tor-browser

hb-aat-map.cc (5994B)

---

/*
* 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_AAT_SHAPE

#include "hb-aat-map.hh"

#include "hb-aat-layout.hh"
#include "hb-aat-layout-feat-table.hh"


void hb_aat_map_builder_t::add_feature (const hb_feature_t &feature)
{
 if (!face->table.feat->has_data ()) return;

 if (feature.tag == HB_TAG ('a','a','l','t'))
 {
   if (!face->table.feat->exposes_feature (HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_ALTERNATIVES))
     return;
   feature_range_t *range = features.push();
   range->start = feature.start;
   range->end = feature.end;
   range->info.type = HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_ALTERNATIVES;
   range->info.setting = (hb_aat_layout_feature_selector_t) feature.value;
   range->info.seq = features.length;
   range->info.is_exclusive = true;
   return;
 }

 const hb_aat_feature_mapping_t *mapping = hb_aat_layout_find_feature_mapping (feature.tag);
 if (!mapping) return;

 const AAT::FeatureName* feature_name = &face->table.feat->get_feature (mapping->aatFeatureType);
 if (!feature_name->has_data ())
 {
   /* Special case: Chain::compile_flags will fall back to the deprecated version of
    * small-caps if necessary, so we need to check for that possibility.
    * https://github.com/harfbuzz/harfbuzz/issues/2307 */
   if (mapping->aatFeatureType == HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE &&
mapping->selectorToEnable == HB_AAT_LAYOUT_FEATURE_SELECTOR_LOWER_CASE_SMALL_CAPS)
   {
     feature_name = &face->table.feat->get_feature (HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE);
     if (!feature_name->has_data ()) return;
   }
   else return;
 }

 feature_range_t *range = features.push();
 range->start = feature.start;
 range->end = feature.end;
 range->info.type = mapping->aatFeatureType;
 range->info.setting = feature.value ? mapping->selectorToEnable : mapping->selectorToDisable;
 range->info.seq = features.length;
 range->info.is_exclusive = feature_name->is_exclusive ();
}

void
hb_aat_map_builder_t::compile (hb_aat_map_t  &m)
{
 /* Compute active features per range, and compile each. */
 if (!features.length)
 {
   hb_aat_layout_compile_map (this, &m);
   return;
 }

 /* Sort features by start/end events. */
 hb_vector_t<feature_event_t> feature_events;
 feature_events.alloc_exact (features.length * 2 + 1);
 for (unsigned int i = 0; i < features.length; i++)
 {
   auto &feature = features.arrayZ[i];

   if (feature.start == feature.end)
     continue;

   feature_event_t *event;

   event = feature_events.push ();
   event->index = feature.start;
   event->start = true;
   event->feature = feature.info;

   event = feature_events.push ();
   event->index = feature.end;
   event->start = false;
   event->feature = feature.info;
 }
 feature_events.qsort ();
 /* Add a strategic final event. */
 {
   feature_info_t feature;
   feature.seq = features.length + 1;

   feature_event_t *event = feature_events.push ();
   event->index = -1; /* This value does magic. */
   event->start = false;
   event->feature = feature;
 }

 /* Scan events and save features for each range. */
 hb_sorted_vector_t<feature_info_t> active_features;
 unsigned int last_index = 0;
 for (unsigned int i = 0; i < feature_events.length; i++)
 {
   feature_event_t *event = &feature_events[i];

   if (event->index != last_index)
   {
     /* Save a snapshot of active features and the range. */

     /* Sort features and merge duplicates */
     current_features = active_features;
     range_first = last_index;
     range_last = event->index - 1;
     if (current_features.length)
     {
current_features.qsort ();
unsigned int j = 0;
for (unsigned int i = 1; i < current_features.length; i++)
  if (current_features.arrayZ[i].type != current_features.arrayZ[j].type ||
      /* Nonexclusive feature selectors come in even/odd pairs to turn a setting on/off
       * respectively, so we mask out the low-order bit when checking for "duplicates"
       * (selectors referring to the same feature setting) here. */
      (!current_features.arrayZ[i].is_exclusive && ((current_features.arrayZ[i].setting & ~1) != (current_features.arrayZ[j].setting & ~1))))
    current_features.arrayZ[++j] = current_features.arrayZ[i];
current_features.shrink (j + 1);
     }

     hb_aat_layout_compile_map (this, &m);

     last_index = event->index;
   }

   if (event->start)
   {
     active_features.push (event->feature);
   } else {
     feature_info_t *feature = active_features.lsearch (event->feature);
     if (feature)
active_features.remove_ordered (feature - active_features.arrayZ);
   }
 }

 for (auto &chain_flags : m.chain_flags)
   // With our above setup this value is one less than desired; adjust it.
   chain_flags.tail().cluster_last = HB_FEATURE_GLOBAL_END;
}


#endif