--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-font.cc	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,2756 @@
+/*
+ * Copyright © 2009  Red Hat, Inc.
+ * Copyright © 2012  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#include "hb.hh"
+
+#include "hb-font.hh"
+#include "hb-draw.hh"
+#include "hb-machinery.hh"
+
+#include "hb-ot.h"
+
+#include "hb-ot-var-avar-table.hh"
+#include "hb-ot-var-fvar-table.hh"
+
+
+/**
+ * SECTION:hb-font
+ * @title: hb-font
+ * @short_description: Font objects
+ * @include: hb.h
+ *
+ * Functions for working with font objects.
+ *
+ * A font object represents a font face at a specific size and with
+ * certain other parameters (pixels-per-em, points-per-em, variation
+ * settings) specified. Font objects are created from font face
+ * objects, and are used as input to hb_shape(), among other things.
+ *
+ * Client programs can optionally pass in their own functions that
+ * implement the basic, lower-level queries of font objects. This set
+ * of font functions is defined by the virtual methods in
+ * #hb_font_funcs_t.
+ *
+ * HarfBuzz provides a built-in set of lightweight default
+ * functions for each method in #hb_font_funcs_t.
+ **/
+
+
+/*
+ * hb_font_funcs_t
+ */
+
+static hb_bool_t
+hb_font_get_font_h_extents_nil (hb_font_t         *font HB_UNUSED,
+				void              *font_data HB_UNUSED,
+				hb_font_extents_t *extents,
+				void              *user_data HB_UNUSED)
+{
+  hb_memset (extents, 0, sizeof (*extents));
+  return false;
+}
+
+static hb_bool_t
+hb_font_get_font_h_extents_default (hb_font_t         *font,
+				    void              *font_data HB_UNUSED,
+				    hb_font_extents_t *extents,
+				    void              *user_data HB_UNUSED)
+{
+  hb_bool_t ret = font->parent->get_font_h_extents (extents);
+  if (ret) {
+    extents->ascender = font->parent_scale_y_distance (extents->ascender);
+    extents->descender = font->parent_scale_y_distance (extents->descender);
+    extents->line_gap = font->parent_scale_y_distance (extents->line_gap);
+  }
+  return ret;
+}
+
+static hb_bool_t
+hb_font_get_font_v_extents_nil (hb_font_t         *font HB_UNUSED,
+				void              *font_data HB_UNUSED,
+				hb_font_extents_t *extents,
+				void              *user_data HB_UNUSED)
+{
+  hb_memset (extents, 0, sizeof (*extents));
+  return false;
+}
+
+static hb_bool_t
+hb_font_get_font_v_extents_default (hb_font_t         *font,
+				    void              *font_data HB_UNUSED,
+				    hb_font_extents_t *extents,
+				    void              *user_data HB_UNUSED)
+{
+  hb_bool_t ret = font->parent->get_font_v_extents (extents);
+  if (ret) {
+    extents->ascender = font->parent_scale_x_distance (extents->ascender);
+    extents->descender = font->parent_scale_x_distance (extents->descender);
+    extents->line_gap = font->parent_scale_x_distance (extents->line_gap);
+  }
+  return ret;
+}
+
+static hb_bool_t
+hb_font_get_nominal_glyph_nil (hb_font_t      *font HB_UNUSED,
+			       void           *font_data HB_UNUSED,
+			       hb_codepoint_t  unicode HB_UNUSED,
+			       hb_codepoint_t *glyph,
+			       void           *user_data HB_UNUSED)
+{
+  *glyph = 0;
+  return false;
+}
+
+static hb_bool_t
+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)
+{
+  if (font->has_nominal_glyphs_func_set ())
+  {
+    return font->get_nominal_glyphs (1, &unicode, 0, glyph, 0);
+  }
+  return font->parent->get_nominal_glyph (unicode, glyph);
+}
+
+#define hb_font_get_nominal_glyphs_nil hb_font_get_nominal_glyphs_default
+
+static unsigned int
+hb_font_get_nominal_glyphs_default (hb_font_t            *font,
+				    void                 *font_data HB_UNUSED,
+				    unsigned int          count,
+				    const hb_codepoint_t *first_unicode,
+				    unsigned int          unicode_stride,
+				    hb_codepoint_t       *first_glyph,
+				    unsigned int          glyph_stride,
+				    void                 *user_data HB_UNUSED)
+{
+  if (font->has_nominal_glyph_func_set ())
+  {
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (!font->get_nominal_glyph (*first_unicode, first_glyph))
+	return i;
+
+      first_unicode = &StructAtOffsetUnaligned<hb_codepoint_t> (first_unicode, unicode_stride);
+      first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
+    }
+    return count;
+  }
+
+  return font->parent->get_nominal_glyphs (count,
+					   first_unicode, unicode_stride,
+					   first_glyph, glyph_stride);
+}
+
+static hb_bool_t
+hb_font_get_variation_glyph_nil (hb_font_t      *font HB_UNUSED,
+				 void           *font_data HB_UNUSED,
+				 hb_codepoint_t  unicode HB_UNUSED,
+				 hb_codepoint_t  variation_selector HB_UNUSED,
+				 hb_codepoint_t *glyph,
+				 void           *user_data HB_UNUSED)
+{
+  *glyph = 0;
+  return false;
+}
+
+static hb_bool_t
+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);
+}
+
+
+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_UNUSED,
+				 void           *user_data HB_UNUSED)
+{
+  return font->x_scale;
+}
+
+static hb_position_t
+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)
+{
+  if (font->has_glyph_h_advances_func_set ())
+  {
+    hb_position_t ret;
+    font->get_glyph_h_advances (1, &glyph, 0, &ret, 0);
+    return ret;
+  }
+  return font->parent_scale_x_distance (font->parent->get_glyph_h_advance (glyph));
+}
+
+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_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_default (hb_font_t      *font,
+				     void           *font_data HB_UNUSED,
+				     hb_codepoint_t  glyph,
+				     void           *user_data HB_UNUSED)
+{
+  if (font->has_glyph_v_advances_func_set ())
+  {
+    hb_position_t ret;
+    font->get_glyph_v_advances (1, &glyph, 0, &ret, 0);
+    return ret;
+  }
+  return font->parent_scale_y_distance (font->parent->get_glyph_v_advance (glyph));
+}
+
+#define hb_font_get_glyph_h_advances_nil hb_font_get_glyph_h_advances_default
+
+static void
+hb_font_get_glyph_h_advances_default (hb_font_t*            font,
+				      void*                 font_data HB_UNUSED,
+				      unsigned int          count,
+				      const 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_set ())
+  {
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance = font->get_glyph_h_advance (*first_glyph);
+      first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffsetUnaligned<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 = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
+  }
+}
+
+#define hb_font_get_glyph_v_advances_nil hb_font_get_glyph_v_advances_default
+static void
+hb_font_get_glyph_v_advances_default (hb_font_t*            font,
+				      void*                 font_data HB_UNUSED,
+				      unsigned int          count,
+				      const 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_set ())
+  {
+    for (unsigned int i = 0; i < count; i++)
+    {
+      *first_advance = font->get_glyph_v_advance (*first_glyph);
+      first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
+      first_advance = &StructAtOffsetUnaligned<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 = &StructAtOffsetUnaligned<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,
+				hb_codepoint_t  glyph HB_UNUSED,
+				hb_position_t  *x,
+				hb_position_t  *y,
+				void           *user_data HB_UNUSED)
+{
+  *x = *y = 0;
+  return true;
+}
+
+static hb_bool_t
+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)
+    font->parent_scale_position (x, y);
+  return ret;
+}
+
+static hb_bool_t
+hb_font_get_glyph_v_origin_nil (hb_font_t      *font HB_UNUSED,
+				void           *font_data HB_UNUSED,
+				hb_codepoint_t  glyph HB_UNUSED,
+				hb_position_t  *x,
+				hb_position_t  *y,
+				void           *user_data HB_UNUSED)
+{
+  *x = *y = 0;
+  return false;
+}
+
+static hb_bool_t
+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)
+    font->parent_scale_position (x, y);
+  return ret;
+}
+
+static hb_position_t
+hb_font_get_glyph_h_kerning_nil (hb_font_t      *font HB_UNUSED,
+				 void           *font_data HB_UNUSED,
+				 hb_codepoint_t  left_glyph HB_UNUSED,
+				 hb_codepoint_t  right_glyph HB_UNUSED,
+				 void           *user_data HB_UNUSED)
+{
+  return 0;
+}
+
+static hb_position_t
+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));
+}
+
+#ifndef HB_DISABLE_DEPRECATED
+static hb_position_t
+hb_font_get_glyph_v_kerning_nil (hb_font_t      *font HB_UNUSED,
+				 void           *font_data HB_UNUSED,
+				 hb_codepoint_t  top_glyph HB_UNUSED,
+				 hb_codepoint_t  bottom_glyph HB_UNUSED,
+				 void           *user_data HB_UNUSED)
+{
+  return 0;
+}
+
+static hb_position_t
+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));
+}
+#endif
+
+static hb_bool_t
+hb_font_get_glyph_extents_nil (hb_font_t          *font HB_UNUSED,
+			       void               *font_data HB_UNUSED,
+			       hb_codepoint_t      glyph HB_UNUSED,
+			       hb_glyph_extents_t *extents,
+			       void               *user_data HB_UNUSED)
+{
+  hb_memset (extents, 0, sizeof (*extents));
+  return false;
+}
+
+static hb_bool_t
+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) {
+    font->parent_scale_position (&extents->x_bearing, &extents->y_bearing);
+    font->parent_scale_distance (&extents->width, &extents->height);
+  }
+  return ret;
+}
+
+static hb_bool_t
+hb_font_get_glyph_contour_point_nil (hb_font_t      *font HB_UNUSED,
+				     void           *font_data HB_UNUSED,
+				     hb_codepoint_t  glyph HB_UNUSED,
+				     unsigned int    point_index HB_UNUSED,
+				     hb_position_t  *x,
+				     hb_position_t  *y,
+				     void           *user_data HB_UNUSED)
+{
+  *x = *y = 0;
+  return false;
+}
+
+static hb_bool_t
+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)
+    font->parent_scale_position (x, y);
+  return ret;
+}
+
+static hb_bool_t
+hb_font_get_glyph_name_nil (hb_font_t      *font HB_UNUSED,
+			    void           *font_data HB_UNUSED,
+			    hb_codepoint_t  glyph HB_UNUSED,
+			    char           *name,
+			    unsigned int    size,
+			    void           *user_data HB_UNUSED)
+{
+  if (size) *name = '\0';
+  return false;
+}
+
+static hb_bool_t
+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);
+}
+
+static hb_bool_t
+hb_font_get_glyph_from_name_nil (hb_font_t      *font HB_UNUSED,
+				 void           *font_data HB_UNUSED,
+				 const char     *name HB_UNUSED,
+				 int             len HB_UNUSED, /* -1 means nul-terminated */
+				 hb_codepoint_t *glyph,
+				 void           *user_data HB_UNUSED)
+{
+  *glyph = 0;
+  return false;
+}
+
+static hb_bool_t
+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);
+}
+
+static void
+hb_font_get_glyph_shape_nil (hb_font_t       *font HB_UNUSED,
+			     void            *font_data HB_UNUSED,
+			     hb_codepoint_t   glyph,
+			     hb_draw_funcs_t *draw_funcs,
+			     void            *draw_data,
+			     void            *user_data HB_UNUSED)
+{
+}
+
+
+typedef struct hb_font_get_glyph_shape_default_adaptor_t {
+  hb_draw_funcs_t *draw_funcs;
+  void		  *draw_data;
+  float		   x_scale;
+  float		   y_scale;
+  float		   slant;
+} hb_font_get_glyph_shape_default_adaptor_t;
+
+static void
+hb_draw_move_to_default (hb_draw_funcs_t *dfuncs HB_UNUSED,
+			 void *draw_data,
+			 hb_draw_state_t *st,
+			 float to_x, float to_y,
+			 void *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t *adaptor = (hb_font_get_glyph_shape_default_adaptor_t *) draw_data;
+  float x_scale = adaptor->x_scale;
+  float y_scale = adaptor->y_scale;
+  float slant   = adaptor->slant;
+
+  adaptor->draw_funcs->emit_move_to (adaptor->draw_data, *st,
+				     x_scale * to_x + slant * to_y, y_scale * to_y);
+}
+
+static void
+hb_draw_line_to_default (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data,
+			 hb_draw_state_t *st,
+			 float to_x, float to_y,
+			 void *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t *adaptor = (hb_font_get_glyph_shape_default_adaptor_t *) draw_data;
+  float x_scale = adaptor->x_scale;
+  float y_scale = adaptor->y_scale;
+  float slant   = adaptor->slant;
+
+  st->current_x = st->current_x * x_scale + st->current_y * slant;
+  st->current_y = st->current_y * y_scale;
+
+  adaptor->draw_funcs->emit_line_to (adaptor->draw_data, *st,
+				     x_scale * to_x + slant * to_y, y_scale * to_y);
+}
+
+static void
+hb_draw_quadratic_to_default (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data,
+			      hb_draw_state_t *st,
+			      float control_x, float control_y,
+			      float to_x, float to_y,
+			      void *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t *adaptor = (hb_font_get_glyph_shape_default_adaptor_t *) draw_data;
+  float x_scale = adaptor->x_scale;
+  float y_scale = adaptor->y_scale;
+  float slant   = adaptor->slant;
+
+  st->current_x = st->current_x * x_scale + st->current_y * slant;
+  st->current_y = st->current_y * y_scale;
+
+  adaptor->draw_funcs->emit_quadratic_to (adaptor->draw_data, *st,
+					  x_scale * control_x + slant * control_y, y_scale * control_y,
+					  x_scale * to_x + slant * to_y, y_scale * to_y);
+}
+
+static void
+hb_draw_cubic_to_default (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data,
+			  hb_draw_state_t *st,
+			  float control1_x, float control1_y,
+			  float control2_x, float control2_y,
+			  float to_x, float to_y,
+			  void *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t *adaptor = (hb_font_get_glyph_shape_default_adaptor_t *) draw_data;
+  float x_scale = adaptor->x_scale;
+  float y_scale = adaptor->y_scale;
+  float slant   = adaptor->slant;
+
+  st->current_x = st->current_x * x_scale + st->current_y * slant;
+  st->current_y = st->current_y * y_scale;
+
+  adaptor->draw_funcs->emit_cubic_to (adaptor->draw_data, *st,
+				      x_scale * control1_x + slant * control1_y, y_scale * control1_y,
+				      x_scale * control2_x + slant * control2_y, y_scale * control2_y,
+				      x_scale * to_x + slant * to_y, y_scale * to_y);
+}
+
+static void
+hb_draw_close_path_default (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data,
+			    hb_draw_state_t *st,
+			    void *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t *adaptor = (hb_font_get_glyph_shape_default_adaptor_t *) draw_data;
+
+  adaptor->draw_funcs->emit_close_path (adaptor->draw_data, *st);
+}
+
+static const hb_draw_funcs_t _hb_draw_funcs_default = {
+  HB_OBJECT_HEADER_STATIC,
+
+  {
+#define HB_DRAW_FUNC_IMPLEMENT(name) hb_draw_##name##_default,
+    HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_DRAW_FUNC_IMPLEMENT
+  }
+};
+
+static void
+hb_font_get_glyph_shape_default (hb_font_t       *font,
+				 void            *font_data HB_UNUSED,
+				 hb_codepoint_t   glyph,
+				 hb_draw_funcs_t *draw_funcs,
+				 void            *draw_data,
+				 void            *user_data HB_UNUSED)
+{
+  hb_font_get_glyph_shape_default_adaptor_t adaptor = {
+    draw_funcs,
+    draw_data,
+    font->parent->x_scale ? (float) font->x_scale / (float) font->parent->x_scale : 0.f,
+    font->parent->y_scale ? (float) font->y_scale / (float) font->parent->y_scale : 0.f,
+    font->parent->y_scale ? (font->slant - font->parent->slant) *
+			    (float) font->x_scale / (float) font->parent->y_scale : 0.f
+  };
+
+  font->parent->get_glyph_shape (glyph,
+				 const_cast<hb_draw_funcs_t *> (&_hb_draw_funcs_default),
+				 &adaptor);
+}
+
+DEFINE_NULL_INSTANCE (hb_font_funcs_t) =
+{
+  HB_OBJECT_HEADER_STATIC,
+
+  nullptr,
+  nullptr,
+  {
+    {
+#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_nil,
+      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+    }
+  }
+};
+
+static const hb_font_funcs_t _hb_font_funcs_default = {
+  HB_OBJECT_HEADER_STATIC,
+
+  nullptr,
+  nullptr,
+  {
+    {
+#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_default,
+      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+    }
+  }
+};
+
+
+/**
+ * hb_font_funcs_create:
+ *
+ * Creates a new #hb_font_funcs_t structure of font functions.
+ *
+ * Return value: (transfer full): The font-functions structure
+ *
+ * Since: 0.9.2
+ **/
+hb_font_funcs_t *
+hb_font_funcs_create ()
+{
+  hb_font_funcs_t *ffuncs;
+
+  if (!(ffuncs = hb_object_create<hb_font_funcs_t> ()))
+    return hb_font_funcs_get_empty ();
+
+  ffuncs->get = _hb_font_funcs_default.get;
+
+  return ffuncs;
+}
+
+/**
+ * hb_font_funcs_get_empty:
+ *
+ * Fetches an empty font-functions structure.
+ *
+ * Return value: (transfer full): The font-functions structure
+ *
+ * Since: 0.9.2
+ **/
+hb_font_funcs_t *
+hb_font_funcs_get_empty ()
+{
+  return const_cast<hb_font_funcs_t *> (&_hb_font_funcs_default);
+}
+
+/**
+ * hb_font_funcs_reference: (skip)
+ * @ffuncs: The font-functions structure
+ *
+ * Increases the reference count on a font-functions structure.
+ *
+ * Return value: The font-functions structure
+ *
+ * Since: 0.9.2
+ **/
+hb_font_funcs_t *
+hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
+{
+  return hb_object_reference (ffuncs);
+}
+
+/**
+ * hb_font_funcs_destroy: (skip)
+ * @ffuncs: The font-functions structure
+ *
+ * Decreases the reference count on a font-functions structure. When
+ * the reference count reaches zero, the font-functions structure is
+ * destroyed, freeing all memory.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
+{
+  if (!hb_object_destroy (ffuncs)) return;
+
+  if (ffuncs->destroy)
+  {
+#define HB_FONT_FUNC_IMPLEMENT(name) if (ffuncs->destroy->name) \
+    ffuncs->destroy->name (!ffuncs->user_data ? nullptr : ffuncs->user_data->name);
+    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+  }
+
+  hb_free (ffuncs->destroy);
+  hb_free (ffuncs->user_data);
+
+  hb_free (ffuncs);
+}
+
+/**
+ * hb_font_funcs_set_user_data: (skip)
+ * @ffuncs: The font-functions structure
+ * @key: The user-data key to set
+ * @data: A pointer to the user data set
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
+ * @replace: Whether to replace an existing data with the same key
+ *
+ * Attaches a user-data key/data pair to the specified font-functions structure.
+ *
+ * Return value: `true` if success, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_funcs_set_user_data (hb_font_funcs_t    *ffuncs,
+			     hb_user_data_key_t *key,
+			     void *              data,
+			     hb_destroy_func_t   destroy /* May be NULL. */,
+			     hb_bool_t           replace)
+{
+  return hb_object_set_user_data (ffuncs, key, data, destroy, replace);
+}
+
+/**
+ * hb_font_funcs_get_user_data: (skip)
+ * @ffuncs: The font-functions structure
+ * @key: The user-data key to query
+ *
+ * Fetches the user data associated with the specified key,
+ * attached to the specified font-functions structure.
+ *
+ * Return value: (transfer none): A pointer to the user data
+ *
+ * Since: 0.9.2
+ **/
+void *
+hb_font_funcs_get_user_data (const hb_font_funcs_t *ffuncs,
+			     hb_user_data_key_t    *key)
+{
+  return hb_object_get_user_data (ffuncs, key);
+}
+
+
+/**
+ * hb_font_funcs_make_immutable:
+ * @ffuncs: The font-functions structure
+ *
+ * Makes a font-functions structure immutable.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
+{
+  if (hb_object_is_immutable (ffuncs))
+    return;
+
+  hb_object_make_immutable (ffuncs);
+}
+
+/**
+ * hb_font_funcs_is_immutable:
+ * @ffuncs: The font-functions structure
+ *
+ * Tests whether a font-functions structure is immutable.
+ *
+ * Return value: `true` if @ffuncs is immutable, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_funcs_is_immutable (hb_font_funcs_t *ffuncs)
+{
+  return hb_object_is_immutable (ffuncs);
+}
+
+
+static bool
+_hb_font_funcs_set_preamble (hb_font_funcs_t    *ffuncs,
+			     bool                func_is_null,
+			     void              **user_data,
+			     hb_destroy_func_t  *destroy)
+{
+  if (hb_object_is_immutable (ffuncs))
+  {
+    if (*destroy)
+      (*destroy) (*user_data);
+    return false;
+  }
+
+  if (func_is_null)
+  {
+    if (*destroy)
+      (*destroy) (*user_data);
+    *destroy = nullptr;
+    *user_data = nullptr;
+  }
+
+  return true;
+}
+
+static bool
+_hb_font_funcs_set_middle (hb_font_funcs_t   *ffuncs,
+			   void              *user_data,
+			   hb_destroy_func_t  destroy)
+{
+  if (user_data && !ffuncs->user_data)
+  {
+    ffuncs->user_data = (decltype (ffuncs->user_data)) hb_calloc (1, sizeof (*ffuncs->user_data));
+    if (unlikely (!ffuncs->user_data))
+      goto fail;
+  }
+  if (destroy && !ffuncs->destroy)
+  {
+    ffuncs->destroy = (decltype (ffuncs->destroy)) hb_calloc (1, sizeof (*ffuncs->destroy));
+    if (unlikely (!ffuncs->destroy))
+      goto fail;
+  }
+
+  return true;
+
+fail:
+  if (destroy)
+    (destroy) (user_data);
+  return false;
+}
+
+#define HB_FONT_FUNC_IMPLEMENT(name) \
+									 \
+void                                                                     \
+hb_font_funcs_set_##name##_func (hb_font_funcs_t             *ffuncs,    \
+				 hb_font_get_##name##_func_t  func,      \
+				 void                        *user_data, \
+				 hb_destroy_func_t            destroy)   \
+{                                                                        \
+  if (!_hb_font_funcs_set_preamble (ffuncs, !func, &user_data, &destroy))\
+      return;                                                            \
+									 \
+  if (ffuncs->destroy && ffuncs->destroy->name)                          \
+    ffuncs->destroy->name (!ffuncs->user_data ? nullptr : ffuncs->user_data->name); \
+                                                                         \
+  if (!_hb_font_funcs_set_middle (ffuncs, user_data, destroy))           \
+      return;                                                            \
+									 \
+  if (func)                                                              \
+    ffuncs->get.f.name = func;                                           \
+  else                                                                   \
+    ffuncs->get.f.name = hb_font_get_##name##_default;                   \
+									 \
+  if (ffuncs->user_data)                                                 \
+    ffuncs->user_data->name = user_data;                                 \
+  if (ffuncs->destroy)                                                   \
+    ffuncs->destroy->name = destroy;                                     \
+}
+
+HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+
+bool
+hb_font_t::has_func_set (unsigned int i)
+{
+  return this->klass->get.array[i] != _hb_font_funcs_default.get.array[i];
+}
+
+bool
+hb_font_t::has_func (unsigned int i)
+{
+  return has_func_set (i) ||
+	 (parent && parent != &_hb_Null_hb_font_t && parent->has_func (i));
+}
+
+/* Public getters */
+
+/**
+ * hb_font_get_h_extents:
+ * @font: #hb_font_t to work upon
+ * @extents: (out): The font extents retrieved
+ *
+ * Fetches the extents for a specified font, for horizontal
+ * text segments.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 1.1.3
+ **/
+hb_bool_t
+hb_font_get_h_extents (hb_font_t         *font,
+		       hb_font_extents_t *extents)
+{
+  return font->get_font_h_extents (extents);
+}
+
+/**
+ * hb_font_get_v_extents:
+ * @font: #hb_font_t to work upon
+ * @extents: (out): The font extents retrieved
+ *
+ * Fetches the extents for a specified font, for vertical
+ * text segments.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 1.1.3
+ **/
+hb_bool_t
+hb_font_get_v_extents (hb_font_t         *font,
+		       hb_font_extents_t *extents)
+{
+  return font->get_font_v_extents (extents);
+}
+
+/**
+ * hb_font_get_glyph:
+ * @font: #hb_font_t to work upon
+ * @unicode: The Unicode code point to query
+ * @variation_selector: A variation-selector code point
+ * @glyph: (out): The glyph ID retrieved
+ *
+ * Fetches the glyph ID for a Unicode code point in the specified
+ * font, with an optional variation selector.
+ *
+ * If @variation_selector is 0, calls hb_font_get_nominal_glyph();
+ * otherwise calls hb_font_get_variation_glyph().
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph (hb_font_t      *font,
+		   hb_codepoint_t  unicode,
+		   hb_codepoint_t  variation_selector,
+		   hb_codepoint_t *glyph)
+{
+  if (unlikely (variation_selector))
+    return font->get_variation_glyph (unicode, variation_selector, glyph);
+  return font->get_nominal_glyph (unicode, glyph);
+}
+
+/**
+ * hb_font_get_nominal_glyph:
+ * @font: #hb_font_t to work upon
+ * @unicode: The Unicode code point to query
+ * @glyph: (out): The glyph ID retrieved
+ *
+ * Fetches the nominal glyph ID for a Unicode code point in the
+ * specified font.
+ *
+ * This version of the function should not be used to fetch glyph IDs
+ * for code points modified by variation selectors. For variation-selector
+ * support, user hb_font_get_variation_glyph() or use hb_font_get_glyph().
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 1.2.3
+ **/
+hb_bool_t
+hb_font_get_nominal_glyph (hb_font_t      *font,
+			   hb_codepoint_t  unicode,
+			   hb_codepoint_t *glyph)
+{
+  return font->get_nominal_glyph (unicode, glyph);
+}
+
+/**
+ * hb_font_get_nominal_glyphs:
+ * @font: #hb_font_t to work upon
+ * @count: number of code points to query
+ * @first_unicode: The first Unicode code point to query
+ * @unicode_stride: The stride between successive code points
+ * @first_glyph: (out): The first glyph ID retrieved
+ * @glyph_stride: The stride between successive glyph IDs
+ *
+ * Fetches the nominal glyph IDs for a sequence of Unicode code points. Glyph
+ * IDs must be returned in a #hb_codepoint_t output parameter.
+ *
+ * Return value: the number of code points processed
+ *
+ * Since: 2.6.3
+ **/
+unsigned int
+hb_font_get_nominal_glyphs (hb_font_t *font,
+			    unsigned int count,
+			    const hb_codepoint_t *first_unicode,
+			    unsigned int unicode_stride,
+			    hb_codepoint_t *first_glyph,
+			    unsigned int glyph_stride)
+{
+  return font->get_nominal_glyphs (count,
+				   first_unicode, unicode_stride,
+				   first_glyph, glyph_stride);
+}
+
+/**
+ * hb_font_get_variation_glyph:
+ * @font: #hb_font_t to work upon
+ * @unicode: The Unicode code point to query
+ * @variation_selector: The  variation-selector code point to query
+ * @glyph: (out): The glyph ID retrieved
+ *
+ * Fetches the glyph ID for a Unicode code point when followed by
+ * by the specified variation-selector code point, in the specified
+ * font.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 1.2.3
+ **/
+hb_bool_t
+hb_font_get_variation_glyph (hb_font_t      *font,
+			     hb_codepoint_t  unicode,
+			     hb_codepoint_t  variation_selector,
+			     hb_codepoint_t *glyph)
+{
+  return font->get_variation_glyph (unicode, variation_selector, glyph);
+}
+
+/**
+ * hb_font_get_glyph_h_advance:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ *
+ * Fetches the advance for a glyph ID in the specified font,
+ * for horizontal text segments.
+ *
+ * Return value: The advance of @glyph within @font
+ *
+ * Since: 0.9.2
+ **/
+hb_position_t
+hb_font_get_glyph_h_advance (hb_font_t      *font,
+			     hb_codepoint_t  glyph)
+{
+  return font->get_glyph_h_advance (glyph);
+}
+
+/**
+ * hb_font_get_glyph_v_advance:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ *
+ * Fetches the advance for a glyph ID in the specified font,
+ * for vertical text segments.
+ *
+ * Return value: The advance of @glyph within @font
+ *
+ * Since: 0.9.2
+ **/
+hb_position_t
+hb_font_get_glyph_v_advance (hb_font_t      *font,
+			     hb_codepoint_t  glyph)
+{
+  return font->get_glyph_v_advance (glyph);
+}
+
+/**
+ * hb_font_get_glyph_h_advances:
+ * @font: #hb_font_t to work upon
+ * @count: The number of glyph IDs in the sequence queried
+ * @first_glyph: The first glyph ID to query
+ * @glyph_stride: The stride between successive glyph IDs
+ * @first_advance: (out): The first advance retrieved
+ * @advance_stride: The stride between successive advances
+ *
+ * Fetches the advances for a sequence of glyph IDs in the specified
+ * font, for horizontal text segments.
+ *
+ * Since: 1.8.6
+ **/
+void
+hb_font_get_glyph_h_advances (hb_font_t*            font,
+			      unsigned int          count,
+			      const hb_codepoint_t *first_glyph,
+			      unsigned              glyph_stride,
+			      hb_position_t        *first_advance,
+			      unsigned              advance_stride)
+{
+  font->get_glyph_h_advances (count, first_glyph, glyph_stride, first_advance, advance_stride);
+}
+/**
+ * hb_font_get_glyph_v_advances:
+ * @font: #hb_font_t to work upon
+ * @count: The number of glyph IDs in the sequence queried
+ * @first_glyph: The first glyph ID to query
+ * @glyph_stride: The stride between successive glyph IDs
+ * @first_advance: (out): The first advance retrieved
+ * @advance_stride: (out): The stride between successive advances
+ *
+ * Fetches the advances for a sequence of glyph IDs in the specified
+ * font, for vertical text segments.
+ *
+ * Since: 1.8.6
+ **/
+void
+hb_font_get_glyph_v_advances (hb_font_t*            font,
+			      unsigned int          count,
+			      const hb_codepoint_t *first_glyph,
+			      unsigned              glyph_stride,
+			      hb_position_t        *first_advance,
+			      unsigned              advance_stride)
+{
+  font->get_glyph_v_advances (count, first_glyph, glyph_stride, first_advance, advance_stride);
+}
+
+/**
+ * hb_font_get_glyph_h_origin:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @x: (out): The X coordinate of the origin
+ * @y: (out): The Y coordinate of the origin
+ *
+ * Fetches the (X,Y) coordinates of the origin for a glyph ID
+ * in the specified font, for horizontal text segments.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_h_origin (hb_font_t      *font,
+			    hb_codepoint_t  glyph,
+			    hb_position_t  *x,
+			    hb_position_t  *y)
+{
+  return font->get_glyph_h_origin (glyph, x, y);
+}
+
+/**
+ * hb_font_get_glyph_v_origin:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @x: (out): The X coordinate of the origin
+ * @y: (out): The Y coordinate of the origin
+ *
+ * Fetches the (X,Y) coordinates of the origin for a glyph ID
+ * in the specified font, for vertical text segments.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_v_origin (hb_font_t      *font,
+			    hb_codepoint_t  glyph,
+			    hb_position_t  *x,
+			    hb_position_t  *y)
+{
+  return font->get_glyph_v_origin (glyph, x, y);
+}
+
+/**
+ * hb_font_get_glyph_h_kerning:
+ * @font: #hb_font_t to work upon
+ * @left_glyph: The glyph ID of the left glyph in the glyph pair
+ * @right_glyph: The glyph ID of the right glyph in the glyph pair
+ *
+ * Fetches the kerning-adjustment value for a glyph-pair in
+ * the specified font, for horizontal text segments.
+ *
+ * <note>It handles legacy kerning only (as returned by the corresponding
+ * #hb_font_funcs_t function).</note>
+ *
+ * Return value: The kerning adjustment value
+ *
+ * Since: 0.9.2
+ **/
+hb_position_t
+hb_font_get_glyph_h_kerning (hb_font_t      *font,
+			     hb_codepoint_t  left_glyph,
+			     hb_codepoint_t  right_glyph)
+{
+  return font->get_glyph_h_kerning (left_glyph, right_glyph);
+}
+
+#ifndef HB_DISABLE_DEPRECATED
+/**
+ * hb_font_get_glyph_v_kerning:
+ * @font: #hb_font_t to work upon
+ * @top_glyph: The glyph ID of the top glyph in the glyph pair
+ * @bottom_glyph: The glyph ID of the bottom glyph in the glyph pair
+ *
+ * Fetches the kerning-adjustment value for a glyph-pair in
+ * the specified font, for vertical text segments.
+ *
+ * <note>It handles legacy kerning only (as returned by the corresponding
+ * #hb_font_funcs_t function).</note>
+ *
+ * Return value: The kerning adjustment value
+ *
+ * Since: 0.9.2
+ * Deprecated: 2.0.0
+ **/
+hb_position_t
+hb_font_get_glyph_v_kerning (hb_font_t      *font,
+			     hb_codepoint_t  top_glyph,
+			     hb_codepoint_t  bottom_glyph)
+{
+  return font->get_glyph_v_kerning (top_glyph, bottom_glyph);
+}
+#endif
+
+/**
+ * hb_font_get_glyph_extents:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @extents: (out): The #hb_glyph_extents_t retrieved
+ *
+ * Fetches the #hb_glyph_extents_t data for a glyph ID
+ * in the specified font.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_extents (hb_font_t          *font,
+			   hb_codepoint_t      glyph,
+			   hb_glyph_extents_t *extents)
+{
+  return font->get_glyph_extents (glyph, extents);
+}
+
+/**
+ * hb_font_get_glyph_contour_point:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @point_index: The contour-point index to query
+ * @x: (out): The X value retrieved for the contour point
+ * @y: (out): The Y value retrieved for the contour point
+ *
+ * Fetches the (x,y) coordinates of a specified contour-point index
+ * in the specified glyph, within the specified font.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_contour_point (hb_font_t      *font,
+				 hb_codepoint_t  glyph,
+				 unsigned int    point_index,
+				 hb_position_t  *x,
+				 hb_position_t  *y)
+{
+  return font->get_glyph_contour_point (glyph, point_index, x, y);
+}
+
+/**
+ * hb_font_get_glyph_name:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @name: (out) (array length=size): Name string retrieved for the glyph ID
+ * @size: Length of the glyph-name string retrieved
+ *
+ * Fetches the glyph-name string for a glyph ID in the specified @font.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_name (hb_font_t      *font,
+			hb_codepoint_t  glyph,
+			char           *name,
+			unsigned int    size)
+{
+  return font->get_glyph_name (glyph, name, size);
+}
+
+/**
+ * hb_font_get_glyph_from_name:
+ * @font: #hb_font_t to work upon
+ * @name: (array length=len): The name string to query
+ * @len: The length of the name queried
+ * @glyph: (out): The glyph ID retrieved
+ *
+ * Fetches the glyph ID that corresponds to a name string in the specified @font.
+ *
+ * <note>Note: @len == -1 means the name string is null-terminated.</note>
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_from_name (hb_font_t      *font,
+			     const char     *name,
+			     int             len, /* -1 means nul-terminated */
+			     hb_codepoint_t *glyph)
+{
+  return font->get_glyph_from_name (name, len, glyph);
+}
+
+/**
+ * hb_font_get_glyph_shape:
+ * @font: #hb_font_t to work upon
+ * @glyph: : The glyph ID
+ * @dfuncs: #hb_draw_funcs_t to draw to
+ * @draw_data: User data to pass to draw callbacks
+ *
+ * Fetches the glyph shape that corresponds to a glyph in the specified @font.
+ * The shape is returned by way of calls to the callbacks of the @dfuncs
+ * objects, with @draw_data passed to them.
+ *
+ * Since: 4.0.0
+ **/
+void
+hb_font_get_glyph_shape (hb_font_t *font,
+			 hb_codepoint_t glyph,
+			 hb_draw_funcs_t *dfuncs, void *draw_data)
+{
+  font->get_glyph_shape (glyph, dfuncs, draw_data);
+}
+
+/* A bit higher-level, and with fallback */
+
+/**
+ * hb_font_get_extents_for_direction:
+ * @font: #hb_font_t to work upon
+ * @direction: The direction of the text segment
+ * @extents: (out): The #hb_font_extents_t retrieved
+ *
+ * Fetches the extents for a font in a text segment of the
+ * specified direction.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 1.1.3
+ **/
+void
+hb_font_get_extents_for_direction (hb_font_t         *font,
+				   hb_direction_t     direction,
+				   hb_font_extents_t *extents)
+{
+  font->get_extents_for_direction (direction, extents);
+}
+/**
+ * hb_font_get_glyph_advance_for_direction:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @direction: The direction of the text segment
+ * @x: (out): The horizontal advance retrieved
+ * @y: (out):  The vertical advance retrieved
+ *
+ * Fetches the advance for a glyph ID from the specified font,
+ * in a text segment of the specified direction.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_get_glyph_advance_for_direction (hb_font_t      *font,
+					 hb_codepoint_t  glyph,
+					 hb_direction_t  direction,
+					 hb_position_t  *x,
+					 hb_position_t  *y)
+{
+  font->get_glyph_advance_for_direction (glyph, direction, x, y);
+}
+/**
+ * hb_font_get_glyph_advances_for_direction:
+ * @font: #hb_font_t to work upon
+ * @direction: The direction of the text segment
+ * @count: The number of glyph IDs in the sequence queried
+ * @first_glyph: The first glyph ID to query
+ * @glyph_stride: The stride between successive glyph IDs
+ * @first_advance: (out): The first advance retrieved
+ * @advance_stride: (out): The stride between successive advances
+ *
+ * Fetches the advances for a sequence of glyph IDs in the specified
+ * font, in a text segment of the specified direction.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 1.8.6
+ **/
+HB_EXTERN void
+hb_font_get_glyph_advances_for_direction (hb_font_t*            font,
+					  hb_direction_t        direction,
+					  unsigned int          count,
+					  const hb_codepoint_t *first_glyph,
+					  unsigned              glyph_stride,
+					  hb_position_t        *first_advance,
+					  unsigned              advance_stride)
+{
+  font->get_glyph_advances_for_direction (direction, count, first_glyph, glyph_stride, first_advance, advance_stride);
+}
+
+/**
+ * hb_font_get_glyph_origin_for_direction:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @direction: The direction of the text segment
+ * @x: (out): The X coordinate retrieved for the origin
+ * @y: (out): The Y coordinate retrieved for the origin
+ *
+ * Fetches the (X,Y) coordinates of the origin for a glyph in
+ * the specified font.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_get_glyph_origin_for_direction (hb_font_t      *font,
+					hb_codepoint_t  glyph,
+					hb_direction_t  direction,
+					hb_position_t  *x,
+					hb_position_t  *y)
+{
+  return font->get_glyph_origin_for_direction (glyph, direction, x, y);
+}
+
+/**
+ * hb_font_add_glyph_origin_for_direction:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @direction: The direction of the text segment
+ * @x: (inout): Input = The original X coordinate
+ *     Output = The X coordinate plus the X-coordinate of the origin
+ * @y: (inout): Input = The original Y coordinate
+ *     Output = The Y coordinate plus the Y-coordinate of the origin
+ *
+ * Adds the origin coordinates to an (X,Y) point coordinate, in
+ * the specified glyph ID in the specified font.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_add_glyph_origin_for_direction (hb_font_t      *font,
+					hb_codepoint_t  glyph,
+					hb_direction_t  direction,
+					hb_position_t  *x,
+					hb_position_t  *y)
+{
+  return font->add_glyph_origin_for_direction (glyph, direction, x, y);
+}
+
+/**
+ * hb_font_subtract_glyph_origin_for_direction:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @direction: The direction of the text segment
+ * @x: (inout): Input = The original X coordinate
+ *     Output = The X coordinate minus the X-coordinate of the origin
+ * @y: (inout): Input = The original Y coordinate
+ *     Output = The Y coordinate minus the Y-coordinate of the origin
+ *
+ * Subtracts the origin coordinates from an (X,Y) point coordinate,
+ * in the specified glyph ID in the specified font.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_subtract_glyph_origin_for_direction (hb_font_t      *font,
+					     hb_codepoint_t  glyph,
+					     hb_direction_t  direction,
+					     hb_position_t  *x,
+					     hb_position_t  *y)
+{
+  return font->subtract_glyph_origin_for_direction (glyph, direction, x, y);
+}
+
+/**
+ * hb_font_get_glyph_kerning_for_direction:
+ * @font: #hb_font_t to work upon
+ * @first_glyph: The glyph ID of the first glyph in the glyph pair to query
+ * @second_glyph: The glyph ID of the second glyph in the glyph pair to query
+ * @direction: The direction of the text segment
+ * @x: (out): The horizontal kerning-adjustment value retrieved
+ * @y: (out): The vertical kerning-adjustment value retrieved
+ *
+ * Fetches the kerning-adjustment value for a glyph-pair in the specified font.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_get_glyph_kerning_for_direction (hb_font_t      *font,
+					 hb_codepoint_t  first_glyph,
+					 hb_codepoint_t  second_glyph,
+					 hb_direction_t  direction,
+					 hb_position_t  *x,
+					 hb_position_t  *y)
+{
+  return font->get_glyph_kerning_for_direction (first_glyph, second_glyph, direction, x, y);
+}
+
+/**
+ * hb_font_get_glyph_extents_for_origin:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @direction: The direction of the text segment
+ * @extents: (out): The #hb_glyph_extents_t retrieved
+ *
+ * Fetches the #hb_glyph_extents_t data for a glyph ID
+ * in the specified font, with respect to the origin in
+ * a text segment in the specified direction.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_extents_for_origin (hb_font_t          *font,
+				      hb_codepoint_t      glyph,
+				      hb_direction_t      direction,
+				      hb_glyph_extents_t *extents)
+{
+  return font->get_glyph_extents_for_origin (glyph, direction, extents);
+}
+
+/**
+ * hb_font_get_glyph_contour_point_for_origin:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @point_index: The contour-point index to query
+ * @direction: The direction of the text segment
+ * @x: (out): The X value retrieved for the contour point
+ * @y: (out): The Y value retrieved for the contour point
+ *
+ * Fetches the (X,Y) coordinates of a specified contour-point index
+ * in the specified glyph ID in the specified font, with respect
+ * to the origin in a text segment in the specified direction.
+ *
+ * Calls the appropriate direction-specific variant (horizontal
+ * or vertical) depending on the value of @direction.
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_get_glyph_contour_point_for_origin (hb_font_t      *font,
+					    hb_codepoint_t  glyph,
+					    unsigned int    point_index,
+					    hb_direction_t  direction,
+					    hb_position_t  *x,
+					    hb_position_t  *y)
+{
+  return font->get_glyph_contour_point_for_origin (glyph, point_index, direction, x, y);
+}
+
+/**
+ * hb_font_glyph_to_string:
+ * @font: #hb_font_t to work upon
+ * @glyph: The glyph ID to query
+ * @s: (out) (array length=size): The string containing the glyph name
+ * @size: Length of string @s
+ *
+ * Fetches the name of the specified glyph ID in @font and returns
+ * it in string @s.
+ *
+ * If the glyph ID has no name in @font, a string of the form `gidDDD` is
+ * generated, with `DDD` being the glyph ID.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_glyph_to_string (hb_font_t      *font,
+			 hb_codepoint_t  glyph,
+			 char           *s,
+			 unsigned int    size)
+{
+  font->glyph_to_string (glyph, s, size);
+}
+
+/**
+ * hb_font_glyph_from_string:
+ * @font: #hb_font_t to work upon
+ * @s: (array length=len) (element-type uint8_t): string to query
+ * @len: The length of the string @s
+ * @glyph: (out): The glyph ID corresponding to the string requested
+ *
+ * Fetches the glyph ID from @font that matches the specified string.
+ * Strings of the format `gidDDD` or `uniUUUU` are parsed automatically.
+ *
+ * <note>Note: @len == -1 means the string is null-terminated.</note>
+ *
+ * Return value: `true` if data found, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_glyph_from_string (hb_font_t      *font,
+			   const char     *s,
+			   int             len,
+			   hb_codepoint_t *glyph)
+{
+  return font->glyph_from_string (s, len, glyph);
+}
+
+
+/*
+ * hb_font_t
+ */
+
+DEFINE_NULL_INSTANCE (hb_font_t) =
+{
+  HB_OBJECT_HEADER_STATIC,
+
+  0, /* serial */
+  0, /* serial_coords */
+
+  nullptr, /* parent */
+  const_cast<hb_face_t *> (&_hb_Null_hb_face_t),
+
+  1000, /* x_scale */
+  1000, /* y_scale */
+  0., /* slant */
+  0., /* slant_xy; */
+  1.f, /* x_multf */
+  1.f, /* y_multf */
+  1<<16, /* x_mult */
+  1<<16, /* y_mult */
+
+  0, /* x_ppem */
+  0, /* y_ppem */
+  0, /* ptem */
+
+  0, /* num_coords */
+  nullptr, /* coords */
+  nullptr, /* design_coords */
+
+  const_cast<hb_font_funcs_t *> (&_hb_Null_hb_font_funcs_t),
+
+  /* Zero for the rest is fine. */
+};
+
+
+static hb_font_t *
+_hb_font_create (hb_face_t *face)
+{
+  hb_font_t *font;
+
+  if (unlikely (!face))
+    face = hb_face_get_empty ();
+
+  if (!(font = hb_object_create<hb_font_t> ()))
+    return hb_font_get_empty ();
+
+  hb_face_make_immutable (face);
+  font->parent = hb_font_get_empty ();
+  font->face = hb_face_reference (face);
+  font->klass = hb_font_funcs_get_empty ();
+  font->data.init0 (font);
+  font->x_scale = font->y_scale = face->get_upem ();
+  font->x_multf = font->y_multf = 1.f;
+  font->x_mult = font->y_mult = 1 << 16;
+
+  return font;
+}
+
+/**
+ * hb_font_create:
+ * @face: a face.
+ *
+ * Constructs a new font object from the specified face.
+ *
+ * <note>Note: If @face's index value (as passed to hb_face_create()
+ * has non-zero top 16-bits, those bits minus one are passed to
+ * hb_font_set_var_named_instance(), effectively loading a named-instance
+ * of a variable font, instead of the default-instance.  This allows
+ * specifying which named-instance to load by default when creating the
+ * face.</note>
+ *
+ * Return value: (transfer full): The new font object
+ *
+ * Since: 0.9.2
+ **/
+hb_font_t *
+hb_font_create (hb_face_t *face)
+{
+  hb_font_t *font = _hb_font_create (face);
+
+#ifndef HB_NO_OT_FONT
+  /* Install our in-house, very lightweight, funcs. */
+  hb_ot_font_set_funcs (font);
+#endif
+
+#ifndef HB_NO_VAR
+  if (face && face->index >> 16)
+    hb_font_set_var_named_instance (font, (face->index >> 16) - 1);
+#endif
+
+  return font;
+}
+
+static void
+_hb_font_adopt_var_coords (hb_font_t *font,
+			   int *coords, /* 2.14 normalized */
+			   float *design_coords,
+			   unsigned int coords_length)
+{
+  hb_free (font->coords);
+  hb_free (font->design_coords);
+
+  font->coords = coords;
+  font->design_coords = design_coords;
+  font->num_coords = coords_length;
+
+  font->mults_changed (); // Easiest to call this to drop cached data
+}
+
+/**
+ * hb_font_create_sub_font:
+ * @parent: The parent font object
+ *
+ * Constructs a sub-font font object from the specified @parent font,
+ * replicating the parent's properties.
+ *
+ * Return value: (transfer full): The new sub-font font object
+ *
+ * Since: 0.9.2
+ **/
+hb_font_t *
+hb_font_create_sub_font (hb_font_t *parent)
+{
+  if (unlikely (!parent))
+    parent = hb_font_get_empty ();
+
+  hb_font_t *font = _hb_font_create (parent->face);
+
+  if (unlikely (hb_object_is_immutable (font)))
+    return font;
+
+  font->parent = hb_font_reference (parent);
+
+  font->x_scale = parent->x_scale;
+  font->y_scale = parent->y_scale;
+  font->slant = parent->slant;
+  font->x_ppem = parent->x_ppem;
+  font->y_ppem = parent->y_ppem;
+  font->ptem = parent->ptem;
+
+  unsigned int num_coords = parent->num_coords;
+  if (num_coords)
+  {
+    int *coords = (int *) hb_calloc (num_coords, sizeof (parent->coords[0]));
+    float *design_coords = (float *) hb_calloc (num_coords, sizeof (parent->design_coords[0]));
+    if (likely (coords && design_coords))
+    {
+      hb_memcpy (coords, parent->coords, num_coords * sizeof (parent->coords[0]));
+      hb_memcpy (design_coords, parent->design_coords, num_coords * sizeof (parent->design_coords[0]));
+      _hb_font_adopt_var_coords (font, coords, design_coords, num_coords);
+    }
+    else
+    {
+      hb_free (coords);
+      hb_free (design_coords);
+    }
+  }
+
+  font->mults_changed ();
+
+  return font;
+}
+
+/**
+ * hb_font_get_empty:
+ *
+ * Fetches the empty font object.
+ *
+ * Return value: (transfer full): The empty font object
+ *
+ * Since: 0.9.2
+ **/
+hb_font_t *
+hb_font_get_empty ()
+{
+  return const_cast<hb_font_t *> (&Null (hb_font_t));
+}
+
+/**
+ * hb_font_reference: (skip)
+ * @font: #hb_font_t to work upon
+ *
+ * Increases the reference count on the given font object.
+ *
+ * Return value: (transfer full): The @font object
+ *
+ * Since: 0.9.2
+ **/
+hb_font_t *
+hb_font_reference (hb_font_t *font)
+{
+  return hb_object_reference (font);
+}
+
+/**
+ * hb_font_destroy: (skip)
+ * @font: #hb_font_t to work upon
+ *
+ * Decreases the reference count on the given font object. When the
+ * reference count reaches zero, the font is destroyed,
+ * freeing all memory.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_destroy (hb_font_t *font)
+{
+  if (!hb_object_destroy (font)) return;
+
+  font->data.fini ();
+
+  if (font->destroy)
+    font->destroy (font->user_data);
+
+  hb_font_destroy (font->parent);
+  hb_face_destroy (font->face);
+  hb_font_funcs_destroy (font->klass);
+
+  hb_free (font->coords);
+  hb_free (font->design_coords);
+
+  hb_free (font);
+}
+
+/**
+ * hb_font_set_user_data: (skip)
+ * @font: #hb_font_t to work upon
+ * @key: The user-data key
+ * @data: A pointer to the user data
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
+ * @replace: Whether to replace an existing data with the same key
+ *
+ * Attaches a user-data key/data pair to the specified font object.
+ *
+ * Return value: `true` if success, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_set_user_data (hb_font_t          *font,
+		       hb_user_data_key_t *key,
+		       void *              data,
+		       hb_destroy_func_t   destroy /* May be NULL. */,
+		       hb_bool_t           replace)
+{
+  if (!hb_object_is_immutable (font))
+    font->serial++;
+
+  return hb_object_set_user_data (font, key, data, destroy, replace);
+}
+
+/**
+ * hb_font_get_user_data: (skip)
+ * @font: #hb_font_t to work upon
+ * @key: The user-data key to query
+ *
+ * Fetches the user-data object associated with the specified key,
+ * attached to the specified font object.
+ *
+ * Return value: (transfer none): Pointer to the user data
+ *
+ * Since: 0.9.2
+ **/
+void *
+hb_font_get_user_data (const hb_font_t    *font,
+		       hb_user_data_key_t *key)
+{
+  return hb_object_get_user_data (font, key);
+}
+
+/**
+ * hb_font_make_immutable:
+ * @font: #hb_font_t to work upon
+ *
+ * Makes @font immutable.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_make_immutable (hb_font_t *font)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (font->parent)
+    hb_font_make_immutable (font->parent);
+
+  hb_object_make_immutable (font);
+}
+
+/**
+ * hb_font_is_immutable:
+ * @font: #hb_font_t to work upon
+ *
+ * Tests whether a font object is immutable.
+ *
+ * Return value: `true` if @font is immutable, `false` otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_font_is_immutable (hb_font_t *font)
+{
+  return hb_object_is_immutable (font);
+}
+
+/**
+ * hb_font_get_serial:
+ * @font: #hb_font_t to work upon
+ *
+ * Returns the internal serial number of the font. The serial
+ * number is increased every time a setting on the font is
+ * changed, using a setter function.
+ *
+ * Return value: serial number
+ *
+ * Since: 4.4.0
+ **/
+unsigned int
+hb_font_get_serial (hb_font_t *font)
+{
+  return font->serial;
+}
+
+/**
+ * hb_font_changed:
+ * @font: #hb_font_t to work upon
+ *
+ * Notifies the @font that underlying font data has changed.
+ * This has the effect of increasing the serial as returned
+ * by hb_font_get_serial(), which invalidates internal caches.
+ *
+ * Since: 4.4.0
+ **/
+void
+hb_font_changed (hb_font_t *font)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  font->serial++;
+
+  font->mults_changed ();
+}
+
+/**
+ * hb_font_set_parent:
+ * @font: #hb_font_t to work upon
+ * @parent: The parent font object to assign
+ *
+ * Sets the parent font of @font.
+ *
+ * Since: 1.0.5
+ **/
+void
+hb_font_set_parent (hb_font_t *font,
+		    hb_font_t *parent)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (parent == font->parent)
+    return;
+
+  font->serial++;
+
+  if (!parent)
+    parent = hb_font_get_empty ();
+
+  hb_font_t *old = font->parent;
+
+  font->parent = hb_font_reference (parent);
+
+  hb_font_destroy (old);
+}
+
+/**
+ * hb_font_get_parent:
+ * @font: #hb_font_t to work upon
+ *
+ * Fetches the parent font of @font.
+ *
+ * Return value: (transfer none): The parent font object
+ *
+ * Since: 0.9.2
+ **/
+hb_font_t *
+hb_font_get_parent (hb_font_t *font)
+{
+  return font->parent;
+}
+
+/**
+ * hb_font_set_face:
+ * @font: #hb_font_t to work upon
+ * @face: The #hb_face_t to assign
+ *
+ * Sets @face as the font-face value of @font.
+ *
+ * Since: 1.4.3
+ **/
+void
+hb_font_set_face (hb_font_t *font,
+		  hb_face_t *face)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (face == font->face)
+    return;
+
+  font->serial++;
+
+  if (unlikely (!face))
+    face = hb_face_get_empty ();
+
+  hb_face_t *old = font->face;
+
+  hb_face_make_immutable (face);
+  font->face = hb_face_reference (face);
+  font->mults_changed ();
+
+  hb_face_destroy (old);
+}
+
+/**
+ * hb_font_get_face:
+ * @font: #hb_font_t to work upon
+ *
+ * Fetches the face associated with the specified font object.
+ *
+ * Return value: (transfer none): The #hb_face_t value
+ *
+ * Since: 0.9.2
+ **/
+hb_face_t *
+hb_font_get_face (hb_font_t *font)
+{
+  return font->face;
+}
+
+
+/**
+ * hb_font_set_funcs:
+ * @font: #hb_font_t to work upon
+ * @klass: (closure font_data) (destroy destroy) (scope notified): The font-functions structure.
+ * @font_data: Data to attach to @font
+ * @destroy: (nullable): The function to call when @font_data is not needed anymore
+ *
+ * Replaces the font-functions structure attached to a font, updating
+ * the font's user-data with @font-data and the @destroy callback.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_set_funcs (hb_font_t         *font,
+		   hb_font_funcs_t   *klass,
+		   void              *font_data,
+		   hb_destroy_func_t  destroy /* May be NULL. */)
+{
+  if (hb_object_is_immutable (font))
+  {
+    if (destroy)
+      destroy (font_data);
+    return;
+  }
+
+  font->serial++;
+
+  if (font->destroy)
+    font->destroy (font->user_data);
+
+  if (!klass)
+    klass = hb_font_funcs_get_empty ();
+
+  hb_font_funcs_reference (klass);
+  hb_font_funcs_destroy (font->klass);
+  font->klass = klass;
+  font->user_data = font_data;
+  font->destroy = destroy;
+}
+
+/**
+ * hb_font_set_funcs_data:
+ * @font: #hb_font_t to work upon
+ * @font_data: (destroy destroy) (scope notified): Data to attach to @font
+ * @destroy: (nullable): The function to call when @font_data is not needed anymore
+ *
+ * Replaces the user data attached to a font, updating the font's
+ * @destroy callback.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_set_funcs_data (hb_font_t         *font,
+		        void              *font_data,
+		        hb_destroy_func_t  destroy /* May be NULL. */)
+{
+  /* Destroy user_data? */
+  if (hb_object_is_immutable (font))
+  {
+    if (destroy)
+      destroy (font_data);
+    return;
+  }
+
+  font->serial++;
+
+  if (font->destroy)
+    font->destroy (font->user_data);
+
+  font->user_data = font_data;
+  font->destroy = destroy;
+}
+
+
+/**
+ * hb_font_set_scale:
+ * @font: #hb_font_t to work upon
+ * @x_scale: Horizontal scale value to assign
+ * @y_scale: Vertical scale value to assign
+ *
+ * Sets the horizontal and vertical scale of a font.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_set_scale (hb_font_t *font,
+		   int        x_scale,
+		   int        y_scale)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (font->x_scale == x_scale && font->y_scale == y_scale)
+    return;
+
+  font->serial++;
+
+  font->x_scale = x_scale;
+  font->y_scale = y_scale;
+  font->mults_changed ();
+}
+
+/**
+ * hb_font_get_scale:
+ * @font: #hb_font_t to work upon
+ * @x_scale: (out): Horizontal scale value
+ * @y_scale: (out): Vertical scale value
+ *
+ * Fetches the horizontal and vertical scale of a font.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_get_scale (hb_font_t *font,
+		   int       *x_scale,
+		   int       *y_scale)
+{
+  if (x_scale) *x_scale = font->x_scale;
+  if (y_scale) *y_scale = font->y_scale;
+}
+
+/**
+ * hb_font_set_ppem:
+ * @font: #hb_font_t to work upon
+ * @x_ppem: Horizontal ppem value to assign
+ * @y_ppem: Vertical ppem value to assign
+ *
+ * Sets the horizontal and vertical pixels-per-em (ppem) of a font.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_set_ppem (hb_font_t    *font,
+		  unsigned int  x_ppem,
+		  unsigned int  y_ppem)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (font->x_ppem == x_ppem && font->y_ppem == y_ppem)
+    return;
+
+  font->serial++;
+
+  font->x_ppem = x_ppem;
+  font->y_ppem = y_ppem;
+}
+
+/**
+ * hb_font_get_ppem:
+ * @font: #hb_font_t to work upon
+ * @x_ppem: (out): Horizontal ppem value
+ * @y_ppem: (out): Vertical ppem value
+ *
+ * Fetches the horizontal and vertical points-per-em (ppem) of a font.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_font_get_ppem (hb_font_t    *font,
+		  unsigned int *x_ppem,
+		  unsigned int *y_ppem)
+{
+  if (x_ppem) *x_ppem = font->x_ppem;
+  if (y_ppem) *y_ppem = font->y_ppem;
+}
+
+/**
+ * hb_font_set_ptem:
+ * @font: #hb_font_t to work upon
+ * @ptem: font size in points.
+ *
+ * Sets the "point size" of a font. Set to zero to unset.
+ * Used in CoreText to implement optical sizing.
+ *
+ * <note>Note: There are 72 points in an inch.</note>
+ *
+ * Since: 1.6.0
+ **/
+void
+hb_font_set_ptem (hb_font_t *font,
+		  float      ptem)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (font->ptem == ptem)
+    return;
+
+  font->serial++;
+
+  font->ptem = ptem;
+}
+
+/**
+ * hb_font_get_ptem:
+ * @font: #hb_font_t to work upon
+ *
+ * Fetches the "point size" of a font. Used in CoreText to
+ * implement optical sizing.
+ *
+ * Return value: Point size.  A value of zero means "not set."
+ *
+ * Since: 1.6.0
+ **/
+float
+hb_font_get_ptem (hb_font_t *font)
+{
+  return font->ptem;
+}
+
+/**
+ * hb_font_set_synthetic_slant:
+ * @font: #hb_font_t to work upon
+ * @slant: synthetic slant value.
+ *
+ * Sets the "synthetic slant" of a font.  By default is zero.
+ * Synthetic slant is the graphical skew applied to the font
+ * at rendering time.
+ *
+ * HarfBuzz needs to know this value to adjust shaping results,
+ * metrics, and style values to match the slanted rendering.
+ *
+ * <note>Note: The glyph shape fetched via the
+ * hb_font_get_glyph_shape() is slanted to reflect this value
+ * as well.</note>
+ *
+ * <note>Note: The slant value is a ratio.  For example, a
+ * 20% slant would be represented as a 0.2 value.</note>
+ *
+ * Since: 3.3.0
+ **/
+HB_EXTERN void
+hb_font_set_synthetic_slant (hb_font_t *font, float slant)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  if (font->slant == slant)
+    return;
+
+  font->serial++;
+
+  font->slant = slant;
+  font->mults_changed ();
+}
+
+/**
+ * hb_font_get_synthetic_slant:
+ * @font: #hb_font_t to work upon
+ *
+ * Fetches the "synthetic slant" of a font.
+ *
+ * Return value: Synthetic slant.  By default is zero.
+ *
+ * Since: 3.3.0
+ **/
+HB_EXTERN float
+hb_font_get_synthetic_slant (hb_font_t *font)
+{
+  return font->slant;
+}
+
+#ifndef HB_NO_VAR
+/*
+ * Variations
+ */
+
+/**
+ * hb_font_set_variations:
+ * @font: #hb_font_t to work upon
+ * @variations: (array length=variations_length): Array of variation settings to apply
+ * @variations_length: Number of variations to apply
+ *
+ * Applies a list of font-variation settings to a font.
+ *
+ * Note that this overrides all existing variations set on @font.
+ * Axes not included in @variations will be effectively set to their
+ * default values.
+ *
+ * Since: 1.4.2
+ */
+void
+hb_font_set_variations (hb_font_t            *font,
+			const hb_variation_t *variations,
+			unsigned int          variations_length)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  font->serial_coords = ++font->serial;
+
+  if (!variations_length)
+  {
+    hb_font_set_var_coords_normalized (font, nullptr, 0);
+    return;
+  }
+
+  const OT::fvar &fvar = *font->face->table.fvar;
+  auto axes = fvar.get_axes ();
+  const unsigned coords_length = axes.length;
+
+  int *normalized = coords_length ? (int *) hb_calloc (coords_length, sizeof (int)) : nullptr;
+  float *design_coords = coords_length ? (float *) hb_calloc (coords_length, sizeof (float)) : nullptr;
+
+  if (unlikely (coords_length && !(normalized && design_coords)))
+  {
+    hb_free (normalized);
+    hb_free (design_coords);
+    return;
+  }
+
+  /* Initialize design coords to default from fvar. */
+  for (unsigned int i = 0; i < coords_length; i++)
+    design_coords[i] = axes[i].get_default ();
+
+  for (unsigned int i = 0; i < variations_length; i++)
+  {
+    const auto tag = variations[i].tag;
+    const auto v = variations[i].value;
+    for (unsigned axis_index = 0; axis_index < coords_length; axis_index++)
+      if (axes[axis_index].axisTag == tag)
+      {
+	design_coords[axis_index] = v;
+	normalized[axis_index] = fvar.normalize_axis_value (axis_index, v);
+      }
+  }
+  font->face->table.avar->map_coords (normalized, coords_length);
+
+  _hb_font_adopt_var_coords (font, normalized, design_coords, coords_length);
+}
+
+/**
+ * hb_font_set_var_coords_design:
+ * @font: #hb_font_t to work upon
+ * @coords: (array length=coords_length): Array of variation coordinates to apply
+ * @coords_length: Number of coordinates to apply
+ *
+ * Applies a list of variation coordinates (in design-space units)
+ * to a font.
+ *
+ * Note that this overrides all existing variations set on @font.
+ * Axes not included in @coords will be effectively set to their
+ * default values.
+ *
+ * Since: 1.4.2
+ */
+void
+hb_font_set_var_coords_design (hb_font_t    *font,
+			       const float  *coords,
+			       unsigned int  coords_length)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  font->serial_coords = ++font->serial;
+
+  int *normalized = coords_length ? (int *) hb_calloc (coords_length, sizeof (int)) : nullptr;
+  float *design_coords = coords_length ? (float *) hb_calloc (coords_length, sizeof (float)) : nullptr;
+
+  if (unlikely (coords_length && !(normalized && design_coords)))
+  {
+    hb_free (normalized);
+    hb_free (design_coords);
+    return;
+  }
+
+  if (coords_length)
+    hb_memcpy (design_coords, coords, coords_length * sizeof (font->design_coords[0]));
+
+  hb_ot_var_normalize_coords (font->face, coords_length, coords, normalized);
+  _hb_font_adopt_var_coords (font, normalized, design_coords, coords_length);
+}
+
+/**
+ * hb_font_set_var_named_instance:
+ * @font: a font.
+ * @instance_index: named instance index.
+ *
+ * Sets design coords of a font from a named instance index.
+ *
+ * Since: 2.6.0
+ */
+void
+hb_font_set_var_named_instance (hb_font_t *font,
+				unsigned instance_index)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  font->serial_coords = ++font->serial;
+
+  unsigned int coords_length = hb_ot_var_named_instance_get_design_coords (font->face, instance_index, nullptr, nullptr);
+
+  float *coords = coords_length ? (float *) hb_calloc (coords_length, sizeof (float)) : nullptr;
+  if (unlikely (coords_length && !coords))
+    return;
+
+  hb_ot_var_named_instance_get_design_coords (font->face, instance_index, &coords_length, coords);
+  hb_font_set_var_coords_design (font, coords, coords_length);
+  hb_free (coords);
+}
+
+/**
+ * hb_font_set_var_coords_normalized:
+ * @font: #hb_font_t to work upon
+ * @coords: (array length=coords_length): Array of variation coordinates to apply
+ * @coords_length: Number of coordinates to apply
+ *
+ * Applies a list of variation coordinates (in normalized units)
+ * to a font.
+ *
+ * Note that this overrides all existing variations set on @font.
+ * Axes not included in @coords will be effectively set to their
+ * default values.
+ *
+ * <note>Note: Coordinates should be normalized to 2.14.</note>
+ *
+ * Since: 1.4.2
+ */
+void
+hb_font_set_var_coords_normalized (hb_font_t    *font,
+				   const int    *coords, /* 2.14 normalized */
+				   unsigned int  coords_length)
+{
+  if (hb_object_is_immutable (font))
+    return;
+
+  font->serial_coords = ++font->serial;
+
+  int *copy = coords_length ? (int *) hb_calloc (coords_length, sizeof (coords[0])) : nullptr;
+  int *unmapped = coords_length ? (int *) hb_calloc (coords_length, sizeof (coords[0])) : nullptr;
+  float *design_coords = coords_length ? (float *) hb_calloc (coords_length, sizeof (design_coords[0])) : nullptr;
+
+  if (unlikely (coords_length && !(copy && unmapped && design_coords)))
+  {
+    hb_free (copy);
+    hb_free (unmapped);
+    hb_free (design_coords);
+    return;
+  }
+
+  if (coords_length)
+  {
+    hb_memcpy (copy, coords, coords_length * sizeof (coords[0]));
+    hb_memcpy (unmapped, coords, coords_length * sizeof (coords[0]));
+  }
+
+  /* Best effort design coords simulation */
+  font->face->table.avar->unmap_coords (unmapped, coords_length);
+  for (unsigned int i = 0; i < coords_length; ++i)
+    design_coords[i] = font->face->table.fvar->unnormalize_axis_value (i, unmapped[i]);
+  hb_free (unmapped);
+
+  _hb_font_adopt_var_coords (font, copy, design_coords, coords_length);
+}
+
+/**
+ * hb_font_get_var_coords_normalized:
+ * @font: #hb_font_t to work upon
+ * @length: (out): Number of coordinates retrieved
+ *
+ * Fetches the list of normalized variation coordinates currently
+ * set on a font.
+ *
+ * Note that this returned array may only contain values for some
+ * (or none) of the axes; omitted axes effectively have zero values.
+ *
+ * Return value is valid as long as variation coordinates of the font
+ * are not modified.
+ *
+ * Return value: coordinates array
+ *
+ * Since: 1.4.2
+ */
+const int *
+hb_font_get_var_coords_normalized (hb_font_t    *font,
+				   unsigned int *length)
+{
+  if (length)
+    *length = font->num_coords;
+
+  return font->coords;
+}
+
+/**
+ * hb_font_get_var_coords_design:
+ * @font: #hb_font_t to work upon
+ * @length: (out): Number of coordinates retrieved
+ *
+ * Fetches the list of variation coordinates (in design-space units) currently
+ * set on a font.
+ *
+ * Note that this returned array may only contain values for some
+ * (or none) of the axes; omitted axes effectively have their default
+ * values.
+ *
+ * Return value is valid as long as variation coordinates of the font
+ * are not modified.
+ *
+ * Return value: coordinates array
+ *
+ * Since: 3.3.0
+ */
+const float *
+hb_font_get_var_coords_design (hb_font_t *font,
+			       unsigned int *length)
+{
+  if (length)
+    *length = font->num_coords;
+
+  return font->design_coords;
+}
+#endif
+
+#ifndef HB_DISABLE_DEPRECATED
+/*
+ * Deprecated get_glyph_func():
+ */
+
+struct hb_trampoline_closure_t
+{
+  void *user_data;
+  hb_destroy_func_t destroy;
+  unsigned int ref_count;
+};
+
+template <typename FuncType>
+struct hb_trampoline_t
+{
+  hb_trampoline_closure_t closure; /* Must be first. */
+  FuncType func;
+};
+
+template <typename FuncType>
+static hb_trampoline_t<FuncType> *
+trampoline_create (FuncType           func,
+		   void              *user_data,
+		   hb_destroy_func_t  destroy)
+{
+  typedef hb_trampoline_t<FuncType> trampoline_t;
+
+  trampoline_t *trampoline = (trampoline_t *) hb_calloc (1, sizeof (trampoline_t));
+
+  if (unlikely (!trampoline))
+    return nullptr;
+
+  trampoline->closure.user_data = user_data;
+  trampoline->closure.destroy = destroy;
+  trampoline->closure.ref_count = 1;
+  trampoline->func = func;
+
+  return trampoline;
+}
+
+static void
+trampoline_reference (hb_trampoline_closure_t *closure)
+{
+  closure->ref_count++;
+}
+
+static void
+trampoline_destroy (void *user_data)
+{
+  hb_trampoline_closure_t *closure = (hb_trampoline_closure_t *) user_data;
+
+  if (--closure->ref_count)
+    return;
+
+  if (closure->destroy)
+    closure->destroy (closure->user_data);
+  hb_free (closure);
+}
+
+typedef hb_trampoline_t<hb_font_get_glyph_func_t> hb_font_get_glyph_trampoline_t;
+
+static hb_bool_t
+hb_font_get_nominal_glyph_trampoline (hb_font_t      *font,
+				      void           *font_data,
+				      hb_codepoint_t  unicode,
+				      hb_codepoint_t *glyph,
+				      void           *user_data)
+{
+  hb_font_get_glyph_trampoline_t *trampoline = (hb_font_get_glyph_trampoline_t *) user_data;
+  return trampoline->func (font, font_data, unicode, 0, glyph, trampoline->closure.user_data);
+}
+
+static hb_bool_t
+hb_font_get_variation_glyph_trampoline (hb_font_t      *font,
+					void           *font_data,
+					hb_codepoint_t  unicode,
+					hb_codepoint_t  variation_selector,
+					hb_codepoint_t *glyph,
+					void           *user_data)
+{
+  hb_font_get_glyph_trampoline_t *trampoline = (hb_font_get_glyph_trampoline_t *) user_data;
+  return trampoline->func (font, font_data, unicode, variation_selector, glyph, trampoline->closure.user_data);
+}
+
+/**
+ * hb_font_funcs_set_glyph_func:
+ * @ffuncs: The font-functions structure
+ * @func: (closure user_data) (destroy destroy) (scope notified): callback function
+ * @user_data: data to pass to @func
+ * @destroy: (nullable): function to call when @user_data is not needed anymore
+ *
+ * Deprecated.  Use hb_font_funcs_set_nominal_glyph_func() and
+ * hb_font_funcs_set_variation_glyph_func() instead.
+ *
+ * Since: 0.9.2
+ * Deprecated: 1.2.3
+ **/
+void
+hb_font_funcs_set_glyph_func (hb_font_funcs_t          *ffuncs,
+			      hb_font_get_glyph_func_t  func,
+			      void                     *user_data,
+			      hb_destroy_func_t         destroy /* May be NULL. */)
+{
+  if (hb_object_is_immutable (ffuncs))
+  {
+    if (destroy)
+      destroy (user_data);
+    return;
+  }
+
+  hb_font_get_glyph_trampoline_t *trampoline;
+
+  trampoline = trampoline_create (func, user_data, destroy);
+  if (unlikely (!trampoline))
+  {
+    if (destroy)
+      destroy (user_data);
+    return;
+  }
+
+  /* Since we pass it to two destroying functions. */
+  trampoline_reference (&trampoline->closure);
+
+  hb_font_funcs_set_nominal_glyph_func (ffuncs,
+					hb_font_get_nominal_glyph_trampoline,
+					trampoline,
+					trampoline_destroy);
+
+  hb_font_funcs_set_variation_glyph_func (ffuncs,
+					  hb_font_get_variation_glyph_trampoline,
+					  trampoline,
+					  trampoline_destroy);
+}
+#endif