harfbuzz/src/hb-ot-map.cc

382 lines
12 KiB
C++

/*
* 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,
unsigned int variations_index,
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]);
offset = 0;
do {
len = ARRAY_LENGTH (lookup_indices);
hb_ot_layout_feature_with_variations_get_lookups (face,
table_tags[table_index],
feature_index,
variations_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)
{
feature_infos.qsort ();
unsigned int j = 0;
for (unsigned int i = 1; i < feature_infos.length; 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 {
if (feature_infos[j].flags & F_GLOBAL)
feature_infos[j].flags ^= F_GLOBAL;
feature_infos[j].max_value = hb_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] = hb_min (feature_infos[j].stage[0], feature_infos[i].stage[0]);
feature_infos[j].stage[1] = hb_min (feature_infos[j].stage[1], feature_infos[i].stage[1]);
}
feature_infos.shrink (j + 1);
}
/* 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;
for (unsigned int i = 0; i < feature_infos.length; 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];
found |= (bool) 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_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 */
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.variations_index[table_index],
global_bit_mask);
for (auto &feature : m.features)
{
if (feature.stage[table_index] == stage)
add_lookups (m, table_index,
feature.index[table_index],
key.variations_index[table_index],
feature.mask,
feature.auto_zwnj,
feature.auto_zwj,
feature.random,
feature.per_syllable,
feature.tag);
}
/* Sort lookups and merge duplicates */
if (last_num_lookups < 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[i].index != lookups[j].index)
lookups[++j] = lookups[i];
else
{
lookups[j].mask |= lookups[i].mask;
lookups[j].auto_zwnj &= lookups[i].auto_zwnj;
lookups[j].auto_zwj &= lookups[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++;
}
}
}
}
#endif