/*

 * 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-ot-map-private.hh"

#include "hb-ot-layout-private.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].len; i++)

    hb_set_add (lookups_out, 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));

  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. */

  hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE};

  hb_tag_t language_tag;

  hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]);

  language_tag = hb_ot_tag_from_language (props.language);

  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_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]);

    hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);

  }

}

void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,

                                       hb_ot_map_feature_flags_t flags)

{

  feature_info_t *info = feature_infos.push();

  if (unlikely (!tag)) return;

  info->tag = tag;

  info->seq = feature_infos.len;

  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)

{

  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;

    }

    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 ();

  current_stage[table_index]++;

}

void

hb_ot_map_builder_t::compile (hb_ot_map_t  &m,

                              const int    *coords,

                              unsigned int  num_coords)

{

  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 */

  {

    feature_infos.qsort ();

    unsigned int j = 0;

    for (unsigned int i = 1; i < feature_infos.len; 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 {

          feature_infos[j].flags &= ~F_GLOBAL;

          feature_infos[j].max_value = 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] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]);

        feature_infos[j].stage[1] = 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.len; 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 to 8 bits per feature. */

      bits_needed = MIN(8u, _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. */

    hb_bool_t 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 |= 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 |= 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);

    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 variations_index;

    hb_ot_layout_table_find_feature_variations (face,

                                                table_tags[table_index],

                                                coords,

                                                num_coords,

                                                &variations_index);

    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],

                     variations_index,

                     global_bit_mask);

      for (unsigned i = 0; i < m.features.len; i++)

        if (m.features[i].stage[table_index] == stage)

          add_lookups (m, table_index,

                       m.features[i].index[table_index],

                       variations_index,

                       m.features[i].mask,

                       m.features[i].auto_zwnj,

                       m.features[i].auto_zwj);

      /* Sort lookups and merge duplicates */

      if (last_num_lookups < m.lookups[table_index].len)

      {

        m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].len);

        unsigned int j = last_num_lookups;

        for (unsigned int i = j + 1; i < m.lookups[table_index].len; 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].len;

      if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) {

        hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();

        stage_index++;

      }

    }

  }

}