1 /*
   2  * Copyright © 2009,2010  Red Hat, Inc.
   3  * Copyright © 2010,2011,2012  Google, Inc.
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Red Hat Author(s): Behdad Esfahbod
  26  * Google Author(s): Behdad Esfahbod
  27  */
  28 
  29 #define HB_SHAPER ot
  30 #define hb_ot_shaper_face_data_t hb_ot_layout_t
  31 #define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
  32 #include "hb-shaper-impl-private.hh"
  33 
  34 #include "hb-ot-shape-private.hh"
  35 #include "hb-ot-shape-complex-private.hh"
  36 #include "hb-ot-shape-fallback-private.hh"
  37 #include "hb-ot-shape-normalize-private.hh"
  38 
  39 #include "hb-ot-layout-private.hh"
  40 #include "hb-unicode-private.hh"
  41 #include "hb-set-private.hh"
  42 
  43 #include "hb-ot-layout-gsubgpos-private.hh"
  44 //#include "hb-aat-layout-private.hh"
  45 
  46 static hb_tag_t common_features[] = {
  47   HB_TAG('c','c','m','p'),
  48   HB_TAG('l','o','c','l'),
  49   HB_TAG('m','a','r','k'),
  50   HB_TAG('m','k','m','k'),
  51   HB_TAG('r','l','i','g'),
  52 };
  53 
  54 
  55 static hb_tag_t horizontal_features[] = {
  56   HB_TAG('c','a','l','t'),
  57   HB_TAG('c','l','i','g'),
  58   HB_TAG('c','u','r','s'),
  59   HB_TAG('k','e','r','n'),
  60   HB_TAG('l','i','g','a'),
  61   HB_TAG('r','c','l','t'),
  62 };
  63 
  64 
  65 
  66 static void
  67 hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
  68                               const hb_segment_properties_t  *props,
  69                               const hb_feature_t             *user_features,
  70                               unsigned int                    num_user_features)
  71 {
  72   hb_ot_map_builder_t *map = &planner->map;
  73 
  74   map->add_global_bool_feature (HB_TAG('r','v','r','n'));
  75   map->add_gsub_pause (nullptr);
  76 
  77   switch (props->direction) {
  78     case HB_DIRECTION_LTR:
  79       map->add_global_bool_feature (HB_TAG ('l','t','r','a'));
  80       map->add_global_bool_feature (HB_TAG ('l','t','r','m'));
  81       break;
  82     case HB_DIRECTION_RTL:
  83       map->add_global_bool_feature (HB_TAG ('r','t','l','a'));
  84       map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE);
  85       break;
  86     case HB_DIRECTION_TTB:
  87     case HB_DIRECTION_BTT:
  88     case HB_DIRECTION_INVALID:
  89     default:
  90       break;
  91   }
  92 
  93   map->add_feature (HB_TAG ('f','r','a','c'), 1, F_NONE);
  94   map->add_feature (HB_TAG ('n','u','m','r'), 1, F_NONE);
  95   map->add_feature (HB_TAG ('d','n','o','m'), 1, F_NONE);
  96 
  97   if (planner->shaper->collect_features)
  98     planner->shaper->collect_features (planner);
  99 
 100   for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
 101     map->add_global_bool_feature (common_features[i]);
 102 
 103   if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
 104     for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
 105       map->add_feature (horizontal_features[i], 1, F_GLOBAL |
 106                         (horizontal_features[i] == HB_TAG('k','e','r','n') ?
 107                          F_HAS_FALLBACK : F_NONE));
 108   else
 109   {
 110     /* We really want to find a 'vert' feature if there's any in the font, no
 111      * matter which script/langsys it is listed (or not) under.
 112      * See various bugs referenced from:
 113      * https://github.com/harfbuzz/harfbuzz/issues/63 */
 114     map->add_feature (HB_TAG ('v','e','r','t'), 1, F_GLOBAL | F_GLOBAL_SEARCH);
 115   }
 116 
 117   if (planner->shaper->override_features)
 118     planner->shaper->override_features (planner);
 119 
 120   for (unsigned int i = 0; i < num_user_features; i++) {
 121     const hb_feature_t *feature = &user_features[i];
 122     map->add_feature (feature->tag, feature->value,
 123                       (feature->start == 0 && feature->end == (unsigned int) -1) ?
 124                        F_GLOBAL : F_NONE);
 125   }
 126 }
 127 
 128 
 129 /*
 130  * shaper face data
 131  */
 132 
 133 HB_SHAPER_DATA_ENSURE_DEFINE(ot, face)
 134 
 135 hb_ot_shaper_face_data_t *
 136 _hb_ot_shaper_face_data_create (hb_face_t *face)
 137 {
 138   return _hb_ot_layout_create (face);
 139 }
 140 
 141 void
 142 _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
 143 {
 144   _hb_ot_layout_destroy (data);
 145 }
 146 
 147 
 148 /*
 149  * shaper font data
 150  */
 151 
 152 HB_SHAPER_DATA_ENSURE_DEFINE(ot, font)
 153 
 154 struct hb_ot_shaper_font_data_t {};
 155 
 156 hb_ot_shaper_font_data_t *
 157 _hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
 158 {
 159   return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
 160 }
 161 
 162 void
 163 _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
 164 {
 165 }
 166 
 167 
 168 /*
 169  * shaper shape_plan data
 170  */
 171 
 172 hb_ot_shaper_shape_plan_data_t *
 173 _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan,
 174                                       const hb_feature_t *user_features,
 175                                       unsigned int        num_user_features,
 176                                       const int          *coords,
 177                                       unsigned int        num_coords)
 178 {
 179   hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
 180   if (unlikely (!plan))
 181     return nullptr;
 182 
 183   plan->init ();
 184 
 185   hb_ot_shape_planner_t planner (shape_plan);
 186 
 187   planner.shaper = hb_ot_shape_complex_categorize (&planner);
 188 
 189   hb_ot_shape_collect_features (&planner, &shape_plan->props,
 190                                 user_features, num_user_features);
 191 
 192   planner.compile (*plan, coords, num_coords);
 193 
 194   if (plan->shaper->data_create) {
 195     plan->data = plan->shaper->data_create (plan);
 196     if (unlikely (!plan->data))
 197       return nullptr;
 198   }
 199 
 200   return plan;
 201 }
 202 
 203 void
 204 _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
 205 {
 206   if (plan->shaper->data_destroy)
 207     plan->shaper->data_destroy (const_cast<void *> (plan->data));
 208 
 209   plan->fini ();
 210 
 211   free (plan);
 212 }
 213 
 214 
 215 /*
 216  * shaper
 217  */
 218 
 219 struct hb_ot_shape_context_t
 220 {
 221   hb_ot_shape_plan_t *plan;
 222   hb_font_t *font;
 223   hb_face_t *face;
 224   hb_buffer_t  *buffer;
 225   const hb_feature_t *user_features;
 226   unsigned int        num_user_features;
 227 
 228   /* Transient stuff */
 229   bool fallback_positioning;
 230   bool fallback_glyph_classes;
 231   hb_direction_t target_direction;
 232 };
 233 
 234 
 235 
 236 /* Main shaper */
 237 
 238 
 239 /* Prepare */
 240 
 241 static void
 242 hb_set_unicode_props (hb_buffer_t *buffer)
 243 {
 244   unsigned int count = buffer->len;
 245   hb_glyph_info_t *info = buffer->info;
 246   for (unsigned int i = 0; i < count; i++)
 247     _hb_glyph_info_set_unicode_props (&info[i], buffer);
 248 }
 249 
 250 static void
 251 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
 252 {
 253   if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
 254       buffer->context_len[0] ||
 255       _hb_glyph_info_get_general_category (&buffer->info[0]) !=
 256       HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
 257     return;
 258 
 259   if (!font->has_glyph (0x25CCu))
 260     return;
 261 
 262   hb_glyph_info_t dottedcircle = {0};
 263   dottedcircle.codepoint = 0x25CCu;
 264   _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
 265 
 266   buffer->clear_output ();
 267 
 268   buffer->idx = 0;
 269   hb_glyph_info_t info = dottedcircle;
 270   info.cluster = buffer->cur().cluster;
 271   info.mask = buffer->cur().mask;
 272   buffer->output_info (info);
 273   while (buffer->idx < buffer->len && buffer->successful)
 274     buffer->next_glyph ();
 275 
 276   buffer->swap_buffers ();
 277 }
 278 
 279 static void
 280 hb_form_clusters (hb_buffer_t *buffer)
 281 {
 282   if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
 283     return;
 284 
 285   /* Loop duplicated in hb_ensure_native_direction(), and in _hb-coretext.cc */
 286   unsigned int base = 0;
 287   unsigned int count = buffer->len;
 288   hb_glyph_info_t *info = buffer->info;
 289   for (unsigned int i = 1; i < count; i++)
 290   {
 291     if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])) &&
 292                 !_hb_glyph_info_is_joiner (&info[i])))
 293     {
 294       if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
 295         buffer->merge_clusters (base, i);
 296       else
 297         buffer->unsafe_to_break (base, i);
 298       base = i;
 299     }
 300   }
 301   if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
 302     buffer->merge_clusters (base, count);
 303   else
 304     buffer->unsafe_to_break (base, count);
 305 }
 306 
 307 static void
 308 hb_ensure_native_direction (hb_buffer_t *buffer)
 309 {
 310   hb_direction_t direction = buffer->props.direction;
 311   hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
 312 
 313   /* TODO vertical:
 314    * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
 315    * Ogham fonts are supposed to be implemented BTT or not.  Need to research that
 316    * first. */
 317   if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
 318        direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
 319       (HB_DIRECTION_IS_VERTICAL   (direction) &&
 320        direction != HB_DIRECTION_TTB))
 321   {
 322     /* Same loop as hb_form_clusters().
 323      * Since form_clusters() merged clusters already, we don't merge. */
 324     unsigned int base = 0;
 325     unsigned int count = buffer->len;
 326     hb_glyph_info_t *info = buffer->info;
 327     for (unsigned int i = 1; i < count; i++)
 328     {
 329       if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))))
 330       {
 331         if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
 332           buffer->merge_clusters (base, i);
 333         buffer->reverse_range (base, i);
 334 
 335         base = i;
 336       }
 337     }
 338     if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
 339       buffer->merge_clusters (base, count);
 340     buffer->reverse_range (base, count);
 341 
 342     buffer->reverse ();
 343 
 344     buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
 345   }
 346 }
 347 
 348 
 349 /* Substitute */
 350 
 351 static inline void
 352 hb_ot_mirror_chars (hb_ot_shape_context_t *c)
 353 {
 354   if (HB_DIRECTION_IS_FORWARD (c->target_direction))
 355     return;
 356 
 357   hb_buffer_t *buffer = c->buffer;
 358   hb_unicode_funcs_t *unicode = buffer->unicode;
 359   hb_mask_t rtlm_mask = c->plan->rtlm_mask;
 360 
 361   unsigned int count = buffer->len;
 362   hb_glyph_info_t *info = buffer->info;
 363   for (unsigned int i = 0; i < count; i++) {
 364     hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
 365     if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
 366       info[i].mask |= rtlm_mask;
 367     else
 368       info[i].codepoint = codepoint;
 369   }
 370 }
 371 
 372 static inline void
 373 hb_ot_shape_setup_masks_fraction (hb_ot_shape_context_t *c)
 374 {
 375   if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
 376       !c->plan->has_frac)
 377     return;
 378 
 379   hb_buffer_t *buffer = c->buffer;
 380 
 381   hb_mask_t pre_mask, post_mask;
 382   if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
 383   {
 384     pre_mask = c->plan->numr_mask | c->plan->frac_mask;
 385     post_mask = c->plan->frac_mask | c->plan->dnom_mask;
 386   }
 387   else
 388   {
 389     pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
 390     post_mask = c->plan->numr_mask | c->plan->frac_mask;
 391   }
 392 
 393   unsigned int count = buffer->len;
 394   hb_glyph_info_t *info = buffer->info;
 395   for (unsigned int i = 0; i < count; i++)
 396   {
 397     if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
 398     {
 399       unsigned int start = i, end = i + 1;
 400       while (start &&
 401              _hb_glyph_info_get_general_category (&info[start - 1]) ==
 402              HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
 403         start--;
 404       while (end < count &&
 405              _hb_glyph_info_get_general_category (&info[end]) ==
 406              HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
 407         end++;
 408 
 409       buffer->unsafe_to_break (start, end);
 410 
 411       for (unsigned int j = start; j < i; j++)
 412         info[j].mask |= pre_mask;
 413       info[i].mask |= c->plan->frac_mask;
 414       for (unsigned int j = i + 1; j < end; j++)
 415         info[j].mask |= post_mask;
 416 
 417       i = end - 1;
 418     }
 419   }
 420 }
 421 
 422 static inline void
 423 hb_ot_shape_initialize_masks (hb_ot_shape_context_t *c)
 424 {
 425   hb_ot_map_t *map = &c->plan->map;
 426   hb_buffer_t *buffer = c->buffer;
 427 
 428   hb_mask_t global_mask = map->get_global_mask ();
 429   buffer->reset_masks (global_mask);
 430 }
 431 
 432 static inline void
 433 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
 434 {
 435   hb_ot_map_t *map = &c->plan->map;
 436   hb_buffer_t *buffer = c->buffer;
 437 
 438   hb_ot_shape_setup_masks_fraction (c);
 439 
 440   if (c->plan->shaper->setup_masks)
 441     c->plan->shaper->setup_masks (c->plan, buffer, c->font);
 442 
 443   for (unsigned int i = 0; i < c->num_user_features; i++)
 444   {
 445     const hb_feature_t *feature = &c->user_features[i];
 446     if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
 447       unsigned int shift;
 448       hb_mask_t mask = map->get_mask (feature->tag, &shift);
 449       buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
 450     }
 451   }
 452 }
 453 
 454 static void
 455 hb_ot_zero_width_default_ignorables (hb_ot_shape_context_t *c)
 456 {
 457   hb_buffer_t *buffer = c->buffer;
 458 
 459   if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
 460       (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
 461       (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
 462     return;
 463 
 464   unsigned int count = buffer->len;
 465   hb_glyph_info_t *info = buffer->info;
 466   hb_glyph_position_t *pos = buffer->pos;
 467   unsigned int i = 0;
 468   for (i = 0; i < count; i++)
 469     if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
 470       pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
 471 }
 472 
 473 static void
 474 hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c)
 475 {
 476   hb_buffer_t *buffer = c->buffer;
 477 
 478   if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
 479       (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
 480     return;
 481 
 482   unsigned int count = buffer->len;
 483   hb_glyph_info_t *info = buffer->info;
 484   hb_glyph_position_t *pos = buffer->pos;
 485   unsigned int i = 0;
 486   for (i = 0; i < count; i++)
 487   {
 488     if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
 489       break;
 490   }
 491 
 492   /* No default-ignorables found; return. */
 493   if (i == count)
 494     return;
 495 
 496   hb_codepoint_t space;
 497   if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
 498       c->font->get_nominal_glyph (' ', &space))
 499   {
 500     /* Replace default-ignorables with a zero-advance space glyph. */
 501     for (/*continue*/; i < count; i++)
 502     {
 503       if (_hb_glyph_info_is_default_ignorable (&info[i]))
 504         info[i].codepoint = space;
 505     }
 506   }
 507   else
 508   {
 509     /* Merge clusters and delete default-ignorables.
 510      * NOTE! We can't use out-buffer as we have positioning data. */
 511     unsigned int j = i;
 512     for (; i < count; i++)
 513     {
 514       if (_hb_glyph_info_is_default_ignorable (&info[i]))
 515       {
 516         /* Merge clusters.
 517          * Same logic as buffer->delete_glyph(), but for in-place removal. */
 518 
 519         unsigned int cluster = info[i].cluster;
 520         if (i + 1 < count && cluster == info[i + 1].cluster)
 521           continue; /* Cluster survives; do nothing. */
 522 
 523         if (j)
 524         {
 525           /* Merge cluster backward. */
 526           if (cluster < info[j - 1].cluster)
 527           {
 528             unsigned int mask = info[i].mask;
 529             unsigned int old_cluster = info[j - 1].cluster;
 530             for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
 531               buffer->set_cluster (info[k - 1], cluster, mask);
 532           }
 533           continue;
 534         }
 535 
 536         if (i + 1 < count)
 537           buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
 538 
 539         continue;
 540       }
 541 
 542       if (j != i)
 543       {
 544         info[j] = info[i];
 545         pos[j] = pos[i];
 546       }
 547       j++;
 548     }
 549     buffer->len = j;
 550   }
 551 }
 552 
 553 
 554 static inline void
 555 hb_ot_map_glyphs_fast (hb_buffer_t  *buffer)
 556 {
 557   /* Normalization process sets up glyph_index(), we just copy it. */
 558   unsigned int count = buffer->len;
 559   hb_glyph_info_t *info = buffer->info;
 560   for (unsigned int i = 0; i < count; i++)
 561     info[i].codepoint = info[i].glyph_index();
 562 
 563   buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
 564 }
 565 
 566 static inline void
 567 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
 568 {
 569   unsigned int count = c->buffer->len;
 570   hb_glyph_info_t *info = c->buffer->info;
 571   for (unsigned int i = 0; i < count; i++)
 572   {
 573     hb_ot_layout_glyph_props_flags_t klass;
 574 
 575     /* Never mark default-ignorables as marks.
 576      * They won't get in the way of lookups anyway,
 577      * but having them as mark will cause them to be skipped
 578      * over if the lookup-flag says so, but at least for the
 579      * Mongolian variation selectors, looks like Uniscribe
 580      * marks them as non-mark.  Some Mongolian fonts without
 581      * GDEF rely on this.  Another notable character that
 582      * this applies to is COMBINING GRAPHEME JOINER. */
 583     klass = (_hb_glyph_info_get_general_category (&info[i]) !=
 584              HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
 585              _hb_glyph_info_is_default_ignorable (&info[i])) ?
 586             HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
 587             HB_OT_LAYOUT_GLYPH_PROPS_MARK;
 588     _hb_glyph_info_set_glyph_props (&info[i], klass);
 589   }
 590 }
 591 
 592 static inline void
 593 hb_ot_substitute_default (hb_ot_shape_context_t *c)
 594 {
 595   hb_buffer_t *buffer = c->buffer;
 596 
 597   hb_ot_mirror_chars (c);
 598 
 599   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
 600 
 601   _hb_ot_shape_normalize (c->plan, buffer, c->font);
 602 
 603   hb_ot_shape_setup_masks (c);
 604 
 605   /* This is unfortunate to go here, but necessary... */
 606   if (c->fallback_positioning)
 607     _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, buffer);
 608 
 609   hb_ot_map_glyphs_fast (buffer);
 610 
 611   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
 612 }
 613 
 614 static inline void
 615 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
 616 {
 617   hb_buffer_t *buffer = c->buffer;
 618 
 619   hb_ot_layout_substitute_start (c->font, buffer);
 620 
 621   if (!hb_ot_layout_has_glyph_classes (c->face))
 622     hb_synthesize_glyph_classes (c);
 623 
 624   c->plan->substitute (c->font, buffer);
 625 
 626   /* XXX Call morx instead. */
 627   //hb_aat_layout_substitute (c->font, c->buffer);
 628 }
 629 
 630 static inline void
 631 hb_ot_substitute (hb_ot_shape_context_t *c)
 632 {
 633   hb_ot_substitute_default (c);
 634 
 635   _hb_buffer_allocate_gsubgpos_vars (c->buffer);
 636 
 637   hb_ot_substitute_complex (c);
 638 }
 639 
 640 /* Position */
 641 
 642 static inline void
 643 adjust_mark_offsets (hb_glyph_position_t *pos)
 644 {
 645   pos->x_offset -= pos->x_advance;
 646   pos->y_offset -= pos->y_advance;
 647 }
 648 
 649 static inline void
 650 zero_mark_width (hb_glyph_position_t *pos)
 651 {
 652   pos->x_advance = 0;
 653   pos->y_advance = 0;
 654 }
 655 
 656 static inline void
 657 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
 658 {
 659   unsigned int count = buffer->len;
 660   hb_glyph_info_t *info = buffer->info;
 661   for (unsigned int i = 0; i < count; i++)
 662     if (_hb_glyph_info_is_mark (&info[i]))
 663     {
 664       if (adjust_offsets)
 665         adjust_mark_offsets (&buffer->pos[i]);
 666       zero_mark_width (&buffer->pos[i]);
 667     }
 668 }
 669 
 670 static inline void
 671 hb_ot_position_default (hb_ot_shape_context_t *c)
 672 {
 673   hb_direction_t direction = c->buffer->props.direction;
 674   unsigned int count = c->buffer->len;
 675   hb_glyph_info_t *info = c->buffer->info;
 676   hb_glyph_position_t *pos = c->buffer->pos;
 677 
 678   if (HB_DIRECTION_IS_HORIZONTAL (direction))
 679   {
 680     for (unsigned int i = 0; i < count; i++)
 681       pos[i].x_advance = c->font->get_glyph_h_advance (info[i].codepoint);
 682     /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
 683     if (c->font->has_glyph_h_origin_func ())
 684       for (unsigned int i = 0; i < count; i++)
 685         c->font->subtract_glyph_h_origin (info[i].codepoint,
 686                                           &pos[i].x_offset,
 687                                           &pos[i].y_offset);
 688   }
 689   else
 690   {
 691     for (unsigned int i = 0; i < count; i++)
 692     {
 693       pos[i].y_advance = c->font->get_glyph_v_advance (info[i].codepoint);
 694       c->font->subtract_glyph_v_origin (info[i].codepoint,
 695                                         &pos[i].x_offset,
 696                                         &pos[i].y_offset);
 697     }
 698   }
 699   if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
 700     _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
 701 }
 702 
 703 static inline void
 704 hb_ot_position_complex (hb_ot_shape_context_t *c)
 705 {
 706   unsigned int count = c->buffer->len;
 707   hb_glyph_info_t *info = c->buffer->info;
 708   hb_glyph_position_t *pos = c->buffer->pos;
 709 
 710   /* If the font has no GPOS, AND, no fallback positioning will
 711    * happen, AND, direction is forward, then when zeroing mark
 712    * widths, we shift the mark with it, such that the mark
 713    * is positioned hanging over the previous glyph.  When
 714    * direction is backward we don't shift and it will end up
 715    * hanging over the next glyph after the final reordering.
 716    * If fallback positinoing happens or GPOS is present, we don't
 717    * care.
 718    */
 719   bool adjust_offsets_when_zeroing = c->fallback_positioning &&
 720                                      !c->plan->shaper->fallback_position &&
 721                                      HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
 722 
 723   /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
 724 
 725   /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
 726   if (c->font->has_glyph_h_origin_func ())
 727     for (unsigned int i = 0; i < count; i++)
 728       c->font->add_glyph_h_origin (info[i].codepoint,
 729                                    &pos[i].x_offset,
 730                                    &pos[i].y_offset);
 731 
 732   hb_ot_layout_position_start (c->font, c->buffer);
 733 
 734   switch (c->plan->shaper->zero_width_marks)
 735   {
 736     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
 737       zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
 738       break;
 739 
 740     default:
 741     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
 742     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
 743       break;
 744   }
 745 
 746   if (likely (!c->fallback_positioning))
 747     c->plan->position (c->font, c->buffer);
 748 
 749   switch (c->plan->shaper->zero_width_marks)
 750   {
 751     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
 752       zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
 753       break;
 754 
 755     default:
 756     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
 757     case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
 758       break;
 759   }
 760 
 761   /* Finishing off GPOS has to follow a certain order. */
 762   hb_ot_layout_position_finish_advances (c->font, c->buffer);
 763   hb_ot_zero_width_default_ignorables (c);
 764   hb_ot_layout_position_finish_offsets (c->font, c->buffer);
 765 
 766   /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
 767   if (c->font->has_glyph_h_origin_func ())
 768     for (unsigned int i = 0; i < count; i++)
 769       c->font->subtract_glyph_h_origin (info[i].codepoint,
 770                                         &pos[i].x_offset,
 771                                         &pos[i].y_offset);
 772 }
 773 
 774 static inline void
 775 hb_ot_position (hb_ot_shape_context_t *c)
 776 {
 777   c->buffer->clear_positions ();
 778 
 779   hb_ot_position_default (c);
 780 
 781   hb_ot_position_complex (c);
 782 
 783   if (c->fallback_positioning && c->plan->shaper->fallback_position)
 784     _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
 785 
 786   if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
 787     hb_buffer_reverse (c->buffer);
 788 
 789   /* Visual fallback goes here. */
 790 
 791   if (c->fallback_positioning)
 792     _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer);
 793 
 794   _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
 795 
 796   //hb_aat_layout_position (c->font, c->buffer);
 797 }
 798 
 799 static inline void
 800 hb_propagate_flags (hb_buffer_t *buffer)
 801 {
 802   /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
 803    * Simplifies using them. */
 804 
 805   if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
 806     return;
 807 
 808   hb_glyph_info_t *info = buffer->info;
 809 
 810   foreach_cluster (buffer, start, end)
 811   {
 812     unsigned int mask = 0;
 813     for (unsigned int i = start; i < end; i++)
 814       if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
 815       {
 816          mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
 817          break;
 818       }
 819     if (mask)
 820       for (unsigned int i = start; i < end; i++)
 821         info[i].mask |= mask;
 822   }
 823 }
 824 
 825 /* Pull it all together! */
 826 
 827 static void
 828 hb_ot_shape_internal (hb_ot_shape_context_t *c)
 829 {
 830   c->buffer->deallocate_var_all ();
 831   c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
 832   if (likely (!_hb_unsigned_int_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
 833   {
 834     c->buffer->max_len = MAX (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
 835                               (unsigned) HB_BUFFER_MAX_LEN_MIN);
 836   }
 837   if (likely (!_hb_unsigned_int_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
 838   {
 839     c->buffer->max_ops = MAX (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
 840                               (unsigned) HB_BUFFER_MAX_OPS_MIN);
 841   }
 842 
 843   bool disable_otl = c->plan->shaper->disable_otl && c->plan->shaper->disable_otl (c->plan);
 844   //c->fallback_substitute     = disable_otl || !hb_ot_layout_has_substitution (c->face);
 845   c->fallback_positioning    = disable_otl || !hb_ot_layout_has_positioning (c->face);
 846   c->fallback_glyph_classes  = disable_otl || !hb_ot_layout_has_glyph_classes (c->face);
 847 
 848   /* Save the original direction, we use it later. */
 849   c->target_direction = c->buffer->props.direction;
 850 
 851   _hb_buffer_allocate_unicode_vars (c->buffer);
 852 
 853   c->buffer->clear_output ();
 854 
 855   hb_ot_shape_initialize_masks (c);
 856   hb_set_unicode_props (c->buffer);
 857   hb_insert_dotted_circle (c->buffer, c->font);
 858 
 859   hb_form_clusters (c->buffer);
 860 
 861   hb_ensure_native_direction (c->buffer);
 862 
 863   if (c->plan->shaper->preprocess_text)
 864     c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
 865 
 866   hb_ot_substitute (c);
 867   hb_ot_position (c);
 868 
 869   hb_ot_hide_default_ignorables (c);
 870 
 871   if (c->plan->shaper->postprocess_glyphs)
 872     c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
 873 
 874   hb_propagate_flags (c->buffer);
 875 
 876   _hb_buffer_deallocate_unicode_vars (c->buffer);
 877 
 878   c->buffer->props.direction = c->target_direction;
 879 
 880   c->buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
 881   c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
 882   c->buffer->deallocate_var_all ();
 883 }
 884 
 885 
 886 hb_bool_t
 887 _hb_ot_shape (hb_shape_plan_t    *shape_plan,
 888               hb_font_t          *font,
 889               hb_buffer_t        *buffer,
 890               const hb_feature_t *features,
 891               unsigned int        num_features)
 892 {
 893   hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
 894   hb_ot_shape_internal (&c);
 895 
 896   return true;
 897 }
 898 
 899 
 900 /**
 901  * hb_ot_shape_plan_collect_lookups:
 902  *
 903  * Since: 0.9.7
 904  **/
 905 void
 906 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
 907                                   hb_tag_t         table_tag,
 908                                   hb_set_t        *lookup_indexes /* OUT */)
 909 {
 910   /* XXX Does the first part always succeed? */
 911   HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes);
 912 }
 913 
 914 
 915 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
 916 static void
 917 add_char (hb_font_t          *font,
 918           hb_unicode_funcs_t *unicode,
 919           hb_bool_t           mirror,
 920           hb_codepoint_t      u,
 921           hb_set_t           *glyphs)
 922 {
 923   hb_codepoint_t glyph;
 924   if (font->get_nominal_glyph (u, &glyph))
 925     glyphs->add (glyph);
 926   if (mirror)
 927   {
 928     hb_codepoint_t m = unicode->mirroring (u);
 929     if (m != u && font->get_nominal_glyph (m, &glyph))
 930       glyphs->add (glyph);
 931   }
 932 }
 933 
 934 
 935 /**
 936  * hb_ot_shape_glyphs_closure:
 937  *
 938  * Since: 0.9.2
 939  **/
 940 void
 941 hb_ot_shape_glyphs_closure (hb_font_t          *font,
 942                             hb_buffer_t        *buffer,
 943                             const hb_feature_t *features,
 944                             unsigned int        num_features,
 945                             hb_set_t           *glyphs)
 946 {
 947   const char *shapers[] = {"ot", nullptr};
 948   hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
 949                                                              features, num_features, shapers);
 950 
 951   bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
 952 
 953   unsigned int count = buffer->len;
 954   hb_glyph_info_t *info = buffer->info;
 955   for (unsigned int i = 0; i < count; i++)
 956     add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
 957 
 958   hb_set_t *lookups = hb_set_create ();
 959   hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
 960   hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
 961 
 962   hb_set_destroy (lookups);
 963 
 964   hb_shape_plan_destroy (shape_plan);
 965 }