/*

 * 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_)

{

  hb_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];

}

bool hb_ot_map_builder_t::has_feature (hb_tag_t tag)

{

  for (unsigned int table_index = 0; table_index < 2; table_index++)

  {

    if (hb_ot_layout_language_find_feature (face,

              table_tags[table_index],

              script_index[table_index],

              language_index[table_index],

              tag,

              nullptr))

      return true;

  }

  return false;

}

void

hb_ot_map_builder_t::add_lookups (hb_ot_map_t  &m,

          unsigned int  table_index,

          unsigned int  feature_index,

          const hb_ot_shape_plan_key_t &key,

          hb_mask_t     mask,

          bool          auto_zwnj,

          bool          auto_zwj,

          bool          random,

          bool          per_syllable,

          hb_tag_t      feature_tag)

{

  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]);

  hb_set_t varied_lookups;

  if (key.get_lookup_variations (face, table_index, feature_index, &varied_lookups))

  {

    if (unlikely (varied_lookups.in_error ()))

    {

      m.lookups[table_index].ensure_error ();

      return;

    }

    for (unsigned int lookup_index : varied_lookups)

    {

      if (lookup_index >= table_lookup_count)

  continue;

      hb_ot_map_t::lookup_map_t *lookup = m.lookups[table_index].push ();

      lookup->mask = mask;

      lookup->index = lookup_index;

      lookup->auto_zwnj = auto_zwnj;

      lookup->auto_zwj = auto_zwj;

      lookup->random = random;

      lookup->per_syllable = per_syllable;

      lookup->feature_tag = feature_tag;

    }

    return;

  }

  offset = 0;

  do {

    len = ARRAY_LENGTH (lookup_indices);

    hb_ot_layout_feature_with_variations_get_lookups (face,

                table_tags[table_index],

                feature_index,

                key.variations_index[table_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;

      lookup->per_syllable = per_syllable;

      lookup->feature_tag = feature_tag;

    }

    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)

{

  unsigned int global_bit_shift = 8 * sizeof (hb_mask_t) - 1;

  unsigned int global_bit_mask = 1u << global_bit_shift;

  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)

  {

    if (!is_simple)

      feature_infos.qsort ();

    auto *f = feature_infos.arrayZ;

    unsigned int j = 0;

    unsigned count = feature_infos.length;

    for (unsigned int i = 1; i < count; i++)

      if (f[i].tag != f[j].tag)

  f[++j] = f[i];

      else {

  if (f[i].flags & F_GLOBAL) {

    f[j].flags |= F_GLOBAL;

    f[j].max_value = f[i].max_value;

    f[j].default_value = f[i].default_value;

  } else {

    if (f[j].flags & F_GLOBAL)

      f[j].flags ^= F_GLOBAL;

    f[j].max_value = hb_max (f[j].max_value, f[i].max_value);

    /* Inherit default_value from j */

  }

  f[j].flags |= (f[i].flags & F_HAS_FALLBACK);

  f[j].stage[0] = hb_min (f[j].stage[0], f[i].stage[0]);

  f[j].stage[1] = hb_min (f[j].stage[1], f[i].stage[1]);

      }

    feature_infos.shrink (j + 1);

  }

  hb_map_t feature_indices[2];

  for (unsigned int table_index = 0; table_index < 2; table_index++)

    hb_ot_layout_collect_features_map (face,

               table_tags[table_index],

               script_index[table_index],

               language_index[table_index],

               &feature_indices[table_index]);

  /* Allocate bits now */

  static_assert ((!(HB_GLYPH_FLAG_DEFINED & (HB_GLYPH_FLAG_DEFINED + 1))), "");

  unsigned int next_bit = hb_popcount (HB_GLYPH_FLAG_DEFINED) + 1;

  unsigned count = feature_infos.length;

  for (unsigned int i = 0; i < count; 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 >= global_bit_shift)

      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];

      hb_codepoint_t *index;

      if (feature_indices[table_index].has (info->tag, &index))

      {

        feature_index[table_index] = *index;

        found = true;

      }

      else

        feature_index[table_index] = HB_OT_LAYOUT_NO_FEATURE_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);

    map->per_syllable = !!(info->flags & F_PER_SYLLABLE);

    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 */

  if (is_simple)

    m.features.qsort ();

  add_gsub_pause (nullptr);

  add_gpos_pause (nullptr);

  for (unsigned int table_index = 0; table_index < 2; table_index++)

  {

    /* Collect lookup indices for features */

    auto &lookups = m.lookups[table_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],

         key,

         global_bit_mask);

      for (auto &feature : m.features)

      {

  if (feature.stage[table_index] == stage)

    add_lookups (m, table_index,

           feature.index[table_index],

           key,

           feature.mask,

           feature.auto_zwnj,

           feature.auto_zwj,

           feature.random,

           feature.per_syllable,

           feature.tag);

      }

      /* Sort lookups and merge duplicates */

      if (last_num_lookups + 1 < lookups.length)

      {

  lookups.as_array ().sub_array (last_num_lookups, lookups.length - last_num_lookups).qsort ();

  unsigned int j = last_num_lookups;

  for (unsigned int i = j + 1; i < lookups.length; i++)

    if (lookups.arrayZ[i].index != lookups.arrayZ[j].index)

      lookups.arrayZ[++j] = lookups.arrayZ[i];

    else

    {

      lookups.arrayZ[j].mask |= lookups.arrayZ[i].mask;

      lookups.arrayZ[j].auto_zwnj &= lookups.arrayZ[i].auto_zwnj;

      lookups.arrayZ[j].auto_zwj &= lookups.arrayZ[i].auto_zwj;

    }

  lookups.shrink (j + 1);

      }

      last_num_lookups = lookups.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++;

      }

    }

  }

}

unsigned int hb_ot_map_t::get_feature_tags (unsigned int start_offset, unsigned int *tag_count, hb_tag_t *tags) const

{

  if (tag_count)

  {

    auto sub_features = features.as_array ().sub_array (start_offset, tag_count);

    if (tags)

    {

      for (unsigned int i = 0; i < sub_features.length; i++)

        tags[i] = sub_features[i].tag;

    }

  }

  return features.length;

}

#endif