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  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.h"
  32 #include "hb-ot-layout-private.h"
  33
  34 #include "hb-ot-layout-open-private.h"
  35 #include "hb-ot-layout-gdef-private.h"
  36 #include "hb-ot-layout-gsub-private.h"
  37
  38
  39 #include <stdlib.h>
  40 #include <string.h>
  41
  42
  43 struct _hb_ot_layout_t {
  44   const GDEF *gdef;
  45   const GSUB *gsub;
  46   const /*XXX*/GSUBGPOS *gpos;
  47
  48   struct {
  49     unsigned char *klasses;
  50     unsigned int len;
  51   } new_gdef;
  52
  53 };
  54
  55 hb_ot_layout_t *
  56 hb_ot_layout_create (void)
  57 {
  58   hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
  59
  60   layout->gdef = &NullGDEF;
  61   layout->gsub = &NullGSUB;
  62   layout->gpos = &/*XXX*/NullGSUBGPOS;
  63
  64   return layout;
  65 }
  66
  67 hb_ot_layout_t *
  68 hb_ot_layout_create_for_data (const char *font_data,
  69                               int         face_index)
  70 {
  71   hb_ot_layout_t *layout;
  72
  73   if (HB_UNLIKELY (font_data == NULL))
  74     return hb_ot_layout_create ();
  75
  76   layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
  77
  78   const OpenTypeFontFile &font = OpenTypeFontFile::get_for_data (font_data);
  79   const OpenTypeFontFace &face = font.get_face (face_index);
  80
  81   layout->gdef = &GDEF::get_for_data (font.get_table_data (face.get_table_by_tag (GDEF::Tag)));
  82   layout->gsub = &GSUB::get_for_data (font.get_table_data (face.get_table_by_tag (GSUB::Tag)));
  83   layout->gpos = &/*XXX*/GSUBGPOS::get_for_data (font.get_table_data (face.get_table_by_tag (/*XXX*/GSUBGPOS::GPOSTag)));
  84
  85   return layout;
  86 }
  87
  88 void
  89 hb_ot_layout_destroy (hb_ot_layout_t *layout)
  90 {
  91   free (layout);
  92 }
  93
  94 /*
  95  * GDEF
  96  */
  97
  98 hb_bool_t
  99 hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout)
 100 {
 101   return layout->gdef->has_glyph_classes ();
 102 }
 103
 104 HB_OT_LAYOUT_INTERNAL hb_bool_t
 105 _hb_ot_layout_has_new_glyph_classes (hb_ot_layout_t *layout)
 106 {
 107   return layout->new_gdef.len > 0;
 108 }
 109
 110 HB_OT_LAYOUT_INTERNAL hb_ot_layout_glyph_properties_t
 111 _hb_ot_layout_get_glyph_properties (hb_ot_layout_t *layout,
 112                                     hb_glyph_t      glyph)
 113 {
 114   hb_ot_layout_class_t klass;
 115
 116   /* TODO old harfbuzz doesn't always parse mark attachments as it says it was
 117    * introduced without a version bump, so it may not be safe */
 118   klass = layout->gdef->get_mark_attachment_type (glyph);
 119   if (klass)
 120     return klass << 8;
 121
 122   klass = layout->gdef->get_glyph_class (glyph);
 123
 124   if (!klass && glyph < layout->new_gdef.len)
 125     klass = layout->new_gdef.klasses[glyph];
 126
 127   switch (klass) {
 128   default:
 129   case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
 130   case GDEF::BaseGlyph:         return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
 131   case GDEF::LigatureGlyph:     return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
 132   case GDEF::MarkGlyph:         return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 133   case GDEF::ComponentGlyph:    return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
 134   }
 135 }
 136
 137 HB_OT_LAYOUT_INTERNAL hb_bool_t
 138 _hb_ot_layout_check_glyph_properties (hb_ot_layout_t                  *layout,
 139                                       HB_GlyphItem                     gitem,
 140                                       hb_ot_layout_lookup_flags_t      lookup_flags,
 141                                       hb_ot_layout_glyph_properties_t *property)
 142 {
 143   hb_ot_layout_glyph_class_t basic_glyph_class;
 144   hb_ot_layout_glyph_properties_t desired_attachment_class;
 145
 146   if (gitem->gproperties == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
 147   {
 148     gitem->gproperties = *property = _hb_ot_layout_get_glyph_properties (layout, gitem->gindex);
 149     if (gitem->gproperties == HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED)
 150       return false;
 151   }
 152
 153   *property = gitem->gproperties;
 154
 155   /* If the glyph was found in the MarkAttachmentClass table,
 156    * then that class value is the high byte of the result,
 157    * otherwise the low byte contains the basic type of the glyph
 158    * as defined by the GlyphClassDef table.
 159    */
 160   if (*property & LookupFlag::MarkAttachmentType)
 161     basic_glyph_class = HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 162   else
 163     basic_glyph_class = (hb_ot_layout_glyph_class_t) *property;
 164
 165   /* Not covered, if, for example, basic_glyph_class
 166    * is HB_GDEF_LIGATURE and lookup_flags includes LookupFlags::IgnoreLigatures
 167    */
 168   if (lookup_flags & basic_glyph_class)
 169     return false;
 170
 171   /* The high byte of lookup_flags has the meaning
 172    * "ignore marks of attachment type different than
 173    * the attachment type specified."
 174    */
 175   desired_attachment_class = lookup_flags & LookupFlag::MarkAttachmentType;
 176   if (desired_attachment_class)
 177   {
 178     if (basic_glyph_class == HB_OT_LAYOUT_GLYPH_CLASS_MARK &&
 179         *property != desired_attachment_class )
 180       return false;
 181   }
 182
 183   return true;
 184 }
 185
 186
 187 hb_ot_layout_glyph_class_t
 188 hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
 189                               hb_glyph_t      glyph)
 190 {
 191   hb_ot_layout_glyph_properties_t properties;
 192   hb_ot_layout_class_t klass;
 193
 194   properties = _hb_ot_layout_get_glyph_properties (layout, glyph);
 195
 196   if (properties & 0xFF00)
 197     return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 198
 199   return (hb_ot_layout_glyph_class_t) properties;
 200 }
 201
 202 void
 203 hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
 204                               hb_glyph_t                  glyph,
 205                               hb_ot_layout_glyph_class_t  klass)
 206 {
 207   /* TODO optimize this, similar to old harfbuzz code for example */
 208
 209   hb_ot_layout_class_t gdef_klass;
 210   int len = layout->new_gdef.len;
 211
 212   if (glyph >= len) {
 213     int new_len;
 214     unsigned char *new_klasses;
 215
 216     new_len = len == 0 ? 120 : 2 * len;
 217     if (new_len > 65535)
 218       new_len = 65535;
 219     new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char));
 220
 221     if (G_UNLIKELY (!new_klasses))
 222       return;
 223
 224     memset (new_klasses + len, 0, new_len - len);
 225
 226     layout->new_gdef.klasses = new_klasses;
 227     layout->new_gdef.len = new_len;
 228   }
 229
 230   switch (klass) {
 231   default:
 232   case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED:   gdef_klass = GDEF::UnclassifiedGlyph;   break;
 233   case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH:     gdef_klass = GDEF::BaseGlyph;           break;
 234   case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE:       gdef_klass = GDEF::LigatureGlyph;       break;
 235   case HB_OT_LAYOUT_GLYPH_CLASS_MARK:           gdef_klass = GDEF::MarkGlyph;           break;
 236   case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT:      gdef_klass = GDEF::ComponentGlyph;      break;
 237   }
 238
 239   layout->new_gdef.klasses[glyph] = gdef_klass;
 240   return;
 241 }
 242
 243 void
 244 hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
 245                                   uint16_t        num_total_glyphs,
 246                                   hb_glyph_t     *glyphs,
 247                                   unsigned char  *klasses,
 248                                   uint16_t        count)
 249 {
 250   int i;
 251
 252   if (G_UNLIKELY (!count || !glyphs || !klasses))
 253     return;
 254
 255   if (layout->new_gdef.len == 0) {
 256     layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char));
 257     layout->new_gdef.len = count;
 258   }
 259
 260   for (i = 0; i < count; i++)
 261     hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
 262 }
 263
 264 /*
 265  * GSUB/GPOS
 266  */
 267
 268 static const GSUBGPOS&
 269 get_gsubgpos_table (hb_ot_layout_t            *layout,
 270                     hb_ot_layout_table_type_t  table_type)
 271 {
 272   switch (table_type) {
 273     case HB_OT_LAYOUT_TABLE_TYPE_GSUB: return *(layout->gsub);
 274     case HB_OT_LAYOUT_TABLE_TYPE_GPOS: return *(layout->gpos);
 275     default:                           return NullGSUBGPOS;
 276   }
 277 }
 278
 279
 280 unsigned int
 281 hb_ot_layout_table_get_script_count (hb_ot_layout_t            *layout,
 282                                      hb_ot_layout_table_type_t  table_type)
 283 {
 284   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 285
 286   return g.get_script_count ();
 287 }
 288
 289 hb_tag_t
 290 hb_ot_layout_table_get_script_tag (hb_ot_layout_t            *layout,
 291                                    hb_ot_layout_table_type_t  table_type,
 292                                    unsigned int               script_index)
 293 {
 294   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 295
 296   return g.get_script_tag (script_index);
 297 }
 298
 299 hb_bool_t
 300 hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
 301                                 hb_ot_layout_table_type_t  table_type,
 302                                 hb_tag_t                   script_tag,
 303                                 unsigned int              *script_index)
 304 {
 305   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
 306   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 307
 308   if (g.find_script_index (script_tag, script_index))
 309     return TRUE;
 310
 311   /* try finding 'DFLT' */
 312   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_SCRIPT, script_index))
 313     return FALSE;
 314
 315   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 316   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, script_index))
 317     return FALSE;
 318
 319   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 320   return FALSE;
 321 }
 322
 323 unsigned int
 324 hb_ot_layout_table_get_feature_count (hb_ot_layout_t            *layout,
 325                                       hb_ot_layout_table_type_t  table_type)
 326 {
 327   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 328
 329   return g.get_feature_count ();
 330 }
 331
 332 hb_tag_t
 333 hb_ot_layout_table_get_feature_tag (hb_ot_layout_t            *layout,
 334                                     hb_ot_layout_table_type_t  table_type,
 335                                     unsigned int               feature_index)
 336 {
 337   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 338
 339   return g.get_feature_tag (feature_index);
 340 }
 341
 342 hb_bool_t
 343 hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
 344                                  hb_ot_layout_table_type_t  table_type,
 345                                  hb_tag_t                   feature_tag,
 346                                  unsigned int              *feature_index)
 347 {
 348   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 349   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 350
 351   if (g.find_feature_index (feature_tag, feature_index))
 352     return TRUE;
 353
 354   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 355   return FALSE;
 356 }
 357
 358 unsigned int
 359 hb_ot_layout_table_get_lookup_count (hb_ot_layout_t            *layout,
 360                                      hb_ot_layout_table_type_t  table_type)
 361 {
 362   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 363
 364   return g.get_lookup_count ();
 365 }
 366
 367
 368 unsigned int
 369 hb_ot_layout_script_get_language_count (hb_ot_layout_t            *layout,
 370                                         hb_ot_layout_table_type_t  table_type,
 371                                         unsigned int               script_index)
 372 {
 373   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 374
 375   return s.get_lang_sys_count ();
 376 }
 377
 378 hb_tag_t
 379 hb_ot_layout_script_get_language_tag (hb_ot_layout_t            *layout,
 380                                       hb_ot_layout_table_type_t  table_type,
 381                                       unsigned int               script_index,
 382                                       unsigned int               language_index)
 383 {
 384   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 385
 386   return s.get_lang_sys_tag (language_index);
 387 }
 388
 389 hb_bool_t
 390 hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
 391                                    hb_ot_layout_table_type_t  table_type,
 392                                    unsigned int               script_index,
 393                                    hb_tag_t                   language_tag,
 394                                    unsigned int              *language_index)
 395 {
 396   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
 397   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 398
 399   if (s.find_lang_sys_index (language_tag, language_index))
 400     return TRUE;
 401
 402   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 403   if (s.find_lang_sys_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, language_index))
 404     return FALSE;
 405
 406   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
 407   return FALSE;
 408 }
 409
 410 hb_bool_t
 411 hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *layout,
 412                                                   hb_ot_layout_table_type_t  table_type,
 413                                                   unsigned int               script_index,
 414                                                   unsigned int               language_index,
 415                                                   unsigned int              *feature_index)
 416 {
 417   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 418
 419   if (feature_index) *feature_index = l.get_required_feature_index ();
 420
 421   return l.has_required_feature ();
 422 }
 423
 424 unsigned int
 425 hb_ot_layout_language_get_feature_count (hb_ot_layout_t            *layout,
 426                                          hb_ot_layout_table_type_t  table_type,
 427                                          unsigned int               script_index,
 428                                          unsigned int               language_index)
 429 {
 430   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 431
 432   return l.get_feature_count ();
 433 }
 434
 435 unsigned int
 436 hb_ot_layout_language_get_feature_index (hb_ot_layout_t            *layout,
 437                                          hb_ot_layout_table_type_t  table_type,
 438                                          unsigned int               script_index,
 439                                          unsigned int               language_index,
 440                                          unsigned int               num_feature)
 441 {
 442   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 443   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 444
 445   return l.get_feature_index (num_feature);
 446 }
 447
 448 hb_tag_t
 449 hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
 450                                        hb_ot_layout_table_type_t  table_type,
 451                                        unsigned int               script_index,
 452                                        unsigned int               language_index,
 453                                        unsigned int               num_feature)
 454 {
 455   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 456   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 457   unsigned int feature_index = l.get_feature_index (num_feature);
 458
 459   return g.get_feature_tag (feature_index);
 460 }
 461
 462
 463 hb_bool_t
 464 hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
 465                                     hb_ot_layout_table_type_t  table_type,
 466                                     unsigned int               script_index,
 467                                     unsigned int               language_index,
 468                                     hb_tag_t                   feature_tag,
 469                                     unsigned int              *feature_index)
 470 {
 471   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 472   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 473   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 474   unsigned int i;
 475
 476   for (i = 0; i < l.get_feature_count (); i++) {
 477     unsigned int f_index = l.get_feature_index (i);
 478
 479     if (feature_tag == g.get_feature_tag (f_index)) {
 480       if (feature_index) *feature_index = f_index;
 481       return TRUE;
 482     }
 483   }
 484
 485   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 486   return FALSE;
 487 }
 488
 489 unsigned int
 490 hb_ot_layout_feature_get_lookup_count (hb_ot_layout_t            *layout,
 491                                        hb_ot_layout_table_type_t  table_type,
 492                                        unsigned int               feature_index)
 493 {
 494   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 495   const Feature &f = g.get_feature (feature_index);
 496
 497   return f.get_lookup_count ();
 498 }
 499
 500 unsigned int
 501 hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
 502                                        hb_ot_layout_table_type_t  table_type,
 503                                        unsigned int               feature_index,
 504                                        unsigned int               num_lookup)
 505 {
 506   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 507   const Feature &f = g.get_feature (feature_index);
 508
 509   return f.get_lookup_index (num_lookup);
 510 }