[layout] Rename API:

-hb_ot_layout_get_optical_bound()
+hb_ot_layout_lookup_get_optical_bound()

src/hb-config.hh

@@ -71,7 +71,7 @@
 #define HB_NO_LANGUAGE_PRIVATE_SUBTAG
 #define HB_NO_LAYOUT_FEATURE_PARAMS
 #define HB_NO_LAYOUT_COLLECT_GLYPHS
-#define HB_NO_LAYOUT_RARELY_UNUSED
+#define HB_NO_LAYOUT_RARELY_USED
 #define HB_NO_LAYOUT_UNUSED
 #define HB_NO_MATH
 #define HB_NO_META

src/hb-ot-layout.cc

@@ -2343,7 +2343,7 @@ struct hb_get_glyph_alternates_dispatch_t :
   ( _dispatch (obj, hb_prioritize, std::forward<Ts> (ds)...) )
 };
 
-#ifndef HB_NO_LAYOUT_RARELY_UNUSED
+#ifndef HB_NO_LAYOUT_RARELY_USED
 /**
  * hb_ot_layout_lookup_get_glyph_alternates:
  * @face: a face.
@@ -2397,10 +2397,10 @@ struct hb_position_single_dispatch_t :
 };
 
 hb_position_t
-hb_ot_layout_get_optical_bound (hb_font_t      *font,
-				unsigned        lookup_index,
-				hb_direction_t  direction,
-				hb_codepoint_t  glyph)
+hb_ot_layout_lookup_get_optical_bound (hb_font_t      *font,
+				       unsigned        lookup_index,
+				       hb_direction_t  direction,
+				       hb_codepoint_t  glyph)
 {
   const OT::PosLookup &lookup = font->face->table.GPOS->table->get_lookup (lookup_index);
   hb_glyph_position_t pos = {0};

src/hb-ot-layout.h

@@ -404,12 +404,16 @@ hb_ot_layout_get_size_params (hb_face_t       *face,
 			      unsigned int    *range_end          /* OUT.  May be NULL */);
 
 HB_EXTERN hb_position_t
-hb_ot_layout_get_optical_bound (hb_font_t      *font,
-				unsigned        lookup_index,
-				hb_direction_t  direction,
-				hb_codepoint_t  glyph);
+hb_ot_layout_lookup_get_optical_bound (hb_font_t      *font,
+				       unsigned        lookup_index,
+				       hb_direction_t  direction,
+				       hb_codepoint_t  glyph);
 
 
+/*
+ * GSUB/GPOS
+ */
+
 HB_EXTERN hb_bool_t
 hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
 				   hb_tag_t         table_tag,
@@ -429,6 +433,7 @@ hb_ot_layout_feature_get_characters (hb_face_t      *face,
 				     unsigned int   *char_count    /* IN/OUT.  May be NULL */,
 				     hb_codepoint_t *characters    /* OUT.     May be NULL */);
 
+
 /*
  * BASE
  */