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 HBUINT16 Value;
55
56 typedef Value ValueRecord[VAR];
57
58 struct ValueFormat : HBUINT16
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 HBINT16 xPlacement; /* Horizontal adjustment for
78 * placement--in design units */
79 HBINT16 yPlacement; /* Vertical adjustment for
80 * placement--in design units */
81 HBINT16 xAdvance; /* Horizontal adjustment for
82 * advance--in design units (only used
83 * for horizontal writing) */
84 HBINT16 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_popcount ((unsigned int) *this); }
103 inline unsigned int get_size (void) const
104 { return get_len () * Value::static_size; }
105
106 void apply_value (hb_ot_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 HBINT16& get_short (const Value* value)
182 { return *CastP<HBINT16> (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_ot_apply_context_t *c, hb_codepoint_t glyph_id HB_UNUSED,
236 float *x, float *y) const
237 {
238 hb_font_t *font = c->font;
239 *x = font->em_fscale_x (xCoordinate);
240 *y = font->em_fscale_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 HBUINT16 format; /* Format identifier--format = 1 */
251 FWORD xCoordinate; /* Horizontal value--in design units */
252 FWORD 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_ot_apply_context_t *c, hb_codepoint_t glyph_id,
260 float *x, float *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 = 0, cy = 0;
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_fscale_x (xCoordinate);
271 *y = ret && y_ppem ? cy : font->em_fscale_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 HBUINT16 format; /* Format identifier--format = 2 */
282 FWORD xCoordinate; /* Horizontal value--in design units */
283 FWORD yCoordinate; /* Vertical value--in design units */
284 HBUINT16 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_ot_apply_context_t *c, hb_codepoint_t glyph_id HB_UNUSED,
292 float *x, float *y) const
293 {
294 hb_font_t *font = c->font;
295 *x = font->em_fscale_x (xCoordinate);
296 *y = font->em_fscale_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 HBUINT16 format; /* Format identifier--format = 3 */
312 FWORD xCoordinate; /* Horizontal value--in design units */
313 FWORD 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_ot_apply_context_t *c, hb_codepoint_t glyph_id,
329 float *x, float *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 HBUINT16 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 HBUINT16 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 HBUINT16 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_ot_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 float mark_x, mark_y, base_x, base_y;
434
435 buffer->unsafe_to_break (glyph_pos, buffer->idx);
436 mark_anchor.get_anchor (c, buffer->cur().codepoint, &mark_x, &mark_y);
437 glyph_anchor.get_anchor (c, buffer->info[glyph_pos].codepoint, &base_x, &base_y);
438
439 hb_glyph_position_t &o = buffer->cur_pos();
440 o.x_offset = round (base_x - mark_x);
441 o.y_offset = round (base_y - mark_y);
442 o.attach_type() = ATTACH_TYPE_MARK;
443 o.attach_chain() = (int) glyph_pos - (int) buffer->idx;
444 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
445
446 buffer->idx++;
447 return_trace (true);
448 }
449
450 inline bool sanitize (hb_sanitize_context_t *c) const
451 {
452 TRACE_SANITIZE (this);
453 return_trace (ArrayOf<MarkRecord>::sanitize (c, this));
454 }
455 };
456
457
458 /* Lookups */
459
460 struct SinglePosFormat1
461 {
462 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
463 {
464 TRACE_COLLECT_GLYPHS (this);
465 if (unlikely (!(this+coverage).add_coverage (c->input))) return;
466 }
467
468 inline const Coverage &get_coverage (void) const
469 {
470 return this+coverage;
471 }
472
473 inline bool apply (hb_ot_apply_context_t *c) const
474 {
475 TRACE_APPLY (this);
476 hb_buffer_t *buffer = c->buffer;
477 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
478 if (likely (index == NOT_COVERED)) return_trace (false);
479
480 valueFormat.apply_value (c, this, values, buffer->cur_pos());
481
482 buffer->idx++;
483 return_trace (true);
484 }
485
486 inline bool sanitize (hb_sanitize_context_t *c) const
487 {
488 TRACE_SANITIZE (this);
489 return_trace (c->check_struct (this) &&
490 coverage.sanitize (c, this) &&
491 valueFormat.sanitize_value (c, this, values));
492 }
493
494 protected:
495 HBUINT16 format; /* Format identifier--format = 1 */
496 OffsetTo<Coverage>
497 coverage; /* Offset to Coverage table--from
498 * beginning of subtable */
499 ValueFormat valueFormat; /* Defines the types of data in the
500 * ValueRecord */
501 ValueRecord values; /* Defines positioning
502 * value(s)--applied to all glyphs in
503 * the Coverage table */
504 public:
505 DEFINE_SIZE_ARRAY (6, values);
506 };
507
508 struct SinglePosFormat2
509 {
510 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
511 {
512 TRACE_COLLECT_GLYPHS (this);
513 if (unlikely (!(this+coverage).add_coverage (c->input))) return;
514 }
515
516 inline const Coverage &get_coverage (void) const
517 {
518 return this+coverage;
519 }
520
521 inline bool apply (hb_ot_apply_context_t *c) const
522 {
523 TRACE_APPLY (this);
524 hb_buffer_t *buffer = c->buffer;
525 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
526 if (likely (index == NOT_COVERED)) return_trace (false);
527
528 if (likely (index >= valueCount)) return_trace (false);
529
530 valueFormat.apply_value (c, this,
531 &values[index * valueFormat.get_len ()],
532 buffer->cur_pos());
533
534 buffer->idx++;
535 return_trace (true);
536 }
537
538 inline bool sanitize (hb_sanitize_context_t *c) const
539 {
540 TRACE_SANITIZE (this);
541 return_trace (c->check_struct (this) &&
542 coverage.sanitize (c, this) &&
543 valueFormat.sanitize_values (c, this, values, valueCount));
544 }
545
546 protected:
547 HBUINT16 format; /* Format identifier--format = 2 */
548 OffsetTo<Coverage>
549 coverage; /* Offset to Coverage table--from
550 * beginning of subtable */
551 ValueFormat valueFormat; /* Defines the types of data in the
552 * ValueRecord */
553 HBUINT16 valueCount; /* Number of ValueRecords */
554 ValueRecord values; /* Array of ValueRecords--positioning
555 * values applied to glyphs */
556 public:
557 DEFINE_SIZE_ARRAY (8, values);
558 };
559
560 struct SinglePos
561 {
562 template <typename context_t>
563 inline typename context_t::return_t dispatch (context_t *c) const
564 {
565 TRACE_DISPATCH (this, u.format);
566 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
567 switch (u.format) {
568 case 1: return_trace (c->dispatch (u.format1));
569 case 2: return_trace (c->dispatch (u.format2));
570 default:return_trace (c->default_return_value ());
571 }
572 }
573
574 protected:
575 union {
576 HBUINT16 format; /* Format identifier */
577 SinglePosFormat1 format1;
578 SinglePosFormat2 format2;
579 } u;
580 };
581
582
583 struct PairValueRecord
584 {
585 friend struct PairSet;
586
587 protected:
588 GlyphID secondGlyph; /* GlyphID of second glyph in the
589 * pair--first glyph is listed in the
590 * Coverage table */
591 ValueRecord values; /* Positioning data for the first glyph
592 * followed by for second glyph */
593 public:
594 DEFINE_SIZE_ARRAY (2, values);
595 };
596
597 struct PairSet
598 {
599 friend struct PairPosFormat1;
600
601 inline void collect_glyphs (hb_collect_glyphs_context_t *c,
602 const ValueFormat *valueFormats) const
603 {
604 TRACE_COLLECT_GLYPHS (this);
605 unsigned int len1 = valueFormats[0].get_len ();
606 unsigned int len2 = valueFormats[1].get_len ();
607 unsigned int record_size = HBUINT16::static_size * (1 + len1 + len2);
608
609 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
610 c->input->add_array (&record->secondGlyph, len, record_size);
611 }
612
613 inline bool apply (hb_ot_apply_context_t *c,
614 const ValueFormat *valueFormats,
615 unsigned int pos) const
616 {
617 TRACE_APPLY (this);
618 hb_buffer_t *buffer = c->buffer;
619 unsigned int len1 = valueFormats[0].get_len ();
620 unsigned int len2 = valueFormats[1].get_len ();
621 unsigned int record_size = HBUINT16::static_size * (1 + len1 + len2);
622
623 const PairValueRecord *record_array = CastP<PairValueRecord> (arrayZ);
624 unsigned int count = len;
625
626 /* Hand-coded bsearch. */
627 if (unlikely (!count))
628 return_trace (false);
629 hb_codepoint_t x = buffer->info[pos].codepoint;
630 int min = 0, max = (int) count - 1;
631 while (min <= max)
632 {
633 int mid = (min + max) / 2;
634 const PairValueRecord *record = &StructAtOffset<PairValueRecord> (record_array, record_size * mid);
635 hb_codepoint_t mid_x = record->secondGlyph;
636 if (x < mid_x)
637 max = mid - 1;
638 else if (x > mid_x)
639 min = mid + 1;
640 else
641 {
642 buffer->unsafe_to_break (buffer->idx, pos + 1);
643 valueFormats[0].apply_value (c, this, &record->values[0], buffer->cur_pos());
644 valueFormats[1].apply_value (c, this, &record->values[len1], buffer->pos[pos]);
645 if (len2)
646 pos++;
647 buffer->idx = pos;
648 return_trace (true);
649 }
650 }
651
652 return_trace (false);
653 }
654
655 struct sanitize_closure_t {
656 const void *base;
657 const ValueFormat *valueFormats;
658 unsigned int len1; /* valueFormats[0].get_len() */
659 unsigned int stride; /* 1 + len1 + len2 */
660 };
661
662 inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
663 {
664 TRACE_SANITIZE (this);
665 if (!(c->check_struct (this)
666 && c->check_array (arrayZ, HBUINT16::static_size * closure->stride, len))) return_trace (false);
667
668 unsigned int count = len;
669 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
670 return_trace (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride) &&
671 closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
672 }
673
674 protected:
675 HBUINT16 len; /* Number of PairValueRecords */
676 HBUINT16 arrayZ[VAR]; /* Array of PairValueRecords--ordered
677 * by GlyphID of the second glyph */
678 public:
679 DEFINE_SIZE_ARRAY (2, arrayZ);
680 };
681
682 struct PairPosFormat1
683 {
684 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
685 {
686 TRACE_COLLECT_GLYPHS (this);
687 if (unlikely (!(this+coverage).add_coverage (c->input))) return;
688 unsigned int count = pairSet.len;
689 for (unsigned int i = 0; i < count; i++)
690 (this+pairSet[i]).collect_glyphs (c, valueFormat);
691 }
692
693 inline const Coverage &get_coverage (void) const
694 {
695 return this+coverage;
696 }
697
698 inline bool apply (hb_ot_apply_context_t *c) const
699 {
700 TRACE_APPLY (this);
701 hb_buffer_t *buffer = c->buffer;
702 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
703 if (likely (index == NOT_COVERED)) return_trace (false);
704
705 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
706 skippy_iter.reset (buffer->idx, 1);
707 if (!skippy_iter.next ()) return_trace (false);
708
709 return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
710 }
711
712 inline bool sanitize (hb_sanitize_context_t *c) const
713 {
714 TRACE_SANITIZE (this);
715
716 if (!c->check_struct (this)) return_trace (false);
717
718 unsigned int len1 = valueFormat[0].get_len ();
719 unsigned int len2 = valueFormat[1].get_len ();
720 PairSet::sanitize_closure_t closure = {
721 this,
722 valueFormat,
723 len1,
724 1 + len1 + len2
725 };
726
727 return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
728 }
729
730 protected:
731 HBUINT16 format; /* Format identifier--format = 1 */
732 OffsetTo<Coverage>
733 coverage; /* Offset to Coverage table--from
734 * beginning of subtable */
735 ValueFormat valueFormat[2]; /* [0] Defines the types of data in
736 * ValueRecord1--for the first glyph
737 * in the pair--may be zero (0) */
738 /* [1] Defines the types of data in
739 * ValueRecord2--for the second glyph
740 * in the pair--may be zero (0) */
741 OffsetArrayOf<PairSet>
742 pairSet; /* Array of PairSet tables
743 * ordered by Coverage Index */
744 public:
745 DEFINE_SIZE_ARRAY (10, pairSet);
746 };
747
748 struct PairPosFormat2
749 {
750 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
751 {
752 TRACE_COLLECT_GLYPHS (this);
753 if (unlikely (!(this+coverage).add_coverage (c->input))) return;
754 if (unlikely (!(this+classDef2).add_coverage (c->input))) return;
755 }
756
757 inline const Coverage &get_coverage (void) const
758 {
759 return this+coverage;
760 }
761
762 inline bool apply (hb_ot_apply_context_t *c) const
763 {
764 TRACE_APPLY (this);
765 hb_buffer_t *buffer = c->buffer;
766 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
767 if (likely (index == NOT_COVERED)) return_trace (false);
768
769 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
770 skippy_iter.reset (buffer->idx, 1);
771 if (!skippy_iter.next ()) return_trace (false);
772
773 unsigned int len1 = valueFormat1.get_len ();
774 unsigned int len2 = valueFormat2.get_len ();
775 unsigned int record_len = len1 + len2;
776
777 unsigned int klass1 = (this+classDef1).get_class (buffer->cur().codepoint);
778 unsigned int klass2 = (this+classDef2).get_class (buffer->info[skippy_iter.idx].codepoint);
779 if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return_trace (false);
780
781 buffer->unsafe_to_break (buffer->idx, skippy_iter.idx + 1);
782 const Value *v = &values[record_len * (klass1 * class2Count + klass2)];
783 valueFormat1.apply_value (c, this, v, buffer->cur_pos());
784 valueFormat2.apply_value (c, this, v + len1, buffer->pos[skippy_iter.idx]);
785
786 buffer->idx = skippy_iter.idx;
787 if (len2)
788 buffer->idx++;
789
790 return_trace (true);
791 }
792
793 inline bool sanitize (hb_sanitize_context_t *c) const
794 {
795 TRACE_SANITIZE (this);
796 if (!(c->check_struct (this)
797 && coverage.sanitize (c, this)
798 && classDef1.sanitize (c, this)
799 && classDef2.sanitize (c, this))) return_trace (false);
800
801 unsigned int len1 = valueFormat1.get_len ();
802 unsigned int len2 = valueFormat2.get_len ();
803 unsigned int stride = len1 + len2;
804 unsigned int record_size = valueFormat1.get_size () + valueFormat2.get_size ();
805 unsigned int count = (unsigned int) class1Count * (unsigned int) class2Count;
806 return_trace (c->check_array (values, record_size, count) &&
807 valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
808 valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
809 }
810
811 protected:
812 HBUINT16 format; /* Format identifier--format = 2 */
813 OffsetTo<Coverage>
814 coverage; /* Offset to Coverage table--from
815 * beginning of subtable */
816 ValueFormat valueFormat1; /* ValueRecord definition--for the
817 * first glyph of the pair--may be zero
818 * (0) */
819 ValueFormat valueFormat2; /* ValueRecord definition--for the
820 * second glyph of the pair--may be
821 * zero (0) */
822 OffsetTo<ClassDef>
823 classDef1; /* Offset to ClassDef table--from
824 * beginning of PairPos subtable--for
825 * the first glyph of the pair */
826 OffsetTo<ClassDef>
827 classDef2; /* Offset to ClassDef table--from
828 * beginning of PairPos subtable--for
829 * the second glyph of the pair */
830 HBUINT16 class1Count; /* Number of classes in ClassDef1
831 * table--includes Class0 */
832 HBUINT16 class2Count; /* Number of classes in ClassDef2
833 * table--includes Class0 */
834 ValueRecord values; /* Matrix of value pairs:
835 * class1-major, class2-minor,
836 * Each entry has value1 and value2 */
837 public:
838 DEFINE_SIZE_ARRAY (16, values);
839 };
840
841 struct PairPos
842 {
843 template <typename context_t>
844 inline typename context_t::return_t dispatch (context_t *c) const
845 {
846 TRACE_DISPATCH (this, u.format);
847 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
848 switch (u.format) {
849 case 1: return_trace (c->dispatch (u.format1));
850 case 2: return_trace (c->dispatch (u.format2));
851 default:return_trace (c->default_return_value ());
852 }
853 }
854
855 protected:
856 union {
857 HBUINT16 format; /* Format identifier */
858 PairPosFormat1 format1;
859 PairPosFormat2 format2;
860 } u;
861 };
862
863
864 struct EntryExitRecord
865 {
866 friend struct CursivePosFormat1;
867
868 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
869 {
870 TRACE_SANITIZE (this);
871 return_trace (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
872 }
873
874 protected:
875 OffsetTo<Anchor>
876 entryAnchor; /* Offset to EntryAnchor table--from
877 * beginning of CursivePos
878 * subtable--may be NULL */
879 OffsetTo<Anchor>
880 exitAnchor; /* Offset to ExitAnchor table--from
881 * beginning of CursivePos
882 * subtable--may be NULL */
883 public:
884 DEFINE_SIZE_STATIC (4);
885 };
886
887 static void
888 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent);
889
890 struct CursivePosFormat1
891 {
892 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
893 {
894 TRACE_COLLECT_GLYPHS (this);
895 if (unlikely (!(this+coverage).add_coverage (c->input))) return;
896 }
897
898 inline const Coverage &get_coverage (void) const
899 {
900 return this+coverage;
901 }
902
903 inline bool apply (hb_ot_apply_context_t *c) const
904 {
905 TRACE_APPLY (this);
906 hb_buffer_t *buffer = c->buffer;
907
908 const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage (buffer->cur().codepoint)];
909 if (!this_record.exitAnchor) return_trace (false);
910
911 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
912 skippy_iter.reset (buffer->idx, 1);
913 if (!skippy_iter.next ()) return_trace (false);
914
915 const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage (buffer->info[skippy_iter.idx].codepoint)];
916 if (!next_record.entryAnchor) return_trace (false);
917
918 unsigned int i = buffer->idx;
919 unsigned int j = skippy_iter.idx;
920
921 buffer->unsafe_to_break (i, j);
922 float entry_x, entry_y, exit_x, exit_y;
923 (this+this_record.exitAnchor).get_anchor (c, buffer->info[i].codepoint, &exit_x, &exit_y);
924 (this+next_record.entryAnchor).get_anchor (c, buffer->info[j].codepoint, &entry_x, &entry_y);
925
926 hb_glyph_position_t *pos = buffer->pos;
927
928 hb_position_t d;
929 /* Main-direction adjustment */
930 switch (c->direction) {
931 case HB_DIRECTION_LTR:
932 pos[i].x_advance = round (exit_x) + pos[i].x_offset;
933
934 d = round (entry_x) + pos[j].x_offset;
935 pos[j].x_advance -= d;
936 pos[j].x_offset -= d;
937 break;
938 case HB_DIRECTION_RTL:
939 d = round (exit_x) + pos[i].x_offset;
940 pos[i].x_advance -= d;
941 pos[i].x_offset -= d;
942
943 pos[j].x_advance = round (entry_x) + pos[j].x_offset;
944 break;
945 case HB_DIRECTION_TTB:
946 pos[i].y_advance = round (exit_y) + pos[i].y_offset;
947
948 d = round (entry_y) + pos[j].y_offset;
949 pos[j].y_advance -= d;
950 pos[j].y_offset -= d;
951 break;
952 case HB_DIRECTION_BTT:
953 d = round (exit_y) + pos[i].y_offset;
954 pos[i].y_advance -= d;
955 pos[i].y_offset -= d;
956
957 pos[j].y_advance = round (entry_y);
958 break;
959 case HB_DIRECTION_INVALID:
960 default:
961 break;
962 }
963
964 /* Cross-direction adjustment */
965
966 /* We attach child to parent (think graph theory and rooted trees whereas
967 * the root stays on baseline and each node aligns itself against its
968 * parent.
969 *
970 * Optimize things for the case of RightToLeft, as that's most common in
971 * Arabinc. */
972 unsigned int child = i;
973 unsigned int parent = j;
974 hb_position_t x_offset = entry_x - exit_x;
975 hb_position_t y_offset = entry_y - exit_y;
976 if (!(c->lookup_props & LookupFlag::RightToLeft))
977 {
978 unsigned int k = child;
979 child = parent;
980 parent = k;
981 x_offset = -x_offset;
982 y_offset = -y_offset;
983 }
984
985 /* If child was already connected to someone else, walk through its old
986 * chain and reverse the link direction, such that the whole tree of its
987 * previous connection now attaches to new parent. Watch out for case
988 * where new parent is on the path from old chain...
989 */
990 reverse_cursive_minor_offset (pos, child, c->direction, parent);
991
992 pos[child].attach_type() = ATTACH_TYPE_CURSIVE;
993 pos[child].attach_chain() = (int) parent - (int) child;
994 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
995 if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
996 pos[child].y_offset = y_offset;
997 else
998 pos[child].x_offset = x_offset;
999
1000 buffer->idx = j;
1001 return_trace (true);
1002 }
1003
1004 inline bool sanitize (hb_sanitize_context_t *c) const
1005 {
1006 TRACE_SANITIZE (this);
1007 return_trace (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
1008 }
1009
1010 protected:
1011 HBUINT16 format; /* Format identifier--format = 1 */
1012 OffsetTo<Coverage>
1013 coverage; /* Offset to Coverage table--from
1014 * beginning of subtable */
1015 ArrayOf<EntryExitRecord>
1016 entryExitRecord; /* Array of EntryExit records--in
1017 * Coverage Index order */
1018 public:
1019 DEFINE_SIZE_ARRAY (6, entryExitRecord);
1020 };
1021
1022 struct CursivePos
1023 {
1024 template <typename context_t>
1025 inline typename context_t::return_t dispatch (context_t *c) const
1026 {
1027 TRACE_DISPATCH (this, u.format);
1028 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1029 switch (u.format) {
1030 case 1: return_trace (c->dispatch (u.format1));
1031 default:return_trace (c->default_return_value ());
1032 }
1033 }
1034
1035 protected:
1036 union {
1037 HBUINT16 format; /* Format identifier */
1038 CursivePosFormat1 format1;
1039 } u;
1040 };
1041
1042
1043 typedef AnchorMatrix BaseArray; /* base-major--
1044 * in order of BaseCoverage Index--,
1045 * mark-minor--
1046 * ordered by class--zero-based. */
1047
1048 struct MarkBasePosFormat1
1049 {
1050 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1051 {
1052 TRACE_COLLECT_GLYPHS (this);
1053 if (unlikely (!(this+markCoverage).add_coverage (c->input))) return;
1054 if (unlikely (!(this+baseCoverage).add_coverage (c->input))) return;
1055 }
1056
1057 inline const Coverage &get_coverage (void) const
1058 {
1059 return this+markCoverage;
1060 }
1061
1062 inline bool apply (hb_ot_apply_context_t *c) const
1063 {
1064 TRACE_APPLY (this);
1065 hb_buffer_t *buffer = c->buffer;
1066 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1067 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1068
1069 /* Now we search backwards for a non-mark glyph */
1070 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1071 skippy_iter.reset (buffer->idx, 1);
1072 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1073 do {
1074 if (!skippy_iter.prev ()) return_trace (false);
1075 /* We only want to attach to the first of a MultipleSubst sequence.
1076 * https://github.com/harfbuzz/harfbuzz/issues/740
1077 * Reject others...
1078 * ...but stop if we find a mark in the MultipleSubst sequence:
1079 * https://github.com/harfbuzz/harfbuzz/issues/1020 */
1080 if (!_hb_glyph_info_multiplied (&buffer->info[skippy_iter.idx]) ||
1081 0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]) ||
1082 (skippy_iter.idx == 0 ||
1083 _hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx - 1]) ||
1084 _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]) !=
1085 _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx - 1]) ||
1086 _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]) !=
1087 _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx - 1]) + 1
1088 ))
1089 break;
1090 skippy_iter.reject ();
1091 } while (1);
1092
1093 /* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */
1094 //if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1095
1096 unsigned int base_index = (this+baseCoverage).get_coverage (buffer->info[skippy_iter.idx].codepoint);
1097 if (base_index == NOT_COVERED) return_trace (false);
1098
1099 return_trace ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
1100 }
1101
1102 inline bool sanitize (hb_sanitize_context_t *c) const
1103 {
1104 TRACE_SANITIZE (this);
1105 return_trace (c->check_struct (this) &&
1106 markCoverage.sanitize (c, this) &&
1107 baseCoverage.sanitize (c, this) &&
1108 markArray.sanitize (c, this) &&
1109 baseArray.sanitize (c, this, (unsigned int) classCount));
1110 }
1111
1112 protected:
1113 HBUINT16 format; /* Format identifier--format = 1 */
1114 OffsetTo<Coverage>
1115 markCoverage; /* Offset to MarkCoverage table--from
1116 * beginning of MarkBasePos subtable */
1117 OffsetTo<Coverage>
1118 baseCoverage; /* Offset to BaseCoverage table--from
1119 * beginning of MarkBasePos subtable */
1120 HBUINT16 classCount; /* Number of classes defined for marks */
1121 OffsetTo<MarkArray>
1122 markArray; /* Offset to MarkArray table--from
1123 * beginning of MarkBasePos subtable */
1124 OffsetTo<BaseArray>
1125 baseArray; /* Offset to BaseArray table--from
1126 * beginning of MarkBasePos subtable */
1127 public:
1128 DEFINE_SIZE_STATIC (12);
1129 };
1130
1131 struct MarkBasePos
1132 {
1133 template <typename context_t>
1134 inline typename context_t::return_t dispatch (context_t *c) const
1135 {
1136 TRACE_DISPATCH (this, u.format);
1137 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1138 switch (u.format) {
1139 case 1: return_trace (c->dispatch (u.format1));
1140 default:return_trace (c->default_return_value ());
1141 }
1142 }
1143
1144 protected:
1145 union {
1146 HBUINT16 format; /* Format identifier */
1147 MarkBasePosFormat1 format1;
1148 } u;
1149 };
1150
1151
1152 typedef AnchorMatrix LigatureAttach; /* component-major--
1153 * in order of writing direction--,
1154 * mark-minor--
1155 * ordered by class--zero-based. */
1156
1157 typedef OffsetListOf<LigatureAttach> LigatureArray;
1158 /* Array of LigatureAttach
1159 * tables ordered by
1160 * LigatureCoverage Index */
1161
1162 struct MarkLigPosFormat1
1163 {
1164 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1165 {
1166 TRACE_COLLECT_GLYPHS (this);
1167 if (unlikely (!(this+markCoverage).add_coverage (c->input))) return;
1168 if (unlikely (!(this+ligatureCoverage).add_coverage (c->input))) return;
1169 }
1170
1171 inline const Coverage &get_coverage (void) const
1172 {
1173 return this+markCoverage;
1174 }
1175
1176 inline bool apply (hb_ot_apply_context_t *c) const
1177 {
1178 TRACE_APPLY (this);
1179 hb_buffer_t *buffer = c->buffer;
1180 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1181 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1182
1183 /* Now we search backwards for a non-mark glyph */
1184 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1185 skippy_iter.reset (buffer->idx, 1);
1186 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1187 if (!skippy_iter.prev ()) return_trace (false);
1188
1189 /* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
1190 //if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1191
1192 unsigned int j = skippy_iter.idx;
1193 unsigned int lig_index = (this+ligatureCoverage).get_coverage (buffer->info[j].codepoint);
1194 if (lig_index == NOT_COVERED) return_trace (false);
1195
1196 const LigatureArray& lig_array = this+ligatureArray;
1197 const LigatureAttach& lig_attach = lig_array[lig_index];
1198
1199 /* Find component to attach to */
1200 unsigned int comp_count = lig_attach.rows;
1201 if (unlikely (!comp_count)) return_trace (false);
1202
1203 /* We must now check whether the ligature ID of the current mark glyph
1204 * is identical to the ligature ID of the found ligature. If yes, we
1205 * can directly use the component index. If not, we attach the mark
1206 * glyph to the last component of the ligature. */
1207 unsigned int comp_index;
1208 unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1209 unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
1210 unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
1211 if (lig_id && lig_id == mark_id && mark_comp > 0)
1212 comp_index = MIN (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
1213 else
1214 comp_index = comp_count - 1;
1215
1216 return_trace ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
1217 }
1218
1219 inline bool sanitize (hb_sanitize_context_t *c) const
1220 {
1221 TRACE_SANITIZE (this);
1222 return_trace (c->check_struct (this) &&
1223 markCoverage.sanitize (c, this) &&
1224 ligatureCoverage.sanitize (c, this) &&
1225 markArray.sanitize (c, this) &&
1226 ligatureArray.sanitize (c, this, (unsigned int) classCount));
1227 }
1228
1229 protected:
1230 HBUINT16 format; /* Format identifier--format = 1 */
1231 OffsetTo<Coverage>
1232 markCoverage; /* Offset to Mark Coverage table--from
1233 * beginning of MarkLigPos subtable */
1234 OffsetTo<Coverage>
1235 ligatureCoverage; /* Offset to Ligature Coverage
1236 * table--from beginning of MarkLigPos
1237 * subtable */
1238 HBUINT16 classCount; /* Number of defined mark classes */
1239 OffsetTo<MarkArray>
1240 markArray; /* Offset to MarkArray table--from
1241 * beginning of MarkLigPos subtable */
1242 OffsetTo<LigatureArray>
1243 ligatureArray; /* Offset to LigatureArray table--from
1244 * beginning of MarkLigPos subtable */
1245 public:
1246 DEFINE_SIZE_STATIC (12);
1247 };
1248
1249 struct MarkLigPos
1250 {
1251 template <typename context_t>
1252 inline typename context_t::return_t dispatch (context_t *c) const
1253 {
1254 TRACE_DISPATCH (this, u.format);
1255 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1256 switch (u.format) {
1257 case 1: return_trace (c->dispatch (u.format1));
1258 default:return_trace (c->default_return_value ());
1259 }
1260 }
1261
1262 protected:
1263 union {
1264 HBUINT16 format; /* Format identifier */
1265 MarkLigPosFormat1 format1;
1266 } u;
1267 };
1268
1269
1270 typedef AnchorMatrix Mark2Array; /* mark2-major--
1271 * in order of Mark2Coverage Index--,
1272 * mark1-minor--
1273 * ordered by class--zero-based. */
1274
1275 struct MarkMarkPosFormat1
1276 {
1277 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1278 {
1279 TRACE_COLLECT_GLYPHS (this);
1280 if (unlikely (!(this+mark1Coverage).add_coverage (c->input))) return;
1281 if (unlikely (!(this+mark2Coverage).add_coverage (c->input))) return;
1282 }
1283
1284 inline const Coverage &get_coverage (void) const
1285 {
1286 return this+mark1Coverage;
1287 }
1288
1289 inline bool apply (hb_ot_apply_context_t *c) const
1290 {
1291 TRACE_APPLY (this);
1292 hb_buffer_t *buffer = c->buffer;
1293 unsigned int mark1_index = (this+mark1Coverage).get_coverage (buffer->cur().codepoint);
1294 if (likely (mark1_index == NOT_COVERED)) return_trace (false);
1295
1296 /* now we search backwards for a suitable mark glyph until a non-mark glyph */
1297 hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1298 skippy_iter.reset (buffer->idx, 1);
1299 skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
1300 if (!skippy_iter.prev ()) return_trace (false);
1301
1302 if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1303
1304 unsigned int j = skippy_iter.idx;
1305
1306 unsigned int id1 = _hb_glyph_info_get_lig_id (&buffer->cur());
1307 unsigned int id2 = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1308 unsigned int comp1 = _hb_glyph_info_get_lig_comp (&buffer->cur());
1309 unsigned int comp2 = _hb_glyph_info_get_lig_comp (&buffer->info[j]);
1310
1311 if (likely (id1 == id2)) {
1312 if (id1 == 0) /* Marks belonging to the same base. */
1313 goto good;
1314 else if (comp1 == comp2) /* Marks belonging to the same ligature component. */
1315 goto good;
1316 } else {
1317 /* If ligature ids don't match, it may be the case that one of the marks
1318 * itself is a ligature. In which case match. */
1319 if ((id1 > 0 && !comp1) || (id2 > 0 && !comp2))
1320 goto good;
1321 }
1322
1323 /* Didn't match. */
1324 return_trace (false);
1325
1326 good:
1327 unsigned int mark2_index = (this+mark2Coverage).get_coverage (buffer->info[j].codepoint);
1328 if (mark2_index == NOT_COVERED) return_trace (false);
1329
1330 return_trace ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
1331 }
1332
1333 inline bool sanitize (hb_sanitize_context_t *c) const
1334 {
1335 TRACE_SANITIZE (this);
1336 return_trace (c->check_struct (this) &&
1337 mark1Coverage.sanitize (c, this) &&
1338 mark2Coverage.sanitize (c, this) &&
1339 mark1Array.sanitize (c, this) &&
1340 mark2Array.sanitize (c, this, (unsigned int) classCount));
1341 }
1342
1343 protected:
1344 HBUINT16 format; /* Format identifier--format = 1 */
1345 OffsetTo<Coverage>
1346 mark1Coverage; /* Offset to Combining Mark1 Coverage
1347 * table--from beginning of MarkMarkPos
1348 * subtable */
1349 OffsetTo<Coverage>
1350 mark2Coverage; /* Offset to Combining Mark2 Coverage
1351 * table--from beginning of MarkMarkPos
1352 * subtable */
1353 HBUINT16 classCount; /* Number of defined mark classes */
1354 OffsetTo<MarkArray>
1355 mark1Array; /* Offset to Mark1Array table--from
1356 * beginning of MarkMarkPos subtable */
1357 OffsetTo<Mark2Array>
1358 mark2Array; /* Offset to Mark2Array table--from
1359 * beginning of MarkMarkPos subtable */
1360 public:
1361 DEFINE_SIZE_STATIC (12);
1362 };
1363
1364 struct MarkMarkPos
1365 {
1366 template <typename context_t>
1367 inline typename context_t::return_t dispatch (context_t *c) const
1368 {
1369 TRACE_DISPATCH (this, u.format);
1370 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1371 switch (u.format) {
1372 case 1: return_trace (c->dispatch (u.format1));
1373 default:return_trace (c->default_return_value ());
1374 }
1375 }
1376
1377 protected:
1378 union {
1379 HBUINT16 format; /* Format identifier */
1380 MarkMarkPosFormat1 format1;
1381 } u;
1382 };
1383
1384
1385 struct ContextPos : Context {};
1386
1387 struct ChainContextPos : ChainContext {};
1388
1389 struct ExtensionPos : Extension<ExtensionPos>
1390 {
1391 typedef struct PosLookupSubTable LookupSubTable;
1392 };
1393
1394
1395
1396 /*
1397 * PosLookup
1398 */
1399
1400
1401 struct PosLookupSubTable
1402 {
1403 friend struct PosLookup;
1404
1405 enum Type {
1406 Single = 1,
1407 Pair = 2,
1408 Cursive = 3,
1409 MarkBase = 4,
1410 MarkLig = 5,
1411 MarkMark = 6,
1412 Context = 7,
1413 ChainContext = 8,
1414 Extension = 9
1415 };
1416
1417 template <typename context_t>
1418 inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1419 {
1420 TRACE_DISPATCH (this, lookup_type);
1421 if (unlikely (!c->may_dispatch (this, &u.sub_format))) return_trace (c->no_dispatch_return_value ());
1422 switch (lookup_type) {
1423 case Single: return_trace (u.single.dispatch (c));
1424 case Pair: return_trace (u.pair.dispatch (c));
1425 case Cursive: return_trace (u.cursive.dispatch (c));
1426 case MarkBase: return_trace (u.markBase.dispatch (c));
1427 case MarkLig: return_trace (u.markLig.dispatch (c));
1428 case MarkMark: return_trace (u.markMark.dispatch (c));
1429 case Context: return_trace (u.context.dispatch (c));
1430 case ChainContext: return_trace (u.chainContext.dispatch (c));
1431 case Extension: return_trace (u.extension.dispatch (c));
1432 default: return_trace (c->default_return_value ());
1433 }
1434 }
1435
1436 protected:
1437 union {
1438 HBUINT16 sub_format;
1439 SinglePos single;
1440 PairPos pair;
1441 CursivePos cursive;
1442 MarkBasePos markBase;
1443 MarkLigPos markLig;
1444 MarkMarkPos markMark;
1445 ContextPos context;
1446 ChainContextPos chainContext;
1447 ExtensionPos extension;
1448 } u;
1449 public:
1450 DEFINE_SIZE_UNION (2, sub_format);
1451 };
1452
1453
1454 struct PosLookup : Lookup
1455 {
1456 inline const PosLookupSubTable& get_subtable (unsigned int i) const
1457 { return Lookup::get_subtable<PosLookupSubTable> (i); }
1458
1459 inline bool is_reverse (void) const
1460 {
1461 return false;
1462 }
1463
1464 inline bool apply (hb_ot_apply_context_t *c) const
1465 {
1466 TRACE_APPLY (this);
1467 return_trace (dispatch (c));
1468 }
1469
1470 inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
1471 {
1472 TRACE_COLLECT_GLYPHS (this);
1473 return_trace (dispatch (c));
1474 }
1475
1476 template <typename set_t>
1477 inline void add_coverage (set_t *glyphs) const
1478 {
1479 hb_add_coverage_context_t<set_t> c (glyphs);
1480 dispatch (&c);
1481 }
1482
1483 static bool apply_recurse_func (hb_ot_apply_context_t *c, unsigned int lookup_index);
1484
1485 template <typename context_t>
1486 static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
1487
1488 template <typename context_t>
1489 inline typename context_t::return_t dispatch (context_t *c) const
1490 { return Lookup::dispatch<PosLookupSubTable> (c); }
1491
1492 inline bool sanitize (hb_sanitize_context_t *c) const
1493 {
1494 TRACE_SANITIZE (this);
1495 if (unlikely (!Lookup::sanitize (c))) return_trace (false);
1496 return_trace (dispatch (c));
1497 }
1498 };
1499
1500 typedef OffsetListOf<PosLookup> PosLookupList;
1501
1502 /*
1503 * GPOS -- Glyph Positioning
1504 * https://docs.microsoft.com/en-us/typography/opentype/spec/gpos
1505 */
1506
1507 struct GPOS : GSUBGPOS
1508 {
1509 static const hb_tag_t tableTag = HB_OT_TAG_GPOS;
1510
1511 inline const PosLookup& get_lookup (unsigned int i) const
1512 { return CastR<PosLookup> (GSUBGPOS::get_lookup (i)); }
1513
1514 static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
1515 static inline void position_finish_advances (hb_font_t *font, hb_buffer_t *buffer);
1516 static inline void position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer);
1517
1518 inline bool sanitize (hb_sanitize_context_t *c) const
1519 {
1520 TRACE_SANITIZE (this);
1521 if (unlikely (!GSUBGPOS::sanitize (c))) return_trace (false);
1522 const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
1523 return_trace (list.sanitize (c, this));
1524 }
1525 };
1526
1527
1528 static void
1529 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent)
1530 {
1531 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1532 if (likely (!chain || 0 == (type & ATTACH_TYPE_CURSIVE)))
1533 return;
1534
1535 pos[i].attach_chain() = 0;
1536
1537 unsigned int j = (int) i + chain;
1538
1539 /* Stop if we see new parent in the chain. */
1540 if (j == new_parent)
1541 return;
1542
1543 reverse_cursive_minor_offset (pos, j, direction, new_parent);
1544
1545 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1546 pos[j].y_offset = -pos[i].y_offset;
1547 else
1548 pos[j].x_offset = -pos[i].x_offset;
1549
1550 pos[j].attach_chain() = -chain;
1551 pos[j].attach_type() = type;
1552 }
1553 static void
1554 propagate_attachment_offsets (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
1555 {
1556 /* Adjusts offsets of attached glyphs (both cursive and mark) to accumulate
1557 * offset of glyph they are attached to. */
1558 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1559 if (likely (!chain))
1560 return;
1561
1562 unsigned int j = (int) i + chain;
1563
1564 pos[i].attach_chain() = 0;
1565
1566 propagate_attachment_offsets (pos, j, direction);
1567
1568 assert (!!(type & ATTACH_TYPE_MARK) ^ !!(type & ATTACH_TYPE_CURSIVE));
1569
1570 if (type & ATTACH_TYPE_CURSIVE)
1571 {
1572 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1573 pos[i].y_offset += pos[j].y_offset;
1574 else
1575 pos[i].x_offset += pos[j].x_offset;
1576 }
1577 else /*if (type & ATTACH_TYPE_MARK)*/
1578 {
1579 pos[i].x_offset += pos[j].x_offset;
1580 pos[i].y_offset += pos[j].y_offset;
1581
1582 assert (j < i);
1583 if (HB_DIRECTION_IS_FORWARD (direction))
1584 for (unsigned int k = j; k < i; k++) {
1585 pos[i].x_offset -= pos[k].x_advance;
1586 pos[i].y_offset -= pos[k].y_advance;
1587 }
1588 else
1589 for (unsigned int k = j + 1; k < i + 1; k++) {
1590 pos[i].x_offset += pos[k].x_advance;
1591 pos[i].y_offset += pos[k].y_advance;
1592 }
1593 }
1594 }
1595
1596 void
1597 GPOS::position_start (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1598 {
1599 unsigned int count = buffer->len;
1600 for (unsigned int i = 0; i < count; i++)
1601 buffer->pos[i].attach_chain() = buffer->pos[i].attach_type() = 0;
1602 }
1603
1604 void
1605 GPOS::position_finish_advances (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1606 {
1607 //_hb_buffer_assert_gsubgpos_vars (buffer);
1608 }
1609
1610 void
1611 GPOS::position_finish_offsets (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1612 {
1613 _hb_buffer_assert_gsubgpos_vars (buffer);
1614
1615 unsigned int len;
1616 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
1617 hb_direction_t direction = buffer->props.direction;
1618
1619 /* Handle attachments */
1620 if (buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT)
1621 for (unsigned int i = 0; i < len; i++)
1622 propagate_attachment_offsets (pos, i, direction);
1623 }
1624
1625
1626 /* Out-of-class implementation for methods recursing */
1627
1628 template <typename context_t>
1629 /*static*/ inline typename context_t::return_t PosLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
1630 {
1631 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1632 const PosLookup &l = gpos.get_lookup (lookup_index);
1633 return l.dispatch (c);
1634 }
1635
1636 /*static*/ inline bool PosLookup::apply_recurse_func (hb_ot_apply_context_t *c, unsigned int lookup_index)
1637 {
1638 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1639 const PosLookup &l = gpos.get_lookup (lookup_index);
1640 unsigned int saved_lookup_props = c->lookup_props;
1641 unsigned int saved_lookup_index = c->lookup_index;
1642 c->set_lookup_index (lookup_index);
1643 c->set_lookup_props (l.get_props ());
1644 bool ret = l.dispatch (c);
1645 c->set_lookup_index (saved_lookup_index);
1646 c->set_lookup_props (saved_lookup_props);
1647 return ret;
1648 }
1649
1650
1651 #undef attach_chain
1652 #undef attach_type
1653
1654
1655 } /* namespace OT */
1656
1657
1658 #endif /* HB_OT_LAYOUT_GPOS_TABLE_HH */