text: /*
   * Copyright © 2009,2010  Red Hat, Inc.
   * Copyright © 2010,2011,2013  Google, Inc.
   *
   *  This is part of HarfBuzz, a text shaping library.
   *
   * Permission is hereby granted, without written agreement and without
   * license or royalty fees, to use, copy, modify, and distribute this
   * software and its documentation for any purpose, provided that the
   * above copyright notice and the following two paragraphs appear in
   * all copies of this software.
   *
   * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
   * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
   * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
   * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
   * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
   * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
   * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
   *
   * Red Hat Author(s): Behdad Esfahbod
   * Google Author(s): Behdad Esfahbod
   */
  
  #include "hb.hh"
  
  #ifndef HB_NO_OT_SHAPE
  
  #include "hb-ot-map.hh"
  #include "hb-ot-shape.hh"
  #include "hb-ot-layout.hh"
  
  
  void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
  {
    for (unsigned int i = 0; i < lookups[table_index].length; i++)
      lookups_out->add (lookups[table_index][i].index);
  }
  
  
  hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
                                            const hb_segment_properties_t *props_)
  {
    memset (this, 0, sizeof (*this));
  
    feature_infos.init ();
    for (unsigned int table_index = 0; table_index < 2; table_index++)
      stages[table_index].init ();
  
    face = face_;
    props = *props_;
  
  
    /* Fetch script/language indices for GSUB/GPOS.  We need these later to skip
     * features not available in either table and not waste precious bits for them. */
  
    unsigned int script_count = HB_OT_MAX_TAGS_PER_SCRIPT;
    unsigned int language_count = HB_OT_MAX_TAGS_PER_LANGUAGE;
    hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT];
    hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE];
  
    hb_ot_tags_from_script_and_language (props.script, props.language, &script_count, script_tags, &language_count, language_tags);
  
    for (unsigned int table_index = 0; table_index < 2; table_index++) {
      hb_tag_t table_tag = table_tags[table_index];
      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]);
      hb_ot_layout_script_select_language (face, table_tag, script_index[table_index], language_count, language_tags, &language_index[table_index]);
    }
  }
  
  hb_ot_map_builder_t::~hb_ot_map_builder_t ()
  {
    feature_infos.fini ();
    for (unsigned int table_index = 0; table_index < 2; table_index++)
      stages[table_index].fini ();
  }
  
  void hb_ot_map_builder_t::add_feature (hb_tag_t tag,
                                         hb_ot_map_feature_flags_t flags,
                                         unsigned int value)
  {
    if (unlikely (!tag)) return;
    feature_info_t *info = feature_infos.push();
    info->tag = tag;
    info->seq = feature_infos.length;
    info->max_value = value;
    info->flags = flags;
    info->default_value = (flags & F_GLOBAL) ? value : 0;
    info->stage[0] = current_stage[0];
    info->stage[1] = current_stage[1];
  }
  
  void
  hb_ot_map_builder_t::add_lookups (hb_ot_map_t  &m,
                                    unsigned int  table_index,
                                    unsigned int  feature_index,
                                    unsigned int  variations_index,
                                    hb_mask_t     mask,
                                    bool          auto_zwnj,
                                    bool          auto_zwj,
                                    bool          random)
  {
    unsigned int lookup_indices[32];
    unsigned int offset, len;
    unsigned int table_lookup_count;
  
    table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
  
    offset = 0;
    do {
      len = ARRAY_LENGTH (lookup_indices);
      hb_ot_layout_feature_with_variations_get_lookups (face,
                                                        table_tags[table_index],
                                                        feature_index,
                                                        variations_index,
                                                        offset, &len,
                                                        lookup_indices);
  
      for (unsigned int i = 0; i < len; i++)
      {
        if (lookup_indices[i] >= table_lookup_count)
          continue;
        hb_ot_map_t::lookup_map_t *lookup = m.lookups[table_index].push ();
        lookup->mask = mask;
        lookup->index = lookup_indices[i];
        lookup->auto_zwnj = auto_zwnj;
        lookup->auto_zwj = auto_zwj;
        lookup->random = random;
      }
  
      offset += len;
    } while (len == ARRAY_LENGTH (lookup_indices));
  }
  
  
  void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
  {
    stage_info_t *s = stages[table_index].push ();
    s->index = current_stage[table_index];
    s->pause_func = pause_func;
  
    current_stage[table_index]++;
  }
  
  void
  hb_ot_map_builder_t::compile (hb_ot_map_t                  &m,
                                const hb_ot_shape_plan_key_t &key)
  {
    static_assert ((!(HB_GLYPH_FLAG_DEFINED & (HB_GLYPH_FLAG_DEFINED + 1))), "");
    unsigned int global_bit_mask = HB_GLYPH_FLAG_DEFINED + 1;
    unsigned int global_bit_shift = hb_popcount (HB_GLYPH_FLAG_DEFINED);
  
    m.global_mask = global_bit_mask;
  
    unsigned int required_feature_index[2];
    hb_tag_t required_feature_tag[2];
    /* We default to applying required feature in stage 0.  If the required
     * feature has a tag that is known to the shaper, we apply required feature
     * in the stage for that tag.
     */
    unsigned int required_feature_stage[2] = {0, 0};
  
    for (unsigned int table_index = 0; table_index < 2; table_index++)
    {
      m.chosen_script[table_index] = chosen_script[table_index];
      m.found_script[table_index] = found_script[table_index];
  
      hb_ot_layout_language_get_required_feature (face,
                                                  table_tags[table_index],
                                                  script_index[table_index],
                                                  language_index[table_index],
                                                  &required_feature_index[table_index],
                                                  &required_feature_tag[table_index]);
    }
  
    /* Sort features and merge duplicates */
    if (feature_infos.length)
    {
      feature_infos.qsort ();
      unsigned int j = 0;
      for (unsigned int i = 1; i < feature_infos.length; i++)
        if (feature_infos[i].tag != feature_infos[j].tag)
          feature_infos[++j] = feature_infos[i];
        else {
          if (feature_infos[i].flags & F_GLOBAL) {
            feature_infos[j].flags |= F_GLOBAL;
            feature_infos[j].max_value = feature_infos[i].max_value;
            feature_infos[j].default_value = feature_infos[i].default_value;
          } else {
            if (feature_infos[j].flags & F_GLOBAL)
              feature_infos[j].flags ^= F_GLOBAL;
            feature_infos[j].max_value = hb_max (feature_infos[j].max_value, feature_infos[i].max_value);
            /* Inherit default_value from j */
          }
          feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
          feature_infos[j].stage[0] = hb_min (feature_infos[j].stage[0], feature_infos[i].stage[0]);
          feature_infos[j].stage[1] = hb_min (feature_infos[j].stage[1], feature_infos[i].stage[1]);
        }
      feature_infos.shrink (j + 1);
    }
  
  
    /* Allocate bits now */
    unsigned int next_bit = global_bit_shift + 1;
  
    for (unsigned int i = 0; i < feature_infos.length; i++)
    {
      const feature_info_t *info = &feature_infos[i];
  
      unsigned int bits_needed;
  
      if ((info->flags & F_GLOBAL) && info->max_value == 1)
        /* Uses the global bit */
        bits_needed = 0;
      else
        /* Limit bits per feature. */
        bits_needed = hb_min (HB_OT_MAP_MAX_BITS, hb_bit_storage (info->max_value));
  
      if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
        continue; /* Feature disabled, or not enough bits. */
  
  
      bool found = false;
      unsigned int feature_index[2];
      for (unsigned int table_index = 0; table_index < 2; table_index++)
      {
        if (required_feature_tag[table_index] == info->tag)
          required_feature_stage[table_index] = info->stage[table_index];
  
        found |= (bool) hb_ot_layout_language_find_feature (face,
                                                            table_tags[table_index],
                                                            script_index[table_index],
                                                            language_index[table_index],
                                                            info->tag,
                                                            &feature_index[table_index]);
      }
      if (!found && (info->flags & F_GLOBAL_SEARCH))
      {
        for (unsigned int table_index = 0; table_index < 2; table_index++)
        {
          found |= (bool) hb_ot_layout_table_find_feature (face,
                                                           table_tags[table_index],
                                                           info->tag,
                                                           &feature_index[table_index]);
        }
      }
      if (!found && !(info->flags & F_HAS_FALLBACK))
        continue;
  
  
      hb_ot_map_t::feature_map_t *map = m.features.push ();
  
      map->tag = info->tag;
      map->index[0] = feature_index[0];
      map->index[1] = feature_index[1];
      map->stage[0] = info->stage[0];
      map->stage[1] = info->stage[1];
      map->auto_zwnj = !(info->flags & F_MANUAL_ZWNJ);
      map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
      map->random = !!(info->flags & F_RANDOM);
      if ((info->flags & F_GLOBAL) && info->max_value == 1) {
        /* Uses the global bit */
        map->shift = global_bit_shift;
        map->mask = global_bit_mask;
      } else {
        map->shift = next_bit;
        map->mask = (1u << (next_bit + bits_needed)) - (1u << next_bit);
        next_bit += bits_needed;
        m.global_mask |= (info->default_value << map->shift) & map->mask;
      }
      map->_1_mask = (1u << map->shift) & map->mask;
      map->needs_fallback = !found;
  
    }
    feature_infos.shrink (0); /* Done with these */
  
  
    add_gsub_pause (nullptr);
    add_gpos_pause (nullptr);
  
    for (unsigned int table_index = 0; table_index < 2; table_index++)
    {
      /* Collect lookup indices for features */
  
      unsigned int stage_index = 0;
      unsigned int last_num_lookups = 0;
      for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
      {
        if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
            required_feature_stage[table_index] == stage)
          add_lookups (m, table_index,
                       required_feature_index[table_index],
                       key.variations_index[table_index],
                       global_bit_mask);
  
        for (unsigned i = 0; i < m.features.length; i++)
          if (m.features[i].stage[table_index] == stage)
            add_lookups (m, table_index,
                         m.features[i].index[table_index],
                         key.variations_index[table_index],
                         m.features[i].mask,
                         m.features[i].auto_zwnj,
                         m.features[i].auto_zwj,
                         m.features[i].random);
  
        /* Sort lookups and merge duplicates */
        if (last_num_lookups < m.lookups[table_index].length)
        {
          m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].length);
  
          unsigned int j = last_num_lookups;
          for (unsigned int i = j + 1; i < m.lookups[table_index].length; i++)
            if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
              m.lookups[table_index][++j] = m.lookups[table_index][i];
            else
            {
              m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
              m.lookups[table_index][j].auto_zwnj &= m.lookups[table_index][i].auto_zwnj;
              m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
            }
          m.lookups[table_index].shrink (j + 1);
        }
  
        last_num_lookups = m.lookups[table_index].length;
  
        if (stage_index < stages[table_index].length && stages[table_index][stage_index].index == stage) {
          hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
          stage_map->last_lookup = last_num_lookups;
          stage_map->pause_func = stages[table_index][stage_index].pause_func;
  
          stage_index++;
        }
      }
    }
  }
  
  
  #endif
  