[subset] Add "--name-languages" and "--name-legacy" options

Make name table subsetting consistent with fontTools

src/hb-ot-name-table.hh

@@ -108,6 +108,15 @@ struct NameRecord
     return_trace (out);
   }
 
+  bool isUnicode () const
+  {
+    unsigned int p = platformID;
+    unsigned int e = encodingID;
+    
+    return (p == 0 ||
+            (p == 3 && (e == 0 || e == 1 || e == 10)));
+  }
+
   bool sanitize (hb_sanitize_context_t *c, const void *base) const
   {
     TRACE_SANITIZE (this);
@@ -210,6 +219,8 @@ struct name
     auto it =
     + nameRecordZ.as_array (count)
     | hb_filter (c->plan->name_ids, &NameRecord::nameID)
+    | hb_filter (c->plan->name_languages, &NameRecord::languageID)
+    | hb_filter ([&] (const NameRecord& namerecord) { return c->plan->name_legacy || namerecord.isUnicode (); })
     ;
 
     name_prime->serialize (c->serializer, it, hb_addressof (this + stringOffset));

src/hb-subset-input.cc

@@ -46,10 +46,13 @@ hb_subset_input_create_or_fail ()
   input->glyphs = hb_set_create ();
   input->name_ids = hb_set_create ();
   hb_set_add_range (input->name_ids, 0, 6);
+  input->name_languages = hb_set_create ();
+  hb_set_add (input->name_languages, 0x0409);
   input->drop_tables = hb_set_create ();
   input->drop_hints = false;
   input->desubroutinize = false;
   input->retain_gids = false;
+  input->name_legacy = false;
 
   hb_tag_t default_drop_tables[] = {
     // Layout disabled by default
@@ -114,6 +117,7 @@ hb_subset_input_destroy (hb_subset_input_t *subset_input)
   hb_set_destroy (subset_input->unicodes);
   hb_set_destroy (subset_input->glyphs);
   hb_set_destroy (subset_input->name_ids);
+  hb_set_destroy (subset_input->name_languages);
   hb_set_destroy (subset_input->drop_tables);
 
   free (subset_input);
@@ -149,6 +153,12 @@ hb_subset_input_nameid_set (hb_subset_input_t *subset_input)
   return subset_input->name_ids;
 }
 
+HB_EXTERN hb_set_t *
+hb_subset_input_namelangid_set (hb_subset_input_t *subset_input)
+{
+  return subset_input->name_languages;
+}
+
 HB_EXTERN hb_set_t *
 hb_subset_input_drop_tables_set (hb_subset_input_t *subset_input)
 {
@@ -204,3 +214,16 @@ hb_subset_input_get_retain_gids (hb_subset_input_t *subset_input)
 {
   return subset_input->retain_gids;
 }
+
+HB_EXTERN void
+hb_subset_input_set_name_legacy (hb_subset_input_t *subset_input,
+				 hb_bool_t name_legacy)
+{
+  subset_input->name_legacy = name_legacy;
+}
+
+HB_EXTERN hb_bool_t
+hb_subset_input_get_name_legacy (hb_subset_input_t *subset_input)
+{
+  return subset_input->name_legacy;
+}

src/hb-subset-input.hh

@@ -41,11 +41,13 @@ struct hb_subset_input_t
   hb_set_t *unicodes;
   hb_set_t *glyphs;
   hb_set_t *name_ids;
+  hb_set_t *name_languages;
   hb_set_t *drop_tables;
 
   bool drop_hints;
   bool desubroutinize;
   bool retain_gids;
+  bool name_legacy;
   /* TODO
    *
    * features

src/hb-subset-plan.cc

@@ -278,9 +278,11 @@ hb_subset_plan_create (hb_face_t         *face,
   plan->drop_hints = input->drop_hints;
   plan->desubroutinize = input->desubroutinize;
   plan->retain_gids = input->retain_gids;
+  plan->name_legacy = input->name_legacy;
   plan->unicodes = hb_set_create ();
   plan->name_ids = hb_set_reference (input->name_ids);
   _nameid_closure (face, plan->name_ids);
+  plan->name_languages = hb_set_reference (input->name_languages);
   plan->drop_tables = hb_set_reference (input->drop_tables);
   plan->source = hb_face_reference (face);
   plan->dest = hb_face_builder_create ();
@@ -323,6 +325,7 @@ hb_subset_plan_destroy (hb_subset_plan_t *plan)
 
   hb_set_destroy (plan->unicodes);
   hb_set_destroy (plan->name_ids);
+  hb_set_destroy (plan->name_languages);
   hb_set_destroy (plan->drop_tables);
   hb_face_destroy (plan->source);
   hb_face_destroy (plan->dest);

src/hb-subset-plan.hh

@@ -42,6 +42,7 @@ struct hb_subset_plan_t
   bool drop_hints : 1;
   bool desubroutinize : 1;
   bool retain_gids : 1;
+  bool name_legacy : 1;
 
   // For each cp that we'd like to retain maps to the corresponding gid.
   hb_set_t *unicodes;
@@ -49,6 +50,9 @@ struct hb_subset_plan_t
   // name_ids we would like to retain
   hb_set_t *name_ids;
 
+  // name_languages we would like to retain
+  hb_set_t *name_languages;
+
   // Tables which should be dropped.
   hb_set_t *drop_tables;
 

src/hb-subset.h

@@ -57,6 +57,9 @@ hb_subset_input_glyph_set (hb_subset_input_t *subset_input);
 HB_EXTERN hb_set_t *
 hb_subset_input_nameid_set (hb_subset_input_t *subset_input);
 
+HB_EXTERN hb_set_t *
+hb_subset_input_namelangid_set (hb_subset_input_t *subset_input);
+
 HB_EXTERN hb_set_t *
 hb_subset_input_drop_tables_set (hb_subset_input_t *subset_input);
 
@@ -78,6 +81,12 @@ hb_subset_input_set_retain_gids (hb_subset_input_t *subset_input,
 HB_EXTERN hb_bool_t
 hb_subset_input_get_retain_gids (hb_subset_input_t *subset_input);
 
+HB_EXTERN void
+hb_subset_input_set_name_legacy (hb_subset_input_t *subset_input,
+				 hb_bool_t name_legacy);
+HB_EXTERN hb_bool_t
+hb_subset_input_get_name_legacy (hb_subset_input_t *subset_input);
+
 /* hb_subset () */
 HB_EXTERN hb_face_t *
 hb_subset (hb_face_t *source, hb_subset_input_t *input);

test/api/hb-subset-test.h

@@ -71,6 +71,11 @@ hb_subset_test_create_input_from_nameids (const hb_set_t *name_ids)
   hb_subset_input_t *input = hb_subset_input_create_or_fail ();
   hb_set_t * input_name_ids  = hb_subset_input_nameid_set (input);
   hb_set_set (input_name_ids, name_ids);
+
+  hb_set_t *name_langids = hb_subset_input_namelangid_set (input);
+  hb_set_add_range (name_langids, 0, 0x5FFF);
+
+  hb_subset_input_set_name_legacy (input, true);
   return input;
 }