src/hb-ot-layout.cc

   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 /* XXX */
  32 #include "hb-buffer-private.h"
  33
  34 #include "hb-ot-layout.h"
  35 #include "hb-ot-layout-private.h"
  36
  37 #include "hb-ot-layout-open-private.h"
  38 #include "hb-ot-layout-gdef-private.h"
  39 #include "hb-ot-layout-gsub-private.h"
  40 #include "hb-ot-layout-gpos-private.h"
  41
  42
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46
  47 hb_ot_layout_t *
  48 hb_ot_layout_create (void)
  49 {
  50   hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
  51
  52   layout->gdef = &Null(GDEF);
  53   layout->gsub = &Null(GSUB);
  54   layout->gpos = &Null(GPOS);
  55
  56   return layout;
  57 }
  58
  59 hb_ot_layout_t *
  60 hb_ot_layout_create_for_data (const char *font_data,
  61                               int         face_index)
  62 {
  63   hb_ot_layout_t *layout;
  64
  65   if (HB_UNLIKELY (font_data == NULL))
  66     return hb_ot_layout_create ();
  67
  68   layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
  69
  70   const OpenTypeFontFile &font = OpenTypeFontFile::get_for_data (font_data);
  71   const OpenTypeFontFace &face = font.get_face (face_index);
  72
  73   layout->gdef = &GDEF::get_for_data (font.get_table_data (face.get_table_by_tag (GDEF::Tag)));
  74   layout->gsub = &GSUB::get_for_data (font.get_table_data (face.get_table_by_tag (GSUB::Tag)));
  75   layout->gpos = &GPOS::get_for_data (font.get_table_data (face.get_table_by_tag (GPOS::Tag)));
  76
  77   return layout;
  78 }
  79
  80 void
  81 hb_ot_layout_destroy (hb_ot_layout_t *layout)
  82 {
  83   free (layout);
  84 }
  85
  86
  87 /*
  88  * GDEF
  89  */
  90
  91 /* TODO the public class_t is a mess */
  92
  93 hb_bool_t
  94 hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout)
  95 {
  96   return layout->gdef->has_glyph_classes ();
  97 }
  98
  99 HB_INTERNAL hb_bool_t
 100 _hb_ot_layout_has_new_glyph_classes (hb_ot_layout_t *layout)
 101 {
 102   return layout->new_gdef.len > 0;
 103 }
 104
 105 HB_INTERNAL unsigned int
 106 _hb_ot_layout_get_glyph_property (hb_ot_layout_t *layout,
 107                                   hb_codepoint_t  glyph)
 108 {
 109   hb_ot_layout_class_t klass;
 110
 111   klass = layout->gdef->get_glyph_class (glyph);
 112
 113   if (!klass && glyph < layout->new_gdef.len)
 114     klass = layout->new_gdef.klasses[glyph];
 115
 116   switch (klass) {
 117   default:
 118   case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
 119   case GDEF::BaseGlyph:         return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
 120   case GDEF::LigatureGlyph:     return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
 121   case GDEF::ComponentGlyph:    return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
 122   case GDEF::MarkGlyph:
 123         /* TODO old harfbuzz doesn't always parse mark attachments as it says it was
 124          * introduced without a version bump, so it may not be safe */
 125         klass = layout->gdef->get_mark_attachment_type (glyph);
 126         return HB_OT_LAYOUT_GLYPH_CLASS_MARK + (klass << 8);
 127   }
 128 }
 129
 130 HB_INTERNAL hb_bool_t
 131 _hb_ot_layout_check_glyph_property (hb_ot_layout_t  *layout,
 132                                     hb_glyph_info_t *ginfo,
 133                                     unsigned int     lookup_flags,
 134                                     unsigned int    *property_out)
 135 {
 136   unsigned int property;
 137
 138   if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
 139     ginfo->gproperty = _hb_ot_layout_get_glyph_property (layout, ginfo->gindex);
 140   property = ginfo->gproperty;
 141   if (property_out)
 142     *property_out = property;
 143
 144   /* Not covered, if, for example, glyph class is ligature and
 145    * lookup_flags includes LookupFlags::IgnoreLigatures
 146    */
 147   if (property & lookup_flags)
 148     return false;
 149
 150   if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
 151   {
 152     /* If using mark filtering sets, the high short of
 153      * lookup_flags has the set index.
 154      */
 155     if (lookup_flags & LookupFlag::UseMarkFilteringSet)
 156       return layout->gdef->mark_set_covers (lookup_flags >> 16, ginfo->gindex);
 157
 158     /* The second byte of lookup_flags has the meaning
 159      * "ignore marks of attachment type different than
 160      * the attachment type specified."
 161      */
 162     if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
 163       return (lookup_flags & LookupFlag::MarkAttachmentType) == (property & LookupFlag::MarkAttachmentType);
 164   }
 165
 166   return true;
 167 }
 168
 169 HB_INTERNAL hb_bool_t
 170 _hb_ot_layout_skip_mark (hb_ot_layout_t  *layout,
 171                          hb_glyph_info_t *ginfo,
 172                          unsigned int     lookup_flags,
 173                          unsigned int    *property_out)
 174 {
 175   unsigned int property;
 176
 177   if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
 178     ginfo->gproperty = _hb_ot_layout_get_glyph_property (layout, ginfo->gindex);
 179   property = ginfo->gproperty;
 180   if (property_out)
 181     *property_out = property;
 182
 183   if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
 184   {
 185     /* Skip mark if lookup_flags includes LookupFlags::IgnoreMarks */
 186     if (lookup_flags & LookupFlag::IgnoreMarks)
 187       return true;
 188
 189     /* If using mark filtering sets, the high short of lookup_flags has the set index. */
 190     if (lookup_flags & LookupFlag::UseMarkFilteringSet)
 191       return !layout->gdef->mark_set_covers (lookup_flags >> 16, ginfo->gindex);
 192
 193     /* The second byte of lookup_flags has the meaning "ignore marks of attachment type
 194      * different than the attachment type specified." */
 195     if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
 196       return (lookup_flags & LookupFlag::MarkAttachmentType) != (property & LookupFlag::MarkAttachmentType);
 197   }
 198
 199   return false;
 200 }
 201
 202 HB_INTERNAL void
 203 _hb_ot_layout_set_glyph_property (hb_ot_layout_t *layout,
 204                                   hb_codepoint_t  glyph,
 205                                   unsigned int    property)
 206 { hb_ot_layout_set_glyph_class (layout, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }
 207
 208
 209 hb_ot_layout_glyph_class_t
 210 hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
 211                               hb_codepoint_t  glyph)
 212 { return (hb_ot_layout_glyph_class_t) (_hb_ot_layout_get_glyph_property (layout, glyph) & 0xff); }
 213
 214 void
 215 hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
 216                               hb_codepoint_t              glyph,
 217                               hb_ot_layout_glyph_class_t  klass)
 218 {
 219   /* TODO optimize this, similar to old harfbuzz code for example */
 220
 221   hb_ot_layout_class_t gdef_klass;
 222   int len = layout->new_gdef.len;
 223
 224   if (HB_UNLIKELY (glyph > 65535))
 225     return;
 226
 227   if (glyph >= len) {
 228     int new_len;
 229     unsigned char *new_klasses;
 230
 231     new_len = len == 0 ? 120 : 2 * len;
 232     if (new_len > 65535)
 233       new_len = 65535;
 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
 258 void
 259 hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
 260                                   uint16_t        num_total_glyphs,
 261                                   hb_codepoint_t *glyphs,
 262                                   unsigned char  *klasses,
 263                                   uint16_t        count)
 264 {
 265   if (HB_UNLIKELY (!count || !glyphs || !klasses))
 266     return;
 267
 268   if (layout->new_gdef.len == 0) {
 269     layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char));
 270     layout->new_gdef.len = count;
 271   }
 272
 273   for (unsigned int i = 0; i < count; i++)
 274     hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
 275 }
 276
 277 hb_bool_t
 278 hb_ot_layout_get_attach_points (hb_ot_layout_t *layout,
 279                                 hb_codepoint_t  glyph,
 280                                 unsigned int   *point_count /* IN/OUT */,
 281                                 unsigned int   *point_array /* OUT */)
 282 {
 283   return layout->gdef->get_attach_points (glyph, point_count, point_array);
 284 }
 285
 286 hb_bool_t
 287 hb_ot_layout_get_lig_carets (hb_ot_layout_t *layout,
 288                              hb_codepoint_t  glyph,
 289                              unsigned int   *caret_count /* IN/OUT */,
 290                              int            *caret_array /* OUT */)
 291 {
 292   return layout->gdef->get_lig_carets (layout, glyph, caret_count, caret_array);
 293 }
 294
 295 /*
 296  * GSUB/GPOS
 297  */
 298
 299 static const GSUBGPOS&
 300 get_gsubgpos_table (hb_ot_layout_t            *layout,
 301                     hb_ot_layout_table_type_t  table_type)
 302 {
 303   switch (table_type) {
 304     case HB_OT_LAYOUT_TABLE_TYPE_GSUB: return *(layout->gsub);
 305     case HB_OT_LAYOUT_TABLE_TYPE_GPOS: return *(layout->gpos);
 306     default:                           return Null(GSUBGPOS);
 307   }
 308 }
 309
 310
 311 unsigned int
 312 hb_ot_layout_table_get_script_count (hb_ot_layout_t            *layout,
 313                                      hb_ot_layout_table_type_t  table_type)
 314 {
 315   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 316
 317   return g.get_script_count ();
 318 }
 319
 320 hb_tag_t
 321 hb_ot_layout_table_get_script_tag (hb_ot_layout_t            *layout,
 322                                    hb_ot_layout_table_type_t  table_type,
 323                                    unsigned int               script_index)
 324 {
 325   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 326
 327   return g.get_script_tag (script_index);
 328 }
 329
 330 hb_bool_t
 331 hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
 332                                 hb_ot_layout_table_type_t  table_type,
 333                                 hb_tag_t                   script_tag,
 334                                 unsigned int              *script_index)
 335 {
 336   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
 337   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 338
 339   if (g.find_script_index (script_tag, script_index))
 340     return TRUE;
 341
 342   /* try finding 'DFLT' */
 343   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_SCRIPT, script_index))
 344     return FALSE;
 345
 346   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 347   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, script_index))
 348     return FALSE;
 349
 350   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 351   return FALSE;
 352 }
 353
 354 unsigned int
 355 hb_ot_layout_table_get_feature_count (hb_ot_layout_t            *layout,
 356                                       hb_ot_layout_table_type_t  table_type)
 357 {
 358   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 359
 360   return g.get_feature_count ();
 361 }
 362
 363 hb_tag_t
 364 hb_ot_layout_table_get_feature_tag (hb_ot_layout_t            *layout,
 365                                     hb_ot_layout_table_type_t  table_type,
 366                                     unsigned int               feature_index)
 367 {
 368   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 369
 370   return g.get_feature_tag (feature_index);
 371 }
 372
 373 hb_bool_t
 374 hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
 375                                  hb_ot_layout_table_type_t  table_type,
 376                                  hb_tag_t                   feature_tag,
 377                                  unsigned int              *feature_index)
 378 {
 379   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 380   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 381
 382   if (g.find_feature_index (feature_tag, feature_index))
 383     return TRUE;
 384
 385   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 386   return FALSE;
 387 }
 388
 389 unsigned int
 390 hb_ot_layout_table_get_lookup_count (hb_ot_layout_t            *layout,
 391                                      hb_ot_layout_table_type_t  table_type)
 392 {
 393   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 394
 395   return g.get_lookup_count ();
 396 }
 397
 398
 399 unsigned int
 400 hb_ot_layout_script_get_language_count (hb_ot_layout_t            *layout,
 401                                         hb_ot_layout_table_type_t  table_type,
 402                                         unsigned int               script_index)
 403 {
 404   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 405
 406   return s.get_lang_sys_count ();
 407 }
 408
 409 hb_tag_t
 410 hb_ot_layout_script_get_language_tag (hb_ot_layout_t            *layout,
 411                                       hb_ot_layout_table_type_t  table_type,
 412                                       unsigned int               script_index,
 413                                       unsigned int               language_index)
 414 {
 415   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 416
 417   return s.get_lang_sys_tag (language_index);
 418 }
 419
 420 hb_bool_t
 421 hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
 422                                    hb_ot_layout_table_type_t  table_type,
 423                                    unsigned int               script_index,
 424                                    hb_tag_t                   language_tag,
 425                                    unsigned int              *language_index)
 426 {
 427   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
 428   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 429
 430   if (s.find_lang_sys_index (language_tag, language_index))
 431     return TRUE;
 432
 433   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 434   if (s.find_lang_sys_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, language_index))
 435     return FALSE;
 436
 437   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
 438   return FALSE;
 439 }
 440
 441 hb_bool_t
 442 hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *layout,
 443                                                   hb_ot_layout_table_type_t  table_type,
 444                                                   unsigned int               script_index,
 445                                                   unsigned int               language_index,
 446                                                   unsigned int              *feature_index)
 447 {
 448   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 449
 450   if (feature_index) *feature_index = l.get_required_feature_index ();
 451
 452   return l.has_required_feature ();
 453 }
 454
 455 unsigned int
 456 hb_ot_layout_language_get_feature_count (hb_ot_layout_t            *layout,
 457                                          hb_ot_layout_table_type_t  table_type,
 458                                          unsigned int               script_index,
 459                                          unsigned int               language_index)
 460 {
 461   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 462
 463   return l.get_feature_count ();
 464 }
 465
 466 unsigned int
 467 hb_ot_layout_language_get_feature_index (hb_ot_layout_t            *layout,
 468                                          hb_ot_layout_table_type_t  table_type,
 469                                          unsigned int               script_index,
 470                                          unsigned int               language_index,
 471                                          unsigned int               num_feature)
 472 {
 473   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 474   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 475
 476   return l.get_feature_index (num_feature);
 477 }
 478
 479 hb_tag_t
 480 hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
 481                                        hb_ot_layout_table_type_t  table_type,
 482                                        unsigned int               script_index,
 483                                        unsigned int               language_index,
 484                                        unsigned int               num_feature)
 485 {
 486   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 487   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 488   unsigned int feature_index = l.get_feature_index (num_feature);
 489
 490   return g.get_feature_tag (feature_index);
 491 }
 492
 493
 494 hb_bool_t
 495 hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
 496                                     hb_ot_layout_table_type_t  table_type,
 497                                     unsigned int               script_index,
 498                                     unsigned int               language_index,
 499                                     hb_tag_t                   feature_tag,
 500                                     unsigned int              *feature_index)
 501 {
 502   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 503   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 504   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 505
 506   unsigned int num_features = l.get_feature_count ();
 507   for (unsigned int i = 0; i < num_features; i++) {
 508     unsigned int f_index = l.get_feature_index (i);
 509
 510     if (feature_tag == g.get_feature_tag (f_index)) {
 511       if (feature_index) *feature_index = f_index;
 512       return TRUE;
 513     }
 514   }
 515
 516   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 517   return FALSE;
 518 }
 519
 520 unsigned int
 521 hb_ot_layout_feature_get_lookup_count (hb_ot_layout_t            *layout,
 522                                        hb_ot_layout_table_type_t  table_type,
 523                                        unsigned int               feature_index)
 524 {
 525   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 526   const Feature &f = g.get_feature (feature_index);
 527
 528   return f.get_lookup_count ();
 529 }
 530
 531 unsigned int
 532 hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
 533                                        hb_ot_layout_table_type_t  table_type,
 534                                        unsigned int               feature_index,
 535                                        unsigned int               num_lookup)
 536 {
 537   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 538   const Feature &f = g.get_feature (feature_index);
 539
 540   return f.get_lookup_index (num_lookup);
 541 }
 542
 543 /*
 544  * GSUB
 545  */
 546
 547 hb_bool_t
 548 hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
 549                                 hb_buffer_t                 *buffer,
 550                                 unsigned int                 lookup_index,
 551                                 hb_ot_layout_feature_mask_t  mask)
 552 {
 553   return layout->gsub->substitute_lookup (layout, buffer, lookup_index, mask);
 554 }
 555
 556 /*
 557  * GPOS
 558  */
 559
 560 hb_bool_t
 561 hb_ot_layout_position_lookup   (hb_ot_layout_t              *layout,
 562                                 hb_buffer_t                 *buffer,
 563                                 unsigned int                 lookup_index,
 564                                 hb_ot_layout_feature_mask_t  mask)
 565 {
 566   return layout->gpos->position_lookup (layout, buffer, lookup_index, mask);
 567 }