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 void
  87 hb_ot_layout_set_direction (hb_ot_layout_t *layout,
  88                             hb_bool_t r2l)
  89 {
  90   layout->gpos_info.r2l = !!r2l;
  91 }
  92
  93 void
  94 hb_ot_layout_set_hinting (hb_ot_layout_t *layout,
  95                           hb_bool_t hinted)
  96 {
  97   layout->gpos_info.dvi = !hinted;
  98 }
  99
 100 void
 101 hb_ot_layout_set_scale (hb_ot_layout_t *layout,
 102                         hb_16dot16_t x_scale, hb_16dot16_t y_scale)
 103 {
 104   layout->gpos_info.x_scale = x_scale;
 105   layout->gpos_info.y_scale = y_scale;
 106 }
 107
 108 void
 109 hb_ot_layout_set_ppem (hb_ot_layout_t *layout,
 110                        unsigned int x_ppem, unsigned int y_ppem)
 111 {
 112   layout->gpos_info.x_ppem = x_ppem;
 113   layout->gpos_info.y_ppem = y_ppem;
 114 }
 115
 116
 117 /*
 118  * GDEF
 119  */
 120
 121 /* TODO the public class_t is a mess */
 122
 123 hb_bool_t
 124 hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout)
 125 {
 126   return layout->gdef->has_glyph_classes ();
 127 }
 128
 129 HB_INTERNAL hb_bool_t
 130 _hb_ot_layout_has_new_glyph_classes (hb_ot_layout_t *layout)
 131 {
 132   return layout->new_gdef.len > 0;
 133 }
 134
 135 HB_INTERNAL unsigned int
 136 _hb_ot_layout_get_glyph_property (hb_ot_layout_t *layout,
 137                                   hb_codepoint_t  glyph)
 138 {
 139   hb_ot_layout_class_t klass;
 140
 141   /* TODO old harfbuzz doesn't always parse mark attachments as it says it was
 142    * introduced without a version bump, so it may not be safe */
 143   klass = layout->gdef->get_mark_attachment_type (glyph);
 144   if (klass)
 145     return klass << 8;
 146
 147   klass = layout->gdef->get_glyph_class (glyph);
 148
 149   if (!klass && glyph < layout->new_gdef.len)
 150     klass = layout->new_gdef.klasses[glyph];
 151
 152   switch (klass) {
 153   default:
 154   case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
 155   case GDEF::BaseGlyph:         return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
 156   case GDEF::LigatureGlyph:     return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
 157   case GDEF::MarkGlyph:         return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 158   case GDEF::ComponentGlyph:    return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
 159   }
 160 }
 161
 162 HB_INTERNAL hb_bool_t
 163 _hb_ot_layout_check_glyph_property (hb_ot_layout_t  *layout,
 164                                     hb_glyph_info_t *ginfo,
 165                                     unsigned int     lookup_flags,
 166                                     unsigned int    *property)
 167 {
 168   hb_ot_layout_glyph_class_t basic_glyph_class;
 169   unsigned int desired_attachment_class;
 170
 171   if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
 172   {
 173     ginfo->gproperty = *property = _hb_ot_layout_get_glyph_property (layout, ginfo->gindex);
 174     if (ginfo->gproperty == HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED)
 175       return false;
 176   }
 177
 178   *property = ginfo->gproperty;
 179
 180   /* If the glyph was found in the MarkAttachmentClass table,
 181    * then that class value is the high byte of the result,
 182    * otherwise the low byte contains the basic type of the glyph
 183    * as defined by the GlyphClassDef table.
 184    */
 185   if (*property & LookupFlag::MarkAttachmentType)
 186     basic_glyph_class = HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 187   else
 188     basic_glyph_class = (hb_ot_layout_glyph_class_t) *property;
 189
 190   /* Not covered, if, for example, basic_glyph_class
 191    * is HB_GDEF_LIGATURE and lookup_flags includes LookupFlags::IgnoreLigatures
 192    */
 193   if (lookup_flags & basic_glyph_class)
 194     return false;
 195
 196   /* The high byte of lookup_flags has the meaning
 197    * "ignore marks of attachment type different than
 198    * the attachment type specified."
 199    */
 200   desired_attachment_class = lookup_flags & LookupFlag::MarkAttachmentType;
 201   if (desired_attachment_class)
 202   {
 203     if (basic_glyph_class == HB_OT_LAYOUT_GLYPH_CLASS_MARK &&
 204         *property != desired_attachment_class)
 205       return false;
 206   }
 207
 208   return true;
 209 }
 210
 211 HB_INTERNAL void
 212 _hb_ot_layout_set_glyph_property (hb_ot_layout_t *layout,
 213                                   hb_codepoint_t  glyph,
 214                                   unsigned int    property)
 215 {
 216   hb_ot_layout_glyph_class_t klass;
 217
 218   if (property & LookupFlag::MarkAttachmentType)
 219     klass = HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 220   else
 221     klass = (hb_ot_layout_glyph_class_t) property;
 222
 223   hb_ot_layout_set_glyph_class (layout, glyph, klass);
 224 }
 225
 226
 227 hb_ot_layout_glyph_class_t
 228 hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
 229                               hb_codepoint_t  glyph)
 230 {
 231   unsigned int property;
 232   hb_ot_layout_class_t klass;
 233
 234   property = _hb_ot_layout_get_glyph_property (layout, glyph);
 235
 236   if (property & LookupFlag::MarkAttachmentType)
 237     return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
 238
 239   return (hb_ot_layout_glyph_class_t) property;
 240 }
 241
 242 void
 243 hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
 244                               hb_codepoint_t              glyph,
 245                               hb_ot_layout_glyph_class_t  klass)
 246 {
 247   /* TODO optimize this, similar to old harfbuzz code for example */
 248
 249   hb_ot_layout_class_t gdef_klass;
 250   int len = layout->new_gdef.len;
 251
 252   if (HB_UNLIKELY (glyph > 65535))
 253     return;
 254
 255   if (glyph >= len) {
 256     int new_len;
 257     unsigned char *new_klasses;
 258
 259     new_len = len == 0 ? 120 : 2 * len;
 260     if (new_len > 65535)
 261       new_len = 65535;
 262     new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char));
 263
 264     if (HB_UNLIKELY (!new_klasses))
 265       return;
 266
 267     memset (new_klasses + len, 0, new_len - len);
 268
 269     layout->new_gdef.klasses = new_klasses;
 270     layout->new_gdef.len = new_len;
 271   }
 272
 273   switch (klass) {
 274   default:
 275   case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED:   gdef_klass = GDEF::UnclassifiedGlyph;   break;
 276   case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH:     gdef_klass = GDEF::BaseGlyph;           break;
 277   case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE:       gdef_klass = GDEF::LigatureGlyph;       break;
 278   case HB_OT_LAYOUT_GLYPH_CLASS_MARK:           gdef_klass = GDEF::MarkGlyph;           break;
 279   case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT:      gdef_klass = GDEF::ComponentGlyph;      break;
 280   }
 281
 282   layout->new_gdef.klasses[glyph] = gdef_klass;
 283   return;
 284 }
 285
 286 void
 287 hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
 288                                   uint16_t        num_total_glyphs,
 289                                   hb_codepoint_t *glyphs,
 290                                   unsigned char  *klasses,
 291                                   uint16_t        count)
 292 {
 293   if (HB_UNLIKELY (!count || !glyphs || !klasses))
 294     return;
 295
 296   if (layout->new_gdef.len == 0) {
 297     layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char));
 298     layout->new_gdef.len = count;
 299   }
 300
 301   for (unsigned int i = 0; i < count; i++)
 302     hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
 303 }
 304
 305 /*
 306  * GSUB/GPOS
 307  */
 308
 309 static const GSUBGPOS&
 310 get_gsubgpos_table (hb_ot_layout_t            *layout,
 311                     hb_ot_layout_table_type_t  table_type)
 312 {
 313   switch (table_type) {
 314     case HB_OT_LAYOUT_TABLE_TYPE_GSUB: return *(layout->gsub);
 315     case HB_OT_LAYOUT_TABLE_TYPE_GPOS: return *(layout->gpos);
 316     default:                           return Null(GSUBGPOS);
 317   }
 318 }
 319
 320
 321 unsigned int
 322 hb_ot_layout_table_get_script_count (hb_ot_layout_t            *layout,
 323                                      hb_ot_layout_table_type_t  table_type)
 324 {
 325   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 326
 327   return g.get_script_count ();
 328 }
 329
 330 hb_tag_t
 331 hb_ot_layout_table_get_script_tag (hb_ot_layout_t            *layout,
 332                                    hb_ot_layout_table_type_t  table_type,
 333                                    unsigned int               script_index)
 334 {
 335   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 336
 337   return g.get_script_tag (script_index);
 338 }
 339
 340 hb_bool_t
 341 hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
 342                                 hb_ot_layout_table_type_t  table_type,
 343                                 hb_tag_t                   script_tag,
 344                                 unsigned int              *script_index)
 345 {
 346   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
 347   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 348
 349   if (g.find_script_index (script_tag, script_index))
 350     return TRUE;
 351
 352   /* try finding 'DFLT' */
 353   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_SCRIPT, script_index))
 354     return FALSE;
 355
 356   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 357   if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, script_index))
 358     return FALSE;
 359
 360   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
 361   return FALSE;
 362 }
 363
 364 unsigned int
 365 hb_ot_layout_table_get_feature_count (hb_ot_layout_t            *layout,
 366                                       hb_ot_layout_table_type_t  table_type)
 367 {
 368   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 369
 370   return g.get_feature_count ();
 371 }
 372
 373 hb_tag_t
 374 hb_ot_layout_table_get_feature_tag (hb_ot_layout_t            *layout,
 375                                     hb_ot_layout_table_type_t  table_type,
 376                                     unsigned int               feature_index)
 377 {
 378   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 379
 380   return g.get_feature_tag (feature_index);
 381 }
 382
 383 hb_bool_t
 384 hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
 385                                  hb_ot_layout_table_type_t  table_type,
 386                                  hb_tag_t                   feature_tag,
 387                                  unsigned int              *feature_index)
 388 {
 389   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 390   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 391
 392   if (g.find_feature_index (feature_tag, feature_index))
 393     return TRUE;
 394
 395   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 396   return FALSE;
 397 }
 398
 399 unsigned int
 400 hb_ot_layout_table_get_lookup_count (hb_ot_layout_t            *layout,
 401                                      hb_ot_layout_table_type_t  table_type)
 402 {
 403   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 404
 405   return g.get_lookup_count ();
 406 }
 407
 408
 409 unsigned int
 410 hb_ot_layout_script_get_language_count (hb_ot_layout_t            *layout,
 411                                         hb_ot_layout_table_type_t  table_type,
 412                                         unsigned int               script_index)
 413 {
 414   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 415
 416   return s.get_lang_sys_count ();
 417 }
 418
 419 hb_tag_t
 420 hb_ot_layout_script_get_language_tag (hb_ot_layout_t            *layout,
 421                                       hb_ot_layout_table_type_t  table_type,
 422                                       unsigned int               script_index,
 423                                       unsigned int               language_index)
 424 {
 425   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 426
 427   return s.get_lang_sys_tag (language_index);
 428 }
 429
 430 hb_bool_t
 431 hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
 432                                    hb_ot_layout_table_type_t  table_type,
 433                                    unsigned int               script_index,
 434                                    hb_tag_t                   language_tag,
 435                                    unsigned int              *language_index)
 436 {
 437   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
 438   const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
 439
 440   if (s.find_lang_sys_index (language_tag, language_index))
 441     return TRUE;
 442
 443   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
 444   if (s.find_lang_sys_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, language_index))
 445     return FALSE;
 446
 447   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
 448   return FALSE;
 449 }
 450
 451 hb_bool_t
 452 hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *layout,
 453                                                   hb_ot_layout_table_type_t  table_type,
 454                                                   unsigned int               script_index,
 455                                                   unsigned int               language_index,
 456                                                   unsigned int              *feature_index)
 457 {
 458   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 459
 460   if (feature_index) *feature_index = l.get_required_feature_index ();
 461
 462   return l.has_required_feature ();
 463 }
 464
 465 unsigned int
 466 hb_ot_layout_language_get_feature_count (hb_ot_layout_t            *layout,
 467                                          hb_ot_layout_table_type_t  table_type,
 468                                          unsigned int               script_index,
 469                                          unsigned int               language_index)
 470 {
 471   const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
 472
 473   return l.get_feature_count ();
 474 }
 475
 476 unsigned int
 477 hb_ot_layout_language_get_feature_index (hb_ot_layout_t            *layout,
 478                                          hb_ot_layout_table_type_t  table_type,
 479                                          unsigned int               script_index,
 480                                          unsigned int               language_index,
 481                                          unsigned int               num_feature)
 482 {
 483   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 484   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 485
 486   return l.get_feature_index (num_feature);
 487 }
 488
 489 hb_tag_t
 490 hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
 491                                        hb_ot_layout_table_type_t  table_type,
 492                                        unsigned int               script_index,
 493                                        unsigned int               language_index,
 494                                        unsigned int               num_feature)
 495 {
 496   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 497   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 498   unsigned int feature_index = l.get_feature_index (num_feature);
 499
 500   return g.get_feature_tag (feature_index);
 501 }
 502
 503
 504 hb_bool_t
 505 hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
 506                                     hb_ot_layout_table_type_t  table_type,
 507                                     unsigned int               script_index,
 508                                     unsigned int               language_index,
 509                                     hb_tag_t                   feature_tag,
 510                                     unsigned int              *feature_index)
 511 {
 512   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
 513   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 514   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 515
 516   unsigned int num_features = l.get_feature_count ();
 517   for (unsigned int i = 0; i < num_features; i++) {
 518     unsigned int f_index = l.get_feature_index (i);
 519
 520     if (feature_tag == g.get_feature_tag (f_index)) {
 521       if (feature_index) *feature_index = f_index;
 522       return TRUE;
 523     }
 524   }
 525
 526   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
 527   return FALSE;
 528 }
 529
 530 unsigned int
 531 hb_ot_layout_feature_get_lookup_count (hb_ot_layout_t            *layout,
 532                                        hb_ot_layout_table_type_t  table_type,
 533                                        unsigned int               feature_index)
 534 {
 535   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 536   const Feature &f = g.get_feature (feature_index);
 537
 538   return f.get_lookup_count ();
 539 }
 540
 541 unsigned int
 542 hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
 543                                        hb_ot_layout_table_type_t  table_type,
 544                                        unsigned int               feature_index,
 545                                        unsigned int               num_lookup)
 546 {
 547   const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
 548   const Feature &f = g.get_feature (feature_index);
 549
 550   return f.get_lookup_index (num_lookup);
 551 }
 552
 553 /*
 554  * GSUB
 555  */
 556
 557 hb_bool_t
 558 hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
 559                                 hb_buffer_t                 *buffer,
 560                                 unsigned int                 lookup_index,
 561                                 hb_ot_layout_feature_mask_t  mask)
 562 {
 563   return layout->gsub->substitute_lookup (layout, buffer, lookup_index, mask);
 564 }
 565
 566 /*
 567  * GPOS
 568  */
 569
 570 hb_bool_t
 571 hb_ot_layout_position_lookup   (hb_ot_layout_t              *layout,
 572                                 hb_buffer_t                 *buffer,
 573                                 unsigned int                 lookup_index,
 574                                 hb_ot_layout_feature_mask_t  mask)
 575 {
 576   return layout->gpos->position_lookup (layout, buffer, lookup_index, mask);
 577 }