Merge pull request #2835 from googlefonts/remove_redundant_sys

[subset] Remove redundant LangSys
This commit is contained in:
Behdad Esfahbod 2021-03-17 14:33:33 -07:00 committed by GitHub
commit a7d120aeab
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GPG Key ID: 4AEE18F83AFDEB23
17 changed files with 284 additions and 26 deletions

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@ -94,6 +94,60 @@ static void ClassDef_remap_and_serialize (hb_serialize_context_t *c,
bool use_class_zero,
hb_map_t *klass_map /*INOUT*/);
struct hb_prune_langsys_context_t
{
hb_prune_langsys_context_t (const void *table_,
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *script_langsys_map_,
const hb_map_t *duplicate_feature_map_,
hb_set_t *new_collected_feature_indexes_)
:table (table_),
script_langsys_map (script_langsys_map_),
duplicate_feature_map (duplicate_feature_map_),
new_feature_indexes (new_collected_feature_indexes_),
script_count (0),langsys_count (0) {}
bool visitedScript (const void *s)
{
if (script_count++ > HB_MAX_SCRIPTS)
return true;
return visited (s, visited_script);
}
bool visitedLangsys (const void *l)
{
if (langsys_count++ > HB_MAX_LANGSYS)
return true;
return visited (l, visited_langsys);
}
private:
template <typename T>
bool visited (const T *p, hb_set_t &visited_set)
{
hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) p - (uintptr_t) table);
if (visited_set.has (delta))
return true;
visited_set.add (delta);
return false;
}
public:
const void *table;
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *script_langsys_map;
const hb_map_t *duplicate_feature_map;
hb_set_t *new_feature_indexes;
private:
hb_set_t visited_script;
hb_set_t visited_langsys;
unsigned script_count;
unsigned langsys_count;
};
struct hb_subset_layout_context_t :
hb_dispatch_context_t<hb_subset_layout_context_t, hb_empty_t, HB_DEBUG_SUBSET>
{
@ -125,16 +179,21 @@ struct hb_subset_layout_context_t :
hb_subset_context_t *subset_context;
const hb_tag_t table_tag;
const hb_map_t *lookup_index_map;
const hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *script_langsys_map;
const hb_map_t *feature_index_map;
unsigned cur_script_index;
hb_subset_layout_context_t (hb_subset_context_t *c_,
hb_tag_t tag_,
hb_map_t *lookup_map_,
hb_map_t *feature_map_) :
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *script_langsys_map_,
hb_map_t *feature_index_map_) :
subset_context (c_),
table_tag (tag_),
lookup_index_map (lookup_map_),
feature_index_map (feature_map_),
script_langsys_map (script_langsys_map_),
feature_index_map (feature_index_map_),
cur_script_index (0xFFFFu),
script_count (0),
langsys_count (0),
feature_index_count (0),
@ -407,6 +466,30 @@ struct RecordListOfFeature : RecordListOf<Feature>
}
};
struct Script;
struct RecordListOfScript : RecordListOf<Script>
{
bool subset (hb_subset_context_t *c,
hb_subset_layout_context_t *l) const
{
TRACE_SUBSET (this);
auto *out = c->serializer->start_embed (*this);
if (unlikely (!out || !c->serializer->extend_min (out))) return_trace (false);
unsigned count = this->len;
for (auto _ : + hb_zip (*this, hb_range (count)))
{
auto snap = c->serializer->snapshot ();
l->cur_script_index = _.second;
bool ret = _.first.subset (l, this);
if (!ret) c->serializer->revert (snap);
else out->len++;
}
return_trace (true);
}
};
struct RangeRecord
{
int cmp (hb_codepoint_t g) const
@ -506,18 +589,46 @@ struct LangSys
return_trace (c->embed (*this));
}
bool operator == (const LangSys& o) const
bool compare (const LangSys& o, const hb_map_t *feature_index_map) const
{
if (featureIndex.len != o.featureIndex.len ||
reqFeatureIndex != o.reqFeatureIndex)
if (reqFeatureIndex != o.reqFeatureIndex)
return false;
for (const auto _ : + hb_zip (featureIndex, o.featureIndex))
auto iter =
+ hb_iter (featureIndex)
| hb_filter (feature_index_map)
| hb_map (feature_index_map)
;
auto o_iter =
+ hb_iter (o.featureIndex)
| hb_filter (feature_index_map)
| hb_map (feature_index_map)
;
if (iter.len () != o_iter.len ())
return false;
for (const auto _ : + hb_zip (iter, o_iter))
if (_.first != _.second) return false;
return true;
}
void collect_features (hb_prune_langsys_context_t *c) const
{
if (!has_required_feature () && !get_feature_count ()) return;
if (c->visitedLangsys (this)) return;
if (has_required_feature () &&
c->duplicate_feature_map->has (reqFeatureIndex))
c->new_feature_indexes->add (get_required_feature_index ());
+ hb_iter (featureIndex)
| hb_filter (c->duplicate_feature_map)
| hb_sink (c->new_feature_indexes)
;
}
bool subset (hb_subset_context_t *c,
hb_subset_layout_context_t *l,
const Tag *tag = nullptr) const
@ -581,6 +692,42 @@ struct Script
bool has_default_lang_sys () const { return defaultLangSys != 0; }
const LangSys& get_default_lang_sys () const { return this+defaultLangSys; }
void prune_langsys (hb_prune_langsys_context_t *c,
unsigned script_index) const
{
if (!has_default_lang_sys () && !get_lang_sys_count ()) return;
if (c->visitedScript (this)) return;
if (!c->script_langsys_map->has (script_index))
c->script_langsys_map->set (script_index, hb_set_create ());
unsigned langsys_count = get_lang_sys_count ();
if (has_default_lang_sys ())
{
//only collect features from non-redundant langsys
const LangSys& d = get_default_lang_sys ();
d.collect_features (c);
for (auto _ : + hb_zip (langSys, hb_range (langsys_count)))
{
const LangSys& l = this+_.first.offset;
if (l.compare (d, c->duplicate_feature_map)) continue;
l.collect_features (c);
c->script_langsys_map->get (script_index)->add (_.second);
}
}
else
{
for (auto _ : + hb_zip (langSys, hb_range (langsys_count)))
{
const LangSys& l = this+_.first.offset;
l.collect_features (c);
c->script_langsys_map->get (script_index)->add (_.second);
}
}
}
bool subset (hb_subset_context_t *c,
hb_subset_layout_context_t *l,
const Tag *tag) const
@ -609,16 +756,17 @@ struct Script
}
}
+ langSys.iter ()
| hb_filter ([=] (const Record<LangSys>& record) {return l->visitLangSys (); })
| hb_filter ([&] (const Record<LangSys>& record)
const hb_set_t *active_langsys = l->script_langsys_map->get (l->cur_script_index);
if (active_langsys)
{
const LangSys& d = this+defaultLangSys;
const LangSys& l = this+record.offset;
return !(l == d);
})
unsigned count = langSys.len;
+ hb_zip (langSys, hb_range (count))
| hb_filter (active_langsys, hb_second)
| hb_map (hb_first)
| hb_filter ([=] (const Record<LangSys>& record) {return l->visitLangSys (); })
| hb_apply (subset_record_array (l, &(out->langSys), this))
;
}
return_trace (bool (out->langSys.len) || defaultLang || l->table_tag == HB_OT_TAG_GSUB);
}
@ -641,7 +789,7 @@ struct Script
DEFINE_SIZE_ARRAY_SIZED (4, langSys);
};
typedef RecordListOf<Script> ScriptList;
typedef RecordListOfScript ScriptList;
/* https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */

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@ -2666,7 +2666,7 @@ struct GPOS : GSUBGPOS
bool subset (hb_subset_context_t *c) const
{
hb_subset_layout_context_t l (c, tableTag, c->plan->gpos_lookups, c->plan->gpos_features);
hb_subset_layout_context_t l (c, tableTag, c->plan->gpos_lookups, c->plan->gpos_langsys, c->plan->gpos_features);
return GSUBGPOS::subset<PosLookup> (&l);
}

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@ -1596,7 +1596,7 @@ struct GSUB : GSUBGPOS
bool subset (hb_subset_context_t *c) const
{
hb_subset_layout_context_t l (c, tableTag, c->plan->gsub_lookups, c->plan->gsub_features);
hb_subset_layout_context_t l (c, tableTag, c->plan->gsub_lookups, c->plan->gsub_langsys, c->plan->gsub_features);
return GSUBGPOS::subset<SubstLookup> (&l);
}

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@ -3587,6 +3587,20 @@ struct GSUBGPOS
hb_set_subtract (lookup_indexes, &inactive_lookups);
}
void prune_langsys (const hb_map_t *duplicate_feature_map,
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *script_langsys_map,
hb_set_t *new_feature_indexes /* OUT */) const
{
hb_prune_langsys_context_t c (this, script_langsys_map, duplicate_feature_map, new_feature_indexes);
unsigned count = get_script_count ();
for (unsigned script_index = 0; script_index < count; script_index++)
{
const Script& s = get_script (script_index);
s.prune_langsys (&c, script_index);
}
}
template <typename TLookup>
bool subset (hb_subset_layout_context_t *c) const
{
@ -3627,6 +3641,63 @@ struct GSUBGPOS
return_trace (true);
}
void find_duplicate_features (const hb_map_t *lookup_indices,
const hb_set_t *feature_indices,
hb_map_t *duplicate_feature_map /* OUT */) const
{
//find out duplicate features after subset
unsigned prev = 0xFFFFu;
for (unsigned i : feature_indices->iter ())
{
if (prev == 0xFFFFu)
{
duplicate_feature_map->set (i, i);
prev = i;
continue;
}
hb_tag_t t = get_feature_tag (i);
hb_tag_t prev_t = get_feature_tag (prev);
if (t != prev_t)
{
duplicate_feature_map->set (i, i);
prev = i;
continue;
}
const Feature& f = get_feature (i);
const Feature& prev_f = get_feature (prev);
auto f_iter =
+ hb_iter (f.lookupIndex)
| hb_filter (lookup_indices)
;
auto prev_iter =
+ hb_iter (prev_f.lookupIndex)
| hb_filter (lookup_indices)
;
if (f_iter.len () != prev_iter.len ())
{
duplicate_feature_map->set (i, i);
prev = i;
continue;
}
bool is_equal = true;
for (auto _ : + hb_zip (f_iter, prev_iter))
if (_.first != _.second) { is_equal = false; break; }
if (is_equal == true) duplicate_feature_map->set (i, prev);
else
{
duplicate_feature_map->set (i, i);
prev = i;
}
}
}
void prune_features (const hb_map_t *lookup_indices, /* IN */
hb_set_t *feature_indices /* IN/OUT */) const
{

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@ -39,6 +39,7 @@
#include "hb-ot-stat-table.hh"
typedef hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> script_langsys_map;
#ifndef HB_NO_SUBSET_CFF
static inline void
_add_cff_seac_components (const OT::cff1::accelerator_t &cff,
@ -70,7 +71,8 @@ static inline void
_gsub_closure_glyphs_lookups_features (hb_face_t *face,
hb_set_t *gids_to_retain,
hb_map_t *gsub_lookups,
hb_map_t *gsub_features)
hb_map_t *gsub_features,
script_langsys_map *gsub_langsys)
{
hb_set_t lookup_indices;
hb_ot_layout_collect_lookups (face,
@ -96,7 +98,13 @@ _gsub_closure_glyphs_lookups_features (hb_face_t *face,
nullptr,
nullptr,
&feature_indices);
gsub->prune_features (gsub_lookups, &feature_indices);
hb_map_t duplicate_feature_map;
gsub->find_duplicate_features (gsub_lookups, &feature_indices, &duplicate_feature_map);
feature_indices.clear ();
gsub->prune_langsys (&duplicate_feature_map, gsub_langsys, &feature_indices);
_remap_indexes (&feature_indices, gsub_features);
gsub.destroy ();
@ -106,7 +114,8 @@ static inline void
_gpos_closure_lookups_features (hb_face_t *face,
const hb_set_t *gids_to_retain,
hb_map_t *gpos_lookups,
hb_map_t *gpos_features)
hb_map_t *gpos_features,
script_langsys_map *gpos_langsys)
{
hb_set_t lookup_indices;
hb_ot_layout_collect_lookups (face,
@ -129,8 +138,15 @@ _gpos_closure_lookups_features (hb_face_t *face,
nullptr,
nullptr,
&feature_indices);
gpos->prune_features (gpos_lookups, &feature_indices);
hb_map_t duplicate_feature_map;
gpos->find_duplicate_features (gpos_lookups, &feature_indices, &duplicate_feature_map);
feature_indices.clear ();
gpos->prune_langsys (&duplicate_feature_map, gpos_langsys, &feature_indices);
_remap_indexes (&feature_indices, gpos_features);
gpos.destroy ();
}
#endif
@ -231,10 +247,10 @@ _populate_gids_to_retain (hb_subset_plan_t* plan,
#ifndef HB_NO_SUBSET_LAYOUT
if (close_over_gsub)
// closure all glyphs/lookups/features needed for GSUB substitutions.
_gsub_closure_glyphs_lookups_features (plan->source, plan->_glyphset_gsub, plan->gsub_lookups, plan->gsub_features);
_gsub_closure_glyphs_lookups_features (plan->source, plan->_glyphset_gsub, plan->gsub_lookups, plan->gsub_features, plan->gsub_langsys);
if (close_over_gpos)
_gpos_closure_lookups_features (plan->source, plan->_glyphset_gsub, plan->gpos_lookups, plan->gpos_features);
_gpos_closure_lookups_features (plan->source, plan->_glyphset_gsub, plan->gpos_lookups, plan->gpos_features, plan->gpos_langsys);
#endif
_remove_invalid_gids (plan->_glyphset_gsub, plan->source->get_num_glyphs ());
@ -356,6 +372,12 @@ hb_subset_plan_create (hb_face_t *face,
plan->reverse_glyph_map = hb_map_create ();
plan->gsub_lookups = hb_map_create ();
plan->gpos_lookups = hb_map_create ();
plan->gsub_langsys = hb_object_create<script_langsys_map> ();
plan->gsub_langsys->init_shallow ();
plan->gpos_langsys = hb_object_create<script_langsys_map> ();
plan->gpos_langsys->init_shallow ();
plan->gsub_features = hb_map_create ();
plan->gpos_features = hb_map_create ();
plan->layout_variation_indices = hb_set_create ();
@ -407,6 +429,19 @@ hb_subset_plan_destroy (hb_subset_plan_t *plan)
hb_set_destroy (plan->layout_variation_indices);
hb_map_destroy (plan->layout_variation_idx_map);
for (auto _ : plan->gsub_langsys->iter ())
hb_set_destroy (_.second);
hb_object_destroy (plan->gsub_langsys);
plan->gsub_langsys->fini_shallow ();
free (plan->gsub_langsys);
for (auto _ : plan->gpos_langsys->iter ())
hb_set_destroy (_.second);
hb_object_destroy (plan->gpos_langsys);
plan->gpos_langsys->fini_shallow ();
free (plan->gpos_langsys);
free (plan);
}

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@ -79,7 +79,11 @@ struct hb_subset_plan_t
hb_map_t *gsub_lookups;
hb_map_t *gpos_lookups;
//active features we'd like to retain
//active langsys we'd like to retain
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *gsub_langsys;
hb_hashmap_t<unsigned, hb_set_t *, (unsigned)-1, nullptr> *gpos_langsys;
//active features after removing redundant langsys and prune_features
hb_map_t *gsub_features;
hb_map_t *gpos_features;