Line data Source code
1 : /*
2 : * Copyright © 2015 Mozilla Foundation.
3 : * Copyright © 2015 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 : * Mozilla Author(s): Jonathan Kew
26 : * Google Author(s): Behdad Esfahbod
27 : */
28 :
29 : #include "hb-ot-shape-complex-use-private.hh"
30 : #include "hb-ot-shape-complex-arabic-private.hh"
31 :
32 : /* buffer var allocations */
33 : #define use_category() complex_var_u8_0()
34 :
35 :
36 : /*
37 : * Universal Shaping Engine.
38 : * https://www.microsoft.com/typography/OpenTypeDev/USE/intro.htm
39 : */
40 :
41 : static const hb_tag_t
42 : basic_features[] =
43 : {
44 : /*
45 : * Basic features.
46 : * These features are applied all at once, before reordering.
47 : */
48 : HB_TAG('r','k','r','f'),
49 : HB_TAG('a','b','v','f'),
50 : HB_TAG('b','l','w','f'),
51 : HB_TAG('h','a','l','f'),
52 : HB_TAG('p','s','t','f'),
53 : HB_TAG('v','a','t','u'),
54 : HB_TAG('c','j','c','t'),
55 : };
56 : static const hb_tag_t
57 : arabic_features[] =
58 : {
59 : HB_TAG('i','s','o','l'),
60 : HB_TAG('i','n','i','t'),
61 : HB_TAG('m','e','d','i'),
62 : HB_TAG('f','i','n','a'),
63 : /* The spec doesn't specify these but we apply anyway, since our Arabic shaper
64 : * does. These are only used in Syriac spec. */
65 : HB_TAG('m','e','d','2'),
66 : HB_TAG('f','i','n','2'),
67 : HB_TAG('f','i','n','3'),
68 : };
69 : /* Same order as arabic_features. Don't need Syriac stuff.*/
70 : enum joining_form_t {
71 : ISOL,
72 : INIT,
73 : MEDI,
74 : FINA,
75 : _NONE
76 : };
77 : static const hb_tag_t
78 : other_features[] =
79 : {
80 : /*
81 : * Other features.
82 : * These features are applied all at once, after reordering.
83 : */
84 : HB_TAG('a','b','v','s'),
85 : HB_TAG('b','l','w','s'),
86 : HB_TAG('h','a','l','n'),
87 : HB_TAG('p','r','e','s'),
88 : HB_TAG('p','s','t','s'),
89 : /* Positioning features, though we don't care about the types. */
90 : HB_TAG('d','i','s','t'),
91 : HB_TAG('a','b','v','m'),
92 : HB_TAG('b','l','w','m'),
93 : };
94 :
95 : static void
96 : setup_syllables (const hb_ot_shape_plan_t *plan,
97 : hb_font_t *font,
98 : hb_buffer_t *buffer);
99 : static void
100 : clear_substitution_flags (const hb_ot_shape_plan_t *plan,
101 : hb_font_t *font,
102 : hb_buffer_t *buffer);
103 : static void
104 : record_rphf (const hb_ot_shape_plan_t *plan,
105 : hb_font_t *font,
106 : hb_buffer_t *buffer);
107 : static void
108 : record_pref (const hb_ot_shape_plan_t *plan,
109 : hb_font_t *font,
110 : hb_buffer_t *buffer);
111 : static void
112 : reorder (const hb_ot_shape_plan_t *plan,
113 : hb_font_t *font,
114 : hb_buffer_t *buffer);
115 :
116 : static void
117 0 : collect_features_use (hb_ot_shape_planner_t *plan)
118 : {
119 0 : hb_ot_map_builder_t *map = &plan->map;
120 :
121 : /* Do this before any lookups have been applied. */
122 0 : map->add_gsub_pause (setup_syllables);
123 :
124 : /* "Default glyph pre-processing group" */
125 0 : map->add_global_bool_feature (HB_TAG('l','o','c','l'));
126 0 : map->add_global_bool_feature (HB_TAG('c','c','m','p'));
127 0 : map->add_global_bool_feature (HB_TAG('n','u','k','t'));
128 0 : map->add_global_bool_feature (HB_TAG('a','k','h','n'));
129 :
130 : /* "Reordering group" */
131 0 : map->add_gsub_pause (clear_substitution_flags);
132 0 : map->add_feature (HB_TAG('r','p','h','f'), 1, F_MANUAL_ZWJ);
133 0 : map->add_gsub_pause (record_rphf);
134 0 : map->add_gsub_pause (clear_substitution_flags);
135 0 : map->add_feature (HB_TAG('p','r','e','f'), 1, F_GLOBAL | F_MANUAL_ZWJ);
136 0 : map->add_gsub_pause (record_pref);
137 :
138 : /* "Orthographic unit shaping group" */
139 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
140 0 : map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
141 :
142 0 : map->add_gsub_pause (reorder);
143 :
144 : /* "Topographical features" */
145 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (arabic_features); i++)
146 0 : map->add_feature (arabic_features[i], 1, F_NONE);
147 0 : map->add_gsub_pause (NULL);
148 :
149 : /* "Standard typographic presentation" and "Positional feature application" */
150 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
151 0 : map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
152 0 : }
153 :
154 : struct use_shape_plan_t
155 : {
156 : ASSERT_POD ();
157 :
158 : hb_mask_t rphf_mask;
159 :
160 : arabic_shape_plan_t *arabic_plan;
161 : };
162 :
163 : static bool
164 0 : has_arabic_joining (hb_script_t script)
165 : {
166 : /* List of scripts that have data in arabic-table. */
167 0 : switch ((int) script)
168 : {
169 : /* Unicode-1.1 additions */
170 : case HB_SCRIPT_ARABIC:
171 :
172 : /* Unicode-3.0 additions */
173 : case HB_SCRIPT_MONGOLIAN:
174 : case HB_SCRIPT_SYRIAC:
175 :
176 : /* Unicode-5.0 additions */
177 : case HB_SCRIPT_NKO:
178 : case HB_SCRIPT_PHAGS_PA:
179 :
180 : /* Unicode-6.0 additions */
181 : case HB_SCRIPT_MANDAIC:
182 :
183 : /* Unicode-7.0 additions */
184 : case HB_SCRIPT_MANICHAEAN:
185 : case HB_SCRIPT_PSALTER_PAHLAVI:
186 :
187 : /* Unicode-9.0 additions */
188 : case HB_SCRIPT_ADLAM:
189 :
190 0 : return true;
191 :
192 : default:
193 0 : return false;
194 : }
195 : }
196 :
197 : static void *
198 0 : data_create_use (const hb_ot_shape_plan_t *plan)
199 : {
200 0 : use_shape_plan_t *use_plan = (use_shape_plan_t *) calloc (1, sizeof (use_shape_plan_t));
201 0 : if (unlikely (!use_plan))
202 0 : return NULL;
203 :
204 0 : use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f'));
205 :
206 0 : if (has_arabic_joining (plan->props.script))
207 : {
208 0 : use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan);
209 0 : if (unlikely (!use_plan->arabic_plan))
210 : {
211 0 : free (use_plan);
212 0 : return NULL;
213 : }
214 : }
215 :
216 0 : return use_plan;
217 : }
218 :
219 : static void
220 0 : data_destroy_use (void *data)
221 : {
222 0 : use_shape_plan_t *use_plan = (use_shape_plan_t *) data;
223 :
224 0 : if (use_plan->arabic_plan)
225 0 : data_destroy_arabic (use_plan->arabic_plan);
226 :
227 0 : free (data);
228 0 : }
229 :
230 : enum syllable_type_t {
231 : independent_cluster,
232 : virama_terminated_cluster,
233 : standard_cluster,
234 : number_joiner_terminated_cluster,
235 : numeral_cluster,
236 : symbol_cluster,
237 : broken_cluster,
238 : non_cluster,
239 : };
240 :
241 : #include "hb-ot-shape-complex-use-machine.hh"
242 :
243 :
244 : static void
245 0 : setup_masks_use (const hb_ot_shape_plan_t *plan,
246 : hb_buffer_t *buffer,
247 : hb_font_t *font HB_UNUSED)
248 : {
249 0 : const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
250 :
251 : /* Do this before allocating use_category(). */
252 0 : if (use_plan->arabic_plan)
253 : {
254 0 : setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script);
255 : }
256 :
257 0 : HB_BUFFER_ALLOCATE_VAR (buffer, use_category);
258 :
259 : /* We cannot setup masks here. We save information about characters
260 : * and setup masks later on in a pause-callback. */
261 :
262 0 : unsigned int count = buffer->len;
263 0 : hb_glyph_info_t *info = buffer->info;
264 0 : for (unsigned int i = 0; i < count; i++)
265 0 : info[i].use_category() = hb_use_get_categories (info[i].codepoint);
266 0 : }
267 :
268 : static void
269 0 : setup_rphf_mask (const hb_ot_shape_plan_t *plan,
270 : hb_buffer_t *buffer)
271 : {
272 0 : const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
273 :
274 0 : hb_mask_t mask = use_plan->rphf_mask;
275 0 : if (!mask) return;
276 :
277 0 : hb_glyph_info_t *info = buffer->info;
278 :
279 0 : foreach_syllable (buffer, start, end)
280 : {
281 0 : unsigned int limit = info[start].use_category() == USE_R ? 1 : MIN (3u, end - start);
282 0 : for (unsigned int i = start; i < start + limit; i++)
283 0 : info[i].mask |= mask;
284 : }
285 : }
286 :
287 : static void
288 0 : setup_topographical_masks (const hb_ot_shape_plan_t *plan,
289 : hb_buffer_t *buffer)
290 : {
291 0 : const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
292 0 : if (use_plan->arabic_plan)
293 0 : return;
294 :
295 : ASSERT_STATIC (INIT < 4 && ISOL < 4 && MEDI < 4 && FINA < 4);
296 0 : hb_mask_t masks[4], all_masks = 0;
297 0 : for (unsigned int i = 0; i < 4; i++)
298 : {
299 0 : masks[i] = plan->map.get_1_mask (arabic_features[i]);
300 0 : if (masks[i] == plan->map.get_global_mask ())
301 0 : masks[i] = 0;
302 0 : all_masks |= masks[i];
303 : }
304 0 : if (!all_masks)
305 0 : return;
306 0 : hb_mask_t other_masks = ~all_masks;
307 :
308 0 : unsigned int last_start = 0;
309 0 : joining_form_t last_form = _NONE;
310 0 : hb_glyph_info_t *info = buffer->info;
311 0 : foreach_syllable (buffer, start, end)
312 : {
313 0 : syllable_type_t syllable_type = (syllable_type_t) (info[start].syllable() & 0x0F);
314 0 : switch (syllable_type)
315 : {
316 : case independent_cluster:
317 : case symbol_cluster:
318 : case non_cluster:
319 : /* These don't join. Nothing to do. */
320 0 : last_form = _NONE;
321 0 : break;
322 :
323 : case virama_terminated_cluster:
324 : case standard_cluster:
325 : case number_joiner_terminated_cluster:
326 : case numeral_cluster:
327 : case broken_cluster:
328 :
329 0 : bool join = last_form == FINA || last_form == ISOL;
330 :
331 0 : if (join)
332 : {
333 : /* Fixup previous syllable's form. */
334 0 : last_form = last_form == FINA ? MEDI : INIT;
335 0 : for (unsigned int i = last_start; i < start; i++)
336 0 : info[i].mask = (info[i].mask & other_masks) | masks[last_form];
337 : }
338 :
339 : /* Form for this syllable. */
340 0 : last_form = join ? FINA : ISOL;
341 0 : for (unsigned int i = start; i < end; i++)
342 0 : info[i].mask = (info[i].mask & other_masks) | masks[last_form];
343 :
344 0 : break;
345 : }
346 :
347 0 : last_start = start;
348 : }
349 : }
350 :
351 : static void
352 0 : setup_syllables (const hb_ot_shape_plan_t *plan,
353 : hb_font_t *font HB_UNUSED,
354 : hb_buffer_t *buffer)
355 : {
356 0 : find_syllables (buffer);
357 0 : setup_rphf_mask (plan, buffer);
358 0 : setup_topographical_masks (plan, buffer);
359 0 : }
360 :
361 : static void
362 0 : clear_substitution_flags (const hb_ot_shape_plan_t *plan,
363 : hb_font_t *font HB_UNUSED,
364 : hb_buffer_t *buffer)
365 : {
366 0 : hb_glyph_info_t *info = buffer->info;
367 0 : unsigned int count = buffer->len;
368 0 : for (unsigned int i = 0; i < count; i++)
369 0 : _hb_glyph_info_clear_substituted (&info[i]);
370 0 : }
371 :
372 : static void
373 0 : record_rphf (const hb_ot_shape_plan_t *plan,
374 : hb_font_t *font,
375 : hb_buffer_t *buffer)
376 : {
377 0 : const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
378 :
379 0 : hb_mask_t mask = use_plan->rphf_mask;
380 0 : if (!mask) return;
381 0 : hb_glyph_info_t *info = buffer->info;
382 :
383 0 : foreach_syllable (buffer, start, end)
384 : {
385 : /* Mark a substituted repha as USE_R. */
386 0 : for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
387 0 : if (_hb_glyph_info_substituted (&info[i]))
388 : {
389 0 : info[i].use_category() = USE_R;
390 0 : break;
391 : }
392 : }
393 : }
394 :
395 : static void
396 0 : record_pref (const hb_ot_shape_plan_t *plan,
397 : hb_font_t *font,
398 : hb_buffer_t *buffer)
399 : {
400 0 : hb_glyph_info_t *info = buffer->info;
401 :
402 0 : foreach_syllable (buffer, start, end)
403 : {
404 : /* Mark a substituted pref as VPre, as they behave the same way. */
405 0 : for (unsigned int i = start; i < end; i++)
406 0 : if (_hb_glyph_info_substituted (&info[i]))
407 : {
408 0 : info[i].use_category() = USE_VPre;
409 0 : break;
410 : }
411 : }
412 0 : }
413 :
414 : static inline bool
415 0 : is_halant (const hb_glyph_info_t &info)
416 : {
417 0 : return info.use_category() == USE_H && !_hb_glyph_info_ligated (&info);
418 : }
419 :
420 : static void
421 0 : reorder_syllable (hb_buffer_t *buffer, unsigned int start, unsigned int end)
422 : {
423 0 : syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
424 : /* Only a few syllable types need reordering. */
425 0 : if (unlikely (!(FLAG_SAFE (syllable_type) &
426 : (FLAG (virama_terminated_cluster) |
427 : FLAG (standard_cluster) |
428 : FLAG (broken_cluster) |
429 : 0))))
430 0 : return;
431 :
432 0 : hb_glyph_info_t *info = buffer->info;
433 :
434 : #define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB))
435 :
436 : /* Move things forward. */
437 0 : if (info[start].use_category() == USE_R && end - start > 1)
438 : {
439 : /* Got a repha. Reorder it to after first base, before first halant. */
440 0 : for (unsigned int i = start + 1; i < end; i++)
441 0 : if ((FLAG_UNSAFE (info[i].use_category()) & (BASE_FLAGS)) || is_halant (info[i]))
442 : {
443 : /* If we hit a halant, move before it; otherwise it's a base: move to it's
444 : * place, and shift things in between backward. */
445 :
446 0 : if (is_halant (info[i]))
447 0 : i--;
448 :
449 0 : buffer->merge_clusters (start, i + 1);
450 0 : hb_glyph_info_t t = info[start];
451 0 : memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0]));
452 0 : info[i] = t;
453 :
454 0 : break;
455 : }
456 : }
457 :
458 : /* Move things back. */
459 0 : unsigned int j = end;
460 0 : for (unsigned int i = start; i < end; i++)
461 : {
462 0 : uint32_t flag = FLAG_UNSAFE (info[i].use_category());
463 0 : if ((flag & (BASE_FLAGS)) || is_halant (info[i]))
464 : {
465 : /* If we hit a halant, move after it; otherwise it's a base: move to it's
466 : * place, and shift things in between backward. */
467 0 : if (is_halant (info[i]))
468 0 : j = i + 1;
469 : else
470 0 : j = i;
471 : }
472 0 : else if (((flag) & (FLAG (USE_VPre) | FLAG (USE_VMPre))) &&
473 : /* Only move the first component of a MultipleSubst. */
474 0 : 0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
475 : j < i)
476 : {
477 0 : buffer->merge_clusters (j, i + 1);
478 0 : hb_glyph_info_t t = info[i];
479 0 : memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0]));
480 0 : info[j] = t;
481 : }
482 : }
483 : }
484 :
485 : static inline void
486 0 : insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
487 : hb_font_t *font,
488 : hb_buffer_t *buffer)
489 : {
490 : /* Note: This loop is extra overhead, but should not be measurable. */
491 0 : bool has_broken_syllables = false;
492 0 : unsigned int count = buffer->len;
493 0 : hb_glyph_info_t *info = buffer->info;
494 0 : for (unsigned int i = 0; i < count; i++)
495 0 : if ((info[i].syllable() & 0x0F) == broken_cluster)
496 : {
497 0 : has_broken_syllables = true;
498 0 : break;
499 : }
500 0 : if (likely (!has_broken_syllables))
501 0 : return;
502 :
503 0 : hb_glyph_info_t dottedcircle = {0};
504 0 : if (!font->get_nominal_glyph (0x25CCu, &dottedcircle.codepoint))
505 0 : return;
506 0 : dottedcircle.use_category() = hb_use_get_categories (0x25CC);
507 :
508 0 : buffer->clear_output ();
509 :
510 0 : buffer->idx = 0;
511 0 : unsigned int last_syllable = 0;
512 0 : while (buffer->idx < buffer->len && !buffer->in_error)
513 : {
514 0 : unsigned int syllable = buffer->cur().syllable();
515 0 : syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
516 0 : if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
517 : {
518 0 : last_syllable = syllable;
519 :
520 0 : hb_glyph_info_t ginfo = dottedcircle;
521 0 : ginfo.cluster = buffer->cur().cluster;
522 0 : ginfo.mask = buffer->cur().mask;
523 0 : ginfo.syllable() = buffer->cur().syllable();
524 : /* TODO Set glyph_props? */
525 :
526 : /* Insert dottedcircle after possible Repha. */
527 0 : while (buffer->idx < buffer->len && !buffer->in_error &&
528 0 : last_syllable == buffer->cur().syllable() &&
529 0 : buffer->cur().use_category() == USE_R)
530 0 : buffer->next_glyph ();
531 :
532 0 : buffer->output_info (ginfo);
533 : }
534 : else
535 0 : buffer->next_glyph ();
536 : }
537 :
538 0 : buffer->swap_buffers ();
539 : }
540 :
541 : static void
542 0 : reorder (const hb_ot_shape_plan_t *plan,
543 : hb_font_t *font,
544 : hb_buffer_t *buffer)
545 : {
546 0 : insert_dotted_circles (plan, font, buffer);
547 :
548 0 : hb_glyph_info_t *info = buffer->info;
549 :
550 0 : foreach_syllable (buffer, start, end)
551 0 : reorder_syllable (buffer, start, end);
552 :
553 : /* Zero syllables now... */
554 0 : unsigned int count = buffer->len;
555 0 : for (unsigned int i = 0; i < count; i++)
556 0 : info[i].syllable() = 0;
557 :
558 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
559 0 : }
560 :
561 : static bool
562 0 : decompose_use (const hb_ot_shape_normalize_context_t *c,
563 : hb_codepoint_t ab,
564 : hb_codepoint_t *a,
565 : hb_codepoint_t *b)
566 : {
567 0 : switch (ab)
568 : {
569 : /* Chakma:
570 : * Special case where the Unicode decomp gives matras in the wrong order
571 : * for cluster validation.
572 : */
573 0 : case 0x1112Eu : *a = 0x11127u; *b= 0x11131u; return true;
574 0 : case 0x1112Fu : *a = 0x11127u; *b= 0x11132u; return true;
575 : }
576 :
577 0 : return (bool) c->unicode->decompose (ab, a, b);
578 : }
579 :
580 : static bool
581 0 : compose_use (const hb_ot_shape_normalize_context_t *c,
582 : hb_codepoint_t a,
583 : hb_codepoint_t b,
584 : hb_codepoint_t *ab)
585 : {
586 : /* Avoid recomposing split matras. */
587 0 : if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
588 0 : return false;
589 :
590 0 : return (bool)c->unicode->compose (a, b, ab);
591 : }
592 :
593 :
594 : const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use =
595 : {
596 : "use",
597 : collect_features_use,
598 : NULL, /* override_features */
599 : data_create_use,
600 : data_destroy_use,
601 : NULL, /* preprocess_text */
602 : NULL, /* postprocess_glyphs */
603 : HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
604 : decompose_use,
605 : compose_use,
606 : setup_masks_use,
607 : NULL, /* disable_otl */
608 : HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
609 : false, /* fallback_position */
610 : };
|
