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 collect_features_use (hb_ot_shape_planner_t *plan) 118 { 119 hb_ot_map_builder_t *map = &plan->map; 120 121 /* Do this before any lookups have been applied. */ 122 map->add_gsub_pause (setup_syllables); 123 124 /* "Default glyph pre-processing group" */ 125 map->add_global_bool_feature (HB_TAG('l','o','c','l')); 126 map->add_global_bool_feature (HB_TAG('c','c','m','p')); 127 map->add_global_bool_feature (HB_TAG('n','u','k','t')); 128 map->add_global_bool_feature (HB_TAG('a','k','h','n')); 129 130 /* "Reordering group" */ 131 map->add_gsub_pause (clear_substitution_flags); 132 map->add_feature (HB_TAG('r','p','h','f'), 1, F_MANUAL_ZWJ); 133 map->add_gsub_pause (record_rphf); 134 map->add_gsub_pause (clear_substitution_flags); 135 map->add_feature (HB_TAG('p','r','e','f'), 1, F_GLOBAL | F_MANUAL_ZWJ); 136 map->add_gsub_pause (record_pref); 137 138 /* "Orthographic unit shaping group" */ 139 for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++) 140 map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); 141 142 map->add_gsub_pause (reorder); 143 144 /* "Topographical features" */ 145 for (unsigned int i = 0; i < ARRAY_LENGTH (arabic_features); i++) 146 map->add_feature (arabic_features[i], 1, F_NONE); 147 map->add_gsub_pause (nullptr); 148 149 /* "Standard typographic presentation" and "Positional feature application" */ 150 for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++) 151 map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); 152 } 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 has_arabic_joining (hb_script_t script) 165 { 166 /* List of scripts that have data in arabic-table. */ 167 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 return true; 191 192 default: 193 return false; 194 } 195 } 196 197 static void * 198 data_create_use (const hb_ot_shape_plan_t *plan) 199 { 200 use_shape_plan_t *use_plan = (use_shape_plan_t *) calloc (1, sizeof (use_shape_plan_t)); 201 if (unlikely (!use_plan)) 202 return nullptr; 203 204 use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f')); 205 206 if (has_arabic_joining (plan->props.script)) 207 { 208 use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan); 209 if (unlikely (!use_plan->arabic_plan)) 210 { 211 free (use_plan); 212 return nullptr; 213 } 214 } 215 216 return use_plan; 217 } 218 219 static void 220 data_destroy_use (void *data) 221 { 222 use_shape_plan_t *use_plan = (use_shape_plan_t *) data; 223 224 if (use_plan->arabic_plan) 225 data_destroy_arabic (use_plan->arabic_plan); 226 227 free (data); 228 } 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 setup_masks_use (const hb_ot_shape_plan_t *plan, 246 hb_buffer_t *buffer, 247 hb_font_t *font HB_UNUSED) 248 { 249 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; 250 251 /* Do this before allocating use_category(). */ 252 if (use_plan->arabic_plan) 253 { 254 setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script); 255 } 256 257 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 unsigned int count = buffer->len; 263 hb_glyph_info_t *info = buffer->info; 264 for (unsigned int i = 0; i < count; i++) 265 info[i].use_category() = hb_use_get_categories (info[i].codepoint); 266 } 267 268 static void 269 setup_rphf_mask (const hb_ot_shape_plan_t *plan, 270 hb_buffer_t *buffer) 271 { 272 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; 273 274 hb_mask_t mask = use_plan->rphf_mask; 275 if (!mask) return; 276 277 hb_glyph_info_t *info = buffer->info; 278 279 foreach_syllable (buffer, start, end) 280 { 281 unsigned int limit = info[start].use_category() == USE_R ? 1 : MIN (3u, end - start); 282 for (unsigned int i = start; i < start + limit; i++) 283 info[i].mask |= mask; 284 } 285 } 286 287 static void 288 setup_topographical_masks (const hb_ot_shape_plan_t *plan, 289 hb_buffer_t *buffer) 290 { 291 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; 292 if (use_plan->arabic_plan) 293 return; 294 295 static_assert ((INIT < 4 && ISOL < 4 && MEDI < 4 && FINA < 4), ""); 296 hb_mask_t masks[4], all_masks = 0; 297 for (unsigned int i = 0; i < 4; i++) 298 { 299 masks[i] = plan->map.get_1_mask (arabic_features[i]); 300 if (masks[i] == plan->map.get_global_mask ()) 301 masks[i] = 0; 302 all_masks |= masks[i]; 303 } 304 if (!all_masks) 305 return; 306 hb_mask_t other_masks = ~all_masks; 307 308 unsigned int last_start = 0; 309 joining_form_t last_form = _NONE; 310 hb_glyph_info_t *info = buffer->info; 311 foreach_syllable (buffer, start, end) 312 { 313 syllable_type_t syllable_type = (syllable_type_t) (info[start].syllable() & 0x0F); 314 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 last_form = _NONE; 321 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 bool join = last_form == FINA || last_form == ISOL; 330 331 if (join) 332 { 333 /* Fixup previous syllable's form. */ 334 last_form = last_form == FINA ? MEDI : INIT; 335 for (unsigned int i = last_start; i < start; i++) 336 info[i].mask = (info[i].mask & other_masks) | masks[last_form]; 337 } 338 339 /* Form for this syllable. */ 340 last_form = join ? FINA : ISOL; 341 for (unsigned int i = start; i < end; i++) 342 info[i].mask = (info[i].mask & other_masks) | masks[last_form]; 343 344 break; 345 } 346 347 last_start = start; 348 } 349 } 350 351 static void 352 setup_syllables (const hb_ot_shape_plan_t *plan, 353 hb_font_t *font HB_UNUSED, 354 hb_buffer_t *buffer) 355 { 356 find_syllables (buffer); 357 foreach_syllable (buffer, start, end) 358 buffer->unsafe_to_break (start, end); 359 setup_rphf_mask (plan, buffer); 360 setup_topographical_masks (plan, buffer); 361 } 362 363 static void 364 clear_substitution_flags (const hb_ot_shape_plan_t *plan, 365 hb_font_t *font HB_UNUSED, 366 hb_buffer_t *buffer) 367 { 368 hb_glyph_info_t *info = buffer->info; 369 unsigned int count = buffer->len; 370 for (unsigned int i = 0; i < count; i++) 371 _hb_glyph_info_clear_substituted (&info[i]); 372 } 373 374 static void 375 record_rphf (const hb_ot_shape_plan_t *plan, 376 hb_font_t *font, 377 hb_buffer_t *buffer) 378 { 379 const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; 380 381 hb_mask_t mask = use_plan->rphf_mask; 382 if (!mask) return; 383 hb_glyph_info_t *info = buffer->info; 384 385 foreach_syllable (buffer, start, end) 386 { 387 /* Mark a substituted repha as USE_R. */ 388 for (unsigned int i = start; i < end && (info[i].mask & mask); i++) 389 if (_hb_glyph_info_substituted (&info[i])) 390 { 391 info[i].use_category() = USE_R; 392 break; 393 } 394 } 395 } 396 397 static void 398 record_pref (const hb_ot_shape_plan_t *plan, 399 hb_font_t *font, 400 hb_buffer_t *buffer) 401 { 402 hb_glyph_info_t *info = buffer->info; 403 404 foreach_syllable (buffer, start, end) 405 { 406 /* Mark a substituted pref as VPre, as they behave the same way. */ 407 for (unsigned int i = start; i < end; i++) 408 if (_hb_glyph_info_substituted (&info[i])) 409 { 410 info[i].use_category() = USE_VPre; 411 break; 412 } 413 } 414 } 415 416 static inline bool 417 is_halant (const hb_glyph_info_t &info) 418 { 419 return info.use_category() == USE_H && !_hb_glyph_info_ligated (&info); 420 } 421 422 static void 423 reorder_syllable (hb_buffer_t *buffer, unsigned int start, unsigned int end) 424 { 425 syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F); 426 /* Only a few syllable types need reordering. */ 427 if (unlikely (!(FLAG_UNSAFE (syllable_type) & 428 (FLAG (virama_terminated_cluster) | 429 FLAG (standard_cluster) | 430 FLAG (broken_cluster) | 431 0)))) 432 return; 433 434 hb_glyph_info_t *info = buffer->info; 435 436 #define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB)) 437 438 /* Move things forward. */ 439 if (info[start].use_category() == USE_R && end - start > 1) 440 { 441 /* Got a repha. Reorder it to after first base, before first halant. */ 442 for (unsigned int i = start + 1; i < end; i++) 443 if ((FLAG_UNSAFE (info[i].use_category()) & (BASE_FLAGS)) || is_halant (info[i])) 444 { 445 /* If we hit a halant, move before it; otherwise it's a base: move to it's 446 * place, and shift things in between backward. */ 447 448 if (is_halant (info[i])) 449 i--; 450 451 buffer->merge_clusters (start, i + 1); 452 hb_glyph_info_t t = info[start]; 453 memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0])); 454 info[i] = t; 455 456 break; 457 } 458 } 459 460 /* Move things back. */ 461 unsigned int j = end; 462 for (unsigned int i = start; i < end; i++) 463 { 464 uint32_t flag = FLAG_UNSAFE (info[i].use_category()); 465 if ((flag & (BASE_FLAGS)) || is_halant (info[i])) 466 { 467 /* If we hit a halant, move after it; otherwise it's a base: move to it's 468 * place, and shift things in between backward. */ 469 if (is_halant (info[i])) 470 j = i + 1; 471 else 472 j = i; 473 } 474 else if (((flag) & (FLAG (USE_VPre) | FLAG (USE_VMPre))) && 475 /* Only move the first component of a MultipleSubst. */ 476 0 == _hb_glyph_info_get_lig_comp (&info[i]) && 477 j < i) 478 { 479 buffer->merge_clusters (j, i + 1); 480 hb_glyph_info_t t = info[i]; 481 memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0])); 482 info[j] = t; 483 } 484 } 485 } 486 487 static inline void 488 insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED, 489 hb_font_t *font, 490 hb_buffer_t *buffer) 491 { 492 /* Note: This loop is extra overhead, but should not be measurable. */ 493 bool has_broken_syllables = false; 494 unsigned int count = buffer->len; 495 hb_glyph_info_t *info = buffer->info; 496 for (unsigned int i = 0; i < count; i++) 497 if ((info[i].syllable() & 0x0F) == broken_cluster) 498 { 499 has_broken_syllables = true; 500 break; 501 } 502 if (likely (!has_broken_syllables)) 503 return; 504 505 hb_glyph_info_t dottedcircle = {0}; 506 if (!font->get_nominal_glyph (0x25CCu, &dottedcircle.codepoint)) 507 return; 508 dottedcircle.use_category() = hb_use_get_categories (0x25CC); 509 510 buffer->clear_output (); 511 512 buffer->idx = 0; 513 unsigned int last_syllable = 0; 514 while (buffer->idx < buffer->len && !buffer->in_error) 515 { 516 unsigned int syllable = buffer->cur().syllable(); 517 syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F); 518 if (unlikely (last_syllable != syllable && syllable_type == broken_cluster)) 519 { 520 last_syllable = syllable; 521 522 hb_glyph_info_t ginfo = dottedcircle; 523 ginfo.cluster = buffer->cur().cluster; 524 ginfo.mask = buffer->cur().mask; 525 ginfo.syllable() = buffer->cur().syllable(); 526 /* TODO Set glyph_props? */ 527 528 /* Insert dottedcircle after possible Repha. */ 529 while (buffer->idx < buffer->len && !buffer->in_error && 530 last_syllable == buffer->cur().syllable() && 531 buffer->cur().use_category() == USE_R) 532 buffer->next_glyph (); 533 534 buffer->output_info (ginfo); 535 } 536 else 537 buffer->next_glyph (); 538 } 539 540 buffer->swap_buffers (); 541 } 542 543 static void 544 reorder (const hb_ot_shape_plan_t *plan, 545 hb_font_t *font, 546 hb_buffer_t *buffer) 547 { 548 insert_dotted_circles (plan, font, buffer); 549 550 hb_glyph_info_t *info = buffer->info; 551 552 foreach_syllable (buffer, start, end) 553 reorder_syllable (buffer, start, end); 554 555 /* Zero syllables now... */ 556 unsigned int count = buffer->len; 557 for (unsigned int i = 0; i < count; i++) 558 info[i].syllable() = 0; 559 560 HB_BUFFER_DEALLOCATE_VAR (buffer, use_category); 561 } 562 563 static bool 564 decompose_use (const hb_ot_shape_normalize_context_t *c, 565 hb_codepoint_t ab, 566 hb_codepoint_t *a, 567 hb_codepoint_t *b) 568 { 569 switch (ab) 570 { 571 /* Chakma: 572 * Special case where the Unicode decomp gives matras in the wrong order 573 * for cluster validation. 574 */ 575 case 0x1112Eu : *a = 0x11127u; *b= 0x11131u; return true; 576 case 0x1112Fu : *a = 0x11127u; *b= 0x11132u; return true; 577 } 578 579 return (bool) c->unicode->decompose (ab, a, b); 580 } 581 582 static bool 583 compose_use (const hb_ot_shape_normalize_context_t *c, 584 hb_codepoint_t a, 585 hb_codepoint_t b, 586 hb_codepoint_t *ab) 587 { 588 /* Avoid recomposing split matras. */ 589 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a))) 590 return false; 591 592 return (bool)c->unicode->compose (a, b, ab); 593 } 594 595 596 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use = 597 { 598 collect_features_use, 599 nullptr, /* override_features */ 600 data_create_use, 601 data_destroy_use, 602 nullptr, /* preprocess_text */ 603 nullptr, /* postprocess_glyphs */ 604 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, 605 decompose_use, 606 compose_use, 607 setup_masks_use, 608 nullptr, /* disable_otl */ 609 nullptr, /* reorder_marks */ 610 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, 611 false, /* fallback_position */ 612 }; 613
