & xPlacement) glyph_pos.x_offset += font->em_scale_x (get_short (values++));
118 if (format & yPlacement) glyph_pos.y_offset += font->em_scale_y (get_short (values++));
119 if (format & xAdvance) {
120 if (likely (horizontal)) glyph_pos.x_advance += font->em_scale_x (get_short (values));
121 values++;
122 }
123 /* y_advance values grow downward but font-space grows upward, hence negation */
124 if (format & yAdvance) {
125 if (unlikely (!horizontal)) glyph_pos.y_advance -= font->em_scale_y (get_short (values));
126 values++;
127 }
128
129 if (!has_device ()) return;
130
131 bool use_x_device = font->x_ppem || font->num_coords;
132 bool use_y_device = font->y_ppem || font->num_coords;
133
134 if (!use_x_device && !use_y_device) return;
135
136 const VariationStore &store = c->var_store;
137
138 /* pixel -> fractional pixel */
139 if (format & xPlaDevice) {
140 if (use_x_device) glyph_pos.x_offset += (base + get_device (values)).get_x_delta (font, store);
141 values++;
142 }
143 if (format & yPlaDevice) {
144 if (use_y_device) glyph_pos.y_offset += (base + get_device (values)).get_y_delta (font, store);
145 values++;
146 }
147 if (format & xAdvDevice) {
148 if (horizontal && use_x_device) glyph_pos.x_advance += (base + get_device (values)).get_x_delta (font, store);
149 values++;
150 }
151 if (format & yAdvDevice) {
152 /* y_advance values grow downward but font-space grows upward, hence negation */
153 if (!horizontal && use_y_device) glyph_pos.y_advance -= (base + get_device (values)).get_y_delta (font, store);
154 values++;
155 }
156 }
157
158 private:
159 inline bool sanitize_value_devices (hb_sanitize_context_t *c, const void *base, const Value *values) const
160 {
161 unsigned int format = *this;
162
163 if (format & xPlacement) values++;
164 if (format & yPlacement) values++;
165 if (format & xAdvance) values++;
166 if (format & yAdvance) values++;
167
168 if ((format & xPlaDevice) && !get_device (values++).sanitize (c, base)) return false;
169 if ((format & yPlaDevice) && !get_device (values++).sanitize (c, base)) return false;
170 if ((format & xAdvDevice) && !get_device (values++).sanitize (c, base)) return false;
171 if ((format & yAdvDevice) && !get_device (values++).sanitize (c, base)) return false;
172
173 return true;
174 }
175
176 static inline OffsetTo<Device>& get_device (Value* value)
177 { return *CastP<OffsetTo<Device> > (value); }
178 static inline const OffsetTo<Device>& get_device (const Value* value)
179 { return *CastP<OffsetTo<Device> > (value); }
180
181 static inline const SHORT& get_short (const Value* value)
182 { return *CastP<SHORT> (value); }
183
184 public:
185
186 inline bool has_device (void) const {
187 unsigned int format = *this;
188 return (format & devices) != 0;
189 }
190
191 inline bool sanitize_value (hb_sanitize_context_t *c, const void *base, const Value *values) const
192 {
193 TRACE_SANITIZE (this);
194 return_trace (c->check_range (values, get_size ()) && (!has_device () || sanitize_value_devices (c, base, values)));
195 }
196
197 inline bool sanitize_values (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count) const
198 {
199 TRACE_SANITIZE (this);
200 unsigned int len = get_len ();
201
202 if (!c->check_array (values, get_size (), count)) return_trace (false);
203
204 if (!has_device ()) return_trace (true);
205
206 for (unsigned int i = 0; i < count; i++) {
207 if (!sanitize_value_devices (c, base, values))
208 return_trace (false);
209 values += len;
210 }
211
212 return_trace (true);
213 }
214
215 /* Just sanitize referenced Device tables. Doesn't check the values themselves. */
216 inline bool sanitize_values_stride_unsafe (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count, unsigned int stride) const
217 {
218 TRACE_SANITIZE (this);
219
220 if (!has_device ()) return_trace (true);
221
222 for (unsigned int i = 0; i < count; i++) {
223 if (!sanitize_value_devices (c, base, values))
224 return_trace (false);
225 values += stride;
226 }
227
228 return_trace (true);
229 }
230 };
231
232
233 struct AnchorFormat1
234 {
235 inline void get_anchor (hb_apply_context_t *c, hb_codepoint_t glyph_id HB_UNUSED,
236 hb_position_t *x, hb_position_t *y) const
237 {
238 hb_font_t *font = c->font;
239 *x = font->em_scale_x (xCoordinate);
240 *y = font->em_scale_y (yCoordinate);
241 }
242
243 inline bool sanitize (hb_sanitize_context_t *c) const
244 {
245 TRACE_SANITIZE (this);
246 return_trace (c->check_struct (this));
247 }
248
249 protected:
250 USHORT format; /* Format identifier--format = 1 */
251 SHORT xCoordinate; /* Horizontal value--in design units */
252 SHORT yCoordinate; /* Vertical value--in design units */
253 public:
254 DEFINE_SIZE_STATIC (6);
255 };
256
257 struct AnchorFormat2
258 {
259 inline void get_anchor (hb_apply_context_t *c, hb_codepoint_t glyph_id,
260 hb_position_t *x, hb_position_t *y) const
261 {
262 hb_font_t *font = c->font;
263 unsigned int x_ppem = font->x_ppem;
264 unsigned int y_ppem = font->y_ppem;
265 hb_position_t cx, cy;
266 hb_bool_t ret;
267
268 ret = (x_ppem || y_ppem) &&
269 font->get_glyph_contour_point_for_origin (glyph_id, anchorPoint, HB_DIRECTION_LTR, &cx, &cy);
270 *x = ret && x_ppem ? cx : font->em_scale_x (xCoordinate);
271 *y = ret && y_ppem ? cy : font->em_scale_y (yCoordinate);
272 }
273
274 inline bool sanitize (hb_sanitize_context_t *c) const
275 {
276 TRACE_SANITIZE (this);
277 return_trace (c->check_struct (this));
278 }
279
280 protected:
281 USHORT format; /* Format identifier--format = 2 */
282 SHORT xCoordinate; /* Horizontal value--in design units */
283 SHORT yCoordinate; /* Vertical value--in design units */
284 USHORT anchorPoint; /* Index to glyph contour point */
285 public:
286 DEFINE_SIZE_STATIC (8);
287 };
288
289 struct AnchorFormat3
290 {
291 inline void get_anchor (hb_apply_context_t *c, hb_codepoint_t glyph_id HB_UNUSED,
292 hb_position_t *x, hb_position_t *y) const
293 {
294 hb_font_t *font = c->font;
295 *x = font->em_scale_x (xCoordinate);
296 *y = font->em_scale_y (yCoordinate);
297
298 if (font->x_ppem || font->num_coords)
299 *x += (this+xDeviceTable).get_x_delta (font, c->var_store);
300 if (font->y_ppem || font->num_coords)
301 *y += (this+yDeviceTable).get_y_delta (font, c->var_store);
302 }
303
304 inline bool sanitize (hb_sanitize_context_t *c) const
305 {
306 TRACE_SANITIZE (this);
307 return_trace (c->check_struct (this) && xDeviceTable.sanitize (c, this) && yDeviceTable.sanitize (c, this));
308 }
309
310 protected:
311 USHORT format; /* Format identifier--format = 3 */
312 SHORT xCoordinate; /* Horizontal value--in design units */
313 SHORT yCoordinate; /* Vertical value--in design units */
314 OffsetTo<Device>
315 xDeviceTable; /* Offset to Device table for X
316 * coordinate-- from beginning of
317 * Anchor table (may be NULL) */
318 OffsetTo<Device>
319 yDeviceTable; /* Offset to Device table for Y
320 * coordinate-- from beginning of
321 * Anchor table (may be NULL) */
322 public:
323 DEFINE_SIZE_STATIC (10);
324 };
325
326 struct Anchor
327 {
328 inline void get_anchor (hb_apply_context_t *c, hb_codepoint_t glyph_id,
329 hb_position_t *x, hb_position_t *y) const
330 {
331 *x = *y = 0;
332 switch (u.format) {
333 case 1: u.format1.get_anchor (c, glyph_id, x, y); return;
334 case 2: u.format2.get_anchor (c, glyph_id, x, y); return;
335 case 3: u.format3.get_anchor (c, glyph_id, x, y); return;
336 default: return;
337 }
338 }
339
340 inline bool sanitize (hb_sanitize_context_t *c) const
341 {
342 TRACE_SANITIZE (this);
343 if (!u.format.sanitize (c)) return_trace (false);
344 switch (u.format) {
345 case 1: return_trace (u.format1.sanitize (c));
346 case 2: return_trace (u.format2.sanitize (c));
347 case 3: return_trace (u.format3.sanitize (c));
348 default:return_trace (true);
349 }
350 }
351
352 protected:
353 union {
354 USHORT format; /* Format identifier */
355 AnchorFormat1 format1;
356 AnchorFormat2 format2;
357 AnchorFormat3 format3;
358 } u;
359 public:
360 DEFINE_SIZE_UNION (2, format);
361 };
362
363
364 struct AnchorMatrix
365 {
366 inline const Anchor& get_anchor (unsigned int row, unsigned int col, unsigned int cols, bool *found) const {
367 *found = false;
368 if (unlikely (row >= rows || col >= cols)) return Null(Anchor);
369 *found = !matrixZ[row * cols + col].is_null ();
370 return this+matrixZ[row * cols + col];
371 }
372
373 inline bool sanitize (hb_sanitize_context_t *c, unsigned int cols) const
374 {
375 TRACE_SANITIZE (this);
376 if (!c->check_struct (this)) return_trace (false);
377 if (unlikely (_hb_unsigned_int_mul_overflows (rows, cols))) return_trace (false);
378 unsigned int count = rows * cols;
379 if (!c->check_array (matrixZ, matrixZ[0].static_size, count)) return_trace (false);
380 for (unsigned int i = 0; i < count; i++)
381 if (!matrixZ[i].sanitize (c, this)) return_trace (false);
382 return_trace (true);
383 }
384
385 USHORT rows; /* Number of rows */
386 protected:
387 OffsetTo<Anchor>
388 matrixZ[VAR]; /* Matrix of offsets to Anchor tables--
389 * from beginning of AnchorMatrix table */
390 public:
391 DEFINE_SIZE_ARRAY (2, matrixZ);
392 };
393
394
395 struct MarkRecord
396 {
397 friend struct MarkArray;
398
399 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
400 {
401 TRACE_SANITIZE (this);
402 return_trace (c->check_struct (this) && markAnchor.sanitize (c, base));
403 }
404
405 protected:
406 USHORT klass; /* Class defined for this mark */
407 OffsetTo<Anchor>
408 markAnchor; /* Offset to Anchor table--from
409 * beginning of MarkArray table */
410 public:
411 DEFINE_SIZE_STATIC (4);
412 };
413
414 struct MarkArray : ArrayOf<MarkRecord> /* Array of MarkRecords--in Coverage order */
415 {
416 inline bool apply (hb_apply_context_t *c,
417 unsigned int mark_index, unsigned int glyph_index,
418 const AnchorMatrix &anchors, unsigned int class_count,
419 unsigned int glyph_pos) const
420 {
421 TRACE_APPLY (this);
422 hb_buffer_t *buffer = c->buffer;
423 const MarkRecord &record = ArrayOf<MarkRecord>::operator[](mark_index);
424 unsigned int mark_class = record.klass;
425
426 const Anchor& mark_anchor = this + record.markAnchor;
427 bool found;
428 const Anchor& glyph_anchor = anchors.get_anchor (glyph_index, mark_class, class_count, &found);
429 /* If this subtable doesn't have an anchor for this base and this class,
430 * return false such that the subsequent subtables have a chance at it. */
431 if (unlikely (!found)) return_trace (false);
432
433 hb_position_t mark_x, mark_y, base_x, base_y;
434
435 mark_anchor.get_anchor (c, buffer->cur().codepoint, &mark_x, &mark_y);
436 glyph_anchor.get_anchor (c, buffer->info[glyph_pos].codepoint, &base_x, &base_y);
437
438 hb_glyph_position_t &o = buffer->cur_pos();
439 o.x_offset = base_x - mark_x;
440 o.y_offset = base_y - mark_y;
441 o.attach_type() = ATTACH_TYPE_MARK;
442 o.attach_chain() = (int) glyph_pos - (int) buffer->idx;
443 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
444
445 buffer->idx++;
446 return_trace (true);
447 }
448
449 inline bool sanitize (hb_sanitize_context_t *c) const
450 {
451 TRACE_SANITIZE (this);
452 return_trace (ArrayOf<MarkRecord>::sanitize (c, this));
453 }
454 };
455
456
457 /* Lookups */
458
459 struct SinglePosFormat1
460 {
461 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
462 {
463 TRACE_COLLECT_GLYPHS (this);
464 (this+coverage).add_coverage (c->input);
465 }
466
467 inline const Coverage &get_coverage (void) const
468 {
469 return this+coverage;
470 }
471
472 inline bool apply (hb_apply_context_t *c) const
473 {
474 TRACE_APPLY (this);
475 hb_buffer_t *buffer = c->buffer;
476 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
477 if (likely (index == NOT_COVERED)) return_trace (false);
478
479 valueFormat.apply_value (c, this, values, buffer->cur_pos());
480
481 buffer->idx++;
482 return_trace (true);
483 }
484
485 inline bool sanitize (hb_sanitize_context_t *c) const
486 {
487 TRACE_SANITIZE (this);
488 return_trace (c->check_struct (this) &&
489 coverage.sanitize (c, this) &&
490 valueFormat.sanitize_value (c, this, values));
491 }
492
493 protected:
494 USHORT format; /* Format identifier--format = 1 */
495 OffsetTo<Coverage>
496 coverage; /* Offset to Coverage table--from
497 * beginning of subtable */
498 ValueFormat valueFormat; /* Defines the types of data in the
499 * ValueRecord */
500 ValueRecord values; /* Defines positioning
501 * value(s)--applied to all glyphs in
502 * the Coverage table */
503 public:
504 DEFINE_SIZE_ARRAY (6, values);
505 };
506
507 struct SinglePosFormat2
508 {
509 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
510 {
511 TRACE_COLLECT_GLYPHS (this);
512 (this+coverage).add_coverage (c->input);
513 }
514
515 inline const Coverage &get_coverage (void) const
516 {
517 return this+coverage;
518 }
519
520 inline bool apply (hb_apply_context_t *c) const
521 {
522 TRACE_APPLY (this);
523 hb_buffer_t *buffer = c->buffer;
524 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
525 if (likely (index == NOT_COVERED)) return_trace (false);
526
527 if (likely (index >= valueCount)) return_trace (false);
528
529 valueFormat.apply_value (c, this,
530 &values[index * valueFormat.get_len ()],
531 buffer->cur_pos());
532
533 buffer->idx++;
534 return_trace (true);
535 }
536
537 inline bool sanitize (hb_sanitize_context_t *c) const
538 {
539 TRACE_SANITIZE (this);
540 return_trace (c->check_struct (this) &&
541 coverage.sanitize (c, this) &&
542 valueFormat.sanitize_values (c, this, values, valueCount));
543 }
544
545 protected:
546 USHORT format; /* Format identifier--format = 2 */
547 OffsetTo<Coverage>
548 coverage; /* Offset to Coverage table--from
549 * beginning of subtable */
550 ValueFormat valueFormat; /* Defines the types of data in the
551 * ValueRecord */
552 USHORT valueCount; /* Number of ValueRecords */
553 ValueRecord values; /* Array of ValueRecords--positioning
554 * values applied to glyphs */
555 public:
556 DEFINE_SIZE_ARRAY (8, values);
557 };
558
559 struct SinglePos
560 {
561 template <typename context_t>
562 inline typename context_t::return_t dispatch (context_t *c) const
563 {
564 TRACE_DISPATCH (this, u.format);
565 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
566 switch (u.format) {
567 case 1: return_trace (c->dispatch (u.format1));
568 case 2: return_trace (c->dispatch (u.format2));
569 default:return_trace (c->default_return_value ());
570 }
571 }
572
573 protected:
574 union {
575 USHORT format; /* Format identifier */
576 SinglePosFormat1 format1;
577 SinglePosFormat2 format2;
578 } u;
579 };
580
581
582 struct PairValueRecord
583 {
584 friend struct PairSet;
585
586 protected:
587 GlyphID secondGlyph; /* GlyphID of second glyph in the
588 * pair--first glyph is listed in the
589 * Coverage table */
590 ValueRecord values; /* Positioning data for the first glyph
591 * followed by for second glyph */
592 public:
593 DEFINE_SIZE_ARRAY (2, values);
594 };
595
596 struct PairSet
597 {
598 friend struct PairPosFormat1;
599
600 inline void collect_glyphs (hb_collect_glyphs_context_t *c,
601 const ValueFormat *valueFormats) const
602 {
603 TRACE_COLLECT_GLYPHS (this);
604 unsigned int len1 = valueFormats[0].get_len ();
605 unsigned int len2 = valueFormats[1].get_len ();
606 unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
607
608 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
609 unsigned int count = len;
610 for (unsigned int i = 0; i < count; i++)
611 {
612 c->input->add (record->secondGlyph);
613 record = &StructAtOffset<PairValueRecord> (record, record_size);
614 }
615 }
616
617 inline bool apply (hb_apply_context_t *c,
618 const ValueFormat *valueFormats,
619 unsigned int pos) const
620 {
621 TRACE_APPLY (this);
622 hb_buffer_t *buffer = c->buffer;
623 unsigned int len1 = valueFormats[0].get_len ();
624 unsigned int len2 = valueFormats[1].get_len ();
625 unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
626
627 const PairValueRecord *record_array = CastP<PairValueRecord> (arrayZ);
628 unsigned int count = len;
629
630 /* Hand-coded bsearch. */
631 if (unlikely (!count))
632 return_trace (false);
633 hb_codepoint_t x = buffer->info[pos].codepoint;
634 int min = 0, max = (int) count - 1;
635 while (min <= max)
636 {
637 int mid = (min + max) / 2;
638 const PairValueRecord *record = &StructAtOffset<PairValueRecord> (record_array, record_size * mid);
639 hb_codepoint_t mid_x = record->secondGlyph;
640 if (x < mid_x)
641 max = mid - 1;
642 else if (x > mid_x)
643 min = mid + 1;
644 else
645 {
646 valueFormats[0].apply_value (c, this, &record->values[0], buffer->cur_pos());
647 valueFormats[1].apply_value (c, this, &record->values[len1], buffer->pos[pos]);
648 if (len2)
649 pos++;
650 buffer->idx = pos;
651 return_trace (true);
652 }
653 }
654
655 return_trace (false);
656 }
657
658 struct sanitize_closure_t {
659 const void *base;
660 const ValueFormat *valueFormats;
661 unsigned int len1; /* valueFormats[0].get_len() */
662 unsigned int stride; /* 1 + len1 + len2 */
663 };
664
665 inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
666 {
667 TRACE_SANITIZE (this);
668 if (!(c->check_struct (this)
669 && c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return_trace (false);
670
671 unsigned int count = len;
672 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
673 return_trace (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride) &&
674 closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
675 }
676
677 protected:
678 USHORT len; /* Number of PairValueRecords */
679 USHORT arrayZ[VAR]; /* Array of PairValueRecords--ordered
680 * by GlyphID of the second glyph */
681 public:
682 DEFINE_SIZE_ARRAY (2, arrayZ);
683 };
684
685 struct PairPosFormat1
686 {
687 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
688 {
689 TRACE_COLLECT_GLYPHS (this);
690 (this+coverage).add_coverage (c->input);
691 unsigned int count = pairSet.len;
692 for (unsigned int i = 0; i < count; i++)
693 (this+pairSet[i]).collect_glyphs (c, valueFormat);
694 }
695
696 inline const Coverage &get_coverage (void) const
697 {
698 return this+coverage;
699 }
700
701 inline bool apply (hb_apply_context_t *c) const
702 {
703 TRACE_APPLY (this);
704 hb_buffer_t *buffer = c->buffer;
705 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
706 if (likely (index == NOT_COVERED)) return_trace (false);
707
708 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
709 skippy_iter.reset (buffer->idx, 1);
710 if (!skippy_iter.next ()) return_trace (false);
711
712 return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
713 }
714
715 inline bool sanitize (hb_sanitize_context_t *c) const
716 {
717 TRACE_SANITIZE (this);
718
719 if (!c->check_struct (this)) return_trace (false);
720
721 unsigned int len1 = valueFormat[0].get_len ();
722 unsigned int len2 = valueFormat[1].get_len ();
723 PairSet::sanitize_closure_t closure = {
724 this,
725 valueFormat,
726 len1,
727 1 + len1 + len2
728 };
729
730 return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
731 }
732
733 protected:
734 USHORT format; /* Format identifier--format = 1 */
735 OffsetTo<Coverage>
736 coverage; /* Offset to Coverage table--from
737 * beginning of subtable */
738 ValueFormat valueFormat[2]; /* [0] Defines the types of data in
739 * ValueRecord1--for the first glyph
740 * in the pair--may be zero (0) */
741 /* [1] Defines the types of data in
742 * ValueRecord2--for the second glyph
743 * in the pair--may be zero (0) */
744 OffsetArrayOf<PairSet>
745 pairSet; /* Array of PairSet tables
746 * ordered by Coverage Index */
747 public:
748 DEFINE_SIZE_ARRAY (10, pairSet);
749 };
750
751 struct PairPosFormat2
752 {
753 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
754 {
755 TRACE_COLLECT_GLYPHS (this);
756 (this+coverage).add_coverage (c->input);
757
758 unsigned int count1 = class1Count;
759 const ClassDef &klass1 = this+classDef1;
760 for (unsigned int i = 0; i < count1; i++)
761 klass1.add_class (c->input, i);
762
763 unsigned int count2 = class2Count;
764 const ClassDef &klass2 = this+classDef2;
765 for (unsigned int i = 0; i < count2; i++)
766 klass2.add_class (c->input, i);
767 }
768
769 inline const Coverage &get_coverage (void) const
770 {
771 return this+coverage;
772 }
773
774 inline bool apply (hb_apply_context_t *c) const
775 {
776 TRACE_APPLY (this);
777 hb_buffer_t *buffer = c->buffer;
778 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
779 if (likely (index == NOT_COVERED)) return_trace (false);
780
781 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
782 skippy_iter.reset (buffer->idx, 1);
783 if (!skippy_iter.next ()) return_trace (false);
784
785 unsigned int len1 = valueFormat1.get_len ();
786 unsigned int len2 = valueFormat2.get_len ();
787 unsigned int record_len = len1 + len2;
788
789 unsigned int klass1 = (this+classDef1).get_class (buffer->cur().codepoint);
790 unsigned int klass2 = (this+classDef2).get_class (buffer->info[skippy_iter.idx].codepoint);
791 if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return_trace (false);
792
793 const Value *v = &values[record_len * (klass1 * class2Count + klass2)];
794 valueFormat1.apply_value (c, this, v, buffer->cur_pos());
795 valueFormat2.apply_value (c, this, v + len1, buffer->pos[skippy_iter.idx]);
796
797 buffer->idx = skippy_iter.idx;
798 if (len2)
799 buffer->idx++;
800
801 return_trace (true);
802 }
803
804 inline bool sanitize (hb_sanitize_context_t *c) const
805 {
806 TRACE_SANITIZE (this);
807 if (!(c->check_struct (this)
808 && coverage.sanitize (c, this)
809 && classDef1.sanitize (c, this)
810 && classDef2.sanitize (c, this))) return_trace (false);
811
812 unsigned int len1 = valueFormat1.get_len ();
813 unsigned int len2 = valueFormat2.get_len ();
814 unsigned int stride = len1 + len2;
815 unsigned int record_size = valueFormat1.get_size () + valueFormat2.get_size ();
816 unsigned int count = (unsigned int) class1Count * (unsigned int) class2Count;
817 return_trace (c->check_array (values, record_size, count) &&
818 valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
819 valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
820 }
821
822 protected:
823 USHORT format; /* Format identifier--format = 2 */
824 OffsetTo<Coverage>
825 coverage; /* Offset to Coverage table--from
826 * beginning of subtable */
827 ValueFormat valueFormat1; /* ValueRecord definition--for the
828 * first glyph of the pair--may be zero
829 * (0) */
830 ValueFormat valueFormat2; /* ValueRecord definition--for the
831 * second glyph of the pair--may be
832 * zero (0) */
833 OffsetTo<ClassDef>
834 classDef1; /* Offset to ClassDef table--from
835 * beginning of PairPos subtable--for
836 * the first glyph of the pair */
837 OffsetTo<ClassDef>
838 classDef2; /* Offset to ClassDef table--from
839 * beginning of PairPos subtable--for
840 * the second glyph of the pair */
841 USHORT class1Count; /* Number of classes in ClassDef1
842 * table--includes Class0 */
843 USHORT class2Count; /* Number of classes in ClassDef2
844 * table--includes Class0 */
845 ValueRecord values; /* Matrix of value pairs:
846 * class1-major, class2-minor,
847 * Each entry has value1 and value2 */
848 public:
849 DEFINE_SIZE_ARRAY (16, values);
850 };
851
852 struct PairPos
853 {
854 template <typename context_t>
855 inline typename context_t::return_t dispatch (context_t *c) const
856 {
857 TRACE_DISPATCH (this, u.format);
858 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
859 switch (u.format) {
860 case 1: return_trace (c->dispatch (u.format1));
861 case 2: return_trace (c->dispatch (u.format2));
862 default:return_trace (c->default_return_value ());
863 }
864 }
865
866 protected:
867 union {
868 USHORT format; /* Format identifier */
869 PairPosFormat1 format1;
870 PairPosFormat2 format2;
871 } u;
872 };
873
874
875 struct EntryExitRecord
876 {
877 friend struct CursivePosFormat1;
878
879 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
880 {
881 TRACE_SANITIZE (this);
882 return_trace (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
883 }
884
885 protected:
886 OffsetTo<Anchor>
887 entryAnchor; /* Offset to EntryAnchor table--from
888 * beginning of CursivePos
889 * subtable--may be NULL */
890 OffsetTo<Anchor>
891 exitAnchor; /* Offset to ExitAnchor table--from
892 * beginning of CursivePos
893 * subtable--may be NULL */
894 public:
895 DEFINE_SIZE_STATIC (4);
896 };
897
898 static void
899 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent);
900
901 struct CursivePosFormat1
902 {
903 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
904 {
905 TRACE_COLLECT_GLYPHS (this);
906 (this+coverage).add_coverage (c->input);
907 }
908
909 inline const Coverage &get_coverage (void) const
910 {
911 return this+coverage;
912 }
913
914 inline bool apply (hb_apply_context_t *c) const
915 {
916 TRACE_APPLY (this);
917 hb_buffer_t *buffer = c->buffer;
918
919 const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage (buffer->cur().codepoint)];
920 if (!this_record.exitAnchor) return_trace (false);
921
922 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
923 skippy_iter.reset (buffer->idx, 1);
924 if (!skippy_iter.next ()) return_trace (false);
925
926 const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage (buffer->info[skippy_iter.idx].codepoint)];
927 if (!next_record.entryAnchor) return_trace (false);
928
929 unsigned int i = buffer->idx;
930 unsigned int j = skippy_iter.idx;
931
932 hb_position_t entry_x, entry_y, exit_x, exit_y;
933 (this+this_record.exitAnchor).get_anchor (c, buffer->info[i].codepoint, &exit_x, &exit_y);
934 (this+next_record.entryAnchor).get_anchor (c, buffer->info[j].codepoint, &entry_x, &entry_y);
935
936 hb_glyph_position_t *pos = buffer->pos;
937
938 hb_position_t d;
939 /* Main-direction adjustment */
940 switch (c->direction) {
941 case HB_DIRECTION_LTR:
942 pos[i].x_advance = exit_x + pos[i].x_offset;
943
944 d = entry_x + pos[j].x_offset;
945 pos[j].x_advance -= d;
946 pos[j].x_offset -= d;
947 break;
948 case HB_DIRECTION_RTL:
949 d = exit_x + pos[i].x_offset;
950 pos[i].x_advance -= d;
951 pos[i].x_offset -= d;
952
953 pos[j].x_advance = entry_x + pos[j].x_offset;
954 break;
955 case HB_DIRECTION_TTB:
956 pos[i].y_advance = exit_y + pos[i].y_offset;
957
958 d = entry_y + pos[j].y_offset;
959 pos[j].y_advance -= d;
960 pos[j].y_offset -= d;
961 break;
962 case HB_DIRECTION_BTT:
963 d = exit_y + pos[i].y_offset;
964 pos[i].y_advance -= d;
965 pos[i].y_offset -= d;
966
967 pos[j].y_advance = entry_y;
968 break;
969 case HB_DIRECTION_INVALID:
970 default:
971 break;
972 }
973
974 /* Cross-direction adjustment */
975
976 /* We attach child to parent (think graph theory and rooted trees whereas
977 * the root stays on baseline and each node aligns itself against its
978 * parent.
979 *
980 * Optimize things for the case of RightToLeft, as that's most common in
981 * Arabinc. */
982 unsigned int child = i;
983 unsigned int parent = j;
984 hb_position_t x_offset = entry_x - exit_x;
985 hb_position_t y_offset = entry_y - exit_y;
986 if (!(c->lookup_props & LookupFlag::RightToLeft))
987 {
988 unsigned int k = child;
989 child = parent;
990 parent = k;
991 x_offset = -x_offset;
992 y_offset = -y_offset;
993 }
994
995 /* If child was already connected to someone else, walk through its old
996 * chain and reverse the link direction, such that the whole tree of its
997 * previous connection now attaches to new parent. Watch out for case
998 * where new parent is on the path from old chain...
999 */
1000 reverse_cursive_minor_offset (pos, child, c->direction, parent);
1001
1002 pos[child].attach_type() = ATTACH_TYPE_CURSIVE;
1003 pos[child].attach_chain() = (int) parent - (int) child;
1004 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
1005 if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
1006 pos[child].y_offset = y_offset;
1007 else
1008 pos[child].x_offset = x_offset;
1009
1010 buffer->idx = j;
1011 return_trace (true);
1012 }
1013
1014 inline bool sanitize (hb_sanitize_context_t *c) const
1015 {
1016 TRACE_SANITIZE (this);
1017 return_trace (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
1018 }
1019
1020 protected:
1021 USHORT format; /* Format identifier--format = 1 */
1022 OffsetTo<Coverage>
1023 coverage; /* Offset to Coverage table--from
1024 * beginning of subtable */
1025 ArrayOf<EntryExitRecord>
1026 entryExitRecord; /* Array of EntryExit records--in
1027 * Coverage Index order */
1028 public:
1029 DEFINE_SIZE_ARRAY (6, entryExitRecord);
1030 };
1031
1032 struct CursivePos
1033 {
1034 template <typename context_t>
1035 inline typename context_t::return_t dispatch (context_t *c) const
1036 {
1037 TRACE_DISPATCH (this, u.format);
1038 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1039 switch (u.format) {
1040 case 1: return_trace (c->dispatch (u.format1));
1041 default:return_trace (c->default_return_value ());
1042 }
1043 }
1044
1045 protected:
1046 union {
1047 USHORT format; /* Format identifier */
1048 CursivePosFormat1 format1;
1049 } u;
1050 };
1051
1052
1053 typedef AnchorMatrix BaseArray; /* base-major--
1054 * in order of BaseCoverage Index--,
1055 * mark-minor--
1056 * ordered by class--zero-based. */
1057
1058 struct MarkBasePosFormat1
1059 {
1060 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1061 {
1062 TRACE_COLLECT_GLYPHS (this);
1063 (this+markCoverage).add_coverage (c->input);
1064 (this+baseCoverage).add_coverage (c->input);
1065 }
1066
1067 inline const Coverage &get_coverage (void) const
1068 {
1069 return this+markCoverage;
1070 }
1071
1072 inline bool apply (hb_apply_context_t *c) const
1073 {
1074 TRACE_APPLY (this);
1075 hb_buffer_t *buffer = c->buffer;
1076 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1077 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1078
1079 /* Now we search backwards for a non-mark glyph */
1080 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1081 skippy_iter.reset (buffer->idx, 1);
1082 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1083 do {
1084 if (!skippy_iter.prev ()) return_trace (false);
1085 /* We only want to attach to the first of a MultipleSubst sequence. Reject others. */
1086 if (0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx])) break;
1087 skippy_iter.reject ();
1088 } while (1);
1089
1090 /* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */
1091 //if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1092
1093 unsigned int base_index = (this+baseCoverage).get_coverage (buffer->info[skippy_iter.idx].codepoint);
1094 if (base_index == NOT_COVERED) return_trace (false);
1095
1096 return_trace ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
1097 }
1098
1099 inline bool sanitize (hb_sanitize_context_t *c) const
1100 {
1101 TRACE_SANITIZE (this);
1102 return_trace (c->check_struct (this) &&
1103 markCoverage.sanitize (c, this) &&
1104 baseCoverage.sanitize (c, this) &&
1105 markArray.sanitize (c, this) &&
1106 baseArray.sanitize (c, this, (unsigned int) classCount));
1107 }
1108
1109 protected:
1110 USHORT format; /* Format identifier--format = 1 */
1111 OffsetTo<Coverage>
1112 markCoverage; /* Offset to MarkCoverage table--from
1113 * beginning of MarkBasePos subtable */
1114 OffsetTo<Coverage>
1115 baseCoverage; /* Offset to BaseCoverage table--from
1116 * beginning of MarkBasePos subtable */
1117 USHORT classCount; /* Number of classes defined for marks */
1118 OffsetTo<MarkArray>
1119 markArray; /* Offset to MarkArray table--from
1120 * beginning of MarkBasePos subtable */
1121 OffsetTo<BaseArray>
1122 baseArray; /* Offset to BaseArray table--from
1123 * beginning of MarkBasePos subtable */
1124 public:
1125 DEFINE_SIZE_STATIC (12);
1126 };
1127
1128 struct MarkBasePos
1129 {
1130 template <typename context_t>
1131 inline typename context_t::return_t dispatch (context_t *c) const
1132 {
1133 TRACE_DISPATCH (this, u.format);
1134 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1135 switch (u.format) {
1136 case 1: return_trace (c->dispatch (u.format1));
1137 default:return_trace (c->default_return_value ());
1138 }
1139 }
1140
1141 protected:
1142 union {
1143 USHORT format; /* Format identifier */
1144 MarkBasePosFormat1 format1;
1145 } u;
1146 };
1147
1148
1149 typedef AnchorMatrix LigatureAttach; /* component-major--
1150 * in order of writing direction--,
1151 * mark-minor--
1152 * ordered by class--zero-based. */
1153
1154 typedef OffsetListOf<LigatureAttach> LigatureArray;
1155 /* Array of LigatureAttach
1156 * tables ordered by
1157 * LigatureCoverage Index */
1158
1159 struct MarkLigPosFormat1
1160 {
1161 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1162 {
1163 TRACE_COLLECT_GLYPHS (this);
1164 (this+markCoverage).add_coverage (c->input);
1165 (this+ligatureCoverage).add_coverage (c->input);
1166 }
1167
1168 inline const Coverage &get_coverage (void) const
1169 {
1170 return this+markCoverage;
1171 }
1172
1173 inline bool apply (hb_apply_context_t *c) const
1174 {
1175 TRACE_APPLY (this);
1176 hb_buffer_t *buffer = c->buffer;
1177 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1178 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1179
1180 /* Now we search backwards for a non-mark glyph */
1181 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1182 skippy_iter.reset (buffer->idx, 1);
1183 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1184 if (!skippy_iter.prev ()) return_trace (false);
1185
1186 /* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
1187 //if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1188
1189 unsigned int j = skippy_iter.idx;
1190 unsigned int lig_index = (this+ligatureCoverage).get_coverage (buffer->info[j].codepoint);
1191 if (lig_index == NOT_COVERED) return_trace (false);
1192
1193 const LigatureArray& lig_array = this+ligatureArray;
1194 const LigatureAttach& lig_attach = lig_array[lig_index];
1195
1196 /* Find component to attach to */
1197 unsigned int comp_count = lig_attach.rows;
1198 if (unlikely (!comp_count)) return_trace (false);
1199
1200 /* We must now check whether the ligature ID of the current mark glyph
1201 * is identical to the ligature ID of the found ligature. If yes, we
1202 * can directly use the component index. If not, we attach the mark
1203 * glyph to the last component of the ligature. */
1204 unsigned int comp_index;
1205 unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1206 unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
1207 unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
1208 if (lig_id && lig_id == mark_id && mark_comp > 0)
1209 comp_index = MIN (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
1210 else
1211 comp_index = comp_count - 1;
1212
1213 return_trace ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
1214 }
1215
1216 inline bool sanitize (hb_sanitize_context_t *c) const
1217 {
1218 TRACE_SANITIZE (this);
1219 return_trace (c->check_struct (this) &&
1220 markCoverage.sanitize (c, this) &&
1221 ligatureCoverage.sanitize (c, this) &&
1222 markArray.sanitize (c, this) &&
1223 ligatureArray.sanitize (c, this, (unsigned int) classCount));
1224 }
1225
1226 protected:
1227 USHORT format; /* Format identifier--format = 1 */
1228 OffsetTo<Coverage>
1229 markCoverage; /* Offset to Mark Coverage table--from
1230 * beginning of MarkLigPos subtable */
1231 OffsetTo<Coverage>
1232 ligatureCoverage; /* Offset to Ligature Coverage
1233 * table--from beginning of MarkLigPos
1234 * subtable */
1235 USHORT classCount; /* Number of defined mark classes */
1236 OffsetTo<MarkArray>
1237 markArray; /* Offset to MarkArray table--from
1238 * beginning of MarkLigPos subtable */
1239 OffsetTo<LigatureArray>
1240 ligatureArray; /* Offset to LigatureArray table--from
1241 * beginning of MarkLigPos subtable */
1242 public:
1243 DEFINE_SIZE_STATIC (12);
1244 };
1245
1246 struct MarkLigPos
1247 {
1248 template <typename context_t>
1249 inline typename context_t::return_t dispatch (context_t *c) const
1250 {
1251 TRACE_DISPATCH (this, u.format);
1252 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1253 switch (u.format) {
1254 case 1: return_trace (c->dispatch (u.format1));
1255 default:return_trace (c->default_return_value ());
1256 }
1257 }
1258
1259 protected:
1260 union {
1261 USHORT format; /* Format identifier */
1262 MarkLigPosFormat1 format1;
1263 } u;
1264 };
1265
1266
1267 typedef AnchorMatrix Mark2Array; /* mark2-major--
1268 * in order of Mark2Coverage Index--,
1269 * mark1-minor--
1270 * ordered by class--zero-based. */
1271
1272 struct MarkMarkPosFormat1
1273 {
1274 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1275 {
1276 TRACE_COLLECT_GLYPHS (this);
1277 (this+mark1Coverage).add_coverage (c->input);
1278 (this+mark2Coverage).add_coverage (c->input);
1279 }
1280
1281 inline const Coverage &get_coverage (void) const
1282 {
1283 return this+mark1Coverage;
1284 }
1285
1286 inline bool apply (hb_apply_context_t *c) const
1287 {
1288 TRACE_APPLY (this);
1289 hb_buffer_t *buffer = c->buffer;
1290 unsigned int mark1_index = (this+mark1Coverage).get_coverage (buffer->cur().codepoint);
1291 if (likely (mark1_index == NOT_COVERED)) return_trace (false);
1292
1293 /* now we search backwards for a suitable mark glyph until a non-mark glyph */
1294 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1295 skippy_iter.reset (buffer->idx, 1);
1296 skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
1297 if (!skippy_iter.prev ()) return_trace (false);
1298
1299 if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1300
1301 unsigned int j = skippy_iter.idx;
1302
1303 unsigned int id1 = _hb_glyph_info_get_lig_id (&buffer->cur());
1304 unsigned int id2 = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1305 unsigned int comp1 = _hb_glyph_info_get_lig_comp (&buffer->cur());
1306 unsigned int comp2 = _hb_glyph_info_get_lig_comp (&buffer->info[j]);
1307
1308 if (likely (id1 == id2)) {
1309 if (id1 == 0) /* Marks belonging to the same base. */
1310 goto good;
1311 else if (comp1 == comp2) /* Marks belonging to the same ligature component. */
1312 goto good;
1313 } else {
1314 /* If ligature ids don't match, it may be the case that one of the marks
1315 * itself is a ligature. In which case match. */
1316 if ((id1 > 0 && !comp1) || (id2 > 0 && !comp2))
1317 goto good;
1318 }
1319
1320 /* Didn't match. */
1321 return_trace (false);
1322
1323 good:
1324 unsigned int mark2_index = (this+mark2Coverage).get_coverage (buffer->info[j].codepoint);
1325 if (mark2_index == NOT_COVERED) return_trace (false);
1326
1327 return_trace ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
1328 }
1329
1330 inline bool sanitize (hb_sanitize_context_t *c) const
1331 {
1332 TRACE_SANITIZE (this);
1333 return_trace (c->check_struct (this) &&
1334 mark1Coverage.sanitize (c, this) &&
1335 mark2Coverage.sanitize (c, this) &&
1336 mark1Array.sanitize (c, this) &&
1337 mark2Array.sanitize (c, this, (unsigned int) classCount));
1338 }
1339
1340 protected:
1341 USHORT format; /* Format identifier--format = 1 */
1342 OffsetTo<Coverage>
1343 mark1Coverage; /* Offset to Combining Mark1 Coverage
1344 * table--from beginning of MarkMarkPos
1345 * subtable */
1346 OffsetTo<Coverage>
1347 mark2Coverage; /* Offset to Combining Mark2 Coverage
1348 * table--from beginning of MarkMarkPos
1349 * subtable */
1350 USHORT classCount; /* Number of defined mark classes */
1351 OffsetTo<MarkArray>
1352 mark1Array; /* Offset to Mark1Array table--from
1353 * beginning of MarkMarkPos subtable */
1354 OffsetTo<Mark2Array>
1355 mark2Array; /* Offset to Mark2Array table--from
1356 * beginning of MarkMarkPos subtable */
1357 public:
1358 DEFINE_SIZE_STATIC (12);
1359 };
1360
1361 struct MarkMarkPos
1362 {
1363 template <typename context_t>
1364 inline typename context_t::return_t dispatch (context_t *c) const
1365 {
1366 TRACE_DISPATCH (this, u.format);
1367 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1368 switch (u.format) {
1369 case 1: return_trace (c->dispatch (u.format1));
1370 default:return_trace (c->default_return_value ());
1371 }
1372 }
1373
1374 protected:
1375 union {
1376 USHORT format; /* Format identifier */
1377 MarkMarkPosFormat1 format1;
1378 } u;
1379 };
1380
1381
1382 struct ContextPos : Context {};
1383
1384 struct ChainContextPos : ChainContext {};
1385
1386 struct ExtensionPos : Extension<ExtensionPos>
1387 {
1388 typedef struct PosLookupSubTable LookupSubTable;
1389 };
1390
1391
1392
1393 /*
1394 * PosLookup
1395 */
1396
1397
1398 struct PosLookupSubTable
1399 {
1400 friend struct PosLookup;
1401
1402 enum Type {
1403 Single = 1,
1404 Pair = 2,
1405 Cursive = 3,
1406 MarkBase = 4,
1407 MarkLig = 5,
1408 MarkMark = 6,
1409 Context = 7,
1410 ChainContext = 8,
1411 Extension = 9
1412 };
1413
1414 template <typename context_t>
1415 inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1416 {
1417 TRACE_DISPATCH (this, lookup_type);
1418 if (unlikely (!c->may_dispatch (this, &u.sub_format))) return_trace (c->no_dispatch_return_value ());
1419 switch (lookup_type) {
1420 case Single: return_trace (u.single.dispatch (c));
1421 case Pair: return_trace (u.pair.dispatch (c));
1422 case Cursive: return_trace (u.cursive.dispatch (c));
1423 case MarkBase: return_trace (u.markBase.dispatch (c));
1424 case MarkLig: return_trace (u.markLig.dispatch (c));
1425 case MarkMark: return_trace (u.markMark.dispatch (c));
1426 case Context: return_trace (u.context.dispatch (c));
1427 case ChainContext: return_trace (u.chainContext.dispatch (c));
1428 case Extension: return_trace (u.extension.dispatch (c));
1429 default: return_trace (c->default_return_value ());
1430 }
1431 }
1432
1433 protected:
1434 union {
1435 USHORT sub_format;
1436 SinglePos single;
1437 PairPos pair;
1438 CursivePos cursive;
1439 MarkBasePos markBase;
1440 MarkLigPos markLig;
1441 MarkMarkPos markMark;
1442 ContextPos context;
1443 ChainContextPos chainContext;
1444 ExtensionPos extension;
1445 } u;
1446 public:
1447 DEFINE_SIZE_UNION (2, sub_format);
1448 };
1449
1450
1451 struct PosLookup : Lookup
1452 {
1453 inline const PosLookupSubTable& get_subtable (unsigned int i) const
1454 { return Lookup::get_subtable<PosLookupSubTable> (i); }
1455
1456 inline bool is_reverse (void) const
1457 {
1458 return false;
1459 }
1460
1461 inline bool apply (hb_apply_context_t *c) const
1462 {
1463 TRACE_APPLY (this);
1464 return_trace (dispatch (c));
1465 }
1466
1467 inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
1468 {
1469 TRACE_COLLECT_GLYPHS (this);
1470 return_trace (dispatch (c));
1471 }
1472
1473 template <typename set_t>
1474 inline void add_coverage (set_t *glyphs) const
1475 {
1476 hb_add_coverage_context_t<set_t> c (glyphs);
1477 dispatch (&c);
1478 }
1479
1480 static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
1481
1482 template <typename context_t>
1483 static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
1484
1485 template <typename context_t>
1486 inline typename context_t::return_t dispatch (context_t *c) const
1487 { return Lookup::dispatch<PosLookupSubTable> (c); }
1488
1489 inline bool sanitize (hb_sanitize_context_t *c) const
1490 {
1491 TRACE_SANITIZE (this);
1492 if (unlikely (!Lookup::sanitize (c))) return_trace (false);
1493 return_trace (dispatch (c));
1494 }
1495 };
1496
1497 typedef OffsetListOf<PosLookup> PosLookupList;
1498
1499 /*
1500 * GPOS -- The Glyph Positioning Table
1501 */
1502
1503 struct GPOS : GSUBGPOS
1504 {
1505 static const hb_tag_t tableTag = HB_OT_TAG_GPOS;
1506
1507 inline const PosLookup& get_lookup (unsigned int i) const
1508 { return CastR<PosLookup> (GSUBGPOS::get_lookup (i)); }
1509
1510 static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
1511 static inline void position_finish_advances (hb_font_t *font, hb_buffer_t *buffer);
1512 static inline void position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer);
1513
1514 inline bool sanitize (hb_sanitize_context_t *c) const
1515 {
1516 TRACE_SANITIZE (this);
1517 if (unlikely (!GSUBGPOS::sanitize (c))) return_trace (false);
1518 const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
1519 return_trace (list.sanitize (c, this));
1520 }
1521 };
1522
1523
1524 static void
1525 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent)
1526 {
1527 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1528 if (likely (!chain || 0 == (type & ATTACH_TYPE_CURSIVE)))
1529 return;
1530
1531 pos[i].attach_chain() = 0;
1532
1533 unsigned int j = (int) i + chain;
1534
1535 /* Stop if we see new parent in the chain. */
1536 if (j == new_parent)
1537 return;
1538
1539 reverse_cursive_minor_offset (pos, j, direction, new_parent);
1540
1541 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1542 pos[j].y_offset = -pos[i].y_offset;
1543 else
1544 pos[j].x_offset = -pos[i].x_offset;
1545
1546 pos[j].attach_chain() = -chain;
1547 pos[j].attach_type() = type;
1548 }
1549 static void
1550 propagate_attachment_offsets (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
1551 {
1552 /* Adjusts offsets of attached glyphs (both cursive and mark) to accumulate
1553 * offset of glyph they are attached to. */
1554 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1555 if (likely (!chain))
1556 return;
1557
1558 unsigned int j = (int) i + chain;
1559
1560 pos[i].attach_chain() = 0;
1561
1562 propagate_attachment_offsets (pos, j, direction);
1563
1564 assert (!!(type & ATTACH_TYPE_MARK) ^ !!(type & ATTACH_TYPE_CURSIVE));
1565
1566 if (type & ATTACH_TYPE_CURSIVE)
1567 {
1568 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1569 pos[i].y_offset += pos[j].y_offset;
1570 else
1571 pos[i].x_offset += pos[j].x_offset;
1572 }
1573 else /*if (type & ATTACH_TYPE_MARK)*/
1574 {
1575 pos[i].x_offset += pos[j].x_offset;
1576 pos[i].y_offset += pos[j].y_offset;
1577
1578 assert (j < i);
1579 if (HB_DIRECTION_IS_FORWARD (direction))
1580 for (unsigned int k = j; k < i; k++) {
1581 pos[i].x_offset -= pos[k].x_advance;
1582 pos[i].y_offset -= pos[k].y_advance;
1583 }
1584 else
1585 for (unsigned int k = j + 1; k < i + 1; k++) {
1586 pos[i].x_offset += pos[k].x_advance;
1587 pos[i].y_offset += pos[k].y_advance;
1588 }
1589 }
1590 }
1591
1592 void
1593 GPOS::position_start (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1594 {
1595 unsigned int count = buffer->len;
1596 for (unsigned int i = 0; i < count; i++)
1597 buffer->pos[i].attach_chain() = buffer->pos[i].attach_type() = 0;
1598 }
1599
1600 void
1601 GPOS::position_finish_advances (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1602 {
1603 //_hb_buffer_assert_gsubgpos_vars (buffer);
1604 }
1605
1606 void
1607 GPOS::position_finish_offsets (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1608 {
1609 _hb_buffer_assert_gsubgpos_vars (buffer);
1610
1611 unsigned int len;
1612 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
1613 hb_direction_t direction = buffer->props.direction;
1614
1615 /* Handle attachments */
1616 if (buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT)
1617 for (unsigned int i = 0; i < len; i++)
1618 propagate_attachment_offsets (pos, i, direction);
1619 }
1620
1621
1622 /* Out-of-class implementation for methods recursing */
1623
1624 template <typename context_t>
1625 /*static*/ inline typename context_t::return_t PosLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
1626 {
1627 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1628 const PosLookup &l = gpos.get_lookup (lookup_index);
1629 return l.dispatch (c);
1630 }
1631
1632 /*static*/ inline bool PosLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
1633 {
1634 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1635 const PosLookup &l = gpos.get_lookup (lookup_index);
1636 unsigned int saved_lookup_props = c->lookup_props;
1637 unsigned int saved_lookup_index = c->lookup_index;
1638 c->set_lookup_index (lookup_index);
1639 c->set_lookup_props (l.get_props ());
1640 bool ret = l.dispatch (c);
1641 c->set_lookup_index (saved_lookup_index);
1642 c->set_lookup_props (saved_lookup_props);
1643 return ret;
1644 }
1645
1646
1647 #undef attach_chain
1648 #undef attach_type
1649
1650
1651 } /* namespace OT */
1652
1653
1654 #endif /* HB_OT_LAYOUT_GPOS_TABLE_HH */