hb-ot-layout.cc revision 52ea47767c7c35650ebddfba6ddc8203a3e33d3a
1/* 2 * Copyright (C) 1998-2004 David Turner and Werner Lemberg 3 * Copyright (C) 2006 Behdad Esfahbod 4 * Copyright (C) 2007,2008,2009 Red Hat, Inc. 5 * 6 * This is part of HarfBuzz, an OpenType Layout engine library. 7 * 8 * Permission is hereby granted, without written agreement and without 9 * license or royalty fees, to use, copy, modify, and distribute this 10 * software and its documentation for any purpose, provided that the 11 * above copyright notice and the following two paragraphs appear in 12 * all copies of this software. 13 * 14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 18 * DAMAGE. 19 * 20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 22 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 25 * 26 * Red Hat Author(s): Behdad Esfahbod 27 */ 28 29#define HB_OT_LAYOUT_CC 30 31#include "hb-ot-layout-private.h" 32 33#include "hb-ot-layout-gdef-private.hh" 34#include "hb-ot-layout-gsub-private.hh" 35#include "hb-ot-layout-gpos-private.hh" 36 37 38#include <stdlib.h> 39#include <string.h> 40 41 42void 43_hb_ot_layout_init (hb_face_t *face) 44{ 45 hb_ot_layout_t *layout = &face->ot_layout; 46 47 layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_get_table (face, HB_OT_TAG_GDEF)); 48 layout->gdef = &Sanitizer<GDEF>::lock_instance (layout->gdef_blob); 49 50 layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_get_table (face, HB_OT_TAG_GSUB)); 51 layout->gsub = &Sanitizer<GSUB>::lock_instance (layout->gsub_blob); 52 53 layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_get_table (face, HB_OT_TAG_GPOS)); 54 layout->gpos = &Sanitizer<GPOS>::lock_instance (layout->gpos_blob); 55} 56 57void 58_hb_ot_layout_fini (hb_face_t *face) 59{ 60 hb_ot_layout_t *layout = &face->ot_layout; 61 62 hb_blob_unlock (layout->gdef_blob); 63 hb_blob_unlock (layout->gsub_blob); 64 hb_blob_unlock (layout->gpos_blob); 65 66 hb_blob_destroy (layout->gdef_blob); 67 hb_blob_destroy (layout->gsub_blob); 68 hb_blob_destroy (layout->gpos_blob); 69 70 free (layout->new_gdef.klasses); 71} 72 73static const GDEF& 74_get_gdef (hb_face_t *face) 75{ 76 return HB_LIKELY (face->ot_layout.gdef) ? *face->ot_layout.gdef : Null(GDEF); 77} 78 79static const GSUB& 80_get_gsub (hb_face_t *face) 81{ 82 return HB_LIKELY (face->ot_layout.gsub) ? *face->ot_layout.gsub : Null(GSUB); 83} 84 85static const GPOS& 86_get_gpos (hb_face_t *face) 87{ 88 return HB_LIKELY (face->ot_layout.gpos) ? *face->ot_layout.gpos : Null(GPOS); 89} 90 91 92/* 93 * GDEF 94 */ 95 96/* TODO the public class_t is a mess */ 97 98hb_bool_t 99hb_ot_layout_has_glyph_classes (hb_face_t *face) 100{ 101 return _get_gdef (face).has_glyph_classes (); 102} 103 104hb_bool_t 105_hb_ot_layout_has_new_glyph_classes (hb_face_t *face) 106{ 107 return face->ot_layout.new_gdef.len > 0; 108} 109 110static unsigned int 111_hb_ot_layout_get_glyph_property (hb_face_t *face, 112 hb_codepoint_t glyph) 113{ 114 hb_ot_layout_class_t klass; 115 const GDEF &gdef = _get_gdef (face); 116 117 klass = gdef.get_glyph_class (glyph); 118 119 if (!klass && glyph < face->ot_layout.new_gdef.len) 120 klass = face->ot_layout.new_gdef.klasses[glyph]; 121 122 switch (klass) { 123 default: 124 case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED; 125 case GDEF::BaseGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH; 126 case GDEF::LigatureGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE; 127 case GDEF::ComponentGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT; 128 case GDEF::MarkGlyph: 129 klass = gdef.get_mark_attachment_type (glyph); 130 return HB_OT_LAYOUT_GLYPH_CLASS_MARK + (klass << 8); 131 } 132} 133 134hb_bool_t 135_hb_ot_layout_check_glyph_property (hb_face_t *face, 136 hb_internal_glyph_info_t *ginfo, 137 unsigned int lookup_flags, 138 unsigned int *property_out) 139{ 140 unsigned int property; 141 142 if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN) 143 ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint); 144 property = ginfo->gproperty; 145 if (property_out) 146 *property_out = property; 147 148 /* Not covered, if, for example, glyph class is ligature and 149 * lookup_flags includes LookupFlags::IgnoreLigatures 150 */ 151 if (property & lookup_flags & LookupFlag::IgnoreFlags) 152 return false; 153 154 if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK) 155 { 156 /* If using mark filtering sets, the high short of 157 * lookup_flags has the set index. 158 */ 159 if (lookup_flags & LookupFlag::UseMarkFilteringSet) 160 return _get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint); 161 162 /* The second byte of lookup_flags has the meaning 163 * "ignore marks of attachment type different than 164 * the attachment type specified." 165 */ 166 if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType) 167 return (lookup_flags & LookupFlag::MarkAttachmentType) == (property & LookupFlag::MarkAttachmentType); 168 } 169 170 return true; 171} 172 173hb_bool_t 174_hb_ot_layout_skip_mark (hb_face_t *face, 175 hb_internal_glyph_info_t *ginfo, 176 unsigned int lookup_flags, 177 unsigned int *property_out) 178{ 179 unsigned int property; 180 181 if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN) 182 ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint); 183 property = ginfo->gproperty; 184 if (property_out) 185 *property_out = property; 186 187 if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK) 188 { 189 /* Skip mark if lookup_flags includes LookupFlags::IgnoreMarks */ 190 if (lookup_flags & LookupFlag::IgnoreMarks) 191 return true; 192 193 /* If using mark filtering sets, the high short of lookup_flags has the set index. */ 194 if (lookup_flags & LookupFlag::UseMarkFilteringSet) 195 return !_get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint); 196 197 /* The second byte of lookup_flags has the meaning "ignore marks of attachment type 198 * different than the attachment type specified." */ 199 if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType) 200 return (lookup_flags & LookupFlag::MarkAttachmentType) != (property & LookupFlag::MarkAttachmentType); 201 } 202 203 return false; 204} 205 206void 207_hb_ot_layout_set_glyph_class (hb_face_t *face, 208 hb_codepoint_t glyph, 209 hb_ot_layout_glyph_class_t klass) 210{ 211 if (HB_OBJECT_IS_INERT (face)) 212 return; 213 214 /* TODO optimize this? similar to old harfbuzz code for example */ 215 216 hb_ot_layout_t *layout = &face->ot_layout; 217 hb_ot_layout_class_t gdef_klass; 218 unsigned int len = layout->new_gdef.len; 219 220 if (HB_UNLIKELY (glyph > 65535)) 221 return; 222 223 /* XXX this is not threadsafe */ 224 if (glyph >= len) { 225 unsigned int new_len; 226 unsigned char *new_klasses; 227 228 new_len = len == 0 ? 120 : 2 * len; 229 while (new_len <= glyph) 230 new_len *= 2; 231 232 if (new_len > 65536) 233 new_len = 65536; 234 new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char)); 235 236 if (HB_UNLIKELY (!new_klasses)) 237 return; 238 239 memset (new_klasses + len, 0, new_len - len); 240 241 layout->new_gdef.klasses = new_klasses; 242 layout->new_gdef.len = new_len; 243 } 244 245 switch (klass) { 246 default: 247 case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: gdef_klass = GDEF::UnclassifiedGlyph; break; 248 case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: gdef_klass = GDEF::BaseGlyph; break; 249 case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: gdef_klass = GDEF::LigatureGlyph; break; 250 case HB_OT_LAYOUT_GLYPH_CLASS_MARK: gdef_klass = GDEF::MarkGlyph; break; 251 case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: gdef_klass = GDEF::ComponentGlyph; break; 252 } 253 254 layout->new_gdef.klasses[glyph] = gdef_klass; 255 return; 256} 257 258void 259_hb_ot_layout_set_glyph_property (hb_face_t *face, 260 hb_codepoint_t glyph, 261 unsigned int property) 262{ _hb_ot_layout_set_glyph_class (face, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); } 263 264 265hb_ot_layout_glyph_class_t 266hb_ot_layout_get_glyph_class (hb_face_t *face, 267 hb_codepoint_t glyph) 268{ 269 return (hb_ot_layout_glyph_class_t) (_hb_ot_layout_get_glyph_property (face, glyph) & 0xff); 270} 271 272void 273hb_ot_layout_set_glyph_class (hb_face_t *face, 274 hb_codepoint_t glyph, 275 hb_ot_layout_glyph_class_t klass) 276{ 277 _hb_ot_layout_set_glyph_class (face, glyph, klass); 278} 279 280void 281hb_ot_layout_build_glyph_classes (hb_face_t *face, 282 uint16_t num_total_glyphs, 283 hb_codepoint_t *glyphs, 284 unsigned char *klasses, 285 uint16_t count) 286{ 287 if (HB_OBJECT_IS_INERT (face)) 288 return; 289 290 hb_ot_layout_t *layout = &face->ot_layout; 291 292 if (HB_UNLIKELY (!count || !glyphs || !klasses)) 293 return; 294 295 if (layout->new_gdef.len == 0) { 296 layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char)); 297 layout->new_gdef.len = count; 298 } 299 300 for (unsigned int i = 0; i < count; i++) 301 _hb_ot_layout_set_glyph_class (face, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]); 302} 303 304unsigned int 305hb_ot_layout_get_attach_points (hb_face_t *face, 306 hb_codepoint_t glyph, 307 unsigned int start_offset, 308 unsigned int *point_count /* IN/OUT */, 309 unsigned int *point_array /* OUT */) 310{ 311 return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array); 312} 313 314unsigned int 315hb_ot_layout_get_lig_carets (hb_font_t *font, 316 hb_face_t *face, 317 hb_codepoint_t glyph, 318 unsigned int start_offset, 319 unsigned int *caret_count /* IN/OUT */, 320 int *caret_array /* OUT */) 321{ 322 hb_ot_layout_context_t context; 323 context.font = font; 324 context.face = face; 325 return _get_gdef (face).get_lig_carets (&context, glyph, start_offset, caret_count, caret_array); 326} 327 328/* 329 * GSUB/GPOS 330 */ 331 332static const GSUBGPOS& 333get_gsubgpos_table (hb_face_t *face, 334 hb_tag_t table_tag) 335{ 336 switch (table_tag) { 337 case HB_OT_TAG_GSUB: return _get_gsub (face); 338 case HB_OT_TAG_GPOS: return _get_gpos (face); 339 default: return Null(GSUBGPOS); 340 } 341} 342 343 344unsigned int 345hb_ot_layout_table_get_script_tags (hb_face_t *face, 346 hb_tag_t table_tag, 347 unsigned int start_offset, 348 unsigned int *script_count /* IN/OUT */, 349 hb_tag_t *script_tags /* OUT */) 350{ 351 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 352 353 return g.get_script_tags (start_offset, script_count, script_tags); 354} 355 356hb_bool_t 357hb_ot_layout_table_find_script (hb_face_t *face, 358 hb_tag_t table_tag, 359 hb_tag_t script_tag, 360 unsigned int *script_index) 361{ 362 ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX); 363 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 364 365 if (g.find_script_index (script_tag, script_index)) 366 return TRUE; 367 368 /* try finding 'DFLT' */ 369 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) 370 return FALSE; 371 372 /* try with 'dflt'; MS site has had typos and many fonts use it now :( */ 373 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) 374 return FALSE; 375 376 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX; 377 return FALSE; 378} 379 380unsigned int 381hb_ot_layout_table_get_feature_tags (hb_face_t *face, 382 hb_tag_t table_tag, 383 unsigned int start_offset, 384 unsigned int *feature_count /* IN/OUT */, 385 hb_tag_t *feature_tags /* OUT */) 386{ 387 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 388 389 return g.get_feature_tags (start_offset, feature_count, feature_tags); 390} 391 392 393unsigned int 394hb_ot_layout_script_get_language_tags (hb_face_t *face, 395 hb_tag_t table_tag, 396 unsigned int script_index, 397 unsigned int start_offset, 398 unsigned int *language_count /* IN/OUT */, 399 hb_tag_t *language_tags /* OUT */) 400{ 401 const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index); 402 403 return s.get_lang_sys_tags (start_offset, language_count, language_tags); 404} 405 406hb_bool_t 407hb_ot_layout_script_find_language (hb_face_t *face, 408 hb_tag_t table_tag, 409 unsigned int script_index, 410 hb_tag_t language_tag, 411 unsigned int *language_index) 412{ 413 ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX); 414 const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index); 415 416 if (s.find_lang_sys_index (language_tag, language_index)) 417 return TRUE; 418 419 /* try with 'dflt'; MS site has had typos and many fonts use it now :( */ 420 if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index)) 421 return FALSE; 422 423 if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX; 424 return FALSE; 425} 426 427hb_bool_t 428hb_ot_layout_language_get_required_feature_index (hb_face_t *face, 429 hb_tag_t table_tag, 430 unsigned int script_index, 431 unsigned int language_index, 432 unsigned int *feature_index) 433{ 434 const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index); 435 436 if (feature_index) *feature_index = l.get_required_feature_index (); 437 438 return l.has_required_feature (); 439} 440 441unsigned int 442hb_ot_layout_language_get_feature_indexes (hb_face_t *face, 443 hb_tag_t table_tag, 444 unsigned int script_index, 445 unsigned int language_index, 446 unsigned int start_offset, 447 unsigned int *feature_count /* IN/OUT */, 448 unsigned int *feature_indexes /* OUT */) 449{ 450 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 451 const LangSys &l = g.get_script (script_index).get_lang_sys (language_index); 452 453 return l.get_feature_indexes (start_offset, feature_count, feature_indexes); 454} 455 456unsigned int 457hb_ot_layout_language_get_feature_tags (hb_face_t *face, 458 hb_tag_t table_tag, 459 unsigned int script_index, 460 unsigned int language_index, 461 unsigned int start_offset, 462 unsigned int *feature_count /* IN/OUT */, 463 hb_tag_t *feature_tags /* OUT */) 464{ 465 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 466 const LangSys &l = g.get_script (script_index).get_lang_sys (language_index); 467 468 ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t)); 469 unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags); 470 471 if (feature_tags) { 472 unsigned int count = *feature_count; 473 for (unsigned int i = 0; i < count; i++) 474 feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]); 475 } 476 477 return ret; 478} 479 480 481hb_bool_t 482hb_ot_layout_language_find_feature (hb_face_t *face, 483 hb_tag_t table_tag, 484 unsigned int script_index, 485 unsigned int language_index, 486 hb_tag_t feature_tag, 487 unsigned int *feature_index) 488{ 489 ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX); 490 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 491 const LangSys &l = g.get_script (script_index).get_lang_sys (language_index); 492 493 unsigned int num_features = l.get_feature_count (); 494 for (unsigned int i = 0; i < num_features; i++) { 495 unsigned int f_index = l.get_feature_index (i); 496 497 if (feature_tag == g.get_feature_tag (f_index)) { 498 if (feature_index) *feature_index = f_index; 499 return TRUE; 500 } 501 } 502 503 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX; 504 return FALSE; 505} 506 507unsigned int 508hb_ot_layout_feature_get_lookup_indexes (hb_face_t *face, 509 hb_tag_t table_tag, 510 unsigned int feature_index, 511 unsigned int start_offset, 512 unsigned int *lookup_count /* IN/OUT */, 513 unsigned int *lookup_indexes /* OUT */) 514{ 515 const GSUBGPOS &g = get_gsubgpos_table (face, table_tag); 516 const Feature &f = g.get_feature (feature_index); 517 518 return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes); 519} 520 521 522/* 523 * GSUB 524 */ 525 526hb_bool_t 527hb_ot_layout_has_substitution (hb_face_t *face) 528{ 529 return &_get_gsub (face) != &Null(GSUB); 530} 531 532hb_bool_t 533hb_ot_layout_substitute_lookup (hb_face_t *face, 534 hb_buffer_t *buffer, 535 unsigned int lookup_index, 536 hb_mask_t mask) 537{ 538 hb_ot_layout_context_t context; 539 context.font = NULL; 540 context.face = face; 541 return _get_gsub (face).substitute_lookup (&context, buffer, lookup_index, mask); 542} 543 544 545/* 546 * GPOS 547 */ 548 549hb_bool_t 550hb_ot_layout_has_positioning (hb_face_t *face) 551{ 552 return &_get_gpos (face) != &Null(GPOS); 553} 554 555hb_bool_t 556hb_ot_layout_position_lookup (hb_font_t *font, 557 hb_face_t *face, 558 hb_buffer_t *buffer, 559 unsigned int lookup_index, 560 hb_mask_t mask) 561{ 562 hb_ot_layout_context_t context; 563 context.font = font; 564 context.face = face; 565 return _get_gpos (face).position_lookup (&context, buffer, lookup_index, mask); 566} 567 568void 569hb_ot_layout_position_finish (hb_font_t *font, 570 hb_face_t *face, 571 hb_buffer_t *buffer) 572{ 573 unsigned int i, j; 574 unsigned int len = hb_buffer_get_length (buffer); 575 hb_internal_glyph_position_t *positions = (hb_internal_glyph_position_t *) hb_buffer_get_glyph_positions (buffer); 576 577 /* TODO: Vertical */ 578 579 /* Handle cursive connections */ 580 /* First handle all left-to-right connections */ 581 for (j = 0; j < len; j++) { 582 if (positions[j].cursive_chain > 0) { 583 positions[j].y_offset += positions[j - positions[j].cursive_chain].y_offset; 584 positions[j].cursive_chain = 0; 585 } 586 } 587 /* Then handle all right-to-left connections */ 588 for (i = len; i > 0; i--) { 589 j = i - 1; 590 if (positions[j].cursive_chain < 0) { 591 positions[j].y_offset += positions[j - positions[j].cursive_chain].y_offset; 592 positions[j].cursive_chain = 0; 593 } 594 } 595 596 /* Handle attachments */ 597 for (i = 0; i < len; i++) 598 if (positions[i].back) 599 { 600 unsigned int back = i - positions[i].back; 601 positions[i].back = 0; 602 positions[i].x_offset += positions[back].x_offset; 603 positions[i].y_offset += positions[back].y_offset; 604 605 if (buffer->direction == HB_DIRECTION_RTL) 606 for (j = back + 1; j < i + 1; j++) { 607 positions[i].x_offset += positions[j].x_advance; 608 positions[i].y_offset += positions[j].y_advance; 609 } 610 else 611 for (j = back; j < i; j++) { 612 positions[i].x_offset -= positions[j].x_advance; 613 positions[i].y_offset -= positions[j].y_advance; 614 } 615 } 616} 617