Source code
Revision control
Copy as Markdown
Other Tools
/*
* 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.
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. */
/* Sort features by start/end events. */
hb_vector_t<feature_event_t> feature_events;
for (unsigned int i = 0; i < features.length; i++)
{
auto &feature = features[i];
if (features[i].start == features[i].end)
continue;
feature_event_t *event;
event = feature_events.push ();
event->index = features[i].start;
event->start = true;
event->feature = feature.info;
event = feature_events.push ();
event->index = features[i].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[i].type != current_features[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[i].is_exclusive && ((current_features[i].setting & ~1) != (current_features[j].setting & ~1))))
current_features[++j] = current_features[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