[subset] support option "--notdef-outline"

src/hb-ot-glyf-table.hh

@@ -209,7 +209,10 @@ struct glyf
 		if (!plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid))
 		  return subset_glyph;
 
-		subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, true);
+		if (new_gid == 0 && !plan->notdef_outline)
+		  subset_glyph.source_glyph = Glyph ();
+		else
+		  subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, true);
 		if (plan->drop_hints) subset_glyph.drop_hints_bytes ();
 		else subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
 

src/hb-ot-var-gvar-table.hh

@@ -419,7 +419,7 @@ struct gvar
     out->glyphCount = num_glyphs;
 
     unsigned int subset_data_size = 0;
-    for (hb_codepoint_t gid = 0; gid < num_glyphs; gid++)
+    for (hb_codepoint_t gid = c->plan->notdef_outline ? 0 : 1; gid < num_glyphs; gid++)
     {
       hb_codepoint_t old_gid;
       if (!c->plan->old_gid_for_new_gid (gid, &old_gid)) continue;
@@ -449,7 +449,7 @@ struct gvar
     out->dataZ = subset_data - (char *) out;
 
     unsigned int glyph_offset = 0;
-    for (hb_codepoint_t gid = 0; gid < num_glyphs; gid++)
+    for (hb_codepoint_t gid = c->plan->notdef_outline ? 0 : 1; gid < num_glyphs; gid++)
     {
       hb_codepoint_t old_gid;
       hb_bytes_t var_data_bytes = c->plan->old_gid_for_new_gid (gid, &old_gid)

src/hb-subset-input.cc

@@ -55,6 +55,7 @@ hb_subset_input_create_or_fail ()
   input->retain_gids = false;
   input->name_legacy = false;
   input->overlaps_flag = false;
+  input->notdef_outline = false;
   input->retain_all_layout_features = false;
 
   hb_tag_t default_drop_tables[] = {
@@ -349,3 +350,17 @@ hb_subset_input_get_overlaps_flag (hb_subset_input_t *subset_input)
 {
   return subset_input->overlaps_flag;
 }
+
+HB_EXTERN void
+hb_subset_input_set_notdef_outline (hb_subset_input_t *subset_input,
+                                    hb_bool_t notdef_outline)
+{
+  subset_input->notdef_outline = notdef_outline;
+}
+
+HB_EXTERN hb_bool_t
+hb_subset_input_get_notdef_outline (hb_subset_input_t *subset_input)
+{
+  return subset_input->notdef_outline;
+}
+

src/hb-subset-input.hh

@@ -45,12 +45,14 @@ struct hb_subset_input_t
   hb_set_t *drop_tables;
   hb_set_t *layout_features;
 
-  bool drop_hints;
-  bool desubroutinize;
-  bool retain_gids;
-  bool name_legacy;
-  bool overlaps_flag;
-  bool retain_all_layout_features;
+  //use hb_bool_t to be consistent with G option parser
+  hb_bool_t drop_hints;
+  hb_bool_t desubroutinize;
+  hb_bool_t retain_gids;
+  hb_bool_t name_legacy;
+  hb_bool_t overlaps_flag;
+  hb_bool_t notdef_outline;
+  hb_bool_t retain_all_layout_features;
   /* TODO
    *
    * features

src/hb-subset-plan.cc

@@ -401,6 +401,7 @@ hb_subset_plan_create (hb_face_t         *face,
   plan->retain_gids = input->retain_gids;
   plan->name_legacy = input->name_legacy;
   plan->overlaps_flag = input->overlaps_flag;
+  plan->notdef_outline = input->notdef_outline;
   plan->retain_all_layout_features = input->retain_all_layout_features;
   plan->unicodes = hb_set_create ();
   plan->name_ids = hb_set_reference (input->name_ids);

src/hb-subset-plan.hh

@@ -45,6 +45,7 @@ struct hb_subset_plan_t
   bool retain_gids : 1;
   bool name_legacy : 1;
   bool overlaps_flag : 1;
+  bool notdef_outline : 1;
   bool retain_all_layout_features : 1;
 
   // For each cp that we'd like to retain maps to the corresponding gid.

src/hb-subset.h

@@ -103,6 +103,13 @@ hb_subset_input_set_overlaps_flag (hb_subset_input_t *subset_input,
 HB_EXTERN hb_bool_t
 hb_subset_input_get_overlaps_flag (hb_subset_input_t *subset_input);
 
+HB_EXTERN void
+hb_subset_input_set_notdef_outline (hb_subset_input_t *subset_input,
+                                    hb_bool_t notdef_outline);
+
+HB_EXTERN hb_bool_t
+hb_subset_input_get_notdef_outline (hb_subset_input_t *subset_input);
+
 /* hb_subset () */
 HB_EXTERN hb_face_t *
 hb_subset (hb_face_t *source, hb_subset_input_t *input);