Add batch advance width callback function

New API:
+hb_font_funcs_set_glyph_h_advances_func
+hb_font_funcs_set_glyph_v_advances_func
+hb_font_get_glyph_h_advances
+hb_font_get_glyph_h_advances_func_t
+hb_font_get_glyph_v_advances
+hb_font_get_glyph_v_advances_func_t

docs/harfbuzz-sections.txt

@@ -208,10 +208,12 @@ hb_font_funcs_set_glyph_contour_point_func
 hb_font_funcs_set_glyph_extents_func
 hb_font_funcs_set_glyph_from_name_func
 hb_font_funcs_set_glyph_h_advance_func
+hb_font_funcs_set_glyph_h_advances_func
 hb_font_funcs_set_glyph_h_kerning_func
 hb_font_funcs_set_glyph_h_origin_func
 hb_font_funcs_set_glyph_name_func
 hb_font_funcs_set_glyph_v_advance_func
+hb_font_funcs_set_glyph_v_advances_func
 hb_font_funcs_set_glyph_v_kerning_func
 hb_font_funcs_set_glyph_v_origin_func
 hb_font_funcs_set_nominal_glyph_func
@@ -233,6 +235,8 @@ hb_font_get_glyph_from_name
 hb_font_get_glyph_from_name_func_t
 hb_font_get_glyph_h_advance
 hb_font_get_glyph_h_advance_func_t
+hb_font_get_glyph_h_advances
+hb_font_get_glyph_h_advances_func_t
 hb_font_get_glyph_h_kerning
 hb_font_get_glyph_h_kerning_func_t
 hb_font_get_glyph_h_origin
@@ -245,6 +249,8 @@ hb_font_get_glyph_origin_for_direction
 hb_font_get_glyph_origin_func_t
 hb_font_get_glyph_v_advance
 hb_font_get_glyph_v_advance_func_t
+hb_font_get_glyph_v_advances
+hb_font_get_glyph_v_advances_func_t
 hb_font_get_glyph_v_kerning
 hb_font_get_glyph_v_kerning_func_t
 hb_font_get_glyph_v_origin

src/hb-font-private.hh

@@ -46,6 +46,8 @@
   HB_FONT_FUNC_IMPLEMENT (variation_glyph) \
   HB_FONT_FUNC_IMPLEMENT (glyph_h_advance) \
   HB_FONT_FUNC_IMPLEMENT (glyph_v_advance) \
+  HB_FONT_FUNC_IMPLEMENT (glyph_h_advances) \
+  HB_FONT_FUNC_IMPLEMENT (glyph_v_advances) \
   HB_FONT_FUNC_IMPLEMENT (glyph_h_origin) \
   HB_FONT_FUNC_IMPLEMENT (glyph_v_origin) \
   HB_FONT_FUNC_IMPLEMENT (glyph_h_kerning) \
@@ -54,7 +56,6 @@
   HB_FONT_FUNC_IMPLEMENT (glyph_contour_point) \
   HB_FONT_FUNC_IMPLEMENT (glyph_name) \
   HB_FONT_FUNC_IMPLEMENT (glyph_from_name) \
-  HB_FONT_FUNC_IMPLEMENT (glyph_h_advances) \
   /* ^--- Add new callbacks here */
 
 struct hb_font_funcs_t
@@ -228,18 +229,6 @@ struct hb_font_t
 					 klass->user_data.glyph_h_advance);
   }
 
-  inline void get_glyph_h_advances(unsigned count,
-                                   hb_codepoint_t* glyphs,
-                                   unsigned glyph_struct_size,
-                                   hb_position_t* advances,
-                                   unsigned advance_struct_size) {
-    return klass->get.f.glyph_h_advances (this, user_data,
-                                          count,
-                                          glyphs, glyph_struct_size,
-                                          advances, advance_struct_size,
-					  klass->user_data.glyph_h_advances);
-  }
-
   inline hb_position_t get_glyph_v_advance (hb_codepoint_t glyph)
   {
     return klass->get.f.glyph_v_advance (this, user_data,
@@ -247,6 +236,32 @@ struct hb_font_t
 					 klass->user_data.glyph_v_advance);
   }
 
+  inline void get_glyph_h_advances (unsigned int count,
+				    hb_codepoint_t *first_glyph,
+				    unsigned int glyph_stride,
+				    hb_position_t *first_advance,
+				    unsigned int advance_stride)
+  {
+    return klass->get.f.glyph_h_advances (this, user_data,
+					  count,
+					  first_glyph, glyph_stride,
+					  first_advance, advance_stride,
+					  klass->user_data.glyph_h_advances);
+  }
+
+  inline void get_glyph_v_advances (unsigned int count,
+				    hb_codepoint_t *first_glyph,
+				    unsigned int glyph_stride,
+				    hb_position_t *first_advance,
+				    unsigned int advance_stride)
+  {
+    return klass->get.f.glyph_v_advances (this, user_data,
+					  count,
+					  first_glyph, glyph_stride,
+					  first_advance, advance_stride,
+					  klass->user_data.glyph_v_advances);
+  }
+
   inline hb_bool_t get_glyph_h_origin (hb_codepoint_t glyph,
 				       hb_position_t *x, hb_position_t *y)
   {

src/hb-font.cc

@@ -29,6 +29,7 @@
 #include "hb-private.hh"
 
 #include "hb-font-private.hh"
+#include "hb-machinery-private.hh"
 
 
 /*
@@ -45,10 +46,10 @@ hb_font_get_font_h_extents_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_font_h_extents_parent (hb_font_t *font,
-				   void *font_data HB_UNUSED,
-				   hb_font_extents_t *metrics,
-				   void *user_data HB_UNUSED)
+hb_font_get_font_h_extents_default (hb_font_t *font,
+				    void *font_data HB_UNUSED,
+				    hb_font_extents_t *metrics,
+				    void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_font_h_extents (metrics);
   if (ret) {
@@ -69,10 +70,10 @@ hb_font_get_font_v_extents_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_font_v_extents_parent (hb_font_t *font,
-				   void *font_data HB_UNUSED,
-				   hb_font_extents_t *metrics,
-				   void *user_data HB_UNUSED)
+hb_font_get_font_v_extents_default (hb_font_t *font,
+				    void *font_data HB_UNUSED,
+				    hb_font_extents_t *metrics,
+				    void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_font_v_extents (metrics);
   if (ret) {
@@ -94,11 +95,11 @@ hb_font_get_nominal_glyph_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_nominal_glyph_parent (hb_font_t *font,
-				  void *font_data HB_UNUSED,
-				  hb_codepoint_t unicode,
-				  hb_codepoint_t *glyph,
-				  void *user_data HB_UNUSED)
+hb_font_get_nominal_glyph_default (hb_font_t *font,
+				   void *font_data HB_UNUSED,
+				   hb_codepoint_t unicode,
+				   hb_codepoint_t *glyph,
+				   void *user_data HB_UNUSED)
 {
   return font->parent->get_nominal_glyph (unicode, glyph);
 }
@@ -115,12 +116,12 @@ hb_font_get_variation_glyph_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_variation_glyph_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    hb_codepoint_t unicode,
-				    hb_codepoint_t variation_selector,
-				    hb_codepoint_t *glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_variation_glyph_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     hb_codepoint_t unicode,
+				     hb_codepoint_t variation_selector,
+				     hb_codepoint_t *glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent->get_variation_glyph (unicode, variation_selector, glyph);
 }
@@ -129,75 +130,134 @@ hb_font_get_variation_glyph_parent (hb_font_t *font,
 static hb_position_t
 hb_font_get_glyph_h_advance_nil (hb_font_t *font,
 				 void *font_data HB_UNUSED,
-				 hb_codepoint_t glyph,
+				 hb_codepoint_t glyph HB_UNUSED,
 				 void *user_data HB_UNUSED)
 {
   return font->x_scale;
 }
 static hb_position_t
-hb_font_get_glyph_h_advance_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    hb_codepoint_t glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_glyph_h_advance_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     hb_codepoint_t glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent_scale_x_distance (font->parent->get_glyph_h_advance (glyph));
 }
 
-template <class T>
-T* advance_by_byte_size(T* p, unsigned byte_size) {
-  return reinterpret_cast<T*>(reinterpret_cast<uint8_t*>(p) + byte_size);
-}
-
-static void
-hb_font_get_glyph_h_advances_nil(hb_font_t *font,
-				 void *font_data HB_UNUSED,
-				 unsigned count,
-                                 hb_codepoint_t* glyphs,
-                                 unsigned glyph_struct_size,
-                                 hb_position_t* advances,
-                                 unsigned advance_struct_size,
-                                 void *user_data HB_UNUSED) {
-  for (; count--;
-       glyphs = advance_by_byte_size(glyphs, glyph_struct_size),
-       advances = advance_by_byte_size(advances, advance_struct_size)) {
-    *advances = hb_font_get_glyph_h_advance_nil(font, font_data, *glyphs, user_data);
-  }
-}
-
-static void
-hb_font_get_glyph_h_advances_parent(hb_font_t* font,
-                                    void* font_data HB_UNUSED,
-                                    unsigned count,
-                                    hb_codepoint_t* glyphs,
-                                    unsigned glyph_struct_size,
-                                    hb_position_t* advances,
-                                    unsigned advance_struct_size,
-                                    void* user_data HB_UNUSED) {
-  for (; count--;
-       glyphs = advance_by_byte_size(glyphs, glyph_struct_size),
-       advances = advance_by_byte_size(advances, advance_struct_size)) {
-    *advances = hb_font_get_glyph_h_advance_parent(font, font_data, *glyphs, user_data);
-  }
-}
-
 static hb_position_t
 hb_font_get_glyph_v_advance_nil (hb_font_t *font,
 				 void *font_data HB_UNUSED,
-				 hb_codepoint_t glyph,
+				 hb_codepoint_t glyph HB_UNUSED,
 				 void *user_data HB_UNUSED)
 {
   /* TODO use font_extents.ascender+descender */
   return font->y_scale;
 }
 static hb_position_t
-hb_font_get_glyph_v_advance_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    hb_codepoint_t glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_glyph_v_advance_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     hb_codepoint_t glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent_scale_y_distance (font->parent->get_glyph_v_advance (glyph));
 }
 
+static void
+hb_font_get_glyph_h_advances_nil (hb_font_t* font,
+				  void* font_data HB_UNUSED,
+				  unsigned int count,
+				  hb_codepoint_t *first_glyph HB_UNUSED,
+				  unsigned int glyph_stride HB_UNUSED,
+				  hb_position_t *first_advance,
+				  unsigned int advance_stride,
+				  void *user_data HB_UNUSED)
+{
+  for (unsigned int i = 0; i < count; i++)
+  {
+    *first_advance = font->get_glyph_h_advance (*first_glyph);
+    first_glyph = &StructAtOffset<hb_codepoint_t> (first_glyph, glyph_stride);
+    first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+  }
+}
+static void
+hb_font_get_glyph_h_advances_default (hb_font_t* font,
+				      void* font_data HB_UNUSED,
+				      unsigned int count,
+				      hb_codepoint_t *first_glyph,
+				      unsigned int glyph_stride,
+				      hb_position_t *first_advance,
+				      unsigned int advance_stride,
+				      void *user_data HB_UNUSED)
+{
+  if (font->has_glyph_h_advance_func ())
+  {
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance = font->get_glyph_h_advance (*first_glyph);
+      first_glyph = &StructAtOffset<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+    }
+    return;
+  }
+
+  font->parent->get_glyph_h_advances (count,
+				      first_glyph, glyph_stride,
+				      first_advance, advance_stride);
+  for (unsigned int i = 0; i < count; i++)
+  {
+    *first_advance = font->parent_scale_x_distance (*first_advance);
+    first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+  }
+}
+
+static void
+hb_font_get_glyph_v_advances_nil (hb_font_t* font,
+				  void* font_data HB_UNUSED,
+				  unsigned int count,
+				  hb_codepoint_t *first_glyph HB_UNUSED,
+				  unsigned int glyph_stride HB_UNUSED,
+				  hb_position_t *first_advance,
+				  unsigned int advance_stride,
+				  void *user_data HB_UNUSED)
+{
+  for (unsigned int i = 0; i < count; i++)
+  {
+    *first_advance = font->get_glyph_v_advance (*first_glyph);
+    first_glyph = &StructAtOffset<hb_codepoint_t> (first_glyph, glyph_stride);
+    first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+  }
+}
+static void
+hb_font_get_glyph_v_advances_default (hb_font_t* font,
+				      void* font_data HB_UNUSED,
+				      unsigned int count,
+				      hb_codepoint_t *first_glyph,
+				      unsigned int glyph_stride,
+				      hb_position_t *first_advance,
+				      unsigned int advance_stride,
+				      void *user_data HB_UNUSED)
+{
+  if (font->has_glyph_v_advance_func ())
+  {
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance = font->get_glyph_v_advance (*first_glyph);
+      first_glyph = &StructAtOffset<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+    }
+    return;
+  }
+
+  font->parent->get_glyph_v_advances (count,
+				      first_glyph, glyph_stride,
+				      first_advance, advance_stride);
+  for (unsigned int i = 0; i < count; i++)
+  {
+    *first_advance = font->parent_scale_y_distance (*first_advance);
+    first_advance = &StructAtOffset<hb_position_t> (first_advance, advance_stride);
+  }
+}
+
 static hb_bool_t
 hb_font_get_glyph_h_origin_nil (hb_font_t *font HB_UNUSED,
 				void *font_data HB_UNUSED,
@@ -210,12 +270,12 @@ hb_font_get_glyph_h_origin_nil (hb_font_t *font HB_UNUSED,
   return true;
 }
 static hb_bool_t
-hb_font_get_glyph_h_origin_parent (hb_font_t *font,
-				   void *font_data HB_UNUSED,
-				   hb_codepoint_t glyph,
-				   hb_position_t *x,
-				   hb_position_t *y,
-				   void *user_data HB_UNUSED)
+hb_font_get_glyph_h_origin_default (hb_font_t *font,
+				    void *font_data HB_UNUSED,
+				    hb_codepoint_t glyph,
+				    hb_position_t *x,
+				    hb_position_t *y,
+				    void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_glyph_h_origin (glyph, x, y);
   if (ret)
@@ -235,12 +295,12 @@ hb_font_get_glyph_v_origin_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_glyph_v_origin_parent (hb_font_t *font,
-				   void *font_data HB_UNUSED,
-				   hb_codepoint_t glyph,
-				   hb_position_t *x,
-				   hb_position_t *y,
-				   void *user_data HB_UNUSED)
+hb_font_get_glyph_v_origin_default (hb_font_t *font,
+				    void *font_data HB_UNUSED,
+				    hb_codepoint_t glyph,
+				    hb_position_t *x,
+				    hb_position_t *y,
+				    void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_glyph_v_origin (glyph, x, y);
   if (ret)
@@ -258,11 +318,11 @@ hb_font_get_glyph_h_kerning_nil (hb_font_t *font HB_UNUSED,
   return 0;
 }
 static hb_position_t
-hb_font_get_glyph_h_kerning_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    hb_codepoint_t left_glyph,
-				    hb_codepoint_t right_glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_glyph_h_kerning_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     hb_codepoint_t left_glyph,
+				     hb_codepoint_t right_glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent_scale_x_distance (font->parent->get_glyph_h_kerning (left_glyph, right_glyph));
 }
@@ -277,11 +337,11 @@ hb_font_get_glyph_v_kerning_nil (hb_font_t *font HB_UNUSED,
   return 0;
 }
 static hb_position_t
-hb_font_get_glyph_v_kerning_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    hb_codepoint_t top_glyph,
-				    hb_codepoint_t bottom_glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_glyph_v_kerning_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     hb_codepoint_t top_glyph,
+				     hb_codepoint_t bottom_glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent_scale_y_distance (font->parent->get_glyph_v_kerning (top_glyph, bottom_glyph));
 }
@@ -297,11 +357,11 @@ hb_font_get_glyph_extents_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_glyph_extents_parent (hb_font_t *font,
-				  void *font_data HB_UNUSED,
-				  hb_codepoint_t glyph,
-				  hb_glyph_extents_t *extents,
-				  void *user_data HB_UNUSED)
+hb_font_get_glyph_extents_default (hb_font_t *font,
+				   void *font_data HB_UNUSED,
+				   hb_codepoint_t glyph,
+				   hb_glyph_extents_t *extents,
+				   void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_glyph_extents (glyph, extents);
   if (ret) {
@@ -324,13 +384,13 @@ hb_font_get_glyph_contour_point_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_glyph_contour_point_parent (hb_font_t *font,
-					void *font_data HB_UNUSED,
-					hb_codepoint_t glyph,
-					unsigned int point_index,
-					hb_position_t *x,
-					hb_position_t *y,
-					void *user_data HB_UNUSED)
+hb_font_get_glyph_contour_point_default (hb_font_t *font,
+					 void *font_data HB_UNUSED,
+					 hb_codepoint_t glyph,
+					 unsigned int point_index,
+					 hb_position_t *x,
+					 hb_position_t *y,
+					 void *user_data HB_UNUSED)
 {
   hb_bool_t ret = font->parent->get_glyph_contour_point (glyph, point_index, x, y);
   if (ret)
@@ -349,11 +409,11 @@ hb_font_get_glyph_name_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_glyph_name_parent (hb_font_t *font,
-			       void *font_data HB_UNUSED,
-			       hb_codepoint_t glyph,
-			       char *name, unsigned int size,
-			       void *user_data HB_UNUSED)
+hb_font_get_glyph_name_default (hb_font_t *font,
+				void *font_data HB_UNUSED,
+				hb_codepoint_t glyph,
+				char *name, unsigned int size,
+				void *user_data HB_UNUSED)
 {
   return font->parent->get_glyph_name (glyph, name, size);
 }
@@ -369,11 +429,11 @@ hb_font_get_glyph_from_name_nil (hb_font_t *font HB_UNUSED,
   return false;
 }
 static hb_bool_t
-hb_font_get_glyph_from_name_parent (hb_font_t *font,
-				    void *font_data HB_UNUSED,
-				    const char *name, int len, /* -1 means nul-terminated */
-				    hb_codepoint_t *glyph,
-				    void *user_data HB_UNUSED)
+hb_font_get_glyph_from_name_default (hb_font_t *font,
+				     void *font_data HB_UNUSED,
+				     const char *name, int len, /* -1 means nul-terminated */
+				     hb_codepoint_t *glyph,
+				     void *user_data HB_UNUSED)
 {
   return font->parent->get_glyph_from_name (name, len, glyph);
 }
@@ -403,7 +463,7 @@ DEFINE_NULL_INSTANCE (hb_font_funcs_t) =
   }
 };
 
-static const hb_font_funcs_t _hb_font_funcs_parent = {
+static const hb_font_funcs_t _hb_font_funcs_default = {
   HB_OBJECT_HEADER_STATIC,
 
   true, /* immutable */
@@ -420,7 +480,7 @@ static const hb_font_funcs_t _hb_font_funcs_parent = {
   },
   {
     {
-#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_parent,
+#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_default,
       HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 #undef HB_FONT_FUNC_IMPLEMENT
     }
@@ -445,7 +505,7 @@ hb_font_funcs_create (void)
   if (!(ffuncs = hb_object_create<hb_font_funcs_t> ()))
     return hb_font_funcs_get_empty ();
 
-  ffuncs->get = _hb_font_funcs_parent.get;
+  ffuncs->get = _hb_font_funcs_default.get;
 
   return ffuncs;
 }
@@ -462,7 +522,7 @@ hb_font_funcs_create (void)
 hb_font_funcs_t *
 hb_font_funcs_get_empty (void)
 {
-  return const_cast<hb_font_funcs_t *> (&_hb_font_funcs_parent);
+  return const_cast<hb_font_funcs_t *> (&_hb_font_funcs_default);
 }
 
 /**
@@ -601,9 +661,9 @@ hb_font_funcs_set_##name##_func (hb_font_funcs_t             *ffuncs,    \
     ffuncs->user_data.name = user_data;                                  \
     ffuncs->destroy.name = destroy;                                      \
   } else {                                                               \
-    ffuncs->get.f.name = hb_font_get_##name##_parent;                    \
-    ffuncs->user_data.name = nullptr;                                       \
-    ffuncs->destroy.name = nullptr;                                         \
+    ffuncs->get.f.name = hb_font_get_##name##_default;                   \
+    ffuncs->user_data.name = nullptr;                                    \
+    ffuncs->destroy.name = nullptr;                                      \
   }                                                                      \
 }
 
@@ -613,9 +673,8 @@ HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 bool
 hb_font_t::has_func (unsigned int i)
 {
-  if (parent && parent != hb_font_get_empty () && parent->has_func (i))
-    return true;
-  return this->klass->get.array[i] != _hb_font_funcs_parent.get.array[i];
+  return (this->klass->get.array[i] != _hb_font_funcs_default.get.array[i]) ||
+	 (parent && parent != &_hb_Null_hb_font_t && parent->has_func (i));
 }
 
 /* Public getters */

src/hb-font.h

@@ -132,15 +132,15 @@ typedef hb_position_t (*hb_font_get_glyph_advance_func_t) (hb_font_t *font, void
 typedef hb_font_get_glyph_advance_func_t hb_font_get_glyph_h_advance_func_t;
 typedef hb_font_get_glyph_advance_func_t hb_font_get_glyph_v_advance_func_t;
 
-typedef void (*hb_font_get_glyph_h_advances_func_t)(
-    hb_font_t* font,
-    void* font_data,
-    unsigned count,
-    hb_codepoint_t* glyphs,
-    unsigned glyph_struct_size,
-    hb_position_t* advances,
-    unsigned advance_struct_size,
-    void* user_data);
+typedef void (*hb_font_get_glyph_advances_func_t) (hb_font_t* font, void* font_data,
+						   unsigned count,
+						   hb_codepoint_t *first_glyph,
+						   unsigned glyph_stride,
+						   hb_position_t *first_advance,
+						   unsigned advance_stride,
+						   void *user_data);
+typedef hb_font_get_glyph_advances_func_t hb_font_get_glyph_h_advances_func_t;
+typedef hb_font_get_glyph_advances_func_t hb_font_get_glyph_v_advances_func_t;
 
 typedef hb_bool_t (*hb_font_get_glyph_origin_func_t) (hb_font_t *font, void *font_data,
 						      hb_codepoint_t glyph,
@@ -258,13 +258,40 @@ hb_font_funcs_set_glyph_h_advance_func (hb_font_funcs_t *ffuncs,
 					hb_font_get_glyph_h_advance_func_t func,
 					void *user_data, hb_destroy_func_t destroy);
 
+/**
+ * hb_font_funcs_set_glyph_v_advance_func:
+ * @ffuncs: font functions.
+ * @func: (closure user_data) (destroy destroy) (scope notified):
+ * @user_data:
+ * @destroy:
+ *
+ * 
+ *
+ * Since: 0.9.2
+ **/
+HB_EXTERN void
+hb_font_funcs_set_glyph_v_advance_func (hb_font_funcs_t *ffuncs,
+					hb_font_get_glyph_v_advance_func_t func,
+					void *user_data, hb_destroy_func_t destroy);
+
+/**
+ * hb_font_funcs_set_glyph_h_advances_func:
+ * @ffuncs: font functions.
+ * @func: (closure user_data) (destroy destroy) (scope notified):
+ * @user_data:
+ * @destroy:
+ *
+ * 
+ *
+ * Since: REPLACEME
+ **/
 HB_EXTERN void
 hb_font_funcs_set_glyph_h_advances_func (hb_font_funcs_t *ffuncs,
 					hb_font_get_glyph_h_advances_func_t func,
 					void *user_data, hb_destroy_func_t destroy);
 
 /**
- * hb_font_funcs_set_glyph_v_advance_func:
+ * hb_font_funcs_set_glyph_v_advances_func:
  * @ffuncs: font functions.
  * @func: (closure user_data) (destroy destroy) (scope notified):
  * @user_data:
@@ -272,11 +299,11 @@ hb_font_funcs_set_glyph_h_advances_func (hb_font_funcs_t *ffuncs,
  *
  * 
  *
- * Since: 0.9.2
+ * Since: REPLACEME
  **/
 HB_EXTERN void
-hb_font_funcs_set_glyph_v_advance_func (hb_font_funcs_t *ffuncs,
-					hb_font_get_glyph_v_advance_func_t func,
+hb_font_funcs_set_glyph_v_advances_func (hb_font_funcs_t *ffuncs,
+					hb_font_get_glyph_v_advances_func_t func,
 					void *user_data, hb_destroy_func_t destroy);
 
 /**

src/hb-ot-shape.cc

@@ -691,9 +691,10 @@ hb_ot_position_default (hb_ot_shape_context_t *c)
   }
   else
   {
+    c->font->get_glyph_v_advances (count, &info[0].codepoint, sizeof(info[0]),
+                                   &pos[0].y_advance, sizeof(pos[0]));
     for (unsigned int i = 0; i < count; i++)
     {
-      pos[i].y_advance = c->font->get_glyph_v_advance (info[i].codepoint);
       c->font->subtract_glyph_v_origin (info[i].codepoint,
 					&pos[i].x_offset,
 					&pos[i].y_offset);