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 /*

  * 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::add_lookups (hb_face_t    *face,

 			  unsigned int  table_index,

 			  unsigned int  feature_index,

 			  hb_mask_t     mask,

 			  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_get_lookups (face,

 				      table_tags[table_index],

 				      feature_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 = lookups[table_index].push ();

       if (unlikely (!lookup))

         return;

       lookup->mask = mask;

       lookup->index = lookup_indices[i];

       lookup->auto_zwj = auto_zwj;

     }

     offset += len;

   } while (len == ARRAY_LENGTH (lookup_indices));

 }

 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] = 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 (!info)) 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_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);

 }

 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 ();

   if (likely (s)) {

     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)

 {

   m.global_mask = 1;

   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];

   }

   if (!feature_infos.len)

     return;

   /* Sort features and merge duplicates */

   {

     feature_infos.sort ();

     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 = 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

       bits_needed = _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++)

       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_HAS_FALLBACK))

       continue;

     hb_ot_map_t::feature_map_t *map = m.features.push ();

     if (unlikely (!map))

       break;

     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_zwj = !(info->flags & F_MANUAL_ZWJ);

     if ((info->flags & F_GLOBAL) && info->max_value == 1) {

       /* Uses the global bit */

       map->shift = 0;

       map->mask = 1;

     } else {

       map->shift = next_bit;

       map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);

       next_bit += bits_needed;

       m.global_mask |= (info->default_value << map->shift) & map->mask;

     }

     map->_1_mask = (1 << map->shift) & map->mask;

     map->needs_fallback = !found;

   }

   feature_infos.shrink (0); /* Done with these */

   add_gsub_pause (NULL);

   add_gpos_pause (NULL);

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

     hb_tag_t table_tag = table_tags[table_index];

     /* Collect lookup indices for features */

     unsigned int required_feature_index;

     if (hb_ot_layout_language_get_required_feature_index (face,

 							  table_tag,

 							  script_index[table_index],

 							  language_index[table_index],

 							  &required_feature_index))

       m.add_lookups (face, table_index, required_feature_index, 1, true);

     unsigned int stage_index = 0;

     unsigned int last_num_lookups = 0;

     for (unsigned stage = 0; stage < current_stage[table_index]; stage++)

     {

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

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

 	  m.add_lookups (face, table_index,

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

 			 m.features[i].mask,

 			 m.features[i].auto_zwj);

       /* Sort lookups and merge duplicates */

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

       {

 	m.lookups[table_index].sort (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_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 ();

 	if (likely (stage_map)) {

 	  stage_map->last_lookup = last_num_lookups;

 	  stage_map->pause_func = stages[table_index][stage_index].pause_func;

 	}

 	stage_index++;

       }

     }

   }

 }