src/hb-ot-map.cc

   1 /*
   2  * Copyright © 2009,2010  Red Hat, Inc.
   3  * Copyright © 2010,2011,2013  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 #include "hb.hh"
  30
  31 #ifndef HB_NO_OT_SHAPE
  32
  33 #include "hb-ot-map.hh"
  34 #include "hb-ot-shape.hh"
  35 #include "hb-ot-layout.hh"
  36
  37
  38 void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
  39 {
  40   for (unsigned int i = 0; i < lookups[table_index].length; i++)
  41     lookups_out->add (lookups[table_index][i].index);
  42 }
  43
  44
  45 hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
  46                                           const hb_segment_properties_t *props_)
  47 {
  48   memset (this, 0, sizeof (*this));
  49
  50   feature_infos.init ();
  51   for (unsigned int table_index = 0; table_index < 2; table_index++)
  52     stages[table_index].init ();
  53
  54   face = face_;
  55   props = *props_;
  56
  57
  58   /* Fetch script/language indices for GSUB/GPOS.  We need these later to skip
  59    * features not available in either table and not waste precious bits for them. */
  60
  61   unsigned int script_count = HB_OT_MAX_TAGS_PER_SCRIPT;
  62   unsigned int language_count = HB_OT_MAX_TAGS_PER_LANGUAGE;
  63   hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT];
  64   hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE];
  65
  66   hb_ot_tags_from_script_and_language (props.script, props.language, &script_count, script_tags, &language_count, language_tags);
  67
  68   for (unsigned int table_index = 0; table_index < 2; table_index++) {
  69     hb_tag_t table_tag = table_tags[table_index];
  70     found_script[table_index] = (bool) hb_ot_layout_table_select_script (face, table_tag, script_count, script_tags, &script_index[table_index], &chosen_script[table_index]);
  71     hb_ot_layout_script_select_language (face, table_tag, script_index[table_index], language_count, language_tags, &language_index[table_index]);
  72   }
  73 }
  74
  75 hb_ot_map_builder_t::~hb_ot_map_builder_t ()
  76 {
  77   feature_infos.fini ();
  78   for (unsigned int table_index = 0; table_index < 2; table_index++)
  79     stages[table_index].fini ();
  80 }
  81
  82 void hb_ot_map_builder_t::add_feature (hb_tag_t tag,
  83                                        hb_ot_map_feature_flags_t flags,
  84                                        unsigned int value)
  85 {
  86   if (unlikely (!tag)) return;
  87   feature_info_t *info = feature_infos.push();
  88   info->tag = tag;
  89   info->seq = feature_infos.length;
  90   info->max_value = value;
  91   info->flags = flags;
  92   info->default_value = (flags & F_GLOBAL) ? value : 0;
  93   info->stage[0] = current_stage[0];
  94   info->stage[1] = current_stage[1];
  95 }
  96
  97 void
  98 hb_ot_map_builder_t::add_lookups (hb_ot_map_t  &m,
  99                                   unsigned int  table_index,
 100                                   unsigned int  feature_index,
 101                                   unsigned int  variations_index,
 102                                   hb_mask_t     mask,
 103                                   bool          auto_zwnj,
 104                                   bool          auto_zwj,
 105                                   bool          random)
 106 {
 107   unsigned int lookup_indices[32];
 108   unsigned int offset, len;
 109   unsigned int table_lookup_count;
 110
 111   table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
 112
 113   offset = 0;
 114   do {
 115     len = ARRAY_LENGTH (lookup_indices);
 116     hb_ot_layout_feature_with_variations_get_lookups (face,
 117                                                       table_tags[table_index],
 118                                                       feature_index,
 119                                                       variations_index,
 120                                                       offset, &len,
 121                                                       lookup_indices);
 122
 123     for (unsigned int i = 0; i < len; i++)
 124     {
 125       if (lookup_indices[i] >= table_lookup_count)
 126         continue;
 127       hb_ot_map_t::lookup_map_t *lookup = m.lookups[table_index].push ();
 128       lookup->mask = mask;
 129       lookup->index = lookup_indices[i];
 130       lookup->auto_zwnj = auto_zwnj;
 131       lookup->auto_zwj = auto_zwj;
 132       lookup->random = random;
 133     }
 134
 135     offset += len;
 136   } while (len == ARRAY_LENGTH (lookup_indices));
 137 }
 138
 139
 140 void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
 141 {
 142   stage_info_t *s = stages[table_index].push ();
 143   s->index = current_stage[table_index];
 144   s->pause_func = pause_func;
 145
 146   current_stage[table_index]++;
 147 }
 148
 149 void
 150 hb_ot_map_builder_t::compile (hb_ot_map_t                  &m,
 151                               const hb_ot_shape_plan_key_t &key)
 152 {
 153   static_assert ((!(HB_GLYPH_FLAG_DEFINED & (HB_GLYPH_FLAG_DEFINED + 1))), "");
 154   unsigned int global_bit_mask = HB_GLYPH_FLAG_DEFINED + 1;
 155   unsigned int global_bit_shift = hb_popcount (HB_GLYPH_FLAG_DEFINED);
 156
 157   m.global_mask = global_bit_mask;
 158
 159   unsigned int required_feature_index[2];
 160   hb_tag_t required_feature_tag[2];
 161   /* We default to applying required feature in stage 0.  If the required
 162    * feature has a tag that is known to the shaper, we apply required feature
 163    * in the stage for that tag.
 164    */
 165   unsigned int required_feature_stage[2] = {0, 0};
 166
 167   for (unsigned int table_index = 0; table_index < 2; table_index++)
 168   {
 169     m.chosen_script[table_index] = chosen_script[table_index];
 170     m.found_script[table_index] = found_script[table_index];
 171
 172     hb_ot_layout_language_get_required_feature (face,
 173                                                 table_tags[table_index],
 174                                                 script_index[table_index],
 175                                                 language_index[table_index],
 176                                                 &required_feature_index[table_index],
 177                                                 &required_feature_tag[table_index]);
 178   }
 179
 180   /* Sort features and merge duplicates */
 181   if (feature_infos.length)
 182   {
 183     feature_infos.qsort ();
 184     unsigned int j = 0;
 185     for (unsigned int i = 1; i < feature_infos.length; i++)
 186       if (feature_infos[i].tag != feature_infos[j].tag)
 187         feature_infos[++j] = feature_infos[i];
 188       else {
 189         if (feature_infos[i].flags & F_GLOBAL) {
 190           feature_infos[j].flags |= F_GLOBAL;
 191           feature_infos[j].max_value = feature_infos[i].max_value;
 192           feature_infos[j].default_value = feature_infos[i].default_value;
 193         } else {
 194           if (feature_infos[j].flags & F_GLOBAL)
 195             feature_infos[j].flags ^= F_GLOBAL;
 196           feature_infos[j].max_value = hb_max (feature_infos[j].max_value, feature_infos[i].max_value);
 197           /* Inherit default_value from j */
 198         }
 199         feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
 200         feature_infos[j].stage[0] = hb_min (feature_infos[j].stage[0], feature_infos[i].stage[0]);
 201         feature_infos[j].stage[1] = hb_min (feature_infos[j].stage[1], feature_infos[i].stage[1]);
 202       }
 203     feature_infos.shrink (j + 1);
 204   }
 205
 206
 207   /* Allocate bits now */
 208   unsigned int next_bit = global_bit_shift + 1;
 209
 210   for (unsigned int i = 0; i < feature_infos.length; i++)
 211   {
 212     const feature_info_t *info = &feature_infos[i];
 213
 214     unsigned int bits_needed;
 215
 216     if ((info->flags & F_GLOBAL) && info->max_value == 1)
 217       /* Uses the global bit */
 218       bits_needed = 0;
 219     else
 220       /* Limit bits per feature. */
 221       bits_needed = hb_min (HB_OT_MAP_MAX_BITS, hb_bit_storage (info->max_value));
 222
 223     if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
 224       continue; /* Feature disabled, or not enough bits. */
 225
 226
 227     bool found = false;
 228     unsigned int feature_index[2];
 229     for (unsigned int table_index = 0; table_index < 2; table_index++)
 230     {
 231       if (required_feature_tag[table_index] == info->tag)
 232         required_feature_stage[table_index] = info->stage[table_index];
 233
 234       found |= (bool) hb_ot_layout_language_find_feature (face,
 235                                                           table_tags[table_index],
 236                                                           script_index[table_index],
 237                                                           language_index[table_index],
 238                                                           info->tag,
 239                                                           &feature_index[table_index]);
 240     }
 241     if (!found && (info->flags & F_GLOBAL_SEARCH))
 242     {
 243       for (unsigned int table_index = 0; table_index < 2; table_index++)
 244       {
 245         found |= (bool) hb_ot_layout_table_find_feature (face,
 246                                                          table_tags[table_index],
 247                                                          info->tag,
 248                                                          &feature_index[table_index]);
 249       }
 250     }
 251     if (!found && !(info->flags & F_HAS_FALLBACK))
 252       continue;
 253
 254
 255     hb_ot_map_t::feature_map_t *map = m.features.push ();
 256
 257     map->tag = info->tag;
 258     map->index[0] = feature_index[0];
 259     map->index[1] = feature_index[1];
 260     map->stage[0] = info->stage[0];
 261     map->stage[1] = info->stage[1];
 262     map->auto_zwnj = !(info->flags & F_MANUAL_ZWNJ);
 263     map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
 264     map->random = !!(info->flags & F_RANDOM);
 265     if ((info->flags & F_GLOBAL) && info->max_value == 1) {
 266       /* Uses the global bit */
 267       map->shift = global_bit_shift;
 268       map->mask = global_bit_mask;
 269     } else {
 270       map->shift = next_bit;
 271       map->mask = (1u << (next_bit + bits_needed)) - (1u << next_bit);
 272       next_bit += bits_needed;
 273       m.global_mask |= (info->default_value << map->shift) & map->mask;
 274     }
 275     map->_1_mask = (1u << map->shift) & map->mask;
 276     map->needs_fallback = !found;
 277
 278   }
 279   feature_infos.shrink (0); /* Done with these */
 280
 281
 282   add_gsub_pause (nullptr);
 283   add_gpos_pause (nullptr);
 284
 285   for (unsigned int table_index = 0; table_index < 2; table_index++)
 286   {
 287     /* Collect lookup indices for features */
 288
 289     unsigned int stage_index = 0;
 290     unsigned int last_num_lookups = 0;
 291     for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
 292     {
 293       if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
 294           required_feature_stage[table_index] == stage)
 295         add_lookups (m, table_index,
 296                      required_feature_index[table_index],
 297                      key.variations_index[table_index],
 298                      global_bit_mask);
 299
 300       for (unsigned i = 0; i < m.features.length; i++)
 301         if (m.features[i].stage[table_index] == stage)
 302           add_lookups (m, table_index,
 303                        m.features[i].index[table_index],
 304                        key.variations_index[table_index],
 305                        m.features[i].mask,
 306                        m.features[i].auto_zwnj,
 307                        m.features[i].auto_zwj,
 308                        m.features[i].random);
 309
 310       /* Sort lookups and merge duplicates */
 311       if (last_num_lookups < m.lookups[table_index].length)
 312       {
 313         m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].length);
 314
 315         unsigned int j = last_num_lookups;
 316         for (unsigned int i = j + 1; i < m.lookups[table_index].length; i++)
 317           if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
 318             m.lookups[table_index][++j] = m.lookups[table_index][i];
 319           else
 320           {
 321             m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
 322             m.lookups[table_index][j].auto_zwnj &= m.lookups[table_index][i].auto_zwnj;
 323             m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
 324           }
 325         m.lookups[table_index].shrink (j + 1);
 326       }
 327
 328       last_num_lookups = m.lookups[table_index].length;
 329
 330       if (stage_index < stages[table_index].length && stages[table_index][stage_index].index == stage) {
 331         hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
 332         stage_map->last_lookup = last_num_lookups;
 333         stage_map->pause_func = stages[table_index][stage_index].pause_func;
 334
 335         stage_index++;
 336       }
 337     }
 338   }
 339 }
 340
 341
 342 #endif