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 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 = base_x - mark_x;
441 o.y_offset = 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 (this+coverage).add_coverage (c->input);
466 }
467
468 inline const Coverage &get_coverage (void) const
469 {
470 return this+coverage;
471 }
472
473 inline bool apply (hb_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 USHORT 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 (this+coverage).add_coverage (c->input);
514 }
515
516 inline const Coverage &get_coverage (void) const
517 {
518 return this+coverage;
519 }
520
521 inline bool apply (hb_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 USHORT 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 USHORT 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 USHORT 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 = USHORT::static_size * (1 + len1 + len2);
608
609 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
610 unsigned int count = len;
611 for (unsigned int i = 0; i < count; i++)
612 {
613 c->input->add (record->secondGlyph);
614 record = &StructAtOffset<PairValueRecord> (record, record_size);
615 }
616 }
617
618 inline bool apply (hb_apply_context_t *c,
619 const ValueFormat *valueFormats,
620 unsigned int pos) const
621 {
622 TRACE_APPLY (this);
623 hb_buffer_t *buffer = c->buffer;
624 unsigned int len1 = valueFormats[0].get_len ();
625 unsigned int len2 = valueFormats[1].get_len ();
626 unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
627
628 const PairValueRecord *record_array = CastP<PairValueRecord> (arrayZ);
629 unsigned int count = len;
630
631 /* Hand-coded bsearch. */
632 if (unlikely (!count))
633 return_trace (false);
634 hb_codepoint_t x = buffer->info[pos].codepoint;
635 int min = 0, max = (int) count - 1;
636 while (min <= max)
637 {
638 int mid = (min + max) / 2;
639 const PairValueRecord *record = &StructAtOffset<PairValueRecord> (record_array, record_size * mid);
640 hb_codepoint_t mid_x = record->secondGlyph;
641 if (x < mid_x)
642 max = mid - 1;
643 else if (x > mid_x)
644 min = mid + 1;
645 else
646 {
647 buffer->unsafe_to_break (buffer->idx, pos + 1);
648 valueFormats[0].apply_value (c, this, &record->values[0], buffer->cur_pos());
649 valueFormats[1].apply_value (c, this, &record->values[len1], buffer->pos[pos]);
650 if (len2)
651 pos++;
652 buffer->idx = pos;
653 return_trace (true);
654 }
655 }
656
657 return_trace (false);
658 }
659
660 struct sanitize_closure_t {
661 const void *base;
662 const ValueFormat *valueFormats;
663 unsigned int len1; /* valueFormats[0].get_len() */
664 unsigned int stride; /* 1 + len1 + len2 */
665 };
666
667 inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
668 {
669 TRACE_SANITIZE (this);
670 if (!(c->check_struct (this)
671 && c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return_trace (false);
672
673 unsigned int count = len;
674 const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
675 return_trace (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride) &&
676 closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
677 }
678
679 protected:
680 USHORT len; /* Number of PairValueRecords */
681 USHORT arrayZ[VAR]; /* Array of PairValueRecords--ordered
682 * by GlyphID of the second glyph */
683 public:
684 DEFINE_SIZE_ARRAY (2, arrayZ);
685 };
686
687 struct PairPosFormat1
688 {
689 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
690 {
691 TRACE_COLLECT_GLYPHS (this);
692 (this+coverage).add_coverage (c->input);
693 unsigned int count = pairSet.len;
694 for (unsigned int i = 0; i < count; i++)
695 (this+pairSet[i]).collect_glyphs (c, valueFormat);
696 }
697
698 inline const Coverage &get_coverage (void) const
699 {
700 return this+coverage;
701 }
702
703 inline bool apply (hb_apply_context_t *c) const
704 {
705 TRACE_APPLY (this);
706 hb_buffer_t *buffer = c->buffer;
707 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
708 if (likely (index == NOT_COVERED)) return_trace (false);
709
710 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
711 skippy_iter.reset (buffer->idx, 1);
712 if (!skippy_iter.next ()) return_trace (false);
713
714 return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
715 }
716
717 inline bool sanitize (hb_sanitize_context_t *c) const
718 {
719 TRACE_SANITIZE (this);
720
721 if (!c->check_struct (this)) return_trace (false);
722
723 unsigned int len1 = valueFormat[0].get_len ();
724 unsigned int len2 = valueFormat[1].get_len ();
725 PairSet::sanitize_closure_t closure = {
726 this,
727 valueFormat,
728 len1,
729 1 + len1 + len2
730 };
731
732 return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
733 }
734
735 protected:
736 USHORT format; /* Format identifier--format = 1 */
737 OffsetTo<Coverage>
738 coverage; /* Offset to Coverage table--from
739 * beginning of subtable */
740 ValueFormat valueFormat[2]; /* [0] Defines the types of data in
741 * ValueRecord1--for the first glyph
742 * in the pair--may be zero (0) */
743 /* [1] Defines the types of data in
744 * ValueRecord2--for the second glyph
745 * in the pair--may be zero (0) */
746 OffsetArrayOf<PairSet>
747 pairSet; /* Array of PairSet tables
748 * ordered by Coverage Index */
749 public:
750 DEFINE_SIZE_ARRAY (10, pairSet);
751 };
752
753 struct PairPosFormat2
754 {
755 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
756 {
757 TRACE_COLLECT_GLYPHS (this);
758 (this+coverage).add_coverage (c->input);
759
760 unsigned int count1 = class1Count;
761 const ClassDef &klass1 = this+classDef1;
762 for (unsigned int i = 0; i < count1; i++)
763 klass1.add_class (c->input, i);
764
765 unsigned int count2 = class2Count;
766 const ClassDef &klass2 = this+classDef2;
767 for (unsigned int i = 0; i < count2; i++)
768 klass2.add_class (c->input, i);
769 }
770
771 inline const Coverage &get_coverage (void) const
772 {
773 return this+coverage;
774 }
775
776 inline bool apply (hb_apply_context_t *c) const
777 {
778 TRACE_APPLY (this);
779 hb_buffer_t *buffer = c->buffer;
780 unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
781 if (likely (index == NOT_COVERED)) return_trace (false);
782
783 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
784 skippy_iter.reset (buffer->idx, 1);
785 if (!skippy_iter.next ()) return_trace (false);
786
787 unsigned int len1 = valueFormat1.get_len ();
788 unsigned int len2 = valueFormat2.get_len ();
789 unsigned int record_len = len1 + len2;
790
791 unsigned int klass1 = (this+classDef1).get_class (buffer->cur().codepoint);
792 unsigned int klass2 = (this+classDef2).get_class (buffer->info[skippy_iter.idx].codepoint);
793 if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return_trace (false);
794
795 buffer->unsafe_to_break (buffer->idx, skippy_iter.idx + 1);
796 const Value *v = &values[record_len * (klass1 * class2Count + klass2)];
797 valueFormat1.apply_value (c, this, v, buffer->cur_pos());
798 valueFormat2.apply_value (c, this, v + len1, buffer->pos[skippy_iter.idx]);
799
800 buffer->idx = skippy_iter.idx;
801 if (len2)
802 buffer->idx++;
803
804 return_trace (true);
805 }
806
807 inline bool sanitize (hb_sanitize_context_t *c) const
808 {
809 TRACE_SANITIZE (this);
810 if (!(c->check_struct (this)
811 && coverage.sanitize (c, this)
812 && classDef1.sanitize (c, this)
813 && classDef2.sanitize (c, this))) return_trace (false);
814
815 unsigned int len1 = valueFormat1.get_len ();
816 unsigned int len2 = valueFormat2.get_len ();
817 unsigned int stride = len1 + len2;
818 unsigned int record_size = valueFormat1.get_size () + valueFormat2.get_size ();
819 unsigned int count = (unsigned int) class1Count * (unsigned int) class2Count;
820 return_trace (c->check_array (values, record_size, count) &&
821 valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
822 valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
823 }
824
825 protected:
826 USHORT format; /* Format identifier--format = 2 */
827 OffsetTo<Coverage>
828 coverage; /* Offset to Coverage table--from
829 * beginning of subtable */
830 ValueFormat valueFormat1; /* ValueRecord definition--for the
831 * first glyph of the pair--may be zero
832 * (0) */
833 ValueFormat valueFormat2; /* ValueRecord definition--for the
834 * second glyph of the pair--may be
835 * zero (0) */
836 OffsetTo<ClassDef>
837 classDef1; /* Offset to ClassDef table--from
838 * beginning of PairPos subtable--for
839 * the first glyph of the pair */
840 OffsetTo<ClassDef>
841 classDef2; /* Offset to ClassDef table--from
842 * beginning of PairPos subtable--for
843 * the second glyph of the pair */
844 USHORT class1Count; /* Number of classes in ClassDef1
845 * table--includes Class0 */
846 USHORT class2Count; /* Number of classes in ClassDef2
847 * table--includes Class0 */
848 ValueRecord values; /* Matrix of value pairs:
849 * class1-major, class2-minor,
850 * Each entry has value1 and value2 */
851 public:
852 DEFINE_SIZE_ARRAY (16, values);
853 };
854
855 struct PairPos
856 {
857 template <typename context_t>
858 inline typename context_t::return_t dispatch (context_t *c) const
859 {
860 TRACE_DISPATCH (this, u.format);
861 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
862 switch (u.format) {
863 case 1: return_trace (c->dispatch (u.format1));
864 case 2: return_trace (c->dispatch (u.format2));
865 default:return_trace (c->default_return_value ());
866 }
867 }
868
869 protected:
870 union {
871 USHORT format; /* Format identifier */
872 PairPosFormat1 format1;
873 PairPosFormat2 format2;
874 } u;
875 };
876
877
878 struct EntryExitRecord
879 {
880 friend struct CursivePosFormat1;
881
882 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
883 {
884 TRACE_SANITIZE (this);
885 return_trace (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
886 }
887
888 protected:
889 OffsetTo<Anchor>
890 entryAnchor; /* Offset to EntryAnchor table--from
891 * beginning of CursivePos
892 * subtable--may be NULL */
893 OffsetTo<Anchor>
894 exitAnchor; /* Offset to ExitAnchor table--from
895 * beginning of CursivePos
896 * subtable--may be NULL */
897 public:
898 DEFINE_SIZE_STATIC (4);
899 };
900
901 static void
902 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent);
903
904 struct CursivePosFormat1
905 {
906 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
907 {
908 TRACE_COLLECT_GLYPHS (this);
909 (this+coverage).add_coverage (c->input);
910 }
911
912 inline const Coverage &get_coverage (void) const
913 {
914 return this+coverage;
915 }
916
917 inline bool apply (hb_apply_context_t *c) const
918 {
919 TRACE_APPLY (this);
920 hb_buffer_t *buffer = c->buffer;
921
922 const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage (buffer->cur().codepoint)];
923 if (!this_record.exitAnchor) return_trace (false);
924
925 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
926 skippy_iter.reset (buffer->idx, 1);
927 if (!skippy_iter.next ()) return_trace (false);
928
929 const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage (buffer->info[skippy_iter.idx].codepoint)];
930 if (!next_record.entryAnchor) return_trace (false);
931
932 unsigned int i = buffer->idx;
933 unsigned int j = skippy_iter.idx;
934
935 buffer->unsafe_to_break (i, j);
936 hb_position_t entry_x, entry_y, exit_x, exit_y;
937 (this+this_record.exitAnchor).get_anchor (c, buffer->info[i].codepoint, &exit_x, &exit_y);
938 (this+next_record.entryAnchor).get_anchor (c, buffer->info[j].codepoint, &entry_x, &entry_y);
939
940 hb_glyph_position_t *pos = buffer->pos;
941
942 hb_position_t d;
943 /* Main-direction adjustment */
944 switch (c->direction) {
945 case HB_DIRECTION_LTR:
946 pos[i].x_advance = exit_x + pos[i].x_offset;
947
948 d = entry_x + pos[j].x_offset;
949 pos[j].x_advance -= d;
950 pos[j].x_offset -= d;
951 break;
952 case HB_DIRECTION_RTL:
953 d = exit_x + pos[i].x_offset;
954 pos[i].x_advance -= d;
955 pos[i].x_offset -= d;
956
957 pos[j].x_advance = entry_x + pos[j].x_offset;
958 break;
959 case HB_DIRECTION_TTB:
960 pos[i].y_advance = exit_y + pos[i].y_offset;
961
962 d = entry_y + pos[j].y_offset;
963 pos[j].y_advance -= d;
964 pos[j].y_offset -= d;
965 break;
966 case HB_DIRECTION_BTT:
967 d = exit_y + pos[i].y_offset;
968 pos[i].y_advance -= d;
969 pos[i].y_offset -= d;
970
971 pos[j].y_advance = entry_y;
972 break;
973 case HB_DIRECTION_INVALID:
974 default:
975 break;
976 }
977
978 /* Cross-direction adjustment */
979
980 /* We attach child to parent (think graph theory and rooted trees whereas
981 * the root stays on baseline and each node aligns itself against its
982 * parent.
983 *
984 * Optimize things for the case of RightToLeft, as that's most common in
985 * Arabinc. */
986 unsigned int child = i;
987 unsigned int parent = j;
988 hb_position_t x_offset = entry_x - exit_x;
989 hb_position_t y_offset = entry_y - exit_y;
990 if (!(c->lookup_props & LookupFlag::RightToLeft))
991 {
992 unsigned int k = child;
993 child = parent;
994 parent = k;
995 x_offset = -x_offset;
996 y_offset = -y_offset;
997 }
998
999 /* If child was already connected to someone else, walk through its old
1000 * chain and reverse the link direction, such that the whole tree of its
1001 * previous connection now attaches to new parent. Watch out for case
1002 * where new parent is on the path from old chain...
1003 */
1004 reverse_cursive_minor_offset (pos, child, c->direction, parent);
1005
1006 pos[child].attach_type() = ATTACH_TYPE_CURSIVE;
1007 pos[child].attach_chain() = (int) parent - (int) child;
1008 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
1009 if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
1010 pos[child].y_offset = y_offset;
1011 else
1012 pos[child].x_offset = x_offset;
1013
1014 buffer->idx = j;
1015 return_trace (true);
1016 }
1017
1018 inline bool sanitize (hb_sanitize_context_t *c) const
1019 {
1020 TRACE_SANITIZE (this);
1021 return_trace (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
1022 }
1023
1024 protected:
1025 USHORT format; /* Format identifier--format = 1 */
1026 OffsetTo<Coverage>
1027 coverage; /* Offset to Coverage table--from
1028 * beginning of subtable */
1029 ArrayOf<EntryExitRecord>
1030 entryExitRecord; /* Array of EntryExit records--in
1031 * Coverage Index order */
1032 public:
1033 DEFINE_SIZE_ARRAY (6, entryExitRecord);
1034 };
1035
1036 struct CursivePos
1037 {
1038 template <typename context_t>
1039 inline typename context_t::return_t dispatch (context_t *c) const
1040 {
1041 TRACE_DISPATCH (this, u.format);
1042 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1043 switch (u.format) {
1044 case 1: return_trace (c->dispatch (u.format1));
1045 default:return_trace (c->default_return_value ());
1046 }
1047 }
1048
1049 protected:
1050 union {
1051 USHORT format; /* Format identifier */
1052 CursivePosFormat1 format1;
1053 } u;
1054 };
1055
1056
1057 typedef AnchorMatrix BaseArray; /* base-major--
1058 * in order of BaseCoverage Index--,
1059 * mark-minor--
1060 * ordered by class--zero-based. */
1061
1062 struct MarkBasePosFormat1
1063 {
1064 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1065 {
1066 TRACE_COLLECT_GLYPHS (this);
1067 (this+markCoverage).add_coverage (c->input);
1068 (this+baseCoverage).add_coverage (c->input);
1069 }
1070
1071 inline const Coverage &get_coverage (void) const
1072 {
1073 return this+markCoverage;
1074 }
1075
1076 inline bool apply (hb_apply_context_t *c) const
1077 {
1078 TRACE_APPLY (this);
1079 hb_buffer_t *buffer = c->buffer;
1080 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1081 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1082
1083 /* Now we search backwards for a non-mark glyph */
1084 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1085 skippy_iter.reset (buffer->idx, 1);
1086 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1087 do {
1088 if (!skippy_iter.prev ()) return_trace (false);
1089 /* We only want to attach to the first of a MultipleSubst sequence. Reject others. */
1090 if (!_hb_glyph_info_multiplied (&buffer->info[skippy_iter.idx]) ||
1091 0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]))
1092 break;
1093 skippy_iter.reject ();
1094 } while (1);
1095
1096 /* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */
1097 //if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1098
1099 unsigned int base_index = (this+baseCoverage).get_coverage (buffer->info[skippy_iter.idx].codepoint);
1100 if (base_index == NOT_COVERED) return_trace (false);
1101
1102 return_trace ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
1103 }
1104
1105 inline bool sanitize (hb_sanitize_context_t *c) const
1106 {
1107 TRACE_SANITIZE (this);
1108 return_trace (c->check_struct (this) &&
1109 markCoverage.sanitize (c, this) &&
1110 baseCoverage.sanitize (c, this) &&
1111 markArray.sanitize (c, this) &&
1112 baseArray.sanitize (c, this, (unsigned int) classCount));
1113 }
1114
1115 protected:
1116 USHORT format; /* Format identifier--format = 1 */
1117 OffsetTo<Coverage>
1118 markCoverage; /* Offset to MarkCoverage table--from
1119 * beginning of MarkBasePos subtable */
1120 OffsetTo<Coverage>
1121 baseCoverage; /* Offset to BaseCoverage table--from
1122 * beginning of MarkBasePos subtable */
1123 USHORT classCount; /* Number of classes defined for marks */
1124 OffsetTo<MarkArray>
1125 markArray; /* Offset to MarkArray table--from
1126 * beginning of MarkBasePos subtable */
1127 OffsetTo<BaseArray>
1128 baseArray; /* Offset to BaseArray table--from
1129 * beginning of MarkBasePos subtable */
1130 public:
1131 DEFINE_SIZE_STATIC (12);
1132 };
1133
1134 struct MarkBasePos
1135 {
1136 template <typename context_t>
1137 inline typename context_t::return_t dispatch (context_t *c) const
1138 {
1139 TRACE_DISPATCH (this, u.format);
1140 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1141 switch (u.format) {
1142 case 1: return_trace (c->dispatch (u.format1));
1143 default:return_trace (c->default_return_value ());
1144 }
1145 }
1146
1147 protected:
1148 union {
1149 USHORT format; /* Format identifier */
1150 MarkBasePosFormat1 format1;
1151 } u;
1152 };
1153
1154
1155 typedef AnchorMatrix LigatureAttach; /* component-major--
1156 * in order of writing direction--,
1157 * mark-minor--
1158 * ordered by class--zero-based. */
1159
1160 typedef OffsetListOf<LigatureAttach> LigatureArray;
1161 /* Array of LigatureAttach
1162 * tables ordered by
1163 * LigatureCoverage Index */
1164
1165 struct MarkLigPosFormat1
1166 {
1167 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1168 {
1169 TRACE_COLLECT_GLYPHS (this);
1170 (this+markCoverage).add_coverage (c->input);
1171 (this+ligatureCoverage).add_coverage (c->input);
1172 }
1173
1174 inline const Coverage &get_coverage (void) const
1175 {
1176 return this+markCoverage;
1177 }
1178
1179 inline bool apply (hb_apply_context_t *c) const
1180 {
1181 TRACE_APPLY (this);
1182 hb_buffer_t *buffer = c->buffer;
1183 unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
1184 if (likely (mark_index == NOT_COVERED)) return_trace (false);
1185
1186 /* Now we search backwards for a non-mark glyph */
1187 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1188 skippy_iter.reset (buffer->idx, 1);
1189 skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
1190 if (!skippy_iter.prev ()) return_trace (false);
1191
1192 /* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
1193 //if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1194
1195 unsigned int j = skippy_iter.idx;
1196 unsigned int lig_index = (this+ligatureCoverage).get_coverage (buffer->info[j].codepoint);
1197 if (lig_index == NOT_COVERED) return_trace (false);
1198
1199 const LigatureArray& lig_array = this+ligatureArray;
1200 const LigatureAttach& lig_attach = lig_array[lig_index];
1201
1202 /* Find component to attach to */
1203 unsigned int comp_count = lig_attach.rows;
1204 if (unlikely (!comp_count)) return_trace (false);
1205
1206 /* We must now check whether the ligature ID of the current mark glyph
1207 * is identical to the ligature ID of the found ligature. If yes, we
1208 * can directly use the component index. If not, we attach the mark
1209 * glyph to the last component of the ligature. */
1210 unsigned int comp_index;
1211 unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1212 unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
1213 unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
1214 if (lig_id && lig_id == mark_id && mark_comp > 0)
1215 comp_index = MIN (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
1216 else
1217 comp_index = comp_count - 1;
1218
1219 return_trace ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
1220 }
1221
1222 inline bool sanitize (hb_sanitize_context_t *c) const
1223 {
1224 TRACE_SANITIZE (this);
1225 return_trace (c->check_struct (this) &&
1226 markCoverage.sanitize (c, this) &&
1227 ligatureCoverage.sanitize (c, this) &&
1228 markArray.sanitize (c, this) &&
1229 ligatureArray.sanitize (c, this, (unsigned int) classCount));
1230 }
1231
1232 protected:
1233 USHORT format; /* Format identifier--format = 1 */
1234 OffsetTo<Coverage>
1235 markCoverage; /* Offset to Mark Coverage table--from
1236 * beginning of MarkLigPos subtable */
1237 OffsetTo<Coverage>
1238 ligatureCoverage; /* Offset to Ligature Coverage
1239 * table--from beginning of MarkLigPos
1240 * subtable */
1241 USHORT classCount; /* Number of defined mark classes */
1242 OffsetTo<MarkArray>
1243 markArray; /* Offset to MarkArray table--from
1244 * beginning of MarkLigPos subtable */
1245 OffsetTo<LigatureArray>
1246 ligatureArray; /* Offset to LigatureArray table--from
1247 * beginning of MarkLigPos subtable */
1248 public:
1249 DEFINE_SIZE_STATIC (12);
1250 };
1251
1252 struct MarkLigPos
1253 {
1254 template <typename context_t>
1255 inline typename context_t::return_t dispatch (context_t *c) const
1256 {
1257 TRACE_DISPATCH (this, u.format);
1258 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1259 switch (u.format) {
1260 case 1: return_trace (c->dispatch (u.format1));
1261 default:return_trace (c->default_return_value ());
1262 }
1263 }
1264
1265 protected:
1266 union {
1267 USHORT format; /* Format identifier */
1268 MarkLigPosFormat1 format1;
1269 } u;
1270 };
1271
1272
1273 typedef AnchorMatrix Mark2Array; /* mark2-major--
1274 * in order of Mark2Coverage Index--,
1275 * mark1-minor--
1276 * ordered by class--zero-based. */
1277
1278 struct MarkMarkPosFormat1
1279 {
1280 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1281 {
1282 TRACE_COLLECT_GLYPHS (this);
1283 (this+mark1Coverage).add_coverage (c->input);
1284 (this+mark2Coverage).add_coverage (c->input);
1285 }
1286
1287 inline const Coverage &get_coverage (void) const
1288 {
1289 return this+mark1Coverage;
1290 }
1291
1292 inline bool apply (hb_apply_context_t *c) const
1293 {
1294 TRACE_APPLY (this);
1295 hb_buffer_t *buffer = c->buffer;
1296 unsigned int mark1_index = (this+mark1Coverage).get_coverage (buffer->cur().codepoint);
1297 if (likely (mark1_index == NOT_COVERED)) return_trace (false);
1298
1299 /* now we search backwards for a suitable mark glyph until a non-mark glyph */
1300 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
1301 skippy_iter.reset (buffer->idx, 1);
1302 skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
1303 if (!skippy_iter.prev ()) return_trace (false);
1304
1305 if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return_trace (false); }
1306
1307 unsigned int j = skippy_iter.idx;
1308
1309 unsigned int id1 = _hb_glyph_info_get_lig_id (&buffer->cur());
1310 unsigned int id2 = _hb_glyph_info_get_lig_id (&buffer->info[j]);
1311 unsigned int comp1 = _hb_glyph_info_get_lig_comp (&buffer->cur());
1312 unsigned int comp2 = _hb_glyph_info_get_lig_comp (&buffer->info[j]);
1313
1314 if (likely (id1 == id2)) {
1315 if (id1 == 0) /* Marks belonging to the same base. */
1316 goto good;
1317 else if (comp1 == comp2) /* Marks belonging to the same ligature component. */
1318 goto good;
1319 } else {
1320 /* If ligature ids don't match, it may be the case that one of the marks
1321 * itself is a ligature. In which case match. */
1322 if ((id1 > 0 && !comp1) || (id2 > 0 && !comp2))
1323 goto good;
1324 }
1325
1326 /* Didn't match. */
1327 return_trace (false);
1328
1329 good:
1330 unsigned int mark2_index = (this+mark2Coverage).get_coverage (buffer->info[j].codepoint);
1331 if (mark2_index == NOT_COVERED) return_trace (false);
1332
1333 return_trace ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
1334 }
1335
1336 inline bool sanitize (hb_sanitize_context_t *c) const
1337 {
1338 TRACE_SANITIZE (this);
1339 return_trace (c->check_struct (this) &&
1340 mark1Coverage.sanitize (c, this) &&
1341 mark2Coverage.sanitize (c, this) &&
1342 mark1Array.sanitize (c, this) &&
1343 mark2Array.sanitize (c, this, (unsigned int) classCount));
1344 }
1345
1346 protected:
1347 USHORT format; /* Format identifier--format = 1 */
1348 OffsetTo<Coverage>
1349 mark1Coverage; /* Offset to Combining Mark1 Coverage
1350 * table--from beginning of MarkMarkPos
1351 * subtable */
1352 OffsetTo<Coverage>
1353 mark2Coverage; /* Offset to Combining Mark2 Coverage
1354 * table--from beginning of MarkMarkPos
1355 * subtable */
1356 USHORT classCount; /* Number of defined mark classes */
1357 OffsetTo<MarkArray>
1358 mark1Array; /* Offset to Mark1Array table--from
1359 * beginning of MarkMarkPos subtable */
1360 OffsetTo<Mark2Array>
1361 mark2Array; /* Offset to Mark2Array table--from
1362 * beginning of MarkMarkPos subtable */
1363 public:
1364 DEFINE_SIZE_STATIC (12);
1365 };
1366
1367 struct MarkMarkPos
1368 {
1369 template <typename context_t>
1370 inline typename context_t::return_t dispatch (context_t *c) const
1371 {
1372 TRACE_DISPATCH (this, u.format);
1373 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1374 switch (u.format) {
1375 case 1: return_trace (c->dispatch (u.format1));
1376 default:return_trace (c->default_return_value ());
1377 }
1378 }
1379
1380 protected:
1381 union {
1382 USHORT format; /* Format identifier */
1383 MarkMarkPosFormat1 format1;
1384 } u;
1385 };
1386
1387
1388 struct ContextPos : Context {};
1389
1390 struct ChainContextPos : ChainContext {};
1391
1392 struct ExtensionPos : Extension<ExtensionPos>
1393 {
1394 typedef struct PosLookupSubTable LookupSubTable;
1395 };
1396
1397
1398
1399 /*
1400 * PosLookup
1401 */
1402
1403
1404 struct PosLookupSubTable
1405 {
1406 friend struct PosLookup;
1407
1408 enum Type {
1409 Single = 1,
1410 Pair = 2,
1411 Cursive = 3,
1412 MarkBase = 4,
1413 MarkLig = 5,
1414 MarkMark = 6,
1415 Context = 7,
1416 ChainContext = 8,
1417 Extension = 9
1418 };
1419
1420 template <typename context_t>
1421 inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1422 {
1423 TRACE_DISPATCH (this, lookup_type);
1424 if (unlikely (!c->may_dispatch (this, &u.sub_format))) return_trace (c->no_dispatch_return_value ());
1425 switch (lookup_type) {
1426 case Single: return_trace (u.single.dispatch (c));
1427 case Pair: return_trace (u.pair.dispatch (c));
1428 case Cursive: return_trace (u.cursive.dispatch (c));
1429 case MarkBase: return_trace (u.markBase.dispatch (c));
1430 case MarkLig: return_trace (u.markLig.dispatch (c));
1431 case MarkMark: return_trace (u.markMark.dispatch (c));
1432 case Context: return_trace (u.context.dispatch (c));
1433 case ChainContext: return_trace (u.chainContext.dispatch (c));
1434 case Extension: return_trace (u.extension.dispatch (c));
1435 default: return_trace (c->default_return_value ());
1436 }
1437 }
1438
1439 protected:
1440 union {
1441 USHORT sub_format;
1442 SinglePos single;
1443 PairPos pair;
1444 CursivePos cursive;
1445 MarkBasePos markBase;
1446 MarkLigPos markLig;
1447 MarkMarkPos markMark;
1448 ContextPos context;
1449 ChainContextPos chainContext;
1450 ExtensionPos extension;
1451 } u;
1452 public:
1453 DEFINE_SIZE_UNION (2, sub_format);
1454 };
1455
1456
1457 struct PosLookup : Lookup
1458 {
1459 inline const PosLookupSubTable& get_subtable (unsigned int i) const
1460 { return Lookup::get_subtable<PosLookupSubTable> (i); }
1461
1462 inline bool is_reverse (void) const
1463 {
1464 return false;
1465 }
1466
1467 inline bool apply (hb_apply_context_t *c) const
1468 {
1469 TRACE_APPLY (this);
1470 return_trace (dispatch (c));
1471 }
1472
1473 inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
1474 {
1475 TRACE_COLLECT_GLYPHS (this);
1476 return_trace (dispatch (c));
1477 }
1478
1479 template <typename set_t>
1480 inline void add_coverage (set_t *glyphs) const
1481 {
1482 hb_add_coverage_context_t<set_t> c (glyphs);
1483 dispatch (&c);
1484 }
1485
1486 static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
1487
1488 template <typename context_t>
1489 static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
1490
1491 template <typename context_t>
1492 inline typename context_t::return_t dispatch (context_t *c) const
1493 { return Lookup::dispatch<PosLookupSubTable> (c); }
1494
1495 inline bool sanitize (hb_sanitize_context_t *c) const
1496 {
1497 TRACE_SANITIZE (this);
1498 if (unlikely (!Lookup::sanitize (c))) return_trace (false);
1499 return_trace (dispatch (c));
1500 }
1501 };
1502
1503 typedef OffsetListOf<PosLookup> PosLookupList;
1504
1505 /*
1506 * GPOS -- The Glyph Positioning Table
1507 */
1508
1509 struct GPOS : GSUBGPOS
1510 {
1511 static const hb_tag_t tableTag = HB_OT_TAG_GPOS;
1512
1513 inline const PosLookup& get_lookup (unsigned int i) const
1514 { return CastR<PosLookup> (GSUBGPOS::get_lookup (i)); }
1515
1516 static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
1517 static inline void position_finish_advances (hb_font_t *font, hb_buffer_t *buffer);
1518 static inline void position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer);
1519
1520 inline bool sanitize (hb_sanitize_context_t *c) const
1521 {
1522 TRACE_SANITIZE (this);
1523 if (unlikely (!GSUBGPOS::sanitize (c))) return_trace (false);
1524 const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
1525 return_trace (list.sanitize (c, this));
1526 }
1527 };
1528
1529
1530 static void
1531 reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent)
1532 {
1533 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1534 if (likely (!chain || 0 == (type & ATTACH_TYPE_CURSIVE)))
1535 return;
1536
1537 pos[i].attach_chain() = 0;
1538
1539 unsigned int j = (int) i + chain;
1540
1541 /* Stop if we see new parent in the chain. */
1542 if (j == new_parent)
1543 return;
1544
1545 reverse_cursive_minor_offset (pos, j, direction, new_parent);
1546
1547 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1548 pos[j].y_offset = -pos[i].y_offset;
1549 else
1550 pos[j].x_offset = -pos[i].x_offset;
1551
1552 pos[j].attach_chain() = -chain;
1553 pos[j].attach_type() = type;
1554 }
1555 static void
1556 propagate_attachment_offsets (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
1557 {
1558 /* Adjusts offsets of attached glyphs (both cursive and mark) to accumulate
1559 * offset of glyph they are attached to. */
1560 int chain = pos[i].attach_chain(), type = pos[i].attach_type();
1561 if (likely (!chain))
1562 return;
1563
1564 unsigned int j = (int) i + chain;
1565
1566 pos[i].attach_chain() = 0;
1567
1568 propagate_attachment_offsets (pos, j, direction);
1569
1570 assert (!!(type & ATTACH_TYPE_MARK) ^ !!(type & ATTACH_TYPE_CURSIVE));
1571
1572 if (type & ATTACH_TYPE_CURSIVE)
1573 {
1574 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1575 pos[i].y_offset += pos[j].y_offset;
1576 else
1577 pos[i].x_offset += pos[j].x_offset;
1578 }
1579 else /*if (type & ATTACH_TYPE_MARK)*/
1580 {
1581 pos[i].x_offset += pos[j].x_offset;
1582 pos[i].y_offset += pos[j].y_offset;
1583
1584 assert (j < i);
1585 if (HB_DIRECTION_IS_FORWARD (direction))
1586 for (unsigned int k = j; k < i; k++) {
1587 pos[i].x_offset -= pos[k].x_advance;
1588 pos[i].y_offset -= pos[k].y_advance;
1589 }
1590 else
1591 for (unsigned int k = j + 1; k < i + 1; k++) {
1592 pos[i].x_offset += pos[k].x_advance;
1593 pos[i].y_offset += pos[k].y_advance;
1594 }
1595 }
1596 }
1597
1598 void
1599 GPOS::position_start (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1600 {
1601 unsigned int count = buffer->len;
1602 for (unsigned int i = 0; i < count; i++)
1603 buffer->pos[i].attach_chain() = buffer->pos[i].attach_type() = 0;
1604 }
1605
1606 void
1607 GPOS::position_finish_advances (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1608 {
1609 //_hb_buffer_assert_gsubgpos_vars (buffer);
1610 }
1611
1612 void
1613 GPOS::position_finish_offsets (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
1614 {
1615 _hb_buffer_assert_gsubgpos_vars (buffer);
1616
1617 unsigned int len;
1618 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
1619 hb_direction_t direction = buffer->props.direction;
1620
1621 /* Handle attachments */
1622 if (buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT)
1623 for (unsigned int i = 0; i < len; i++)
1624 propagate_attachment_offsets (pos, i, direction);
1625 }
1626
1627
1628 /* Out-of-class implementation for methods recursing */
1629
1630 template <typename context_t>
1631 /*static*/ inline typename context_t::return_t PosLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
1632 {
1633 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1634 const PosLookup &l = gpos.get_lookup (lookup_index);
1635 return l.dispatch (c);
1636 }
1637
1638 /*static*/ inline bool PosLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
1639 {
1640 const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
1641 const PosLookup &l = gpos.get_lookup (lookup_index);
1642 unsigned int saved_lookup_props = c->lookup_props;
1643 unsigned int saved_lookup_index = c->lookup_index;
1644 c->set_lookup_index (lookup_index);
1645 c->set_lookup_props (l.get_props ());
1646 bool ret = l.dispatch (c);
1647 c->set_lookup_index (saved_lookup_index);
1648 c->set_lookup_props (saved_lookup_props);
1649 return ret;
1650 }
1651
1652
1653 #undef attach_chain
1654 #undef attach_type
1655
1656
1657 } /* namespace OT */
1658
1659
1660 #endif /* HB_OT_LAYOUT_GPOS_TABLE_HH */