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hb-subset-plan.cc (28926B)


      1 /*
      2 * Copyright © 2018  Google, Inc.
      3 *
      4 *  This is part of HarfBuzz, a text shaping library.
      5 *
      6 * Permission is hereby granted, without written agreement and without
      7 * license or royalty fees, to use, copy, modify, and distribute this
      8 * software and its documentation for any purpose, provided that the
      9 * above copyright notice and the following two paragraphs appear in
     10 * all copies of this software.
     11 *
     12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     16 * DAMAGE.
     17 *
     18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     23 *
     24 * Google Author(s): Garret Rieger, Roderick Sheeter
     25 */
     26 
     27 #include "hb-subset-plan.hh"
     28 #include "hb-subset-accelerator.hh"
     29 #include "hb-map.hh"
     30 #include "hb-multimap.hh"
     31 #include "hb-set.hh"
     32 #include "hb-subset.h"
     33 #include "hb-unicode.h"
     34 
     35 #include "hb-ot-cmap-table.hh"
     36 #include "hb-ot-glyf-table.hh"
     37 #include "hb-ot-layout-base-table.hh"
     38 #include "hb-ot-cff1-table.hh"
     39 #include "hb-ot-cff2-table.hh"
     40 #include "OT/Color/COLR/COLR.hh"
     41 #include "OT/Color/COLR/colrv1-closure.hh"
     42 #include "OT/Color/CPAL/CPAL.hh"
     43 #include "hb-ot-var-fvar-table.hh"
     44 #include "hb-ot-stat-table.hh"
     45 #include "hb-ot-math-table.hh"
     46 
     47 hb_subset_accelerator_t::~hb_subset_accelerator_t ()
     48 {
     49  if (cmap_cache && destroy_cmap_cache)
     50    destroy_cmap_cache ((void*) cmap_cache);
     51 
     52 #ifndef HB_NO_SUBSET_CFF
     53  cff1_accel.fini ();
     54  cff2_accel.fini ();
     55 #endif
     56  hb_face_destroy (source);
     57 }
     58 
     59 
     60 #ifndef HB_NO_SUBSET_CFF
     61 static inline bool
     62 _add_cff_seac_components (const OT::cff1::accelerator_subset_t &cff,
     63 		  hb_codepoint_t gid,
     64 		  hb_set_t *gids_to_retain)
     65 {
     66  hb_codepoint_t base_gid, accent_gid;
     67  if (cff.get_seac_components (gid, &base_gid, &accent_gid))
     68  {
     69    gids_to_retain->add (base_gid);
     70    gids_to_retain->add (accent_gid);
     71    return true;
     72  }
     73  return false;
     74 }
     75 #endif
     76 
     77 static void
     78 _remap_palette_indexes (const hb_set_t *palette_indexes,
     79 		hb_map_t       *mapping /* OUT */)
     80 {
     81  unsigned new_idx = 0;
     82  for (unsigned palette_index : palette_indexes->iter ())
     83  {
     84    if (palette_index == 0xFFFF)
     85    {
     86      mapping->set (palette_index, palette_index);
     87      continue;
     88    }
     89    mapping->set (palette_index, new_idx);
     90    new_idx++;
     91  }
     92 }
     93 
     94 void
     95 remap_indexes (const hb_set_t *indexes,
     96               hb_map_t       *mapping /* OUT */)
     97 {
     98  for (auto _ : + hb_enumerate (indexes->iter ()))
     99    mapping->set (_.second, _.first);
    100 }
    101 
    102 static inline void
    103 _cmap_closure (hb_face_t	   *face,
    104        const hb_set_t	   *unicodes,
    105        hb_set_t		   *glyphset)
    106 {
    107  OT::cmap::accelerator_t cmap (face);
    108  cmap.table->closure_glyphs (unicodes, glyphset);
    109 }
    110 
    111 static void _colr_closure (hb_subset_plan_t* plan,
    112                           hb_set_t *glyphs_colred)
    113 {
    114  OT::COLR::accelerator_t colr (plan->source);
    115  if (!colr.is_valid ()) return;
    116 
    117  hb_set_t palette_indices, layer_indices;
    118  // Collect all glyphs referenced by COLRv0
    119  hb_set_t glyphset_colrv0;
    120  for (hb_codepoint_t gid : *glyphs_colred)
    121    colr.closure_glyphs (gid, &glyphset_colrv0);
    122 
    123  glyphs_colred->union_ (glyphset_colrv0);
    124 
    125  //closure for COLRv1
    126  hb_set_t variation_indices, delta_set_indices;
    127  colr.closure_forV1 (glyphs_colred, &layer_indices, &palette_indices, &variation_indices, &delta_set_indices);
    128 
    129  colr.closure_V0palette_indices (glyphs_colred, &palette_indices);
    130  remap_indexes (&layer_indices, &plan->colrv1_layers);
    131  _remap_palette_indexes (&palette_indices, &plan->colr_palettes);
    132 
    133 #ifndef HB_NO_VAR
    134  if (!colr.has_var_store () || !variation_indices) return;
    135 
    136  const OT::ItemVariationStore &var_store = colr.get_var_store ();
    137  // generated inner_maps is used by ItemVariationStore serialize(), which is subset only
    138  unsigned subtable_count = var_store.get_sub_table_count ();
    139  generate_varstore_inner_maps (variation_indices, subtable_count, plan->colrv1_varstore_inner_maps);
    140 
    141  /* colr variation indices mapping during planning phase:
    142   * generate colrv1_variation_idx_delta_map. When delta set index map is not
    143   * included, it's a mapping from varIdx-> (new varIdx,delta). Otherwise, it's
    144   * a mapping from old delta set idx-> (new delta set idx, delta). Mapping
    145   * delta set indices is the same as gid mapping.
    146   * Besides, we need to generate a delta set idx-> new var_idx map for updating
    147   * delta set index map if exists. This map will be updated again after
    148   * instancing. */
    149  if (!plan->all_axes_pinned)
    150  {
    151    remap_variation_indices (var_store,
    152                              variation_indices,
    153                              plan->normalized_coords,
    154                              false, /* no need to calculate delta for COLR during planning */
    155                              plan->all_axes_pinned,
    156                              plan->colrv1_variation_idx_delta_map);
    157 
    158    if (colr.has_delta_set_index_map ())
    159      remap_colrv1_delta_set_index_indices (colr.get_delta_set_index_map (),
    160                                             delta_set_indices,
    161                                             plan->colrv1_variation_idx_delta_map,
    162                                             plan->colrv1_new_deltaset_idx_varidx_map);
    163  }
    164 #endif
    165 }
    166 
    167 static inline void
    168 _math_closure (hb_subset_plan_t *plan,
    169               hb_set_t         *glyphset)
    170 {
    171  hb_blob_ptr_t<OT::MATH> math = plan->source_table<OT::MATH> ();
    172  if (math->has_data ())
    173    math->closure_glyphs (glyphset);
    174  math.destroy ();
    175 }
    176 
    177 static inline void
    178 _remove_invalid_gids (hb_set_t *glyphs,
    179 	      unsigned int num_glyphs)
    180 {
    181  glyphs->del_range (num_glyphs, HB_SET_VALUE_INVALID);
    182 }
    183 
    184 template<bool GID_ALWAYS_EXISTS = false, typename I, typename F, typename G, hb_requires (hb_is_iterator (I))>
    185 static void
    186 _fill_unicode_and_glyph_map(hb_subset_plan_t *plan,
    187                            I unicode_iterator,
    188                            F unicode_to_gid_for_iterator,
    189                            G unicode_to_gid_general)
    190 {
    191  for (hb_codepoint_t cp : unicode_iterator)
    192  {
    193    hb_codepoint_t gid = unicode_to_gid_for_iterator(cp);
    194    if (!GID_ALWAYS_EXISTS && gid == HB_MAP_VALUE_INVALID)
    195    {
    196      DEBUG_MSG(SUBSET, nullptr, "Drop U+%04X; no gid", cp);
    197      continue;
    198    }
    199 
    200    plan->codepoint_to_glyph->set (cp, gid);
    201    plan->unicode_to_new_gid_list.push (hb_pair (cp, gid));
    202  }
    203 }
    204 
    205 template<bool GID_ALWAYS_EXISTS = false, typename I, typename F, hb_requires (hb_is_iterator (I))>
    206 static void
    207 _fill_unicode_and_glyph_map(hb_subset_plan_t *plan,
    208                            I unicode_iterator,
    209                            F unicode_to_gid_for_iterator)
    210 {
    211  _fill_unicode_and_glyph_map(plan, unicode_iterator, unicode_to_gid_for_iterator, unicode_to_gid_for_iterator);
    212 }
    213 
    214 /*
    215 * Finds additional unicode codepoints which are reachable from the input unicode set.
    216 * Currently this adds in mirrored variants (needed for bidi) of any input unicodes.
    217 */
    218 static hb_set_t
    219 _unicode_closure (const hb_set_t* unicodes, bool bidi_closure) {
    220  // TODO: we may want to also consider pulling in reachable unicode composition and decompositions.
    221  //       see: https://github.com/harfbuzz/harfbuzz/issues/2283
    222  hb_set_t out = *unicodes;
    223  if (!bidi_closure) return out;
    224 
    225  if (out.is_inverted()) {
    226    // don't closure inverted sets, they are asking to specifically exclude certain codepoints.
    227    // otherwise everything is already included.
    228    return out;
    229  }
    230 
    231  auto unicode_funcs = hb_unicode_funcs_get_default ();
    232  for (hb_codepoint_t cp : *unicodes) {
    233   hb_codepoint_t mirror = hb_unicode_mirroring(unicode_funcs, cp);
    234   if (unlikely (mirror != cp)) {
    235     out.add(mirror);
    236   }
    237  }
    238 
    239  return out;
    240 }
    241 
    242 static void
    243 _populate_unicodes_to_retain (const hb_set_t *unicodes_in,
    244                              const hb_set_t *glyphs,
    245                              hb_subset_plan_t *plan)
    246 {
    247  hb_set_t unicodes = _unicode_closure(unicodes_in,
    248    !(plan->flags & HB_SUBSET_FLAGS_NO_BIDI_CLOSURE));
    249 
    250  OT::cmap::accelerator_t cmap (plan->source);
    251  unsigned size_threshold = plan->source->get_num_glyphs ();
    252 
    253  if (glyphs->is_empty () && unicodes.get_population () < size_threshold)
    254  {
    255 
    256    const hb_map_t* unicode_to_gid = nullptr;
    257    if (plan->accelerator)
    258      unicode_to_gid = &plan->accelerator->unicode_to_gid;
    259 
    260    // This is approach to collection is faster, but can only be used  if glyphs
    261    // are not being explicitly added to the subset and the input unicodes set is
    262    // not excessively large (eg. an inverted set).
    263    plan->unicode_to_new_gid_list.alloc (unicodes.get_population ());
    264    if (!unicode_to_gid) {
    265      _fill_unicode_and_glyph_map(plan, unicodes.iter(), [&] (hb_codepoint_t cp) {
    266        hb_codepoint_t gid;
    267        if (!cmap.get_nominal_glyph (cp, &gid)) {
    268          return HB_MAP_VALUE_INVALID;
    269        }
    270        return gid;
    271      });
    272    } else {
    273      // Use in memory unicode to gid map it's faster then looking up from
    274      // the map. This code is mostly duplicated from above to avoid doing
    275      // conditionals on the presence of the unicode_to_gid map each
    276      // iteration.
    277      _fill_unicode_and_glyph_map(plan, unicodes.iter(), [&] (hb_codepoint_t cp) {
    278        return unicode_to_gid->get (cp);
    279      });
    280    }
    281  }
    282  else
    283  {
    284    // This approach is slower, but can handle adding in glyphs to the subset and will match
    285    // them with cmap entries.
    286 
    287    hb_map_t unicode_glyphid_map_storage;
    288    hb_set_t cmap_unicodes_storage;
    289    const hb_map_t* unicode_glyphid_map = &unicode_glyphid_map_storage;
    290    const hb_set_t* cmap_unicodes = &cmap_unicodes_storage;
    291 
    292    if (!plan->accelerator) {
    293      cmap.collect_mapping (&cmap_unicodes_storage, &unicode_glyphid_map_storage);
    294      plan->unicode_to_new_gid_list.alloc (hb_min(unicodes.get_population ()
    295                                                  + glyphs->get_population (),
    296                                                  cmap_unicodes->get_population ()));
    297    } else {
    298      unicode_glyphid_map = &plan->accelerator->unicode_to_gid;
    299      cmap_unicodes = &plan->accelerator->unicodes;
    300    }
    301 
    302    if (plan->accelerator &&
    303 unicodes.get_population () < cmap_unicodes->get_population () &&
    304 glyphs->get_population () < cmap_unicodes->get_population ())
    305    {
    306      plan->codepoint_to_glyph->alloc (unicodes.get_population () + glyphs->get_population ());
    307 
    308      auto &gid_to_unicodes = plan->accelerator->gid_to_unicodes;
    309 
    310      for (hb_codepoint_t gid : *glyphs)
    311      {
    312        auto unicodes = gid_to_unicodes.get (gid);
    313        _fill_unicode_and_glyph_map<true>(plan, unicodes, [&] (hb_codepoint_t cp) {
    314          return gid;
    315        },
    316        [&] (hb_codepoint_t cp) {
    317          return unicode_glyphid_map->get(cp);
    318        });
    319      }
    320 
    321      _fill_unicode_and_glyph_map(plan, unicodes.iter(), [&] (hb_codepoint_t cp) {
    322          /* Don't double-add entry. */
    323 if (plan->codepoint_to_glyph->has (cp))
    324          return HB_MAP_VALUE_INVALID;
    325 
    326        return unicode_glyphid_map->get(cp);
    327      },
    328      [&] (hb_codepoint_t cp) {
    329          return unicode_glyphid_map->get(cp);
    330      });
    331 
    332      plan->unicode_to_new_gid_list.qsort ();
    333    }
    334    else
    335    {
    336      plan->codepoint_to_glyph->alloc (cmap_unicodes->get_population ());
    337      hb_codepoint_t first = HB_SET_VALUE_INVALID, last = HB_SET_VALUE_INVALID;
    338      for (; cmap_unicodes->next_range (&first, &last); )
    339      {
    340        _fill_unicode_and_glyph_map(plan, hb_range(first, last + 1), [&] (hb_codepoint_t cp) {
    341          hb_codepoint_t gid = (*unicode_glyphid_map)[cp];
    342   if (!unicodes.has (cp) && !glyphs->has (gid))
    343     return HB_MAP_VALUE_INVALID;
    344          return gid;
    345        },
    346        [&] (hb_codepoint_t cp) {
    347          return unicode_glyphid_map->get(cp);
    348        });
    349      }
    350    }
    351 
    352    /* Add gids which where requested, but not mapped in cmap */
    353    unsigned num_glyphs = plan->source->get_num_glyphs ();
    354    hb_codepoint_t first = HB_SET_VALUE_INVALID, last = HB_SET_VALUE_INVALID;
    355    for (; glyphs->next_range (&first, &last); )
    356    {
    357      if (first >= num_glyphs)
    358 break;
    359      if (last >= num_glyphs)
    360        last = num_glyphs - 1;
    361      plan->_glyphset_gsub.add_range (first, last);
    362    }
    363  }
    364 
    365  auto &arr = plan->unicode_to_new_gid_list;
    366  if (arr.length)
    367  {
    368    plan->unicodes.add_sorted_array (&arr.arrayZ->first, arr.length, sizeof (*arr.arrayZ));
    369    plan->_glyphset_gsub.add_array (&arr.arrayZ->second, arr.length, sizeof (*arr.arrayZ));
    370  }
    371 
    372  // Variation selectors don't have glyphs associated with them in the cmap so they will have been filtered out above
    373  // but should still be retained. Add them back here.
    374 
    375  // However, the min and max codepoints for OS/2 should be calculated without considering variation selectors,
    376  // so record those first.
    377  plan->os2_info.min_cmap_codepoint = plan->unicodes.get_min();
    378  plan->os2_info.max_cmap_codepoint = plan->unicodes.get_max();
    379 
    380  hb_set_t variation_selectors_to_retain;
    381  cmap.collect_variation_selectors(&variation_selectors_to_retain);
    382  + variation_selectors_to_retain.iter()
    383  | hb_filter(unicodes)
    384  | hb_sink(&plan->unicodes)
    385  ;
    386 }
    387 
    388 static unsigned
    389 _glyf_add_gid_and_children (const OT::glyf_accelerator_t &glyf,
    390 		    hb_codepoint_t gid,
    391 		    hb_set_t *gids_to_retain,
    392 		    int operation_count,
    393 		    unsigned depth = 0)
    394 {
    395  /* Check if is already visited */
    396  if (gids_to_retain->has (gid)) return operation_count;
    397 
    398  gids_to_retain->add (gid);
    399 
    400  if (unlikely (depth++ > HB_MAX_NESTING_LEVEL)) return operation_count;
    401  if (unlikely (--operation_count < 0)) return operation_count;
    402 
    403  auto glyph = glyf.glyph_for_gid (gid);
    404 
    405  for (auto &item : glyph.get_composite_iterator ())
    406    operation_count =
    407      _glyf_add_gid_and_children (glyf,
    408 			  item.get_gid (),
    409 			  gids_to_retain,
    410 			  operation_count,
    411 			  depth);
    412 
    413  return operation_count;
    414 }
    415 
    416 static void
    417 _nameid_closure (hb_subset_plan_t* plan,
    418 	 hb_set_t* drop_tables)
    419 {
    420 #ifndef HB_NO_STYLE
    421  if (!drop_tables->has (HB_OT_TAG_STAT))
    422    plan->source->table.STAT->collect_name_ids (&plan->user_axes_location, &plan->name_ids);
    423 #endif
    424 #ifndef HB_NO_VAR
    425  if (!plan->all_axes_pinned)
    426    plan->source->table.fvar->collect_name_ids (&plan->user_axes_location, &plan->axes_old_index_tag_map, &plan->name_ids);
    427 #endif
    428 #ifndef HB_NO_COLOR
    429  if (!drop_tables->has (HB_OT_TAG_CPAL))
    430    plan->source->table.CPAL->collect_name_ids (&plan->colr_palettes, &plan->name_ids);
    431 #endif
    432 
    433 #ifndef HB_NO_SUBSET_LAYOUT
    434  layout_nameid_closure(plan, drop_tables);
    435 #endif
    436 }
    437 
    438 static void
    439 _populate_gids_to_retain (hb_subset_plan_t* plan,
    440 	          hb_set_t* drop_tables)
    441 {
    442  OT::glyf_accelerator_t glyf (plan->source);
    443 #ifndef HB_NO_SUBSET_CFF
    444  // Note: we cannot use inprogress_accelerator here, since it has not been
    445  // created yet. So in case of preprocessed-face (and otherwise), we do an
    446  // extra sanitize pass here, which is not ideal.
    447  OT::cff1::accelerator_subset_t stack_cff (plan->accelerator ? nullptr : plan->source);
    448  const OT::cff1::accelerator_subset_t *cff (plan->accelerator ? plan->accelerator->cff1_accel.get () : &stack_cff);
    449 #endif
    450 
    451  plan->_glyphset_gsub.add (0); // Not-def
    452 
    453  _cmap_closure (plan->source, &plan->unicodes, &plan->_glyphset_gsub);
    454 
    455 #ifndef HB_NO_SUBSET_LAYOUT
    456  layout_populate_gids_to_retain(plan, drop_tables);
    457 #endif
    458 
    459  _remove_invalid_gids (&plan->_glyphset_gsub, plan->source->get_num_glyphs ());
    460 
    461  plan->_glyphset_mathed = plan->_glyphset_gsub;
    462  if (!drop_tables->has (HB_OT_TAG_MATH))
    463  {
    464    _math_closure (plan, &plan->_glyphset_mathed);
    465    _remove_invalid_gids (&plan->_glyphset_mathed, plan->source->get_num_glyphs ());
    466  }
    467 
    468  hb_set_t cur_glyphset = plan->_glyphset_mathed;
    469  if (!drop_tables->has (HB_OT_TAG_COLR))
    470  {
    471    _colr_closure (plan, &cur_glyphset);
    472    _remove_invalid_gids (&cur_glyphset, plan->source->get_num_glyphs ());
    473  }
    474 
    475  plan->_glyphset_colred = cur_glyphset;
    476 
    477  // XXX TODO VARC closure / subset
    478 
    479  _nameid_closure (plan, drop_tables);
    480  /* Populate a full set of glyphs to retain by adding all referenced
    481   * composite glyphs. */
    482  if (glyf.has_data ())
    483    for (hb_codepoint_t gid : cur_glyphset)
    484      _glyf_add_gid_and_children (glyf, gid, &plan->_glyphset,
    485 			  cur_glyphset.get_population () * HB_MAX_COMPOSITE_OPERATIONS_PER_GLYPH);
    486  else
    487    plan->_glyphset.union_ (cur_glyphset);
    488 #ifndef HB_NO_SUBSET_CFF
    489  if (!plan->accelerator || plan->accelerator->has_seac)
    490  {
    491    bool has_seac = false;
    492    if (cff->is_valid ())
    493      for (hb_codepoint_t gid : cur_glyphset)
    494 if (_add_cff_seac_components (*cff, gid, &plan->_glyphset))
    495   has_seac = true;
    496    plan->has_seac = has_seac;
    497  }
    498 #endif
    499 
    500  _remove_invalid_gids (&plan->_glyphset, plan->source->get_num_glyphs ());
    501 
    502 #ifndef HB_NO_VAR
    503 #ifndef HB_NO_SUBSET_LAYOUT
    504  if (!drop_tables->has (HB_OT_TAG_GDEF))
    505    collect_layout_variation_indices (plan);
    506 #endif
    507 #endif
    508 }
    509 
    510 static void
    511 _create_glyph_map_gsub (const hb_set_t* glyph_set_gsub,
    512                        const hb_map_t* glyph_map,
    513                        hb_map_t* out)
    514 {
    515  out->alloc (glyph_set_gsub->get_population ());
    516  + hb_iter (glyph_set_gsub)
    517  | hb_map ([&] (hb_codepoint_t gid) {
    518    return hb_codepoint_pair_t (gid, glyph_map->get (gid));
    519  })
    520  | hb_sink (out)
    521  ;
    522 }
    523 
    524 static bool
    525 _create_old_gid_to_new_gid_map (const hb_face_t *face,
    526 			bool		 retain_gids,
    527 			const hb_set_t	*all_gids_to_retain,
    528                                const hb_map_t  *requested_glyph_map,
    529 			hb_map_t	*glyph_map, /* OUT */
    530 			hb_map_t	*reverse_glyph_map, /* OUT */
    531 			hb_sorted_vector_t<hb_codepoint_pair_t> *new_to_old_gid_list /* OUT */,
    532 			unsigned int	*num_glyphs /* OUT */)
    533 {
    534  unsigned pop = all_gids_to_retain->get_population ();
    535  reverse_glyph_map->alloc (pop);
    536  glyph_map->alloc (pop);
    537  new_to_old_gid_list->alloc (pop);
    538 
    539  if (*requested_glyph_map)
    540  {
    541    hb_set_t new_gids(requested_glyph_map->values());
    542    if (new_gids.get_population() != requested_glyph_map->get_population())
    543    {
    544      DEBUG_MSG (SUBSET, nullptr, "The provided custom glyph mapping is not unique.");
    545      return false;
    546    }
    547 
    548    if (retain_gids)
    549    {
    550      DEBUG_MSG (SUBSET, nullptr,
    551        "HB_SUBSET_FLAGS_RETAIN_GIDS cannot be set if "
    552        "a custom glyph mapping has been provided.");
    553      return false;
    554    }
    555 
    556    hb_codepoint_t max_glyph = 0;
    557    hb_set_t remaining;
    558    for (auto old_gid : all_gids_to_retain->iter ())
    559    {
    560      if (old_gid == 0) {
    561 new_to_old_gid_list->push (hb_pair<hb_codepoint_t, hb_codepoint_t> (0u, 0u));
    562        continue;
    563      }
    564 
    565      hb_codepoint_t* new_gid;
    566      if (!requested_glyph_map->has (old_gid, &new_gid))
    567      {
    568        remaining.add(old_gid);
    569        continue;
    570      }
    571 
    572      if (*new_gid > max_glyph)
    573        max_glyph = *new_gid;
    574      new_to_old_gid_list->push (hb_pair (*new_gid, old_gid));
    575    }
    576    new_to_old_gid_list->qsort ();
    577 
    578    // Anything that wasn't mapped by the requested mapping should
    579    // be placed after the requested mapping.
    580    for (auto old_gid : remaining)
    581      new_to_old_gid_list->push (hb_pair (++max_glyph, old_gid));
    582 
    583    *num_glyphs = max_glyph + 1;
    584  }
    585  else if (!retain_gids)
    586  {
    587    + hb_enumerate (hb_iter (all_gids_to_retain), (hb_codepoint_t) 0)
    588    | hb_sink (new_to_old_gid_list)
    589    ;
    590    *num_glyphs = new_to_old_gid_list->length;
    591  }
    592  else
    593  {
    594    + hb_iter (all_gids_to_retain)
    595    | hb_map ([] (hb_codepoint_t _) {
    596 	return hb_codepoint_pair_t (_, _);
    597       })
    598    | hb_sink (new_to_old_gid_list)
    599    ;
    600 
    601    hb_codepoint_t max_glyph = HB_SET_VALUE_INVALID;
    602    hb_set_previous (all_gids_to_retain, &max_glyph);
    603 
    604    *num_glyphs = max_glyph + 1;
    605  }
    606 
    607  reverse_glyph_map->alloc (reverse_glyph_map->get_population () + new_to_old_gid_list->length);
    608  + hb_iter (new_to_old_gid_list)
    609  | hb_sink (reverse_glyph_map)
    610  ;
    611  glyph_map->alloc (glyph_map->get_population () + new_to_old_gid_list->length);
    612  + hb_iter (new_to_old_gid_list)
    613  | hb_map (&hb_codepoint_pair_t::reverse)
    614  | hb_sink (glyph_map)
    615  ;
    616 
    617  return true;
    618 }
    619 
    620 hb_subset_plan_t::hb_subset_plan_t (hb_face_t *face,
    621 			    const hb_subset_input_t *input)
    622 {
    623  successful = true;
    624  flags = input->flags;
    625 
    626  unicode_to_new_gid_list.init ();
    627 
    628  name_ids = *input->sets.name_ids;
    629  name_languages = *input->sets.name_languages;
    630  layout_features = *input->sets.layout_features;
    631  layout_scripts = *input->sets.layout_scripts;
    632  glyphs_requested = *input->sets.glyphs;
    633  drop_tables = *input->sets.drop_tables;
    634  no_subset_tables = *input->sets.no_subset_tables;
    635  source = hb_face_reference (face);
    636  dest = hb_face_builder_create ();
    637 
    638  codepoint_to_glyph = hb_map_create ();
    639  glyph_map = hb_map_create ();
    640  reverse_glyph_map = hb_map_create ();
    641 
    642  gsub_insert_catch_all_feature_variation_rec = false;
    643  gpos_insert_catch_all_feature_variation_rec = false;
    644  gdef_varstore_inner_maps.init ();
    645 
    646  user_axes_location = input->axes_location;
    647  all_axes_pinned = false;
    648  pinned_at_default = true;
    649  has_gdef_varstore = false;
    650 
    651 #ifdef HB_EXPERIMENTAL_API
    652  for (auto _ : input->name_table_overrides)
    653  {
    654    hb_bytes_t name_bytes = _.second;
    655    unsigned len = name_bytes.length;
    656    char *name_str = (char *) hb_malloc (len);
    657    if (unlikely (!check_success (name_str)))
    658      break;
    659 
    660    hb_memcpy (name_str, name_bytes.arrayZ, len);
    661    name_table_overrides.set (_.first, hb_bytes_t (name_str, len));
    662  }
    663 #endif
    664 
    665  void* accel = hb_face_get_user_data(face, hb_subset_accelerator_t::user_data_key());
    666 
    667  attach_accelerator_data = input->attach_accelerator_data;
    668  force_long_loca = input->force_long_loca;
    669 #ifdef HB_EXPERIMENTAL_API
    670  force_long_loca = force_long_loca || (flags & HB_SUBSET_FLAGS_IFTB_REQUIREMENTS);
    671 #endif
    672 
    673  if (accel)
    674    accelerator = (hb_subset_accelerator_t*) accel;
    675 
    676  if (unlikely (in_error ()))
    677    return;
    678 
    679 #ifndef HB_NO_VAR
    680  if (!check_success (normalize_axes_location (face, this)))
    681      return;
    682 #endif
    683 
    684  _populate_unicodes_to_retain (input->sets.unicodes, input->sets.glyphs, this);
    685 
    686  _populate_gids_to_retain (this, input->sets.drop_tables);
    687  if (unlikely (in_error ()))
    688    return;
    689 
    690  if (!check_success(_create_old_gid_to_new_gid_map(
    691          face,
    692          input->flags & HB_SUBSET_FLAGS_RETAIN_GIDS,
    693          &_glyphset,
    694          &input->glyph_map,
    695          glyph_map,
    696          reverse_glyph_map,
    697   &new_to_old_gid_list,
    698          &_num_output_glyphs))) {
    699    return;
    700  }
    701 
    702 #ifdef HB_EXPERIMENTAL_API  
    703  if ((input->flags & HB_SUBSET_FLAGS_RETAIN_GIDS) &&
    704      (input->flags & HB_SUBSET_FLAGS_RETAIN_NUM_GLYPHS)) {
    705    // We've been requested to maintain the num glyphs count from the
    706    // input face.
    707    _num_output_glyphs = source->get_num_glyphs ();
    708  }
    709 #endif
    710 
    711  _create_glyph_map_gsub (
    712      &_glyphset_gsub,
    713      glyph_map,
    714      &glyph_map_gsub);
    715 
    716  // Now that we have old to new gid map update the unicode to new gid list.
    717  for (unsigned i = 0; i < unicode_to_new_gid_list.length; i++)
    718  {
    719    // Use raw array access for performance.
    720    unicode_to_new_gid_list.arrayZ[i].second =
    721        glyph_map->get(unicode_to_new_gid_list.arrayZ[i].second);
    722  }
    723 
    724  bounds_width_vec.resize_dirty  (_num_output_glyphs);
    725  for (auto &v : bounds_width_vec)
    726    v = 0xFFFFFFFF;
    727  bounds_height_vec.resize_dirty  (_num_output_glyphs);
    728  for (auto &v : bounds_height_vec)
    729    v = 0xFFFFFFFF;
    730 
    731 #ifndef HB_NO_SUBSET_LAYOUT    
    732  if (!drop_tables.has (HB_OT_TAG_GDEF))
    733    remap_used_mark_sets (this, used_mark_sets_map);
    734 #endif
    735 
    736 #ifndef HB_NO_VAR
    737 #ifndef HB_NO_BASE
    738  if (!drop_tables.has (HB_OT_TAG_BASE))
    739    collect_base_variation_indices (this);
    740 #endif
    741 #endif
    742 
    743  if (unlikely (in_error ()))
    744    return;
    745 
    746 #ifndef HB_NO_VAR
    747  update_instance_metrics_map_from_cff2 (this);
    748  if (!check_success (get_instance_glyphs_contour_points (this)))
    749      return;
    750 #endif
    751 
    752  if (attach_accelerator_data)
    753  {
    754    inprogress_accelerator =
    755      hb_subset_accelerator_t::create (source,
    756 			       *codepoint_to_glyph,
    757                                       unicodes,
    758 			       has_seac);
    759 
    760    check_success (inprogress_accelerator);
    761  }
    762 
    763 #define HB_SUBSET_PLAN_MEMBER(Type, Name) check_success (!Name.in_error ());
    764 #include "hb-subset-plan-member-list.hh"
    765 #undef HB_SUBSET_PLAN_MEMBER
    766 }
    767 
    768 hb_subset_plan_t::~hb_subset_plan_t()
    769 {
    770  hb_face_destroy (dest);
    771 
    772  hb_map_destroy (codepoint_to_glyph);
    773  hb_map_destroy (glyph_map);
    774  hb_map_destroy (reverse_glyph_map);
    775 #ifndef HB_NO_SUBSET_CFF
    776  cff1_accel.fini ();
    777  cff2_accel.fini ();
    778 #endif
    779  hb_face_destroy (source);
    780 
    781 #ifdef HB_EXPERIMENTAL_API
    782  for (auto _ : name_table_overrides.iter_ref ())
    783    _.second.fini ();
    784 #endif
    785 
    786  if (inprogress_accelerator)
    787    hb_subset_accelerator_t::destroy ((void*) inprogress_accelerator);
    788 }
    789 
    790 
    791 /**
    792 * hb_subset_plan_create_or_fail:
    793 * @face: font face to create the plan for.
    794 * @input: a #hb_subset_input_t input.
    795 *
    796 * Computes a plan for subsetting the supplied face according
    797 * to a provided input. The plan describes
    798 * which tables and glyphs should be retained.
    799 *
    800 * Return value: (transfer full): New subset plan. Destroy with
    801 * hb_subset_plan_destroy(). If there is a failure creating the plan
    802 * nullptr will be returned.
    803 *
    804 * Since: 4.0.0
    805 **/
    806 hb_subset_plan_t *
    807 hb_subset_plan_create_or_fail (hb_face_t	 *face,
    808                               const hb_subset_input_t *input)
    809 {
    810  hb_subset_plan_t *plan;
    811  if (unlikely (!(plan = hb_object_create<hb_subset_plan_t> (face, input))))
    812    return nullptr;
    813 
    814  if (unlikely (plan->in_error ()))
    815  {
    816    hb_subset_plan_destroy (plan);
    817    return nullptr;
    818  }
    819 
    820  return plan;
    821 }
    822 
    823 /**
    824 * hb_subset_plan_destroy:
    825 * @plan: a #hb_subset_plan_t
    826 *
    827 * Decreases the reference count on @plan, and if it reaches zero, destroys
    828 * @plan, freeing all memory.
    829 *
    830 * Since: 4.0.0
    831 **/
    832 void
    833 hb_subset_plan_destroy (hb_subset_plan_t *plan)
    834 {
    835  if (!hb_object_destroy (plan)) return;
    836 
    837  hb_free (plan);
    838 }
    839 
    840 /**
    841 * hb_subset_plan_old_to_new_glyph_mapping:
    842 * @plan: a subsetting plan.
    843 *
    844 * Returns the mapping between glyphs in the original font to glyphs in the
    845 * subset that will be produced by @plan
    846 *
    847 * Return value: (transfer none):
    848 * A pointer to the #hb_map_t of the mapping.
    849 *
    850 * Since: 4.0.0
    851 **/
    852 hb_map_t *
    853 hb_subset_plan_old_to_new_glyph_mapping (const hb_subset_plan_t *plan)
    854 {
    855  return plan->glyph_map;
    856 }
    857 
    858 /**
    859 * hb_subset_plan_new_to_old_glyph_mapping:
    860 * @plan: a subsetting plan.
    861 *
    862 * Returns the mapping between glyphs in the subset that will be produced by
    863 * @plan and the glyph in the original font.
    864 *
    865 * Return value: (transfer none):
    866 * A pointer to the #hb_map_t of the mapping.
    867 *
    868 * Since: 4.0.0
    869 **/
    870 hb_map_t *
    871 hb_subset_plan_new_to_old_glyph_mapping (const hb_subset_plan_t *plan)
    872 {
    873  return plan->reverse_glyph_map;
    874 }
    875 
    876 /**
    877 * hb_subset_plan_unicode_to_old_glyph_mapping:
    878 * @plan: a subsetting plan.
    879 *
    880 * Returns the mapping between codepoints in the original font and the
    881 * associated glyph id in the original font.
    882 *
    883 * Return value: (transfer none):
    884 * A pointer to the #hb_map_t of the mapping.
    885 *
    886 * Since: 4.0.0
    887 **/
    888 hb_map_t *
    889 hb_subset_plan_unicode_to_old_glyph_mapping (const hb_subset_plan_t *plan)
    890 {
    891  return plan->codepoint_to_glyph;
    892 }
    893 
    894 /**
    895 * hb_subset_plan_reference: (skip)
    896 * @plan: a #hb_subset_plan_t object.
    897 *
    898 * Increases the reference count on @plan.
    899 *
    900 * Return value: @plan.
    901 *
    902 * Since: 4.0.0
    903 **/
    904 hb_subset_plan_t *
    905 hb_subset_plan_reference (hb_subset_plan_t *plan)
    906 {
    907  return hb_object_reference (plan);
    908 }
    909 
    910 /**
    911 * hb_subset_plan_set_user_data: (skip)
    912 * @plan: a #hb_subset_plan_t object.
    913 * @key: The user-data key to set
    914 * @data: A pointer to the user data
    915 * @destroy: (nullable): A callback to call when @data is not needed anymore
    916 * @replace: Whether to replace an existing data with the same key
    917 *
    918 * Attaches a user-data key/data pair to the given subset plan object.
    919 *
    920 * Return value: `true` if success, `false` otherwise
    921 *
    922 * Since: 4.0.0
    923 **/
    924 hb_bool_t
    925 hb_subset_plan_set_user_data (hb_subset_plan_t   *plan,
    926                              hb_user_data_key_t *key,
    927                              void               *data,
    928                              hb_destroy_func_t   destroy,
    929                              hb_bool_t	          replace)
    930 {
    931  return hb_object_set_user_data (plan, key, data, destroy, replace);
    932 }
    933 
    934 /**
    935 * hb_subset_plan_get_user_data: (skip)
    936 * @plan: a #hb_subset_plan_t object.
    937 * @key: The user-data key to query
    938 *
    939 * Fetches the user data associated with the specified key,
    940 * attached to the specified subset plan object.
    941 *
    942 * Return value: (transfer none): A pointer to the user data
    943 *
    944 * Since: 4.0.0
    945 **/
    946 void *
    947 hb_subset_plan_get_user_data (const hb_subset_plan_t *plan,
    948                              hb_user_data_key_t     *key)
    949 {
    950  return hb_object_get_user_data (plan, key);
    951 }