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comparison mupdf-source/thirdparty/harfbuzz/src/hb-ot-shaper-use.cc @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1:1d09e1dec1d9 2:b50eed0cc0ef
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.hh"
30
31 #ifndef HB_NO_OT_SHAPE
32
33 #include "hb-ot-shaper-use-machine.hh"
34 #include "hb-ot-shaper-use-table.hh"
35 #include "hb-ot-shaper-arabic.hh"
36 #include "hb-ot-shaper-arabic-joining-list.hh"
37 #include "hb-ot-shaper-vowel-constraints.hh"
38
39
40 /*
41 * Universal Shaping Engine.
42 * https://docs.microsoft.com/en-us/typography/script-development/use
43 */
44
45 static const hb_tag_t
46 use_basic_features[] =
47 {
48 /*
49 * Basic features.
50 * These features are applied all at once, before reordering, constrained
51 * to the syllable.
52 */
53 HB_TAG('r','k','r','f'),
54 HB_TAG('a','b','v','f'),
55 HB_TAG('b','l','w','f'),
56 HB_TAG('h','a','l','f'),
57 HB_TAG('p','s','t','f'),
58 HB_TAG('v','a','t','u'),
59 HB_TAG('c','j','c','t'),
60 };
61 static const hb_tag_t
62 use_topographical_features[] =
63 {
64 HB_TAG('i','s','o','l'),
65 HB_TAG('i','n','i','t'),
66 HB_TAG('m','e','d','i'),
67 HB_TAG('f','i','n','a'),
68 };
69 /* Same order as use_topographical_features. */
70 enum joining_form_t {
71 JOINING_FORM_ISOL,
72 JOINING_FORM_INIT,
73 JOINING_FORM_MEDI,
74 JOINING_FORM_FINA,
75 _JOINING_FORM_NONE
76 };
77 static const hb_tag_t
78 use_other_features[] =
79 {
80 /*
81 * Other features.
82 * These features are applied all at once, after reordering and
83 * clearing syllables.
84 */
85 HB_TAG('a','b','v','s'),
86 HB_TAG('b','l','w','s'),
87 HB_TAG('h','a','l','n'),
88 HB_TAG('p','r','e','s'),
89 HB_TAG('p','s','t','s'),
90 };
91
92 static bool
93 setup_syllables_use (const hb_ot_shape_plan_t *plan,
94 hb_font_t *font,
95 hb_buffer_t *buffer);
96 static bool
97 record_rphf_use (const hb_ot_shape_plan_t *plan,
98 hb_font_t *font,
99 hb_buffer_t *buffer);
100 static bool
101 record_pref_use (const hb_ot_shape_plan_t *plan,
102 hb_font_t *font,
103 hb_buffer_t *buffer);
104 static bool
105 reorder_use (const hb_ot_shape_plan_t *plan,
106 hb_font_t *font,
107 hb_buffer_t *buffer);
108
109 static void
110 collect_features_use (hb_ot_shape_planner_t *plan)
111 {
112 hb_ot_map_builder_t *map = &plan->map;
113
114 /* Do this before any lookups have been applied. */
115 map->add_gsub_pause (setup_syllables_use);
116
117 /* "Default glyph pre-processing group" */
118 map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE);
119 map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE);
120 map->enable_feature (HB_TAG('n','u','k','t'), F_PER_SYLLABLE);
121 map->enable_feature (HB_TAG('a','k','h','n'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
122
123 /* "Reordering group" */
124 map->add_gsub_pause (_hb_clear_substitution_flags);
125 map->add_feature (HB_TAG('r','p','h','f'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
126 map->add_gsub_pause (record_rphf_use);
127 map->add_gsub_pause (_hb_clear_substitution_flags);
128 map->enable_feature (HB_TAG('p','r','e','f'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
129 map->add_gsub_pause (record_pref_use);
130
131 /* "Orthographic unit shaping group" */
132 for (unsigned int i = 0; i < ARRAY_LENGTH (use_basic_features); i++)
133 map->enable_feature (use_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
134
135 map->add_gsub_pause (reorder_use);
136 map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
137
138 /* "Topographical features" */
139 for (unsigned int i = 0; i < ARRAY_LENGTH (use_topographical_features); i++)
140 map->add_feature (use_topographical_features[i]);
141 map->add_gsub_pause (nullptr);
142
143 /* "Standard typographic presentation" */
144 for (unsigned int i = 0; i < ARRAY_LENGTH (use_other_features); i++)
145 map->enable_feature (use_other_features[i], F_MANUAL_ZWJ);
146 }
147
148 struct use_shape_plan_t
149 {
150 hb_mask_t rphf_mask;
151
152 arabic_shape_plan_t *arabic_plan;
153 };
154
155 static void *
156 data_create_use (const hb_ot_shape_plan_t *plan)
157 {
158 use_shape_plan_t *use_plan = (use_shape_plan_t *) hb_calloc (1, sizeof (use_shape_plan_t));
159 if (unlikely (!use_plan))
160 return nullptr;
161
162 use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f'));
163
164 if (has_arabic_joining (plan->props.script))
165 {
166 use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan);
167 if (unlikely (!use_plan->arabic_plan))
168 {
169 hb_free (use_plan);
170 return nullptr;
171 }
172 }
173
174 return use_plan;
175 }
176
177 static void
178 data_destroy_use (void *data)
179 {
180 use_shape_plan_t *use_plan = (use_shape_plan_t *) data;
181
182 if (use_plan->arabic_plan)
183 data_destroy_arabic (use_plan->arabic_plan);
184
185 hb_free (data);
186 }
187
188 static void
189 setup_masks_use (const hb_ot_shape_plan_t *plan,
190 hb_buffer_t *buffer,
191 hb_font_t *font HB_UNUSED)
192 {
193 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
194
195 /* Do this before allocating use_category(). */
196 if (use_plan->arabic_plan)
197 {
198 setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script);
199 }
200
201 HB_BUFFER_ALLOCATE_VAR (buffer, use_category);
202
203 /* We cannot setup masks here. We save information about characters
204 * and setup masks later on in a pause-callback. */
205
206 unsigned int count = buffer->len;
207 hb_glyph_info_t *info = buffer->info;
208 for (unsigned int i = 0; i < count; i++)
209 info[i].use_category() = hb_use_get_category (info[i].codepoint);
210 }
211
212 static void
213 setup_rphf_mask (const hb_ot_shape_plan_t *plan,
214 hb_buffer_t *buffer)
215 {
216 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
217
218 hb_mask_t mask = use_plan->rphf_mask;
219 if (!mask) return;
220
221 hb_glyph_info_t *info = buffer->info;
222
223 foreach_syllable (buffer, start, end)
224 {
225 unsigned int limit = info[start].use_category() == USE(R) ? 1 : hb_min (3u, end - start);
226 for (unsigned int i = start; i < start + limit; i++)
227 info[i].mask |= mask;
228 }
229 }
230
231 static void
232 setup_topographical_masks (const hb_ot_shape_plan_t *plan,
233 hb_buffer_t *buffer)
234 {
235 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
236 if (use_plan->arabic_plan)
237 return;
238
239 static_assert ((JOINING_FORM_INIT < 4 && JOINING_FORM_ISOL < 4 && JOINING_FORM_MEDI < 4 && JOINING_FORM_FINA < 4), "");
240 hb_mask_t masks[4], all_masks = 0;
241 for (unsigned int i = 0; i < 4; i++)
242 {
243 masks[i] = plan->map.get_1_mask (use_topographical_features[i]);
244 if (masks[i] == plan->map.get_global_mask ())
245 masks[i] = 0;
246 all_masks |= masks[i];
247 }
248 if (!all_masks)
249 return;
250 hb_mask_t other_masks = ~all_masks;
251
252 unsigned int last_start = 0;
253 joining_form_t last_form = _JOINING_FORM_NONE;
254 hb_glyph_info_t *info = buffer->info;
255 foreach_syllable (buffer, start, end)
256 {
257 use_syllable_type_t syllable_type = (use_syllable_type_t) (info[start].syllable() & 0x0F);
258 switch (syllable_type)
259 {
260 case use_hieroglyph_cluster:
261 case use_non_cluster:
262 /* These don't join. Nothing to do. */
263 last_form = _JOINING_FORM_NONE;
264 break;
265
266 case use_virama_terminated_cluster:
267 case use_sakot_terminated_cluster:
268 case use_standard_cluster:
269 case use_number_joiner_terminated_cluster:
270 case use_numeral_cluster:
271 case use_symbol_cluster:
272 case use_broken_cluster:
273
274 bool join = last_form == JOINING_FORM_FINA || last_form == JOINING_FORM_ISOL;
275
276 if (join)
277 {
278 /* Fixup previous syllable's form. */
279 last_form = last_form == JOINING_FORM_FINA ? JOINING_FORM_MEDI : JOINING_FORM_INIT;
280 for (unsigned int i = last_start; i < start; i++)
281 info[i].mask = (info[i].mask & other_masks) | masks[last_form];
282 }
283
284 /* Form for this syllable. */
285 last_form = join ? JOINING_FORM_FINA : JOINING_FORM_ISOL;
286 for (unsigned int i = start; i < end; i++)
287 info[i].mask = (info[i].mask & other_masks) | masks[last_form];
288
289 break;
290 }
291
292 last_start = start;
293 }
294 }
295
296 static bool
297 setup_syllables_use (const hb_ot_shape_plan_t *plan,
298 hb_font_t *font HB_UNUSED,
299 hb_buffer_t *buffer)
300 {
301 HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
302 find_syllables_use (buffer);
303 foreach_syllable (buffer, start, end)
304 buffer->unsafe_to_break (start, end);
305 setup_rphf_mask (plan, buffer);
306 setup_topographical_masks (plan, buffer);
307 return false;
308 }
309
310 static bool
311 record_rphf_use (const hb_ot_shape_plan_t *plan,
312 hb_font_t *font HB_UNUSED,
313 hb_buffer_t *buffer)
314 {
315 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
316
317 hb_mask_t mask = use_plan->rphf_mask;
318 if (!mask) return false;
319 hb_glyph_info_t *info = buffer->info;
320
321 foreach_syllable (buffer, start, end)
322 {
323 /* Mark a substituted repha as USE(R). */
324 for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
325 if (_hb_glyph_info_substituted (&info[i]))
326 {
327 info[i].use_category() = USE(R);
328 break;
329 }
330 }
331 return false;
332 }
333
334 static bool
335 record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
336 hb_font_t *font HB_UNUSED,
337 hb_buffer_t *buffer)
338 {
339 hb_glyph_info_t *info = buffer->info;
340
341 foreach_syllable (buffer, start, end)
342 {
343 /* Mark a substituted pref as VPre, as they behave the same way. */
344 for (unsigned int i = start; i < end; i++)
345 if (_hb_glyph_info_substituted (&info[i]))
346 {
347 info[i].use_category() = USE(VPre);
348 break;
349 }
350 }
351 return false;
352 }
353
354 static inline bool
355 is_halant_use (const hb_glyph_info_t &info)
356 {
357 return (info.use_category() == USE(H) || info.use_category() == USE(HVM) || info.use_category() == USE(IS)) &&
358 !_hb_glyph_info_ligated (&info);
359 }
360
361 static void
362 reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
363 {
364 use_syllable_type_t syllable_type = (use_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
365 /* Only a few syllable types need reordering. */
366 if (unlikely (!(FLAG_UNSAFE (syllable_type) &
367 (FLAG (use_virama_terminated_cluster) |
368 FLAG (use_sakot_terminated_cluster) |
369 FLAG (use_standard_cluster) |
370 FLAG (use_symbol_cluster) |
371 FLAG (use_broken_cluster) |
372 0))))
373 return;
374
375 hb_glyph_info_t *info = buffer->info;
376
377 #define POST_BASE_FLAGS64 (FLAG64 (USE(FAbv)) | \
378 FLAG64 (USE(FBlw)) | \
379 FLAG64 (USE(FPst)) | \
380 FLAG64 (USE(MAbv)) | \
381 FLAG64 (USE(MBlw)) | \
382 FLAG64 (USE(MPst)) | \
383 FLAG64 (USE(MPre)) | \
384 FLAG64 (USE(VAbv)) | \
385 FLAG64 (USE(VBlw)) | \
386 FLAG64 (USE(VPst)) | \
387 FLAG64 (USE(VPre)) | \
388 FLAG64 (USE(VMAbv)) | \
389 FLAG64 (USE(VMBlw)) | \
390 FLAG64 (USE(VMPst)) | \
391 FLAG64 (USE(VMPre)))
392
393 /* Move things forward. */
394 if (info[start].use_category() == USE(R) && end - start > 1)
395 {
396 /* Got a repha. Reorder it towards the end, but before the first post-base
397 * glyph. */
398 for (unsigned int i = start + 1; i < end; i++)
399 {
400 bool is_post_base_glyph = (FLAG64_UNSAFE (info[i].use_category()) & POST_BASE_FLAGS64) ||
401 is_halant_use (info[i]);
402 if (is_post_base_glyph || i == end - 1)
403 {
404 /* If we hit a post-base glyph, move before it; otherwise move to the
405 * end. Shift things in between backward. */
406
407 if (is_post_base_glyph)
408 i--;
409
410 buffer->merge_clusters (start, i + 1);
411 hb_glyph_info_t t = info[start];
412 memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0]));
413 info[i] = t;
414
415 break;
416 }
417 }
418 }
419
420 /* Move things back. */
421 unsigned int j = start;
422 for (unsigned int i = start; i < end; i++)
423 {
424 uint32_t flag = FLAG_UNSAFE (info[i].use_category());
425 if (is_halant_use (info[i]))
426 {
427 /* If we hit a halant, move after it; otherwise move to the beginning, and
428 * shift things in between forward. */
429 j = i + 1;
430 }
431 else if (((flag) & (FLAG (USE(VPre)) | FLAG (USE(VMPre)))) &&
432 /* Only move the first component of a MultipleSubst. */
433 0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
434 j < i)
435 {
436 buffer->merge_clusters (j, i + 1);
437 hb_glyph_info_t t = info[i];
438 memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0]));
439 info[j] = t;
440 }
441 }
442 }
443
444 static bool
445 reorder_use (const hb_ot_shape_plan_t *plan,
446 hb_font_t *font,
447 hb_buffer_t *buffer)
448 {
449 bool ret = false;
450 if (buffer->message (font, "start reordering USE"))
451 {
452 if (hb_syllabic_insert_dotted_circles (font, buffer,
453 use_broken_cluster,
454 USE(B),
455 USE(R)))
456 ret = true;
457
458 foreach_syllable (buffer, start, end)
459 reorder_syllable_use (buffer, start, end);
460
461 (void) buffer->message (font, "end reordering USE");
462 }
463
464 HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
465
466 return ret;
467 }
468
469
470 static void
471 preprocess_text_use (const hb_ot_shape_plan_t *plan,
472 hb_buffer_t *buffer,
473 hb_font_t *font)
474 {
475 _hb_preprocess_text_vowel_constraints (plan, buffer, font);
476 }
477
478 static bool
479 compose_use (const hb_ot_shape_normalize_context_t *c,
480 hb_codepoint_t a,
481 hb_codepoint_t b,
482 hb_codepoint_t *ab)
483 {
484 /* Avoid recomposing split matras. */
485 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
486 return false;
487
488 return (bool)c->unicode->compose (a, b, ab);
489 }
490
491
492 const hb_ot_shaper_t _hb_ot_shaper_use =
493 {
494 collect_features_use,
495 nullptr, /* override_features */
496 data_create_use,
497 data_destroy_use,
498 preprocess_text_use,
499 nullptr, /* postprocess_glyphs */
500 nullptr, /* decompose */
501 compose_use,
502 setup_masks_use,
503 nullptr, /* reorder_marks */
504 HB_TAG_NONE, /* gpos_tag */
505 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
506 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
507 false, /* fallback_position */
508 };
509
510
511 #endif