src/hb-ot-layout.cc

   1 /*
   2  * Copyright © 1998-2004  David Turner and Werner Lemberg
   3  * Copyright © 2006  Behdad Esfahbod
   4  * Copyright © 2007,2008,2009  Red Hat, Inc.
   5  * Copyright © 2012  Google, Inc.
   6  *
   7  *  This is part of HarfBuzz, a text shaping library.
   8  *
   9  * Permission is hereby granted, without written agreement and without
  10  * license or royalty fees, to use, copy, modify, and distribute this
  11  * software and its documentation for any purpose, provided that the
  12  * above copyright notice and the following two paragraphs appear in
  13  * all copies of this software.
  14  *
  15  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  16  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  17  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  18  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  19  * DAMAGE.
  20  *
  21  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  22  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  23  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  24  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  25  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  26  *
  27  * Red Hat Author(s): Behdad Esfahbod
  28  * Google Author(s): Behdad Esfahbod
  29  */
  30
  31 #include "hb-ot-layout-private.hh"
  32
  33 #include "hb-ot-layout-gdef-table.hh"
  34 #include "hb-ot-layout-gsub-table.hh"
  35 #include "hb-ot-layout-gpos-table.hh"
  36 #include "hb-ot-maxp-table.hh"
  37
  38
  39 #include <stdlib.h>
  40 #include <string.h>
  41
  42
  43 HB_SHAPER_DATA_ENSURE_DECLARE(ot, face)
  44
  45 hb_ot_layout_t *
  46 _hb_ot_layout_create (hb_face_t *face)
  47 {
  48   hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
  49   if (unlikely (!layout))
  50     return NULL;
  51
  52   layout->gdef_blob = Sanitizer<GDEF>::sanitize (face->reference_table (HB_OT_TAG_GDEF));
  53   layout->gdef = Sanitizer<GDEF>::lock_instance (layout->gdef_blob);
  54
  55   layout->gsub_blob = Sanitizer<GSUB>::sanitize (face->reference_table (HB_OT_TAG_GSUB));
  56   layout->gsub = Sanitizer<GSUB>::lock_instance (layout->gsub_blob);
  57
  58   layout->gpos_blob = Sanitizer<GPOS>::sanitize (face->reference_table (HB_OT_TAG_GPOS));
  59   layout->gpos = Sanitizer<GPOS>::lock_instance (layout->gpos_blob);
  60
  61   layout->gsub_lookup_count = layout->gsub->get_lookup_count ();
  62   layout->gpos_lookup_count = layout->gpos->get_lookup_count ();
  63
  64   layout->gsub_digests = (hb_set_digest_t *) calloc (layout->gsub->get_lookup_count (), sizeof (hb_set_digest_t));
  65   layout->gpos_digests = (hb_set_digest_t *) calloc (layout->gpos->get_lookup_count (), sizeof (hb_set_digest_t));
  66
  67   if (unlikely ((layout->gsub_lookup_count && !layout->gsub_digests) ||
  68                 (layout->gpos_lookup_count && !layout->gpos_digests)))
  69   {
  70     _hb_ot_layout_destroy (layout);
  71     return NULL;
  72   }
  73
  74   for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
  75     layout->gsub->add_coverage (&layout->gsub_digests[i], i);
  76   for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
  77     layout->gpos->add_coverage (&layout->gpos_digests[i], i);
  78
  79   return layout;
  80 }
  81
  82 void
  83 _hb_ot_layout_destroy (hb_ot_layout_t *layout)
  84 {
  85   hb_blob_destroy (layout->gdef_blob);
  86   hb_blob_destroy (layout->gsub_blob);
  87   hb_blob_destroy (layout->gpos_blob);
  88
  89   free (layout->gsub_digests);
  90   free (layout->gpos_digests);
  91
  92   free (layout);
  93 }
  94
  95 static inline const GDEF&
  96 _get_gdef (hb_face_t *face)
  97 {
  98   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return Null(GDEF);
  99   return *hb_ot_layout_from_face (face)->gdef;
 100 }
 101 static inline const GSUB&
 102 _get_gsub (hb_face_t *face)
 103 {
 104   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return Null(GSUB);
 105   return *hb_ot_layout_from_face (face)->gsub;
 106 }
 107 static inline const GPOS&
 108 _get_gpos (hb_face_t *face)
 109 {
 110   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return Null(GPOS);
 111   return *hb_ot_layout_from_face (face)->gpos;
 112 }
 113
 114
 115 /*
 116  * GDEF
 117  */
 118
 119 hb_bool_t
 120 hb_ot_layout_has_glyph_classes (hb_face_t *face)
 121 {
 122   return _get_gdef (face).has_glyph_classes ();
 123 }
 124
 125
 126 unsigned int
 127 hb_ot_layout_get_attach_points (hb_face_t      *face,
 128                                 hb_codepoint_t  glyph,
 129                                 unsigned int    start_offset,
 130                                 unsigned int   *point_count /* IN/OUT */,
 131                                 unsigned int   *point_array /* OUT */)
 132 {
 133   return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
 134 }
 135
 136 unsigned int
 137 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
 138                                   hb_direction_t  direction,
 139                                   hb_codepoint_t  glyph,
 140                                   unsigned int    start_offset,
 141                                   unsigned int   *caret_count /* IN/OUT */,
 142                                   int            *caret_array /* OUT */)
 143 {
 144   return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
 145 }
 146
 147
 148 /*
 149  * GSUB/GPOS
 150  */
 151
 152 static const GSUBGPOS&
 153 get_gsubgpos_table (hb_face_t *face,
 154                     hb_tag_t   table_tag)
 155 {
 156   switch (table_tag) {
 157     case HB_OT_TAG_GSUB: return _get_gsub (face);
 158     case HB_OT_TAG_GPOS: return _get_gpos (face);
 159     default:             return Null(GSUBGPOS);
 160   }
 161 }
 162
 163
 164 unsigned int
 165 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 166                                     hb_tag_t      table_tag,
 167                                     unsigned int  start_offset,
 168                                     unsigned int *script_count /* IN/OUT */,
 169                                     hb_tag_t     *script_tags /* OUT */)
 170 {
 171   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 172
 173   return g.get_script_tags (start_offset, script_count, script_tags);
 174 }
 175
 176 hb_bool_t
 177 hb_ot_layout_table_find_script (hb_face_t    *face,
 178                                 hb_tag_t      table_tag,
 179                                 hb_tag_t      script_tag,
 180                                 unsigned int *script_index)
 181 {
 182   ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
 183   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 184
 185   if (g.find_script_index (script_tag, script_index))
 186     return true;
 187
 188   /* try finding 'DFLT' */
 189   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
 190     return false;
 191
 192   /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
 193    * including many versions of DejaVu Sans Mono! */
 194   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
 195     return false;
 196
 197   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 198   return false;
 199 }
 200
 201 hb_bool_t
 202 hb_ot_layout_table_choose_script (hb_face_t      *face,
 203                                   hb_tag_t        table_tag,
 204                                   const hb_tag_t *script_tags,
 205                                   unsigned int   *script_index,
 206                                   hb_tag_t       *chosen_script)
 207 {
 208   ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
 209   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 210
 211   while (*script_tags)
 212   {
 213     if (g.find_script_index (*script_tags, script_index)) {
 214       if (chosen_script)
 215         *chosen_script = *script_tags;
 216       return true;
 217     }
 218     script_tags++;
 219   }
 220
 221   /* try finding 'DFLT' */
 222   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
 223     if (chosen_script)
 224       *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
 225     return false;
 226   }
 227
 228   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 229   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
 230     if (chosen_script)
 231       *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
 232     return false;
 233   }
 234
 235   /* try with 'latn'; some old fonts put their features there even though
 236      they're really trying to support Thai, for example :( */
 237 #define HB_OT_TAG_LATIN_SCRIPT          HB_TAG ('l', 'a', 't', 'n')
 238   if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
 239     if (chosen_script)
 240       *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
 241     return false;
 242   }
 243
 244   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 245   if (chosen_script)
 246     *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 247   return false;
 248 }
 249
 250 unsigned int
 251 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 252                                      hb_tag_t      table_tag,
 253                                      unsigned int  start_offset,
 254                                      unsigned int *feature_count /* IN/OUT */,
 255                                      hb_tag_t     *feature_tags /* OUT */)
 256 {
 257   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 258
 259   return g.get_feature_tags (start_offset, feature_count, feature_tags);
 260 }
 261
 262
 263 unsigned int
 264 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 265                                        hb_tag_t      table_tag,
 266                                        unsigned int  script_index,
 267                                        unsigned int  start_offset,
 268                                        unsigned int *language_count /* IN/OUT */,
 269                                        hb_tag_t     *language_tags /* OUT */)
 270 {
 271   const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
 272
 273   return s.get_lang_sys_tags (start_offset, language_count, language_tags);
 274 }
 275
 276 hb_bool_t
 277 hb_ot_layout_script_find_language (hb_face_t    *face,
 278                                    hb_tag_t      table_tag,
 279                                    unsigned int  script_index,
 280                                    hb_tag_t      language_tag,
 281                                    unsigned int *language_index)
 282 {
 283   ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
 284   const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
 285
 286   if (s.find_lang_sys_index (language_tag, language_index))
 287     return true;
 288
 289   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 290   if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
 291     return false;
 292
 293   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
 294   return false;
 295 }
 296
 297 hb_bool_t
 298 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 299                                                   hb_tag_t      table_tag,
 300                                                   unsigned int  script_index,
 301                                                   unsigned int  language_index,
 302                                                   unsigned int *feature_index)
 303 {
 304   const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
 305
 306   if (feature_index) *feature_index = l.get_required_feature_index ();
 307
 308   return l.has_required_feature ();
 309 }
 310
 311 unsigned int
 312 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 313                                            hb_tag_t      table_tag,
 314                                            unsigned int  script_index,
 315                                            unsigned int  language_index,
 316                                            unsigned int  start_offset,
 317                                            unsigned int *feature_count /* IN/OUT */,
 318                                            unsigned int *feature_indexes /* OUT */)
 319 {
 320   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 321   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 322
 323   return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
 324 }
 325
 326 unsigned int
 327 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 328                                         hb_tag_t      table_tag,
 329                                         unsigned int  script_index,
 330                                         unsigned int  language_index,
 331                                         unsigned int  start_offset,
 332                                         unsigned int *feature_count /* IN/OUT */,
 333                                         hb_tag_t     *feature_tags /* OUT */)
 334 {
 335   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 336   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 337
 338   ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
 339   unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
 340
 341   if (feature_tags) {
 342     unsigned int count = *feature_count;
 343     for (unsigned int i = 0; i < count; i++)
 344       feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
 345   }
 346
 347   return ret;
 348 }
 349
 350
 351 hb_bool_t
 352 hb_ot_layout_language_find_feature (hb_face_t    *face,
 353                                     hb_tag_t      table_tag,
 354                                     unsigned int  script_index,
 355                                     unsigned int  language_index,
 356                                     hb_tag_t      feature_tag,
 357                                     unsigned int *feature_index)
 358 {
 359   ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 360   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 361   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 362
 363   unsigned int num_features = l.get_feature_count ();
 364   for (unsigned int i = 0; i < num_features; i++) {
 365     unsigned int f_index = l.get_feature_index (i);
 366
 367     if (feature_tag == g.get_feature_tag (f_index)) {
 368       if (feature_index) *feature_index = f_index;
 369       return true;
 370     }
 371   }
 372
 373   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 374   return false;
 375 }
 376
 377 unsigned int
 378 hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
 379                                          hb_tag_t      table_tag,
 380                                          unsigned int  feature_index,
 381                                          unsigned int  start_offset,
 382                                          unsigned int *lookup_count /* IN/OUT */,
 383                                          unsigned int *lookup_indexes /* OUT */)
 384 {
 385   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
 386   const Feature &f = g.get_feature (feature_index);
 387
 388   return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
 389 }
 390
 391
 392 /*
 393  * GSUB
 394  */
 395
 396 hb_bool_t
 397 hb_ot_layout_has_substitution (hb_face_t *face)
 398 {
 399   return &_get_gsub (face) != &Null(GSUB);
 400 }
 401
 402 hb_bool_t
 403 hb_ot_layout_would_substitute_lookup (hb_face_t            *face,
 404                                       const hb_codepoint_t *glyphs,
 405                                       unsigned int          glyphs_length,
 406                                       unsigned int          lookup_index)
 407 {
 408   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
 409   return hb_ot_layout_would_substitute_lookup_fast (face, glyphs, glyphs_length, lookup_index);
 410 }
 411
 412 hb_bool_t
 413 hb_ot_layout_would_substitute_lookup_fast (hb_face_t            *face,
 414                                            const hb_codepoint_t *glyphs,
 415                                            unsigned int          glyphs_length,
 416                                            unsigned int          lookup_index)
 417 {
 418   if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
 419   hb_would_apply_context_t c (face, glyphs, glyphs_length, &hb_ot_layout_from_face (face)->gsub_digests[lookup_index]);
 420   return hb_ot_layout_from_face (face)->gsub->would_substitute_lookup (&c, lookup_index);
 421 }
 422
 423 void
 424 hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
 425 {
 426   GSUB::substitute_start (font, buffer);
 427 }
 428
 429 hb_bool_t
 430 hb_ot_layout_substitute_lookup (hb_font_t    *font,
 431                                 hb_buffer_t  *buffer,
 432                                 unsigned int  lookup_index,
 433                                 hb_mask_t     mask)
 434 {
 435   if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gsub_lookup_count)) return false;
 436   hb_apply_context_t c (font, buffer, mask, &hb_ot_layout_from_face (font->face)->gsub_digests[lookup_index]);
 437   return hb_ot_layout_from_face (font->face)->gsub->substitute_lookup (&c, lookup_index);
 438 }
 439
 440 void
 441 hb_ot_layout_substitute_finish (hb_font_t *font, hb_buffer_t *buffer)
 442 {
 443   GSUB::substitute_finish (font, buffer);
 444 }
 445
 446 void
 447 hb_ot_layout_substitute_closure_lookup (hb_face_t    *face,
 448                                         hb_set_t     *glyphs,
 449                                         unsigned int  lookup_index)
 450 {
 451   hb_closure_context_t c (face, glyphs);
 452   _get_gsub (face).closure_lookup (&c, lookup_index);
 453 }
 454
 455 /*
 456  * GPOS
 457  */
 458
 459 hb_bool_t
 460 hb_ot_layout_has_positioning (hb_face_t *face)
 461 {
 462   return &_get_gpos (face) != &Null(GPOS);
 463 }
 464
 465 void
 466 hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
 467 {
 468   GPOS::position_start (font, buffer);
 469 }
 470
 471 hb_bool_t
 472 hb_ot_layout_position_lookup (hb_font_t    *font,
 473                               hb_buffer_t  *buffer,
 474                               unsigned int  lookup_index,
 475                               hb_mask_t     mask)
 476 {
 477   if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gpos_lookup_count)) return false;
 478   hb_apply_context_t c (font, buffer, mask, &hb_ot_layout_from_face (font->face)->gpos_digests[lookup_index]);
 479   return hb_ot_layout_from_face (font->face)->gpos->position_lookup (&c, lookup_index);
 480 }
 481
 482 void
 483 hb_ot_layout_position_finish (hb_font_t *font, hb_buffer_t *buffer, hb_bool_t zero_width_attached_marks)
 484 {
 485   GPOS::position_finish (font, buffer, zero_width_attached_marks);
 486 }