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 typedef enum 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 } hb_ot_layout_glyph_class_mask_t; 68 69 70 /* 71 * GSUB/GPOS 72 */ 73 74 HB_INTERNAL hb_bool_t 75 hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face, 76 unsigned int lookup_index, 77 const hb_codepoint_t *glyphs, 78 unsigned int glyphs_length, 79 hb_bool_t zero_context); 80 81 82 /* Should be called before all the substitute_lookup's are done. */ 83 HB_INTERNAL void 84 hb_ot_layout_substitute_start (hb_font_t *font, 85 hb_buffer_t *buffer); 86 87 88 struct hb_ot_layout_lookup_accelerator_t; 89 90 namespace OT { 91 struct hb_apply_context_t; 92 struct SubstLookup; 93 } 94 95 HB_INTERNAL void 96 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c, 97 const OT::SubstLookup &lookup, 98 const hb_ot_layout_lookup_accelerator_t &accel); 99 100 101 /* Should be called after all the substitute_lookup's are done */ 102 HB_INTERNAL void 103 hb_ot_layout_substitute_finish (hb_font_t *font, 104 hb_buffer_t *buffer); 105 106 107 /* Should be called before all the position_lookup's are done. Resets positions to zero. */ 108 HB_INTERNAL void 109 hb_ot_layout_position_start (hb_font_t *font, 110 hb_buffer_t *buffer); 111 112 /* Should be called after all the position_lookup's are done */ 113 HB_INTERNAL void 114 hb_ot_layout_position_finish (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_props0() var2.u8[0] 184 #define unicode_props1() var2.u8[1] 185 186 /* buffer var allocations, used during the GSUB/GPOS processing */ 187 #define glyph_props() var1.u16[0] /* GDEF glyph properties */ 188 #define lig_props() var1.u8[2] /* GSUB/GPOS ligature tracking */ 189 #define syllable() var1.u8[3] /* GSUB/GPOS shaping boundaries */ 190 191 192 /* loop over syllables */ 193 194 #define foreach_syllable(buffer, start, end) \ 195 for (unsigned int \ 196 _count = buffer->len, \ 197 start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \ 198 start < _count; \ 199 start = end, end = _next_syllable (buffer, start)) 200 201 static inline unsigned int 202 _next_syllable (hb_buffer_t *buffer, unsigned int start) 203 { 204 hb_glyph_info_t *info = buffer->info; 205 unsigned int count = buffer->len; 206 207 unsigned int syllable = info[start].syllable(); 208 while (++start < count && syllable == info[start].syllable()) 209 ; 210 211 return start; 212 } 213 214 215 /* unicode_props */ 216 217 enum { 218 MASK0_ZWJ = 0x20u, 219 MASK0_ZWNJ = 0x40u, 220 MASK0_IGNORABLE = 0x80u, 221 MASK0_GEN_CAT = 0x1Fu 222 }; 223 224 static inline void 225 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode) 226 { 227 /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */ 228 info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) | 229 (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) | 230 (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) | 231 (info->codepoint == 0x200Du ? MASK0_ZWJ : 0); 232 info->unicode_props1() = unicode->modified_combining_class (info->codepoint); 233 } 234 235 static inline void 236 _hb_glyph_info_set_general_category (hb_glyph_info_t *info, 237 hb_unicode_general_category_t gen_cat) 238 { 239 info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT); 240 } 241 242 static inline hb_unicode_general_category_t 243 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info) 244 { 245 return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT); 246 } 247 248 static inline void 249 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info, 250 unsigned int modified_class) 251 { 252 info->unicode_props1() = modified_class; 253 } 254 255 static inline unsigned int 256 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info) 257 { 258 return info->unicode_props1(); 259 } 260 261 static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info); 262 263 static inline hb_bool_t 264 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info) 265 { 266 return (info->unicode_props0() & MASK0_IGNORABLE) && !_hb_glyph_info_ligated (info); 267 } 268 269 static inline hb_bool_t 270 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info) 271 { 272 return !!(info->unicode_props0() & MASK0_ZWNJ); 273 } 274 275 static inline hb_bool_t 276 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info) 277 { 278 return !!(info->unicode_props0() & MASK0_ZWJ); 279 } 280 281 static inline void 282 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info) 283 { 284 info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ; 285 } 286 287 /* lig_props: aka lig_id / lig_comp 288 * 289 * When a ligature is formed: 290 * 291 * - The ligature glyph and any marks in between all the same newly allocated 292 * lig_id, 293 * - The ligature glyph will get lig_num_comps set to the number of components 294 * - The marks get lig_comp > 0, reflecting which component of the ligature 295 * they were applied to. 296 * - This is used in GPOS to attach marks to the right component of a ligature 297 * in MarkLigPos, 298 * - Note that when marks are ligated together, much of the above is skipped 299 * and the current lig_id reused. 300 * 301 * When a multiple-substitution is done: 302 * 303 * - All resulting glyphs will have lig_id = 0, 304 * - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively. 305 * - This is used in GPOS to attach marks to the first component of a 306 * multiple substitution in MarkBasePos. 307 * 308 * The numbers are also used in GPOS to do mark-to-mark positioning only 309 * to marks that belong to the same component of the same ligature. 310 */ 311 312 static inline void 313 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info) 314 { 315 info->lig_props() = 0; 316 } 317 318 #define IS_LIG_BASE 0x10 319 320 static inline void 321 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info, 322 unsigned int lig_id, 323 unsigned int lig_num_comps) 324 { 325 info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F); 326 } 327 328 static inline void 329 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info, 330 unsigned int lig_id, 331 unsigned int lig_comp) 332 { 333 info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F); 334 } 335 336 static inline void 337 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp) 338 { 339 _hb_glyph_info_set_lig_props_for_mark (info, 0, comp); 340 } 341 342 static inline unsigned int 343 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info) 344 { 345 return info->lig_props() >> 5; 346 } 347 348 static inline bool 349 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info) 350 { 351 return !!(info->lig_props() & IS_LIG_BASE); 352 } 353 354 static inline unsigned int 355 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info) 356 { 357 if (_hb_glyph_info_ligated_internal (info)) 358 return 0; 359 else 360 return info->lig_props() & 0x0F; 361 } 362 363 static inline unsigned int 364 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info) 365 { 366 if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) && 367 _hb_glyph_info_ligated_internal (info)) 368 return info->lig_props() & 0x0F; 369 else 370 return 1; 371 } 372 373 static inline uint8_t 374 _hb_allocate_lig_id (hb_buffer_t *buffer) { 375 uint8_t lig_id = buffer->next_serial () & 0x07; 376 if (unlikely (!lig_id)) 377 lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */ 378 return lig_id; 379 } 380 381 /* glyph_props: */ 382 383 static inline void 384 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props) 385 { 386 info->glyph_props() = props; 387 } 388 389 static inline unsigned int 390 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info) 391 { 392 return info->glyph_props(); 393 } 394 395 static inline bool 396 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info) 397 { 398 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH); 399 } 400 401 static inline bool 402 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info) 403 { 404 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE); 405 } 406 407 static inline bool 408 _hb_glyph_info_is_mark (const hb_glyph_info_t *info) 409 { 410 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK); 411 } 412 413 static inline bool 414 _hb_glyph_info_substituted (const hb_glyph_info_t *info) 415 { 416 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED); 417 } 418 419 static inline bool 420 _hb_glyph_info_ligated (const hb_glyph_info_t *info) 421 { 422 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED); 423 } 424 425 static inline bool 426 _hb_glyph_info_multiplied (const hb_glyph_info_t *info) 427 { 428 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); 429 } 430 431 static inline bool 432 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info) 433 { 434 return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info); 435 } 436 437 static inline void 438 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info) 439 { 440 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | 441 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); 442 } 443 444 static inline void 445 _hb_glyph_info_clear_substituted_and_ligated_and_multiplied (hb_glyph_info_t *info) 446 { 447 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED | 448 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | 449 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); 450 } 451 452 453 /* Allocation / deallocation. */ 454 455 static inline void 456 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer) 457 { 458 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0); 459 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1); 460 } 461 462 static inline void 463 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer) 464 { 465 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0); 466 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1); 467 } 468 469 static inline void 470 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer) 471 { 472 HB_BUFFER_ASSERT_VAR (buffer, unicode_props0); 473 HB_BUFFER_ASSERT_VAR (buffer, unicode_props1); 474 } 475 476 static inline void 477 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer) 478 { 479 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props); 480 HB_BUFFER_ALLOCATE_VAR (buffer, lig_props); 481 HB_BUFFER_ALLOCATE_VAR (buffer, syllable); 482 } 483 484 static inline void 485 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer) 486 { 487 HB_BUFFER_DEALLOCATE_VAR (buffer, syllable); 488 HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props); 489 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props); 490 } 491 492 static inline void 493 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer) 494 { 495 HB_BUFFER_ASSERT_VAR (buffer, glyph_props); 496 HB_BUFFER_ASSERT_VAR (buffer, lig_props); 497 HB_BUFFER_ASSERT_VAR (buffer, syllable); 498 } 499 500 /* Make sure no one directly touches our props... */ 501 #undef unicode_props0 502 #undef unicode_props1 503 #undef lig_props 504 #undef glyph_props 505 506 507 #endif /* HB_OT_LAYOUT_PRIVATE_HH */