michael@0: /*
michael@0:  * Copyright © 2009,2010  Red Hat, Inc.
michael@0:  * Copyright © 2010,2011,2013  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #include "hb-ot-map-private.hh"
michael@0: 
michael@0: #include "hb-ot-layout-private.hh"
michael@0: 
michael@0: 
michael@0: void
michael@0: hb_ot_map_t::add_lookups (hb_face_t    *face,
michael@0: 			  unsigned int  table_index,
michael@0: 			  unsigned int  feature_index,
michael@0: 			  hb_mask_t     mask,
michael@0: 			  bool          auto_zwj)
michael@0: {
michael@0:   unsigned int lookup_indices[32];
michael@0:   unsigned int offset, len;
michael@0:   unsigned int table_lookup_count;
michael@0: 
michael@0:   table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
michael@0: 
michael@0:   offset = 0;
michael@0:   do {
michael@0:     len = ARRAY_LENGTH (lookup_indices);
michael@0:     hb_ot_layout_feature_get_lookups (face,
michael@0: 				      table_tags[table_index],
michael@0: 				      feature_index,
michael@0: 				      offset, &len,
michael@0: 				      lookup_indices);
michael@0: 
michael@0:     for (unsigned int i = 0; i < len; i++)
michael@0:     {
michael@0:       if (lookup_indices[i] >= table_lookup_count)
michael@0: 	continue;
michael@0:       hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push ();
michael@0:       if (unlikely (!lookup))
michael@0:         return;
michael@0:       lookup->mask = mask;
michael@0:       lookup->index = lookup_indices[i];
michael@0:       lookup->auto_zwj = auto_zwj;
michael@0:     }
michael@0: 
michael@0:     offset += len;
michael@0:   } while (len == ARRAY_LENGTH (lookup_indices));
michael@0: }
michael@0: 
michael@0: hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
michael@0: 					  const hb_segment_properties_t *props_)
michael@0: {
michael@0:   memset (this, 0, sizeof (*this));
michael@0: 
michael@0:   face = face_;
michael@0:   props = *props_;
michael@0: 
michael@0: 
michael@0:   /* Fetch script/language indices for GSUB/GPOS.  We need these later to skip
michael@0:    * features not available in either table and not waste precious bits for them. */
michael@0: 
michael@0:   hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE};
michael@0:   hb_tag_t language_tag;
michael@0: 
michael@0:   hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]);
michael@0:   language_tag = hb_ot_tag_from_language (props.language);
michael@0: 
michael@0:   for (unsigned int table_index = 0; table_index < 2; table_index++) {
michael@0:     hb_tag_t table_tag = table_tags[table_index];
michael@0:     found_script[table_index] = hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]);
michael@0:     hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,
michael@0: 				       hb_ot_map_feature_flags_t flags)
michael@0: {
michael@0:   feature_info_t *info = feature_infos.push();
michael@0:   if (unlikely (!info)) return;
michael@0:   info->tag = tag;
michael@0:   info->seq = feature_infos.len;
michael@0:   info->max_value = value;
michael@0:   info->flags = flags;
michael@0:   info->default_value = (flags & F_GLOBAL) ? value : 0;
michael@0:   info->stage[0] = current_stage[0];
michael@0:   info->stage[1] = current_stage[1];
michael@0: }
michael@0: 
michael@0: 
michael@0: void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
michael@0: {
michael@0:   for (unsigned int i = 0; i < lookups[table_index].len; i++)
michael@0:     hb_set_add (lookups_out, lookups[table_index][i].index);
michael@0: }
michael@0: 
michael@0: void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
michael@0: {
michael@0:   stage_info_t *s = stages[table_index].push ();
michael@0:   if (likely (s)) {
michael@0:     s->index = current_stage[table_index];
michael@0:     s->pause_func = pause_func;
michael@0:   }
michael@0: 
michael@0:   current_stage[table_index]++;
michael@0: }
michael@0: 
michael@0: void
michael@0: hb_ot_map_builder_t::compile (hb_ot_map_t &m)
michael@0: {
michael@0:   m.global_mask = 1;
michael@0: 
michael@0:   for (unsigned int table_index = 0; table_index < 2; table_index++) {
michael@0:     m.chosen_script[table_index] = chosen_script[table_index];
michael@0:     m.found_script[table_index] = found_script[table_index];
michael@0:   }
michael@0: 
michael@0:   if (!feature_infos.len)
michael@0:     return;
michael@0: 
michael@0:   /* Sort features and merge duplicates */
michael@0:   {
michael@0:     feature_infos.sort ();
michael@0:     unsigned int j = 0;
michael@0:     for (unsigned int i = 1; i < feature_infos.len; i++)
michael@0:       if (feature_infos[i].tag != feature_infos[j].tag)
michael@0: 	feature_infos[++j] = feature_infos[i];
michael@0:       else {
michael@0: 	if (feature_infos[i].flags & F_GLOBAL) {
michael@0: 	  feature_infos[j].flags |= F_GLOBAL;
michael@0: 	  feature_infos[j].max_value = feature_infos[i].max_value;
michael@0: 	  feature_infos[j].default_value = feature_infos[i].default_value;
michael@0: 	} else {
michael@0: 	  feature_infos[j].flags &= ~F_GLOBAL;
michael@0: 	  feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value);
michael@0: 	  /* Inherit default_value from j */
michael@0: 	}
michael@0: 	feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
michael@0: 	feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]);
michael@0: 	feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]);
michael@0:       }
michael@0:     feature_infos.shrink (j + 1);
michael@0:   }
michael@0: 
michael@0: 
michael@0:   /* Allocate bits now */
michael@0:   unsigned int next_bit = 1;
michael@0:   for (unsigned int i = 0; i < feature_infos.len; i++) {
michael@0:     const feature_info_t *info = &feature_infos[i];
michael@0: 
michael@0:     unsigned int bits_needed;
michael@0: 
michael@0:     if ((info->flags & F_GLOBAL) && info->max_value == 1)
michael@0:       /* Uses the global bit */
michael@0:       bits_needed = 0;
michael@0:     else
michael@0:       bits_needed = _hb_bit_storage (info->max_value);
michael@0: 
michael@0:     if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
michael@0:       continue; /* Feature disabled, or not enough bits. */
michael@0: 
michael@0: 
michael@0:     hb_bool_t found = false;
michael@0:     unsigned int feature_index[2];
michael@0:     for (unsigned int table_index = 0; table_index < 2; table_index++)
michael@0:       found |= hb_ot_layout_language_find_feature (face,
michael@0: 						   table_tags[table_index],
michael@0: 						   script_index[table_index],
michael@0: 						   language_index[table_index],
michael@0: 						   info->tag,
michael@0: 						   &feature_index[table_index]);
michael@0:     if (!found && !(info->flags & F_HAS_FALLBACK))
michael@0:       continue;
michael@0: 
michael@0: 
michael@0:     hb_ot_map_t::feature_map_t *map = m.features.push ();
michael@0:     if (unlikely (!map))
michael@0:       break;
michael@0: 
michael@0:     map->tag = info->tag;
michael@0:     map->index[0] = feature_index[0];
michael@0:     map->index[1] = feature_index[1];
michael@0:     map->stage[0] = info->stage[0];
michael@0:     map->stage[1] = info->stage[1];
michael@0:     map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
michael@0:     if ((info->flags & F_GLOBAL) && info->max_value == 1) {
michael@0:       /* Uses the global bit */
michael@0:       map->shift = 0;
michael@0:       map->mask = 1;
michael@0:     } else {
michael@0:       map->shift = next_bit;
michael@0:       map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
michael@0:       next_bit += bits_needed;
michael@0:       m.global_mask |= (info->default_value << map->shift) & map->mask;
michael@0:     }
michael@0:     map->_1_mask = (1 << map->shift) & map->mask;
michael@0:     map->needs_fallback = !found;
michael@0: 
michael@0:   }
michael@0:   feature_infos.shrink (0); /* Done with these */
michael@0: 
michael@0: 
michael@0:   add_gsub_pause (NULL);
michael@0:   add_gpos_pause (NULL);
michael@0: 
michael@0:   for (unsigned int table_index = 0; table_index < 2; table_index++) {
michael@0:     hb_tag_t table_tag = table_tags[table_index];
michael@0: 
michael@0:     /* Collect lookup indices for features */
michael@0: 
michael@0:     unsigned int required_feature_index;
michael@0:     if (hb_ot_layout_language_get_required_feature_index (face,
michael@0: 							  table_tag,
michael@0: 							  script_index[table_index],
michael@0: 							  language_index[table_index],
michael@0: 							  &required_feature_index))
michael@0:       m.add_lookups (face, table_index, required_feature_index, 1, true);
michael@0: 
michael@0:     unsigned int stage_index = 0;
michael@0:     unsigned int last_num_lookups = 0;
michael@0:     for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
michael@0:     {
michael@0:       for (unsigned i = 0; i < m.features.len; i++)
michael@0:         if (m.features[i].stage[table_index] == stage)
michael@0: 	  m.add_lookups (face, table_index,
michael@0: 			 m.features[i].index[table_index],
michael@0: 			 m.features[i].mask,
michael@0: 			 m.features[i].auto_zwj);
michael@0: 
michael@0:       /* Sort lookups and merge duplicates */
michael@0:       if (last_num_lookups < m.lookups[table_index].len)
michael@0:       {
michael@0: 	m.lookups[table_index].sort (last_num_lookups, m.lookups[table_index].len);
michael@0: 
michael@0: 	unsigned int j = last_num_lookups;
michael@0: 	for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++)
michael@0: 	  if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
michael@0: 	    m.lookups[table_index][++j] = m.lookups[table_index][i];
michael@0: 	  else
michael@0: 	  {
michael@0: 	    m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
michael@0: 	    m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
michael@0: 	  }
michael@0: 	m.lookups[table_index].shrink (j + 1);
michael@0:       }
michael@0: 
michael@0:       last_num_lookups = m.lookups[table_index].len;
michael@0: 
michael@0:       if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) {
michael@0: 	hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
michael@0: 	if (likely (stage_map)) {
michael@0: 	  stage_map->last_lookup = last_num_lookups;
michael@0: 	  stage_map->pause_func = stages[table_index][stage_index].pause_func;
michael@0: 	}
michael@0: 
michael@0: 	stage_index++;
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }