1 /* 2 * Copyright 2007,2008,2009 Red Hat, Inc. 3 * Copyright 2012,2013 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 * Red Hat Author(s): Behdad Esfahbod 26 * Google Author(s): Behdad Esfahbod 27 */ 28 29 #ifndef HB_OT_LAYOUT_PRIVATE_HH 30 #define HB_OT_LAYOUT_PRIVATE_HH 31 32 #include "hb-private.hh" 33 34 #include "hb-font-private.hh" 35 #include "hb-buffer-private.hh" 36 #include "hb-set-private.hh" 37 38 39 /* Private API corresponding to hb-ot-layout.h: */ 40 41 HB_INTERNAL hb_bool_t 42 hb_ot_layout_table_find_feature (hb_face_t *face, 43 hb_tag_t table_tag, 44 hb_tag_t feature_tag, 45 unsigned int *feature_index); 46 47 48 /* 49 * GDEF 50 */ 51 52 enum hb_ot_layout_glyph_props_flags_t 53 { 54 /* The following three match LookupFlags::Ignore* numbers. */ 55 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH = 0x02u, 56 HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE = 0x04u, 57 HB_OT_LAYOUT_GLYPH_PROPS_MARK = 0x08u, 58 59 /* The following are used internally; not derived from GDEF. */ 60 HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED = 0x10u, 61 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED = 0x20u, 62 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED = 0x40u, 63 64 HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED | 65 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | 66 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED 67 }; 68 HB_MARK_AS_FLAG_T (hb_ot_layout_glyph_props_flags_t); 69 70 71 /* 72 * GSUB/GPOS 73 */ 74 75 HB_INTERNAL hb_bool_t 76 hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face, 77 unsigned int lookup_index, 78 const hb_codepoint_t *glyphs, 79 unsigned int glyphs_length, 80 hb_bool_t zero_context); 81 82 83 /* Should be called before all the substitute_lookup's are done. */ 84 HB_INTERNAL void 85 hb_ot_layout_substitute_start (hb_font_t *font, 86 hb_buffer_t *buffer); 87 88 89 struct hb_ot_layout_lookup_accelerator_t; 90 91 namespace OT { 92 struct hb_apply_context_t; 93 struct SubstLookup; 94 } 95 96 HB_INTERNAL void 97 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c, 98 const OT::SubstLookup &lookup, 99 const hb_ot_layout_lookup_accelerator_t &accel); 100 101 102 /* Should be called before all the position_lookup's are done. */ 103 HB_INTERNAL void 104 hb_ot_layout_position_start (hb_font_t *font, 105 hb_buffer_t *buffer); 106 107 /* Should be called after all the position_lookup's are done, to finish advances. */ 108 HB_INTERNAL void 109 hb_ot_layout_position_finish_advances (hb_font_t *font, 110 hb_buffer_t *buffer); 111 112 /* Should be called after hb_ot_layout_position_finish_advances, to finish offsets. */ 113 HB_INTERNAL void 114 hb_ot_layout_position_finish_offsets (hb_font_t *font, 115 hb_buffer_t *buffer); 116 117 118 119 /* 120 * hb_ot_layout_t 121 */ 122 123 namespace OT { 124 struct GDEF; 125 struct GSUB; 126 struct GPOS; 127 } 128 129 struct hb_ot_layout_lookup_accelerator_t 130 { 131 template <typename TLookup> 132 inline void init (const TLookup &lookup) 133 { 134 digest.init (); 135 lookup.add_coverage (&digest); 136 } 137 138 inline void fini (void) 139 { 140 } 141 142 inline bool may_have (hb_codepoint_t g) const { 143 return digest.may_have (g); 144 } 145 146 private: 147 hb_set_digest_t digest; 148 }; 149 150 struct hb_ot_layout_t 151 { 152 hb_blob_t *gdef_blob; 153 hb_blob_t *gsub_blob; 154 hb_blob_t *gpos_blob; 155 156 const struct OT::GDEF *gdef; 157 const struct OT::GSUB *gsub; 158 const struct OT::GPOS *gpos; 159 160 unsigned int gsub_lookup_count; 161 unsigned int gpos_lookup_count; 162 163 hb_ot_layout_lookup_accelerator_t *gsub_accels; 164 hb_ot_layout_lookup_accelerator_t *gpos_accels; 165 }; 166 167 168 HB_INTERNAL hb_ot_layout_t * 169 _hb_ot_layout_create (hb_face_t *face); 170 171 HB_INTERNAL void 172 _hb_ot_layout_destroy (hb_ot_layout_t *layout); 173 174 175 #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot) 176 177 178 /* 179 * Buffer var routines. 180 */ 181 182 /* buffer var allocations, used during the entire shaping process */ 183 #define unicode_props() var2.u16[0] 184 185 /* buffer var allocations, used during the GSUB/GPOS processing */ 186 #define glyph_props() var1.u16[0] /* GDEF glyph properties */ 187 #define lig_props() var1.u8[2] /* GSUB/GPOS ligature tracking */ 188 #define syllable() var1.u8[3] /* GSUB/GPOS shaping boundaries */ 189 190 191 /* loop over syllables */ 192 193 #define foreach_syllable(buffer, start, end) \ 194 for (unsigned int \ 195 _count = buffer->len, \ 196 start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \ 197 start < _count; \ 198 start = end, end = _next_syllable (buffer, start)) 199 200 static inline unsigned int 201 _next_syllable (hb_buffer_t *buffer, unsigned int start) 202 { 203 hb_glyph_info_t *info = buffer->info; 204 unsigned int count = buffer->len; 205 206 unsigned int syllable = info[start].syllable(); 207 while (++start < count && syllable == info[start].syllable()) 208 ; 209 210 return start; 211 } 212 213 214 /* unicode_props */ 215 216 /* Design: 217 * unicode_props() is a two-byte number. The low byte includes: 218 * - General_Category: 5 bits. 219 * - A bit each for: 220 * * Is it Default_Ignorable(); we have a modified Default_Ignorable(). 221 * * Is it U+200D ZWJ? 222 * * Is it U+200C ZWNJ? 223 * 224 * The high-byte has different meanings, switched by the Gen-Cat: 225 * - For Mn,Mc,Me: the modified Combining_Class. 226 * - For Ws: index of which space character this is, if space fallback 227 * is needed, ie. we don't set this by default, only if asked to. 228 * 229 * If needed, we can use the ZWJ/ZWNJ to use the high byte as well, 230 * freeing two more bits. 231 */ 232 233 enum hb_unicode_props_flags_t { 234 UPROPS_MASK_ZWJ = 0x20u, 235 UPROPS_MASK_ZWNJ = 0x40u, 236 UPROPS_MASK_IGNORABLE = 0x80u, 237 UPROPS_MASK_GEN_CAT = 0x1Fu 238 }; 239 HB_MARK_AS_FLAG_T (hb_unicode_props_flags_t); 240 241 static inline void 242 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer) 243 { 244 hb_unicode_funcs_t *unicode = buffer->unicode; 245 unsigned int u = info->codepoint; 246 unsigned int gen_cat = (unsigned int) unicode->general_category (u); 247 unsigned int props = gen_cat; 248 249 if (u >= 0x80) 250 { 251 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII; 252 if (unlikely (unicode->is_default_ignorable (u))) 253 { 254 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES; 255 props |= UPROPS_MASK_IGNORABLE; 256 if (u == 0x200Cu) props |= UPROPS_MASK_ZWNJ; 257 if (u == 0x200Du) props |= UPROPS_MASK_ZWJ; 258 } 259 else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK_OR_MODIFIER_SYMBOL (gen_cat))) 260 { 261 /* The above check is just an optimization to let in only things we need further 262 * processing on. */ 263 264 /* Only Mn and Mc can have non-zero ccc: 265 * http://www.unicode.org/policies/stability_policy.html#Property_Value 266 * """ 267 * Canonical_Combining_Class, General_Category 268 * All characters other than those with General_Category property values 269 * Spacing_Mark (Mc) and Nonspacing_Mark (Mn) have the Canonical_Combining_Class 270 * property value 0. 271 * 1.1.5+ 272 * """ 273 * 274 * Also, all Mn's that are Default_Ignorable, have ccc=0, hence 275 * the "else if". 276 */ 277 props |= unicode->modified_combining_class (info->codepoint)<<8; 278 279 /* Recategorize emoji skin-tone modifiers as Unicode mark, so they 280 * behave correctly in non-native directionality. They originally 281 * are MODIFIER_SYMBOL. Fixes: 282 * https://github.com/behdad/harfbuzz/issues/169 283 */ 284 if (unlikely (hb_in_range (u, 0x1F3FBu, 0x1F3FFu))) 285 { 286 props = gen_cat = HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK; 287 } 288 } 289 } 290 291 info->unicode_props() = props; 292 } 293 294 static inline void 295 _hb_glyph_info_set_general_category (hb_glyph_info_t *info, 296 hb_unicode_general_category_t gen_cat) 297 { 298 /* Clears top-byte. */ 299 info->unicode_props() = (unsigned int) gen_cat | (info->unicode_props() & (0xFF & ~UPROPS_MASK_GEN_CAT)); 300 } 301 302 static inline hb_unicode_general_category_t 303 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info) 304 { 305 return (hb_unicode_general_category_t) (info->unicode_props() & UPROPS_MASK_GEN_CAT); 306 } 307 308 static inline bool 309 _hb_glyph_info_is_unicode_mark (const hb_glyph_info_t *info) 310 { 311 return HB_UNICODE_GENERAL_CATEGORY_IS_MARK (info->unicode_props() & UPROPS_MASK_GEN_CAT); 312 } 313 static inline void 314 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info, 315 unsigned int modified_class) 316 { 317 if (unlikely (!_hb_glyph_info_is_unicode_mark (info))) 318 return; 319 info->unicode_props() = (modified_class<<8) | (info->unicode_props() & 0xFF); 320 } 321 static inline unsigned int 322 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info) 323 { 324 return _hb_glyph_info_is_unicode_mark (info) ? info->unicode_props()>>8 : 0; 325 } 326 327 static inline bool 328 _hb_glyph_info_is_unicode_space (const hb_glyph_info_t *info) 329 { 330 return _hb_glyph_info_get_general_category (info) == 331 HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR; 332 } 333 static inline void 334 _hb_glyph_info_set_unicode_space_fallback_type (hb_glyph_info_t *info, hb_unicode_funcs_t::space_t s) 335 { 336 if (unlikely (!_hb_glyph_info_is_unicode_space (info))) 337 return; 338 info->unicode_props() = (((unsigned int) s)<<8) | (info->unicode_props() & 0xFF); 339 } 340 static inline hb_unicode_funcs_t::space_t 341 _hb_glyph_info_get_unicode_space_fallback_type (const hb_glyph_info_t *info) 342 { 343 return _hb_glyph_info_is_unicode_space (info) ? 344 (hb_unicode_funcs_t::space_t) (info->unicode_props()>>8) : 345 hb_unicode_funcs_t::NOT_SPACE; 346 } 347 348 static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info); 349 350 static inline hb_bool_t 351 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info) 352 { 353 return (info->unicode_props() & UPROPS_MASK_IGNORABLE) && !_hb_glyph_info_ligated (info); 354 } 355 356 static inline hb_bool_t 357 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info) 358 { 359 return !!(info->unicode_props() & UPROPS_MASK_ZWNJ); 360 } 361 362 static inline hb_bool_t 363 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info) 364 { 365 return !!(info->unicode_props() & UPROPS_MASK_ZWJ); 366 } 367 368 static inline hb_bool_t 369 _hb_glyph_info_is_joiner (const hb_glyph_info_t *info) 370 { 371 return !!(info->unicode_props() & (UPROPS_MASK_ZWNJ | UPROPS_MASK_ZWJ)); 372 } 373 374 static inline void 375 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info) 376 { 377 info->unicode_props() ^= UPROPS_MASK_ZWNJ | UPROPS_MASK_ZWJ; 378 } 379 380 /* lig_props: aka lig_id / lig_comp 381 * 382 * When a ligature is formed: 383 * 384 * - The ligature glyph and any marks in between all the same newly allocated 385 * lig_id, 386 * - The ligature glyph will get lig_num_comps set to the number of components 387 * - The marks get lig_comp > 0, reflecting which component of the ligature 388 * they were applied to. 389 * - This is used in GPOS to attach marks to the right component of a ligature 390 * in MarkLigPos, 391 * - Note that when marks are ligated together, much of the above is skipped 392 * and the current lig_id reused. 393 * 394 * When a multiple-substitution is done: 395 * 396 * - All resulting glyphs will have lig_id = 0, 397 * - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively. 398 * - This is used in GPOS to attach marks to the first component of a 399 * multiple substitution in MarkBasePos. 400 * 401 * The numbers are also used in GPOS to do mark-to-mark positioning only 402 * to marks that belong to the same component of the same ligature. 403 */ 404 405 static inline void 406 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info) 407 { 408 info->lig_props() = 0; 409 } 410 411 #define IS_LIG_BASE 0x10 412 413 static inline void 414 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info, 415 unsigned int lig_id, 416 unsigned int lig_num_comps) 417 { 418 info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F); 419 } 420 421 static inline void 422 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info, 423 unsigned int lig_id, 424 unsigned int lig_comp) 425 { 426 info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F); 427 } 428 429 static inline void 430 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp) 431 { 432 _hb_glyph_info_set_lig_props_for_mark (info, 0, comp); 433 } 434 435 static inline unsigned int 436 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info) 437 { 438 return info->lig_props() >> 5; 439 } 440 441 static inline bool 442 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info) 443 { 444 return !!(info->lig_props() & IS_LIG_BASE); 445 } 446 447 static inline unsigned int 448 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info) 449 { 450 if (_hb_glyph_info_ligated_internal (info)) 451 return 0; 452 else 453 return info->lig_props() & 0x0F; 454 } 455 456 static inline unsigned int 457 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info) 458 { 459 if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) && 460 _hb_glyph_info_ligated_internal (info)) 461 return info->lig_props() & 0x0F; 462 else 463 return 1; 464 } 465 466 static inline uint8_t 467 _hb_allocate_lig_id (hb_buffer_t *buffer) { 468 uint8_t lig_id = buffer->next_serial () & 0x07; 469 if (unlikely (!lig_id)) 470 lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */ 471 return lig_id; 472 } 473 474 /* glyph_props: */ 475 476 static inline void 477 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props) 478 { 479 info->glyph_props() = props; 480 } 481 482 static inline unsigned int 483 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info) 484 { 485 return info->glyph_props(); 486 } 487 488 static inline bool 489 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info) 490 { 491 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH); 492 } 493 494 static inline bool 495 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info) 496 { 497 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE); 498 } 499 500 static inline bool 501 _hb_glyph_info_is_mark (const hb_glyph_info_t *info) 502 { 503 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK); 504 } 505 506 static inline bool 507 _hb_glyph_info_substituted (const hb_glyph_info_t *info) 508 { 509 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED); 510 } 511 512 static inline bool 513 _hb_glyph_info_ligated (const hb_glyph_info_t *info) 514 { 515 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED); 516 } 517 518 static inline bool 519 _hb_glyph_info_multiplied (const hb_glyph_info_t *info) 520 { 521 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); 522 } 523 524 static inline bool 525 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info) 526 { 527 return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info); 528 } 529 530 static inline void 531 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info) 532 { 533 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | 534 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); 535 } 536 537 static inline void 538 _hb_glyph_info_clear_substituted (hb_glyph_info_t *info) 539 { 540 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED); 541 } 542 543 544 /* Allocation / deallocation. */ 545 546 static inline void 547 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer) 548 { 549 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props); 550 } 551 552 static inline void 553 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer) 554 { 555 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props); 556 } 557 558 static inline void 559 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer) 560 { 561 HB_BUFFER_ASSERT_VAR (buffer, unicode_props); 562 } 563 564 static inline void 565 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer) 566 { 567 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props); 568 HB_BUFFER_ALLOCATE_VAR (buffer, lig_props); 569 HB_BUFFER_ALLOCATE_VAR (buffer, syllable); 570 } 571 572 static inline void 573 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer) 574 { 575 HB_BUFFER_DEALLOCATE_VAR (buffer, syllable); 576 HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props); 577 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props); 578 } 579 580 static inline void 581 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer) 582 { 583 HB_BUFFER_ASSERT_VAR (buffer, glyph_props); 584 HB_BUFFER_ASSERT_VAR (buffer, lig_props); 585 HB_BUFFER_ASSERT_VAR (buffer, syllable); 586 } 587 588 /* Make sure no one directly touches our props... */ 589 #undef unicode_props0 590 #undef unicode_props1 591 #undef lig_props 592 #undef glyph_props 593 594 595 #endif /* HB_OT_LAYOUT_PRIVATE_HH */ 596
