7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27 #include "hb-ot-shape-fallback-private.hh"
28 #include "hb-ot-layout-gsubgpos-private.hh"
29
30 static unsigned int
31 recategorize_combining_class (hb_codepoint_t u,
32 unsigned int klass)
33 {
34 if (klass >= 200)
35 return klass;
36
37 /* Thai / Lao need some per-character work. */
38 if ((u & ~0xFF) == 0x0E00u)
39 {
40 if (unlikely (klass == 0))
41 {
42 switch (u)
43 {
44 case 0x0E31u:
45 case 0x0E34u:
46 case 0x0E35u:
47 case 0x0E36u:
48 case 0x0E37u:
145 return HB_UNICODE_COMBINING_CLASS_ABOVE;
146
147
148 /* Tibetan */
149
150 case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
151 return HB_UNICODE_COMBINING_CLASS_BELOW;
152
153 case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
154 return HB_UNICODE_COMBINING_CLASS_ABOVE;
155
156 case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
157 return HB_UNICODE_COMBINING_CLASS_BELOW;
158
159 }
160
161 return klass;
162 }
163
164 void
165 _hb_ot_shape_fallback_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
166 hb_font_t *font HB_UNUSED,
167 hb_buffer_t *buffer)
168 {
169 unsigned int count = buffer->len;
170 hb_glyph_info_t *info = buffer->info;
171 for (unsigned int i = 0; i < count; i++)
172 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
173 unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]);
174 combining_class = recategorize_combining_class (info[i].codepoint, combining_class);
175 _hb_glyph_info_set_modified_combining_class (&info[i], combining_class);
176 }
177 }
178
179
180 static void
181 zero_mark_advances (hb_buffer_t *buffer,
182 unsigned int start,
183 unsigned int end)
184 {
185 hb_glyph_info_t *info = buffer->info;
186 for (unsigned int i = start; i < end; i++)
187 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
188 {
189 buffer->pos[i].x_advance = 0;
190 buffer->pos[i].y_advance = 0;
191 }
192 }
193
194 static inline void
195 position_mark (const hb_ot_shape_plan_t *plan,
196 hb_font_t *font,
197 hb_buffer_t *buffer,
198 hb_glyph_extents_t &base_extents,
199 unsigned int i,
200 unsigned int combining_class)
201 {
202 hb_glyph_extents_t mark_extents;
203 if (!font->get_glyph_extents (buffer->info[i].codepoint, &mark_extents))
204 return;
205
206 hb_position_t y_gap = font->y_scale / 16;
207
208 hb_glyph_position_t &pos = buffer->pos[i];
209 pos.x_offset = pos.y_offset = 0;
210
211
212 /* We don't position LEFT and RIGHT marks. */
213
214 /* X positioning */
215 switch (combining_class)
286 pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
287 /* Don't shift down "above" marks too much. */
288 if ((y_gap > 0) != (pos.y_offset > 0))
289 {
290 unsigned int correction = -pos.y_offset / 2;
291 base_extents.y_bearing += correction;
292 base_extents.height -= correction;
293 pos.y_offset += correction;
294 }
295 base_extents.y_bearing -= mark_extents.height;
296 base_extents.height += mark_extents.height;
297 break;
298 }
299 }
300
301 static inline void
302 position_around_base (const hb_ot_shape_plan_t *plan,
303 hb_font_t *font,
304 hb_buffer_t *buffer,
305 unsigned int base,
306 unsigned int end)
307 {
308 hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
309
310 buffer->unsafe_to_break (base, end);
311
312 hb_glyph_extents_t base_extents;
313 if (!font->get_glyph_extents (buffer->info[base].codepoint,
314 &base_extents))
315 {
316 /* If extents don't work, zero marks and go home. */
317 zero_mark_advances (buffer, base + 1, end);
318 return;
319 }
320 base_extents.x_bearing += buffer->pos[base].x_offset;
321 base_extents.y_bearing += buffer->pos[base].y_offset;
322
323 unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]);
324 /* Use integer for num_lig_components such that it doesn't convert to unsigned
325 * when we divide or multiply by it. */
326 int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]);
327
328 hb_position_t x_offset = 0, y_offset = 0;
329 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
330 x_offset -= buffer->pos[base].x_advance;
331 y_offset -= buffer->pos[base].y_advance;
332 }
333
334 hb_glyph_extents_t component_extents = base_extents;
335 int last_lig_component = -1;
336 unsigned int last_combining_class = 255;
337 hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
338 hb_glyph_info_t *info = buffer->info;
339 for (unsigned int i = base + 1; i < end; i++)
340 if (_hb_glyph_info_get_modified_combining_class (&info[i]))
341 {
377 buffer->pos[i].y_advance = 0;
378 buffer->pos[i].x_offset += x_offset;
379 buffer->pos[i].y_offset += y_offset;
380
381 } else {
382 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
383 x_offset -= buffer->pos[i].x_advance;
384 y_offset -= buffer->pos[i].y_advance;
385 } else {
386 x_offset += buffer->pos[i].x_advance;
387 y_offset += buffer->pos[i].y_advance;
388 }
389 }
390 }
391
392 static inline void
393 position_cluster (const hb_ot_shape_plan_t *plan,
394 hb_font_t *font,
395 hb_buffer_t *buffer,
396 unsigned int start,
397 unsigned int end)
398 {
399 if (end - start < 2)
400 return;
401
402 /* Find the base glyph */
403 hb_glyph_info_t *info = buffer->info;
404 for (unsigned int i = start; i < end; i++)
405 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])))
406 {
407 /* Find mark glyphs */
408 unsigned int j;
409 for (j = i + 1; j < end; j++)
410 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[j])))
411 break;
412
413 position_around_base (plan, font, buffer, i, j);
414
415 i = j - 1;
416 }
417 }
418
419 void
420 _hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan,
421 hb_font_t *font,
422 hb_buffer_t *buffer)
423 {
424 _hb_buffer_assert_gsubgpos_vars (buffer);
425
426 unsigned int start = 0;
427 unsigned int count = buffer->len;
428 hb_glyph_info_t *info = buffer->info;
429 for (unsigned int i = 1; i < count; i++)
430 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])))) {
431 position_cluster (plan, font, buffer, start, i);
432 start = i;
433 }
434 position_cluster (plan, font, buffer, start, count);
435 }
436
437
438 /* Performs old-style TrueType kerning. */
439 void
440 _hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
441 hb_font_t *font,
442 hb_buffer_t *buffer)
443 {
444 if (!plan->has_kern) return;
445
446 OT::hb_ot_apply_context_t c (1, font, buffer);
447 c.set_lookup_mask (plan->kern_mask);
448 c.set_lookup_props (OT::LookupFlag::IgnoreMarks);
449 OT::hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c.iter_input;
450 skippy_iter.init (&c);
451
452 unsigned int count = buffer->len;
453 hb_glyph_info_t *info = buffer->info;
454 hb_glyph_position_t *pos = buffer->pos;
455 for (unsigned int idx = 0; idx < count;)
456 {
457 skippy_iter.reset (idx, 1);
458 if (!skippy_iter.next ())
459 {
460 idx++;
461 continue;
462 }
463
464 hb_position_t x_kern, y_kern;
465 font->get_glyph_kerning_for_direction (info[idx].codepoint,
466 info[skippy_iter.idx].codepoint,
467 buffer->props.direction,
468 &x_kern, &y_kern);
469
470 if (x_kern)
471 {
472 hb_position_t kern1 = x_kern >> 1;
473 hb_position_t kern2 = x_kern - kern1;
474 pos[idx].x_advance += kern1;
475 pos[skippy_iter.idx].x_advance += kern2;
476 pos[skippy_iter.idx].x_offset += kern2;
477 buffer->unsafe_to_break (idx, skippy_iter.idx + 1);
478 }
479
480 if (y_kern)
481 {
482 hb_position_t kern1 = y_kern >> 1;
483 hb_position_t kern2 = y_kern - kern1;
484 pos[idx].y_advance += kern1;
485 pos[skippy_iter.idx].y_advance += kern2;
486 pos[skippy_iter.idx].y_offset += kern2;
487 buffer->unsafe_to_break (idx, skippy_iter.idx + 1);
488 }
489
490 idx = skippy_iter.idx;
491 }
492 }
493
494
495 /* Adjusts width of various spaces. */
496 void
497 _hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan,
498 hb_font_t *font,
499 hb_buffer_t *buffer)
500 {
501 if (!HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
502 return;
503
504 hb_glyph_info_t *info = buffer->info;
505 hb_glyph_position_t *pos = buffer->pos;
506 unsigned int count = buffer->len;
507 for (unsigned int i = 0; i < count; i++)
508 if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i]))
509 {
510 hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]);
511 hb_codepoint_t glyph;
512 typedef hb_unicode_funcs_t t;
513 switch (space_type)
514 {
515 case t::NOT_SPACE: /* Shouldn't happen. */
516 case t::SPACE:
517 break;
518
519 case t::SPACE_EM:
520 case t::SPACE_EM_2:
521 case t::SPACE_EM_3:
522 case t::SPACE_EM_4:
523 case t::SPACE_EM_5:
524 case t::SPACE_EM_6:
525 case t::SPACE_EM_16:
526 pos[i].x_advance = (font->x_scale + ((int) space_type)/2) / (int) space_type;
527 break;
528
529 case t::SPACE_4_EM_18:
530 pos[i].x_advance = (int64_t) font->x_scale * 4 / 18;
531 break;
532
533 case t::SPACE_FIGURE:
534 for (char u = '0'; u <= '9'; u++)
535 if (font->get_nominal_glyph (u, &glyph))
536 {
537 pos[i].x_advance = font->get_glyph_h_advance (glyph);
538 break;
539 }
540 break;
541
542 case t::SPACE_PUNCTUATION:
543 if (font->get_nominal_glyph ('.', &glyph))
544 pos[i].x_advance = font->get_glyph_h_advance (glyph);
545 else if (font->get_nominal_glyph (',', &glyph))
546 pos[i].x_advance = font->get_glyph_h_advance (glyph);
547 break;
548
549 case t::SPACE_NARROW:
550 /* Half-space?
551 * Unicode doc https://unicode.org/charts/PDF/U2000.pdf says ~1/4 or 1/5 of EM.
552 * However, in my testing, many fonts have their regular space being about that
553 * size. To me, a percentage of the space width makes more sense. Half is as
554 * good as any. */
555 pos[i].x_advance /= 2;
556 break;
557 }
558 }
559 }
|
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27 #include "hb-ot-shape-fallback.hh"
28 #include "hb-kern.hh"
29
30 static unsigned int
31 recategorize_combining_class (hb_codepoint_t u,
32 unsigned int klass)
33 {
34 if (klass >= 200)
35 return klass;
36
37 /* Thai / Lao need some per-character work. */
38 if ((u & ~0xFF) == 0x0E00u)
39 {
40 if (unlikely (klass == 0))
41 {
42 switch (u)
43 {
44 case 0x0E31u:
45 case 0x0E34u:
46 case 0x0E35u:
47 case 0x0E36u:
48 case 0x0E37u:
145 return HB_UNICODE_COMBINING_CLASS_ABOVE;
146
147
148 /* Tibetan */
149
150 case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
151 return HB_UNICODE_COMBINING_CLASS_BELOW;
152
153 case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
154 return HB_UNICODE_COMBINING_CLASS_ABOVE;
155
156 case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
157 return HB_UNICODE_COMBINING_CLASS_BELOW;
158
159 }
160
161 return klass;
162 }
163
164 void
165 _hb_ot_shape_fallback_mark_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
166 hb_font_t *font HB_UNUSED,
167 hb_buffer_t *buffer)
168 {
169 unsigned int count = buffer->len;
170 hb_glyph_info_t *info = buffer->info;
171 for (unsigned int i = 0; i < count; i++)
172 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
173 unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]);
174 combining_class = recategorize_combining_class (info[i].codepoint, combining_class);
175 _hb_glyph_info_set_modified_combining_class (&info[i], combining_class);
176 }
177 }
178
179
180 static void
181 zero_mark_advances (hb_buffer_t *buffer,
182 unsigned int start,
183 unsigned int end,
184 bool adjust_offsets_when_zeroing)
185 {
186 hb_glyph_info_t *info = buffer->info;
187 for (unsigned int i = start; i < end; i++)
188 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
189 {
190 if (adjust_offsets_when_zeroing)
191 {
192 buffer->pos[i].x_offset -= buffer->pos[i].x_advance;
193 buffer->pos[i].y_offset -= buffer->pos[i].y_advance;
194 }
195 buffer->pos[i].x_advance = 0;
196 buffer->pos[i].y_advance = 0;
197 }
198 }
199
200 static inline void
201 position_mark (const hb_ot_shape_plan_t *plan HB_UNUSED,
202 hb_font_t *font,
203 hb_buffer_t *buffer,
204 hb_glyph_extents_t &base_extents,
205 unsigned int i,
206 unsigned int combining_class)
207 {
208 hb_glyph_extents_t mark_extents;
209 if (!font->get_glyph_extents (buffer->info[i].codepoint, &mark_extents))
210 return;
211
212 hb_position_t y_gap = font->y_scale / 16;
213
214 hb_glyph_position_t &pos = buffer->pos[i];
215 pos.x_offset = pos.y_offset = 0;
216
217
218 /* We don't position LEFT and RIGHT marks. */
219
220 /* X positioning */
221 switch (combining_class)
292 pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
293 /* Don't shift down "above" marks too much. */
294 if ((y_gap > 0) != (pos.y_offset > 0))
295 {
296 unsigned int correction = -pos.y_offset / 2;
297 base_extents.y_bearing += correction;
298 base_extents.height -= correction;
299 pos.y_offset += correction;
300 }
301 base_extents.y_bearing -= mark_extents.height;
302 base_extents.height += mark_extents.height;
303 break;
304 }
305 }
306
307 static inline void
308 position_around_base (const hb_ot_shape_plan_t *plan,
309 hb_font_t *font,
310 hb_buffer_t *buffer,
311 unsigned int base,
312 unsigned int end,
313 bool adjust_offsets_when_zeroing)
314 {
315 hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
316
317 buffer->unsafe_to_break (base, end);
318
319 hb_glyph_extents_t base_extents;
320 if (!font->get_glyph_extents (buffer->info[base].codepoint,
321 &base_extents))
322 {
323 /* If extents don't work, zero marks and go home. */
324 zero_mark_advances (buffer, base + 1, end, adjust_offsets_when_zeroing);
325 return;
326 }
327 base_extents.y_bearing += buffer->pos[base].y_offset;
328 /* Use horizontal advance for horizontal positioning.
329 * Generally a better idea. Also works for zero-ink glyphs. See:
330 * https://github.com/harfbuzz/harfbuzz/issues/1532 */
331 base_extents.x_bearing = 0;
332 base_extents.width = font->get_glyph_h_advance (buffer->info[base].codepoint);
333
334 unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]);
335 /* Use integer for num_lig_components such that it doesn't convert to unsigned
336 * when we divide or multiply by it. */
337 int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]);
338
339 hb_position_t x_offset = 0, y_offset = 0;
340 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
341 x_offset -= buffer->pos[base].x_advance;
342 y_offset -= buffer->pos[base].y_advance;
343 }
344
345 hb_glyph_extents_t component_extents = base_extents;
346 int last_lig_component = -1;
347 unsigned int last_combining_class = 255;
348 hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
349 hb_glyph_info_t *info = buffer->info;
350 for (unsigned int i = base + 1; i < end; i++)
351 if (_hb_glyph_info_get_modified_combining_class (&info[i]))
352 {
388 buffer->pos[i].y_advance = 0;
389 buffer->pos[i].x_offset += x_offset;
390 buffer->pos[i].y_offset += y_offset;
391
392 } else {
393 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
394 x_offset -= buffer->pos[i].x_advance;
395 y_offset -= buffer->pos[i].y_advance;
396 } else {
397 x_offset += buffer->pos[i].x_advance;
398 y_offset += buffer->pos[i].y_advance;
399 }
400 }
401 }
402
403 static inline void
404 position_cluster (const hb_ot_shape_plan_t *plan,
405 hb_font_t *font,
406 hb_buffer_t *buffer,
407 unsigned int start,
408 unsigned int end,
409 bool adjust_offsets_when_zeroing)
410 {
411 if (end - start < 2)
412 return;
413
414 /* Find the base glyph */
415 hb_glyph_info_t *info = buffer->info;
416 for (unsigned int i = start; i < end; i++)
417 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])))
418 {
419 /* Find mark glyphs */
420 unsigned int j;
421 for (j = i + 1; j < end; j++)
422 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[j])))
423 break;
424
425 position_around_base (plan, font, buffer, i, j, adjust_offsets_when_zeroing);
426
427 i = j - 1;
428 }
429 }
430
431 void
432 _hb_ot_shape_fallback_mark_position (const hb_ot_shape_plan_t *plan,
433 hb_font_t *font,
434 hb_buffer_t *buffer,
435 bool adjust_offsets_when_zeroing)
436 {
437 _hb_buffer_assert_gsubgpos_vars (buffer);
438
439 unsigned int start = 0;
440 unsigned int count = buffer->len;
441 hb_glyph_info_t *info = buffer->info;
442 for (unsigned int i = 1; i < count; i++)
443 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])))) {
444 position_cluster (plan, font, buffer, start, i, adjust_offsets_when_zeroing);
445 start = i;
446 }
447 position_cluster (plan, font, buffer, start, count, adjust_offsets_when_zeroing);
448 }
449
450
451 struct hb_ot_shape_fallback_kern_driver_t
452 {
453 hb_ot_shape_fallback_kern_driver_t (hb_font_t *font_,
454 hb_buffer_t *buffer) :
455 font (font_), direction (buffer->props.direction) {}
456
457 hb_position_t get_kerning (hb_codepoint_t first, hb_codepoint_t second) const
458 {
459 hb_position_t kern = 0;
460 font->get_glyph_kerning_for_direction (first, second,
461 direction,
462 &kern, &kern);
463 return kern;
464 }
465
466 hb_font_t *font;
467 hb_direction_t direction;
468 };
469
470 /* Performs font-assisted kerning. */
471 void
472 _hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
473 hb_font_t *font,
474 hb_buffer_t *buffer)
475 {
476 if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction) ?
477 !font->has_glyph_h_kerning_func () :
478 !font->has_glyph_v_kerning_func ())
479 return;
480
481 bool reverse = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
482
483 if (reverse)
484 buffer->reverse ();
485
486 hb_ot_shape_fallback_kern_driver_t driver (font, buffer);
487 OT::hb_kern_machine_t<hb_ot_shape_fallback_kern_driver_t> machine (driver);
488 machine.kern (font, buffer, plan->kern_mask, false);
489
490 if (reverse)
491 buffer->reverse ();
492 }
493
494
495 /* Adjusts width of various spaces. */
496 void
497 _hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan HB_UNUSED,
498 hb_font_t *font,
499 hb_buffer_t *buffer)
500 {
501 hb_glyph_info_t *info = buffer->info;
502 hb_glyph_position_t *pos = buffer->pos;
503 bool horizontal = HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction);
504 unsigned int count = buffer->len;
505 for (unsigned int i = 0; i < count; i++)
506 if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i]))
507 {
508 hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]);
509 hb_codepoint_t glyph;
510 typedef hb_unicode_funcs_t t;
511 switch (space_type)
512 {
513 case t::NOT_SPACE: /* Shouldn't happen. */
514 case t::SPACE:
515 break;
516
517 case t::SPACE_EM:
518 case t::SPACE_EM_2:
519 case t::SPACE_EM_3:
520 case t::SPACE_EM_4:
521 case t::SPACE_EM_5:
522 case t::SPACE_EM_6:
523 case t::SPACE_EM_16:
524 if (horizontal)
525 pos[i].x_advance = +(font->x_scale + ((int) space_type)/2) / (int) space_type;
526 else
527 pos[i].y_advance = -(font->y_scale + ((int) space_type)/2) / (int) space_type;
528 break;
529
530 case t::SPACE_4_EM_18:
531 if (horizontal)
532 pos[i].x_advance = (int64_t) +font->x_scale * 4 / 18;
533 else
534 pos[i].y_advance = (int64_t) -font->y_scale * 4 / 18;
535 break;
536
537 case t::SPACE_FIGURE:
538 for (char u = '0'; u <= '9'; u++)
539 if (font->get_nominal_glyph (u, &glyph))
540 {
541 if (horizontal)
542 pos[i].x_advance = font->get_glyph_h_advance (glyph);
543 else
544 pos[i].y_advance = font->get_glyph_v_advance (glyph);
545 break;
546 }
547 break;
548
549 case t::SPACE_PUNCTUATION:
550 if (font->get_nominal_glyph ('.', &glyph) ||
551 font->get_nominal_glyph (',', &glyph))
552 {
553 if (horizontal)
554 pos[i].x_advance = font->get_glyph_h_advance (glyph);
555 else
556 pos[i].y_advance = font->get_glyph_v_advance (glyph);
557 }
558 break;
559
560 case t::SPACE_NARROW:
561 /* Half-space?
562 * Unicode doc https://unicode.org/charts/PDF/U2000.pdf says ~1/4 or 1/5 of EM.
563 * However, in my testing, many fonts have their regular space being about that
564 * size. To me, a percentage of the space width makes more sense. Half is as
565 * good as any. */
566 if (horizontal)
567 pos[i].x_advance /= 2;
568 else
569 pos[i].y_advance /= 2;
570 break;
571 }
572 }
573 }
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