hb-ot-shaper-use.cc (14493B)
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(FMAbv)) | \ 381 FLAG64 (USE(FMBlw)) | \ 382 FLAG64 (USE(FMPst)) | \ 383 FLAG64 (USE(MAbv)) | \ 384 FLAG64 (USE(MBlw)) | \ 385 FLAG64 (USE(MPst)) | \ 386 FLAG64 (USE(MPre)) | \ 387 FLAG64 (USE(VAbv)) | \ 388 FLAG64 (USE(VBlw)) | \ 389 FLAG64 (USE(VPst)) | \ 390 FLAG64 (USE(VPre)) | \ 391 FLAG64 (USE(VMAbv)) | \ 392 FLAG64 (USE(VMBlw)) | \ 393 FLAG64 (USE(VMPst)) | \ 394 FLAG64 (USE(VMPre))) 395 396 /* Move things forward. */ 397 if (info[start].use_category() == USE(R) && end - start > 1) 398 { 399 /* Got a repha. Reorder it towards the end, but before the first post-base 400 * glyph. */ 401 for (unsigned int i = start + 1; i < end; i++) 402 { 403 bool is_post_base_glyph = (FLAG64_UNSAFE (info[i].use_category()) & POST_BASE_FLAGS64) || 404 is_halant_use (info[i]); 405 if (is_post_base_glyph || i == end - 1) 406 { 407 /* If we hit a post-base glyph, move before it; otherwise move to the 408 * end. Shift things in between backward. */ 409 410 if (is_post_base_glyph) 411 i--; 412 413 buffer->merge_clusters (start, i + 1); 414 hb_glyph_info_t t = info[start]; 415 memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0])); 416 info[i] = t; 417 418 break; 419 } 420 } 421 } 422 423 /* Move things back. */ 424 unsigned int j = start; 425 for (unsigned int i = start; i < end; i++) 426 { 427 uint32_t flag = FLAG_UNSAFE (info[i].use_category()); 428 if (is_halant_use (info[i])) 429 { 430 /* If we hit a halant, move after it; otherwise move to the beginning, and 431 * shift things in between forward. */ 432 j = i + 1; 433 } 434 else if (((flag) & (FLAG (USE(VPre)) | FLAG (USE(VMPre)))) && 435 /* Only move the first component of a MultipleSubst. */ 436 0 == _hb_glyph_info_get_lig_comp (&info[i]) && 437 j < i) 438 { 439 buffer->merge_clusters (j, i + 1); 440 hb_glyph_info_t t = info[i]; 441 memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0])); 442 info[j] = t; 443 } 444 } 445 } 446 447 static bool 448 reorder_use (const hb_ot_shape_plan_t *plan, 449 hb_font_t *font, 450 hb_buffer_t *buffer) 451 { 452 bool ret = false; 453 if (buffer->message (font, "start reordering USE")) 454 { 455 if (hb_syllabic_insert_dotted_circles (font, buffer, 456 use_broken_cluster, 457 USE(B), 458 USE(R))) 459 ret = true; 460 461 foreach_syllable (buffer, start, end) 462 reorder_syllable_use (buffer, start, end); 463 464 (void) buffer->message (font, "end reordering USE"); 465 } 466 467 HB_BUFFER_DEALLOCATE_VAR (buffer, use_category); 468 469 return ret; 470 } 471 472 473 static void 474 preprocess_text_use (const hb_ot_shape_plan_t *plan, 475 hb_buffer_t *buffer, 476 hb_font_t *font) 477 { 478 _hb_preprocess_text_vowel_constraints (plan, buffer, font); 479 } 480 481 static bool 482 compose_use (const hb_ot_shape_normalize_context_t *c, 483 hb_codepoint_t a, 484 hb_codepoint_t b, 485 hb_codepoint_t *ab) 486 { 487 /* Avoid recomposing split matras. */ 488 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a))) 489 return false; 490 491 return (bool)c->unicode->compose (a, b, ab); 492 } 493 494 495 const hb_ot_shaper_t _hb_ot_shaper_use = 496 { 497 collect_features_use, 498 nullptr, /* override_features */ 499 data_create_use, 500 data_destroy_use, 501 preprocess_text_use, 502 nullptr, /* postprocess_glyphs */ 503 nullptr, /* decompose */ 504 compose_use, 505 setup_masks_use, 506 nullptr, /* reorder_marks */ 507 HB_TAG_NONE, /* gpos_tag */ 508 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, 509 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, 510 false, /* fallback_position */ 511 }; 512 513 514 #endif