diff --git a/CMakeLists.txt b/CMakeLists.txt
index c41579c1c..ac857ef8f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -43,6 +43,7 @@ if (APPLE)
 endif ()
 if (WIN32)
   option(HB_HAVE_UNISCRIBE "Enable Uniscribe shaper backend on Windows" OFF)
+  option(HB_HAVE_GDI "Enable GDI integration helpers on Windows" OFF)
   option(HB_HAVE_DIRECTWRITE "Enable DirectWrite shaper backend on Windows" OFF)
 endif ()
 option(HB_BUILD_UTILS "Build harfbuzz utils, needs cairo, freetype, and glib properly be installed" OFF)
@@ -77,6 +78,7 @@ if (HB_CHECK)
   set (HB_HAVE_GRAPHITE2 ON)
   if (WIN32)
     set (HB_HAVE_UNISCRIBE ON)
+    set (HB_HAVE_GDI ON)
     set (HB_HAVE_DIRECTWRITE ON)
   elseif (APPLE)
     set (HB_HAVE_CORETEXT ON)
@@ -305,6 +307,12 @@ if (APPLE AND HB_HAVE_CORETEXT)
   endif ()
 endif ()
 
+if (WIN32 AND HB_HAVE_GDI)
+  add_definitions(-DHAVE_GDI)
+  list(APPEND project_headers ${PROJECT_SOURCE_DIR}/src/hb-gdi.h)
+  list(APPEND THIRD_PARTY_LIBS gdi32)
+endif ()
+
 if (WIN32 AND HB_HAVE_UNISCRIBE)
   add_definitions(-DHAVE_UNISCRIBE)
   list(APPEND project_headers ${PROJECT_SOURCE_DIR}/src/hb-uniscribe.h)
diff --git a/appveyor.yml b/appveyor.yml
index 236bb1b12..6daf8d225 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -73,7 +73,7 @@ build_script:
   - 'if "%compiler%"=="msvc2" cmake --build build --config %configuration%'
 
   - 'if "%compiler%"=="msys2" C:\msys64\usr\bin\bash -lc "curl https://raw.githubusercontent.com/mirror/mingw-w64/023eb04c396d4e8d8fcf604cfababc53dae13398/mingw-w64-headers/include/dwrite_1.h > %MINGW_PREFIX%/%MINGW_CHOST%/include/dwrite_1.h"'
-  - 'if "%compiler%"=="msys2" C:\msys64\usr\bin\bash -lc "cd $APPVEYOR_BUILD_FOLDER; PATH=$PATH:/mingw64/bin:/mingw32/bin; ./autogen.sh --with-uniscribe --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2 --with-directwrite --build=%MINGW_CHOST% --host=%MINGW_CHOST% --prefix=%MINGW_PREFIX%; make -j3 check || .ci/fail.sh"'
+  - 'if "%compiler%"=="msys2" C:\msys64\usr\bin\bash -lc "cd $APPVEYOR_BUILD_FOLDER; PATH=$PATH:/mingw64/bin:/mingw32/bin; ./autogen.sh --with-uniscribe --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2 --with-directwrite --with-gdi --build=%MINGW_CHOST% --host=%MINGW_CHOST% --prefix=%MINGW_PREFIX%; make -j3 check || .ci/fail.sh"'
 
 cache:
   - c:\tools\vcpkg\installed\
diff --git a/configure.ac b/configure.ac
index 09ce4e6ec..cebb10adf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -361,6 +361,28 @@ AM_CONDITIONAL(HAVE_UNISCRIBE, $have_uniscribe)
 
 dnl ===========================================================================
 
+AC_ARG_WITH(gdi,
+	[AS_HELP_STRING([--with-gdi=@<:@yes/no/auto@:>@],
+			[Provide GDI integration helpers @<:@default=no@:>@])],,
+	[with_gdi=no])
+have_gdi=false
+if test "x$with_gdi" = "xyes" -o "x$with_gdi" = "xauto"; then
+	AC_CHECK_HEADERS(windows.h, have_gdi=true)
+fi
+if test "x$with_gdi" = "xyes" -a "x$have_gdi" != "xtrue"; then
+	AC_MSG_ERROR([gdi support requested but not found])
+fi
+if $have_gdi; then
+	GDI_CFLAGS=
+	GDI_LIBS="-lgdi32"
+	AC_SUBST(GDI_CFLAGS)
+	AC_SUBST(GDI_LIBS)
+	AC_DEFINE(HAVE_GDI, 1, [Have GDI library])
+fi
+AM_CONDITIONAL(HAVE_GDI, $have_gdi)
+
+dnl ===========================================================================
+
 AC_ARG_WITH(directwrite,
 	[AS_HELP_STRING([--with-directwrite=@<:@yes/no/auto@:>@],
 			[Use the DirectWrite library (experimental) @<:@default=no@:>@])],,
@@ -510,6 +532,7 @@ Additional shapers (the more the merrier):
 Platform shapers (not normally needed):
 	CoreText:		${have_coretext}
 	DirectWrite:		${have_directwrite}
+	GDI:			${have_gdi}
 	Uniscribe:		${have_uniscribe}
 
 Other features:
diff --git a/docs/harfbuzz-sections.txt b/docs/harfbuzz-sections.txt
index 4be248d30..43fd76115 100644
--- a/docs/harfbuzz-sections.txt
+++ b/docs/harfbuzz-sections.txt
@@ -1,6 +1,7 @@
 <SUBSECTION Private>
 HB_H_IN
 HB_OT_H_IN
+HB_AAT_H_IN
 </SECTION>
 
 <SECTION>
@@ -179,6 +180,7 @@ HB_BUFFER_SERIALIZE_FLAGS_DEFAULT
 HB_SCRIPT_CANADIAN_ABORIGINAL
 hb_font_funcs_set_glyph_func
 hb_font_get_glyph_func_t
+HB_MATH_GLYPH_PART_FLAG_EXTENDER
 hb_ot_layout_table_choose_script
 hb_ot_layout_table_find_script
 hb_ot_tag_from_language
@@ -367,6 +369,11 @@ hb_ft_font_get_load_flags
 hb_ft_font_set_funcs
 </SECTION>
 
+<SECTION>
+<FILE>hb-gdi</FILE>
+hb_gdi_face_create
+</SECTION>
+
 <SECTION>
 <FILE>hb-glib</FILE>
 hb_glib_get_unicode_funcs
@@ -600,6 +607,15 @@ hb_ot_math_get_min_connector_overlap
 hb_ot_math_get_glyph_assembly
 </SECTION>
 
+<SECTION>
+<FILE>hb-ot-metrics</FILE>
+hb_ot_metrics_t
+hb_ot_metrics_get_position
+hb_ot_metrics_get_variation
+hb_ot_metrics_get_x_variation
+hb_ot_metrics_get_y_variation
+</SECTION>
+
 <SECTION>
 <FILE>hb-ot-shape</FILE>
 hb_ot_shape_glyphs_closure
diff --git a/src/Makefile.am b/src/Makefile.am
index 1e79483c9..54e4a02cf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -82,6 +82,13 @@ HBSOURCES += $(HB_DIRECTWRITE_sources)
 HBHEADERS += $(HB_DIRECTWRITE_headers)
 endif
 
+if HAVE_GDI
+HBCFLAGS += $(GDI_CXXFLAGS)
+HBNONPCLIBS += $(GDI_LIBS)
+HBSOURCES += $(HB_GDI_sources)
+HBHEADERS += $(HB_GDI_headers)
+endif
+
 if HAVE_CORETEXT
 HBCFLAGS += $(CORETEXT_CFLAGS)
 HBNONPCLIBS += $(CORETEXT_LIBS)
@@ -313,6 +320,7 @@ harfbuzz.cc: Makefile.sources
 		$(HB_FT_sources) \
 		$(HB_GRAPHITE2_sources) \
 		$(HB_UNISCRIBE_sources) \
+		$(HB_GDI_sources) \
 		$(HB_DIRECTWRITE_sources) \
 		$(HB_CORETEXT_sources) \
 		; do echo '#include "'$$f'"'; done | \
diff --git a/src/Makefile.sources b/src/Makefile.sources
index b48b2f2d5..985301af2 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -89,6 +89,9 @@ HB_BASE_sources = \
 	hb-ot-math-table.hh \
 	hb-ot-math.cc \
 	hb-ot-maxp-table.hh \
+	hb-ot-meta-table.hh \
+	hb-ot-metrics.cc \
+	hb-ot-metrics.hh \
 	hb-ot-name-language-static.hh \
 	hb-ot-name-language.hh \
 	hb-ot-name-table.hh \
@@ -193,6 +196,7 @@ HB_BASE_headers = \
 	hb-ot-font.h \
 	hb-ot-layout.h \
 	hb-ot-math.h \
+	hb-ot-metrics.h \
 	hb-ot-name.h \
 	hb-ot-shape.h \
 	hb-ot-var.h \
@@ -224,6 +228,9 @@ HB_CORETEXT_headers = hb-coretext.h
 HB_DIRECTWRITE_sources = hb-directwrite.cc
 HB_DIRECTWRITE_headers = hb-directwrite.h
 
+HB_GDI_sources = hb-gdi.cc
+HB_GDI_headers = hb-gdi.h
+
 HB_UNISCRIBE_sources = hb-uniscribe.cc
 HB_UNISCRIBE_headers = hb-uniscribe.h
 
diff --git a/src/harfbuzz.cc b/src/harfbuzz.cc
index 5e6527f13..0701b7024 100644
--- a/src/harfbuzz.cc
+++ b/src/harfbuzz.cc
@@ -17,6 +17,7 @@
 #include "hb-ot-layout.cc"
 #include "hb-ot-map.cc"
 #include "hb-ot-math.cc"
+#include "hb-ot-metrics.cc"
 #include "hb-ot-name.cc"
 #include "hb-ot-shape-complex-arabic.cc"
 #include "hb-ot-shape-complex-default.cc"
@@ -47,5 +48,6 @@
 #include "hb-ft.cc"
 #include "hb-graphite2.cc"
 #include "hb-uniscribe.cc"
+#include "hb-gdi.cc"
 #include "hb-directwrite.cc"
 #include "hb-coretext.cc"
diff --git a/src/hb-config.hh b/src/hb-config.hh
index adf2b3348..bd440050e 100644
--- a/src/hb-config.hh
+++ b/src/hb-config.hh
@@ -66,6 +66,7 @@
 #define HB_NO_LAYOUT_COLLECT_GLYPHS
 #define HB_NO_LAYOUT_UNUSED
 #define HB_NO_MATH
+#define HB_NO_METRICS
 #define HB_NO_MMAP
 #define HB_NO_NAME
 #define HB_NO_OPEN
diff --git a/src/hb-directwrite.cc b/src/hb-directwrite.cc
index 810c5e553..c14e9d2be 100644
--- a/src/hb-directwrite.cc
+++ b/src/hb-directwrite.cc
@@ -539,11 +539,6 @@ protected:
   Run  mRunHead;
 };
 
-static inline uint16_t hb_dw_uint16_swap (const uint16_t v)
-{ return (v >> 8) | (v << 8); }
-static inline uint32_t hb_dw_uint32_swap (const uint32_t v)
-{ return (hb_dw_uint16_swap (v) << 16) | hb_dw_uint16_swap (v >> 16); }
-
 /*
  * shaper
  */
@@ -653,7 +648,7 @@ _hb_directwrite_shape_full (hb_shape_plan_t    *shape_plan,
     for (unsigned int i = 0; i < num_features; ++i)
     {
       typographic_features.features[i].nameTag = (DWRITE_FONT_FEATURE_TAG)
-						 hb_dw_uint32_swap (features[i].tag);
+						 hb_uint32_swap (features[i].tag);
       typographic_features.features[i].parameter = features[i].value;
     }
   }
@@ -941,7 +936,7 @@ _hb_directwrite_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *
   uint32_t length;
   void *table_context;
   BOOL exists;
-  if (!dw_face || FAILED (dw_face->TryGetFontTable (hb_dw_uint32_swap (tag), &data,
+  if (!dw_face || FAILED (dw_face->TryGetFontTable (hb_uint32_swap (tag), &data,
 						    &length, &table_context, &exists)))
     return nullptr;
 
diff --git a/src/hb-gdi.cc b/src/hb-gdi.cc
new file mode 100644
index 000000000..526f1cd9e
--- /dev/null
+++ b/src/hb-gdi.cc
@@ -0,0 +1,73 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#include "hb.hh"
+
+#ifdef HAVE_GDI
+
+#include "hb-gdi.h"
+
+static hb_blob_t *
+_hb_gdi_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
+{
+  char *buffer = nullptr;
+  DWORD length = 0;
+
+  HDC hdc = GetDC (nullptr);
+  if (unlikely (!SelectObject (hdc, (HFONT) user_data))) goto fail;
+
+  length = GetFontData (hdc, hb_uint32_swap (tag), 0, buffer, length);
+  if (unlikely (length == GDI_ERROR)) goto fail_with_releasedc;
+
+  buffer = (char *) malloc (length);
+  if (unlikely (!buffer)) goto fail_with_releasedc;
+  length = GetFontData (hdc, hb_uint32_swap (tag), 0, buffer, length);
+  if (unlikely (length == GDI_ERROR)) goto fail_with_releasedc_and_free;
+  ReleaseDC (nullptr, hdc);
+
+  return hb_blob_create ((const char *) buffer, length, HB_MEMORY_MODE_WRITABLE, buffer, free);
+
+fail_with_releasedc_and_free:
+  free (buffer);
+fail_with_releasedc:
+  ReleaseDC (nullptr, hdc);
+fail:
+  return hb_blob_get_empty ();
+}
+
+/**
+ * hb_gdi_face_create:
+ * @hdc: a HFONT object.
+ *
+ * Return value: #hb_face_t object corresponding to the given input
+ *
+ * Since: REPLACEME
+ **/
+hb_face_t *
+hb_gdi_face_create (HFONT hfont)
+{
+  return hb_face_create_for_tables (_hb_gdi_reference_table, (void *) hfont, nullptr);
+}
+
+#endif
diff --git a/src/hb-gdi.h b/src/hb-gdi.h
new file mode 100644
index 000000000..68cc43917
--- /dev/null
+++ b/src/hb-gdi.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#ifndef HB_GDI_H
+#define HB_GDI_H
+
+#include "hb.h"
+
+#include <windows.h>
+
+HB_BEGIN_DECLS
+
+HB_EXTERN hb_face_t *
+hb_gdi_face_create (HFONT hfont);
+
+HB_END_DECLS
+
+#endif /* HB_GDI_H */
diff --git a/src/hb-ot-color-sbix-table.hh b/src/hb-ot-color-sbix-table.hh
index 9b725c46e..8a915a661 100644
--- a/src/hb-ot-color-sbix-table.hh
+++ b/src/hb-ot-color-sbix-table.hh
@@ -235,9 +235,9 @@ struct sbix
       const PNGHeader &png = *blob->as<PNGHeader>();
 
       extents->x_bearing = x_offset;
-      extents->y_bearing = y_offset;
+      extents->y_bearing = png.IHDR.height + y_offset;
       extents->width     = png.IHDR.width;
-      extents->height    = png.IHDR.height;
+      extents->height    = -png.IHDR.height;
 
       /* Convert to font units. */
       if (strike_ppem)
diff --git a/src/hb-ot-face-table-list.hh b/src/hb-ot-face-table-list.hh
index ac7052751..4ec622c57 100644
--- a/src/hb-ot-face-table-list.hh
+++ b/src/hb-ot-face-table-list.hh
@@ -50,9 +50,10 @@ HB_OT_TABLE (OT, head)
 #if !defined(HB_NO_FACE_COLLECT_UNICODES) || !defined(HB_NO_OT_FONT)
 HB_OT_ACCELERATOR (OT, cmap)
 #endif
+HB_OT_TABLE (OT, hhea)
 HB_OT_ACCELERATOR (OT, hmtx)
 HB_OT_TABLE (OT, OS2)
-#ifndef HB_NO_OT_FONT_GLYPH_NAMES
+#if !defined(HB_NO_OT_FONT_GLYPH_NAMES) || !defined(HB_NO_METRICS)
 HB_OT_ACCELERATOR (OT, post)
 #endif
 #ifndef HB_NO_NAME
@@ -61,8 +62,10 @@ HB_OT_ACCELERATOR (OT, name)
 #ifndef HB_NO_STAT
 HB_OT_TABLE (OT, STAT)
 #endif
+//HB_OT_TABLE (OT, meta)
 
 /* Vertical layout. */
+HB_OT_TABLE (OT, vhea)
 HB_OT_ACCELERATOR (OT, vmtx)
 
 /* TrueType outlines. */
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 4b447d000..2470f233b 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -231,32 +231,24 @@ hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
 
 static hb_bool_t
 hb_ot_get_font_h_extents (hb_font_t *font,
-			  void *font_data,
+			  void *font_data HB_UNUSED,
 			  hb_font_extents_t *metrics,
 			  void *user_data HB_UNUSED)
 {
-  const hb_ot_face_t *ot_face = (const hb_ot_face_t *) font_data;
-  const OT::hmtx_accelerator_t &hmtx = *ot_face->hmtx;
-  metrics->ascender = font->em_scale_y (hmtx.ascender);
-  metrics->descender = font->em_scale_y (hmtx.descender);
-  metrics->line_gap = font->em_scale_y (hmtx.line_gap);
-  // TODO Hook up variations.
-  return hmtx.has_font_extents;
+  return _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_HORIZONTAL_ASCENDER, &metrics->ascender) &&
+	 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_HORIZONTAL_DESCENDER, &metrics->descender) &&
+	 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_HORIZONTAL_LINE_GAP, &metrics->line_gap);
 }
 
 static hb_bool_t
 hb_ot_get_font_v_extents (hb_font_t *font,
-			  void *font_data,
+			  void *font_data HB_UNUSED,
 			  hb_font_extents_t *metrics,
 			  void *user_data HB_UNUSED)
 {
-  const hb_ot_face_t *ot_face = (const hb_ot_face_t *) font_data;
-  const OT::vmtx_accelerator_t &vmtx = *ot_face->vmtx;
-  metrics->ascender = font->em_scale_x (vmtx.ascender);
-  metrics->descender = font->em_scale_x (vmtx.descender);
-  metrics->line_gap = font->em_scale_x (vmtx.line_gap);
-  // TODO Hook up variations.
-  return vmtx.has_font_extents;
+  return _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_VERTICAL_ASCENDER, &metrics->ascender) &&
+	 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_VERTICAL_DESCENDER, &metrics->descender) &&
+	 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_VERTICAL_LINE_GAP, &metrics->line_gap);
 }
 
 #if HB_USE_ATEXIT
diff --git a/src/hb-ot-hhea-table.hh b/src/hb-ot-hhea-table.hh
index c3155b79e..778b6c513 100644
--- a/src/hb-ot-hhea-table.hh
+++ b/src/hb-ot-hhea-table.hh
@@ -45,6 +45,8 @@ namespace OT {
 template <typename T>
 struct _hea
 {
+  bool has_data () const { return version.major; }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
diff --git a/src/hb-ot-hmtx-table.hh b/src/hb-ot-hmtx-table.hh
index bae18b807..240aac636 100644
--- a/src/hb-ot-hmtx-table.hh
+++ b/src/hb-ot-hmtx-table.hh
@@ -29,8 +29,8 @@
 
 #include "hb-open-type.hh"
 #include "hb-ot-hhea-table.hh"
-#include "hb-ot-os2-table.hh"
 #include "hb-ot-var-hvar-table.hh"
+#include "hb-ot-metrics.hh"
 
 /*
  * hmtx -- Horizontal Metrics
@@ -169,28 +169,7 @@ struct hmtxvmtx
       memset (this, 0, sizeof (*this));
       default_advance = default_advance_ ? default_advance_ : hb_face_get_upem (face);
 
-      bool got_font_extents = false;
-      if (T::os2Tag != HB_TAG_NONE && face->table.OS2->is_typo_metrics ())
-      {
-	ascender = abs (face->table.OS2->sTypoAscender);
-	descender = -abs (face->table.OS2->sTypoDescender);
-	line_gap = face->table.OS2->sTypoLineGap;
-	got_font_extents = (ascender | descender) != 0;
-      }
-
-      hb_blob_t *_hea_blob = hb_sanitize_context_t().reference_table<H> (face);
-      const H *_hea_table = _hea_blob->as<H> ();
-      num_advances = _hea_table->numberOfLongMetrics;
-      if (!got_font_extents)
-      {
-	ascender = abs (_hea_table->ascender);
-	descender = -abs (_hea_table->descender);
-	line_gap = _hea_table->lineGap;
-	got_font_extents = (ascender | descender) != 0;
-      }
-      hb_blob_destroy (_hea_blob);
-
-      has_font_extents = got_font_extents;
+      num_advances = T::is_horizontal ? face->table.hhea->numberOfLongMetrics : face->table.vhea->numberOfLongMetrics;
 
       table = hb_sanitize_context_t().reference_table<hmtxvmtx> (face, T::tableTag);
 
@@ -307,12 +286,6 @@ struct hmtxvmtx
       return get_advance (old_gid);
     }
 
-    public:
-    bool has_font_extents;
-    int ascender;
-    int descender;
-    int line_gap;
-
     protected:
     unsigned int num_metrics;
     unsigned int num_advances;
@@ -352,12 +325,12 @@ struct hmtxvmtx
 struct hmtx : hmtxvmtx<hmtx, hhea> {
   static constexpr hb_tag_t tableTag = HB_OT_TAG_hmtx;
   static constexpr hb_tag_t variationsTag = HB_OT_TAG_HVAR;
-  static constexpr hb_tag_t os2Tag = HB_OT_TAG_OS2;
+  static constexpr bool is_horizontal = true;
 };
 struct vmtx : hmtxvmtx<vmtx, vhea> {
   static constexpr hb_tag_t tableTag = HB_OT_TAG_vmtx;
   static constexpr hb_tag_t variationsTag = HB_OT_TAG_VVAR;
-  static constexpr hb_tag_t os2Tag = HB_TAG_NONE;
+  static constexpr bool is_horizontal = false;
 };
 
 struct hmtx_accelerator_t : hmtx::accelerator_t {};
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index 98cd10923..f493005bc 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -43,12 +43,12 @@
 #include "hb-map.hh"
 
 #include "hb-ot-kern-table.hh"
-#include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-layout-gdef-table.hh"
 #include "hb-ot-layout-gsub-table.hh"
 #include "hb-ot-layout-gpos-table.hh"
 #include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
+#include "hb-ot-meta-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-name-table.hh"
 #include "hb-ot-os2-table.hh"
 
@@ -109,7 +109,7 @@ hb_ot_layout_has_machine_kerning (hb_face_t *face)
  *
  * Tests whether a face has any cross-stream kerning (i.e., kerns
  * that make adjustments perpendicular to the direction of the text
- * flow: Y adjustments in horizontal text or X adjustments in 
+ * flow: Y adjustments in horizontal text or X adjustments in
  * vertical text) in the 'kern' table.
  *
  * Does NOT examine the GPOS table.
@@ -286,7 +286,7 @@ hb_ot_layout_has_glyph_classes (hb_face_t *face)
  *
  * Fetches the GDEF class of the requested glyph in the specified face.
  *
- * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code 
+ * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code
  * point in the GDEF table of the face.
  *
  * Since: 0.9.7
@@ -330,7 +330,7 @@ hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
  * @point_array: (out) (array length=point_count): The array of attachment points found for the query
  *
  * Fetches a list of all attachment points for the specified glyph in the GDEF
- * table of the face. The list returned will begin at the offset provided. 
+ * table of the face. The list returned will begin at the offset provided.
  *
  * Useful if the client program wishes to cache the list.
  *
@@ -980,7 +980,7 @@ hb_ot_layout_feature_get_lookups (hb_face_t    *face,
  * @face: #hb_face_t to work upon
  * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
  *
- * Fetches the total number of lookups enumerated in the specified 
+ * Fetches the total number of lookups enumerated in the specified
  * face's GSUB table or GPOS table.
  *
  * Since: 0.9.22
@@ -1188,7 +1188,7 @@ hb_ot_layout_collect_features (hb_face_t      *face,
  * table or GPOS table, underneath the specified scripts, languages, and
  * features. If no list of scripts is provided, all scripts will be queried.
  * If no list of languages is provided, all languages will be queried. If no
- * list of features is provided, all features will be queried. 
+ * list of features is provided, all features will be queried.
  *
  * Since: 0.9.8
  **/
@@ -1582,7 +1582,7 @@ hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
  * as used here are defined as pertaining only to fonts within a font family that differ
  * specifically in their respective size ranges; other ways to differentiate fonts within
  * a subfamily are not covered by the `size` feature.
- * 
+ *
  * For more information on this distinction, see the `size` documentation at
  * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-39size39
  *
@@ -1724,7 +1724,7 @@ hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
  *       returned. This function can be called with incrementally larger start_offset
  *       until the char_count output value is lower than its input value, or the size
  *       of the characters array can be increased.</note>
- * 
+ *
  * Return value: Number of total sample characters in the cvXX feature.
  *
  * Since: 2.0.0
diff --git a/src/hb-ot-math.h b/src/hb-ot-math.h
index 7b2befbce..ad864a762 100644
--- a/src/hb-ot-math.h
+++ b/src/hb-ot-math.h
@@ -158,7 +158,7 @@ typedef enum { /*< flags >*/
  * hb_ot_math_glyph_part_t:
  * @glyph: The glyph index of the variant part
  * @start_connector_length: The length of the connector on the starting side of the variant part
- * @end_connection_length: The length of the connector on the ending side of the variant part
+ * @end_connector_length: The length of the connector on the ending side of the variant part
  * @full_advance: The total advance of the part
  * @flags: #hb_ot_math_glyph_part_flags_t flags for the part
  * 
diff --git a/src/hb-ot-meta-table.hh b/src/hb-ot-meta-table.hh
new file mode 100644
index 000000000..dac55e47f
--- /dev/null
+++ b/src/hb-ot-meta-table.hh
@@ -0,0 +1,89 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#ifndef HB_OT_META_TABLE_HH
+#define HB_OT_META_TABLE_HH
+
+#include "hb-open-type.hh"
+
+/*
+ * meta -- Metadata Table
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/meta
+ * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html
+ */
+#define HB_OT_TAG_meta HB_TAG('m','e','t','a')
+
+
+namespace OT {
+
+
+struct DataMap
+{
+  bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this) &&
+			  dataZ.sanitize (c, base, dataLength)));
+  }
+
+  protected:
+  Tag		tag;		/* A tag indicating the type of metadata. */
+  LOffsetTo<UnsizedArrayOf<HBUINT8>>
+		dataZ;		/* Offset in bytes from the beginning of the
+				 * metadata table to the data for this tag. */
+  HBUINT32	dataLength;	/* Length of the data. The data is not required to
+				 * be padded to any byte boundary. */
+  public:
+  DEFINE_SIZE_STATIC (12);
+};
+
+struct meta
+{
+  static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this) &&
+			  version == 1 &&
+			  dataMaps.sanitize (c, this)));
+  }
+
+  protected:
+  HBUINT32	version;	/* Version number of the metadata table — set to 1. */
+  HBUINT32	flags;		/* Flags — currently unused; set to 0. */
+  HBUINT32	dataOffset;	/* Per Apple specification:
+				 * Offset from the beginning of the table to the data.
+				 * Per OT specification:
+				 * Reserved. Not used; should be set to 0. */
+  LArrayOf<DataMap>
+		dataMaps;	/* Array of data map records. */
+  public:
+  DEFINE_SIZE_ARRAY (16, dataMaps);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_META_TABLE_HH */
diff --git a/src/hb-ot-metrics.cc b/src/hb-ot-metrics.cc
new file mode 100644
index 000000000..910d826b9
--- /dev/null
+++ b/src/hb-ot-metrics.cc
@@ -0,0 +1,215 @@
+/*
+ * Copyright © 2018-2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#include "hb.hh"
+
+#include "hb-ot-var-mvar-table.hh"
+#include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise.
+#include "hb-ot-os2-table.hh"
+#include "hb-ot-post-table.hh"
+#include "hb-ot-hhea-table.hh"
+#include "hb-ot-metrics.hh"
+#include "hb-ot-face.hh"
+
+
+static float
+_fix_ascender_descender (float value, hb_ot_metrics_t metrics_tag)
+{
+  if (metrics_tag == HB_OT_METRICS_HORIZONTAL_ASCENDER ||
+      metrics_tag == HB_OT_METRICS_VERTICAL_ASCENDER)
+    return fabs ((double) value);
+  if (metrics_tag == HB_OT_METRICS_HORIZONTAL_DESCENDER ||
+      metrics_tag == HB_OT_METRICS_VERTICAL_DESCENDER)
+    return -fabs ((double) value);
+  return value;
+}
+
+/* The common part of _get_position logic needed on hb-ot-font and here
+   to be able to have slim builds without the not always needed parts */
+bool
+_hb_ot_metrics_get_position_common (hb_font_t       *font,
+				    hb_ot_metrics_t  metrics_tag,
+				    hb_position_t   *position     /* OUT.  May be NULL. */)
+{
+  hb_face_t *face = font->face;
+  switch ((unsigned int) metrics_tag)
+  {
+#ifndef HB_NO_VAR
+#define GET_VAR face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords)
+#else
+#define GET_VAR .0f
+#endif
+#define GET_METRIC_X(TABLE, ATTR) \
+  (face->table.TABLE->has_data () && \
+    (position && (*position = font->em_scalef_x (_fix_ascender_descender ( \
+      face->table.TABLE->ATTR + GET_VAR, metrics_tag))), true))
+#define GET_METRIC_Y(TABLE, ATTR) \
+  (face->table.TABLE->has_data () && \
+    (position && (*position = font->em_scalef_y (_fix_ascender_descender ( \
+      face->table.TABLE->ATTR + GET_VAR, metrics_tag))), true))
+  case HB_OT_METRICS_HORIZONTAL_ASCENDER:
+    return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoAscender)) ||
+	   GET_METRIC_Y (hhea, ascender);
+  case HB_OT_METRICS_HORIZONTAL_DESCENDER:
+    return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoDescender)) ||
+	   GET_METRIC_Y (hhea, descender);
+  case HB_OT_METRICS_HORIZONTAL_LINE_GAP:
+    return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoLineGap)) ||
+	   GET_METRIC_Y (hhea, lineGap);
+  case HB_OT_METRICS_VERTICAL_ASCENDER:  return GET_METRIC_X (vhea, ascender);
+  case HB_OT_METRICS_VERTICAL_DESCENDER: return GET_METRIC_X (vhea, descender);
+  case HB_OT_METRICS_VERTICAL_LINE_GAP:  return GET_METRIC_X (vhea, lineGap);
+#undef GET_METRIC_Y
+#undef GET_METRIC_X
+#undef GET_VAR
+  default:                               assert (0); return false;
+  }
+}
+
+#ifndef HB_NO_METRICS
+
+#if 0
+static bool
+_get_gasp (hb_face_t *face, float *result, hb_ot_metrics_t metrics_tag)
+{
+  const OT::GaspRange& range = face->table.gasp->get_gasp_range (metrics_tag - HB_TAG ('g','s','p','0'));
+  if (&range == &Null (OT::GaspRange)) return false;
+  if (result) *result = range.rangeMaxPPEM + font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords);
+  return true;
+}
+#endif
+
+/**
+ * hb_ot_metrics_get_position:
+ * @font: a #hb_font_t object.
+ * @metrics_tag: tag of metrics value you like to fetch.
+ * @position: (out) (optional): result of metrics value from the font.
+ *
+ * It fetches metrics value corresponding to a given tag from a font.
+ *
+ * Returns: Whether found the requested metrics in the font.
+ * Since: REPLACEME
+ **/
+hb_bool_t
+hb_ot_metrics_get_position (hb_font_t       *font,
+			    hb_ot_metrics_t  metrics_tag,
+			    hb_position_t   *position     /* OUT.  May be NULL. */)
+{
+  hb_face_t *face = font->face;
+  switch (metrics_tag)
+  {
+  case HB_OT_METRICS_HORIZONTAL_ASCENDER:
+  case HB_OT_METRICS_HORIZONTAL_DESCENDER:
+  case HB_OT_METRICS_HORIZONTAL_LINE_GAP:
+  case HB_OT_METRICS_VERTICAL_ASCENDER:
+  case HB_OT_METRICS_VERTICAL_DESCENDER:
+  case HB_OT_METRICS_VERTICAL_LINE_GAP:           return _hb_ot_metrics_get_position_common (font, metrics_tag, position);
+#ifndef HB_NO_VAR
+#define GET_VAR hb_ot_metrics_get_variation (font, metrics_tag)
+#else
+#define GET_VAR 0
+#endif
+#define GET_METRIC_X(TABLE, ATTR) \
+  (face->table.TABLE->has_data () && \
+    (position && (*position = font->em_scalef_x (face->table.TABLE->ATTR + GET_VAR)), true))
+#define GET_METRIC_Y(TABLE, ATTR) \
+  (face->table.TABLE->has_data () && \
+    (position && (*position = font->em_scalef_y (face->table.TABLE->ATTR + GET_VAR)), true))
+  case HB_OT_METRICS_HORIZONTAL_CLIPPING_ASCENT:  return GET_METRIC_Y (OS2, usWinAscent);
+  case HB_OT_METRICS_HORIZONTAL_CLIPPING_DESCENT: return GET_METRIC_Y (OS2, usWinDescent);
+  case HB_OT_METRICS_HORIZONTAL_CARET_RISE:       return GET_METRIC_Y (hhea, caretSlopeRise);
+  case HB_OT_METRICS_HORIZONTAL_CARET_RUN:        return GET_METRIC_X (hhea, caretSlopeRun);
+  case HB_OT_METRICS_HORIZONTAL_CARET_OFFSET:     return GET_METRIC_X (hhea, caretOffset);
+  case HB_OT_METRICS_VERTICAL_CARET_RISE:         return GET_METRIC_X (vhea, caretSlopeRise);
+  case HB_OT_METRICS_VERTICAL_CARET_RUN:          return GET_METRIC_Y (vhea, caretSlopeRun);
+  case HB_OT_METRICS_VERTICAL_CARET_OFFSET:       return GET_METRIC_Y (vhea, caretOffset);
+  case HB_OT_METRICS_X_HEIGHT:                    return GET_METRIC_Y (OS2->v2 (), sxHeight);
+  case HB_OT_METRICS_CAP_HEIGHT:                  return GET_METRIC_Y (OS2->v2 (), sCapHeight);
+  case HB_OT_METRICS_SUBSCRIPT_EM_X_SIZE:         return GET_METRIC_X (OS2, ySubscriptXSize);
+  case HB_OT_METRICS_SUBSCRIPT_EM_Y_SIZE:         return GET_METRIC_Y (OS2, ySubscriptYSize);
+  case HB_OT_METRICS_SUBSCRIPT_EM_X_OFFSET:       return GET_METRIC_X (OS2, ySubscriptXOffset);
+  case HB_OT_METRICS_SUBSCRIPT_EM_Y_OFFSET:       return GET_METRIC_Y (OS2, ySubscriptYOffset);
+  case HB_OT_METRICS_SUPERSCRIPT_EM_X_SIZE:       return GET_METRIC_X (OS2, ySuperscriptXSize);
+  case HB_OT_METRICS_SUPERSCRIPT_EM_Y_SIZE:       return GET_METRIC_Y (OS2, ySuperscriptYSize);
+  case HB_OT_METRICS_SUPERSCRIPT_EM_X_OFFSET:     return GET_METRIC_X (OS2, ySuperscriptXOffset);
+  case HB_OT_METRICS_SUPERSCRIPT_EM_Y_OFFSET:     return GET_METRIC_Y (OS2, ySuperscriptYOffset);
+  case HB_OT_METRICS_STRIKEOUT_SIZE:              return GET_METRIC_Y (OS2, yStrikeoutSize);
+  case HB_OT_METRICS_STRIKEOUT_OFFSET:            return GET_METRIC_Y (OS2, yStrikeoutPosition);
+  case HB_OT_METRICS_UNDERLINE_SIZE:              return GET_METRIC_Y (post->table, underlineThickness);
+  case HB_OT_METRICS_UNDERLINE_OFFSET:            return GET_METRIC_Y (post->table, underlinePosition);
+#undef GET_METRIC_Y
+#undef GET_METRIC_X
+#undef GET_VAR
+  default:                                        return false;
+  }
+}
+
+#ifndef HB_NO_VAR
+/**
+ * hb_ot_metrics_get_variation:
+ * @font:
+ * @metrics_tag:
+ *
+ * Returns:
+ *
+ * Since: REPLACEME
+ **/
+float
+hb_ot_metrics_get_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag)
+{
+  return font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords);
+}
+
+/**
+ * hb_ot_metrics_get_x_variation:
+ * @font:
+ * @metrics_tag:
+ *
+ * Returns:
+ *
+ * Since: REPLACEME
+ **/
+hb_position_t
+hb_ot_metrics_get_x_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag)
+{
+  return font->em_scalef_x (hb_ot_metrics_get_variation (font, metrics_tag));
+}
+
+/**
+ * hb_ot_metrics_get_y_variation:
+ * @font:
+ * @metrics_tag:
+ *
+ * Returns:
+ *
+ * Since: REPLACEME
+ **/
+hb_position_t
+hb_ot_metrics_get_y_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag)
+{
+  return font->em_scalef_y (hb_ot_metrics_get_variation (font, metrics_tag));
+}
+#endif
+
+#endif
diff --git a/src/hb-ot-metrics.h b/src/hb-ot-metrics.h
new file mode 100644
index 000000000..4d22837f2
--- /dev/null
+++ b/src/hb-ot-metrics.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright © 2018  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#ifndef HB_OT_H_IN
+#error "Include <hb-ot.h> instead."
+#endif
+
+#ifndef HB_OT_METRICS_H
+#define HB_OT_METRICS_H
+
+#include "hb.h"
+#include "hb-ot-name.h"
+
+HB_BEGIN_DECLS
+
+
+/**
+ * hb_ot_metrics_t:
+ *
+ * From https://docs.microsoft.com/en-us/typography/opentype/spec/mvar#value-tags
+ *
+ * Since: REPLACEME
+ **/
+typedef enum {
+  HB_OT_METRICS_HORIZONTAL_ASCENDER		= HB_TAG ('h','a','s','c'),
+  HB_OT_METRICS_HORIZONTAL_DESCENDER		= HB_TAG ('h','d','s','c'),
+  HB_OT_METRICS_HORIZONTAL_LINE_GAP		= HB_TAG ('h','l','g','p'),
+  HB_OT_METRICS_HORIZONTAL_CLIPPING_ASCENT	= HB_TAG ('h','c','l','a'),
+  HB_OT_METRICS_HORIZONTAL_CLIPPING_DESCENT	= HB_TAG ('h','c','l','d'),
+  HB_OT_METRICS_VERTICAL_ASCENDER		= HB_TAG ('v','a','s','c'),
+  HB_OT_METRICS_VERTICAL_DESCENDER		= HB_TAG ('v','d','s','c'),
+  HB_OT_METRICS_VERTICAL_LINE_GAP		= HB_TAG ('v','l','g','p'),
+  HB_OT_METRICS_HORIZONTAL_CARET_RISE		= HB_TAG ('h','c','r','s'),
+  HB_OT_METRICS_HORIZONTAL_CARET_RUN		= HB_TAG ('h','c','r','n'),
+  HB_OT_METRICS_HORIZONTAL_CARET_OFFSET		= HB_TAG ('h','c','o','f'),
+  HB_OT_METRICS_VERTICAL_CARET_RISE		= HB_TAG ('v','c','r','s'),
+  HB_OT_METRICS_VERTICAL_CARET_RUN		= HB_TAG ('v','c','r','n'),
+  HB_OT_METRICS_VERTICAL_CARET_OFFSET		= HB_TAG ('v','c','o','f'),
+  HB_OT_METRICS_X_HEIGHT			= HB_TAG ('x','h','g','t'),
+  HB_OT_METRICS_CAP_HEIGHT			= HB_TAG ('c','p','h','t'),
+  HB_OT_METRICS_SUBSCRIPT_EM_X_SIZE		= HB_TAG ('s','b','x','s'),
+  HB_OT_METRICS_SUBSCRIPT_EM_Y_SIZE		= HB_TAG ('s','b','y','s'),
+  HB_OT_METRICS_SUBSCRIPT_EM_X_OFFSET		= HB_TAG ('s','b','x','o'),
+  HB_OT_METRICS_SUBSCRIPT_EM_Y_OFFSET		= HB_TAG ('s','b','y','o'),
+  HB_OT_METRICS_SUPERSCRIPT_EM_X_SIZE		= HB_TAG ('s','p','x','s'),
+  HB_OT_METRICS_SUPERSCRIPT_EM_Y_SIZE		= HB_TAG ('s','p','y','s'),
+  HB_OT_METRICS_SUPERSCRIPT_EM_X_OFFSET		= HB_TAG ('s','p','x','o'),
+  HB_OT_METRICS_SUPERSCRIPT_EM_Y_OFFSET		= HB_TAG ('s','p','y','o'),
+  HB_OT_METRICS_STRIKEOUT_SIZE			= HB_TAG ('s','t','r','s'),
+  HB_OT_METRICS_STRIKEOUT_OFFSET		= HB_TAG ('s','t','r','o'),
+  HB_OT_METRICS_UNDERLINE_SIZE			= HB_TAG ('u','n','d','s'),
+  HB_OT_METRICS_UNDERLINE_OFFSET		= HB_TAG ('u','n','d','o')
+} hb_ot_metrics_t;
+
+HB_EXTERN hb_bool_t
+hb_ot_metrics_get_position (hb_font_t       *font,
+			    hb_ot_metrics_t  metrics_tag,
+			    hb_position_t   *position     /* OUT.  May be NULL. */);
+
+HB_EXTERN float
+hb_ot_metrics_get_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag);
+
+HB_EXTERN hb_position_t
+hb_ot_metrics_get_x_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag);
+
+HB_EXTERN hb_position_t
+hb_ot_metrics_get_y_variation (hb_font_t *font, hb_ot_metrics_t metrics_tag);
+
+HB_END_DECLS
+
+#endif /* HB_OT_METRICS_H */
diff --git a/src/hb-ot-metrics.hh b/src/hb-ot-metrics.hh
new file mode 100644
index 000000000..f9ae46fc9
--- /dev/null
+++ b/src/hb-ot-metrics.hh
@@ -0,0 +1,35 @@
+/*
+ * Copyright © 2018  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#ifndef HB_OT_METRICS_HH
+#define HB_OT_METRICS_HH
+
+#include "hb.hh"
+
+HB_INTERNAL bool
+_hb_ot_metrics_get_position_common (hb_font_t       *font,
+				    hb_ot_metrics_t  metrics_tag,
+				    hb_position_t   *position     /* OUT.  May be NULL. */);
+
+#endif /* HB_OT_METRICS_HH */
diff --git a/src/hb-ot-os2-table.hh b/src/hb-ot-os2-table.hh
index 16e29caf3..67f21eb34 100644
--- a/src/hb-ot-os2-table.hh
+++ b/src/hb-ot-os2-table.hh
@@ -59,6 +59,10 @@ struct OS2V1Tail
 
 struct OS2V2Tail
 {
+  bool has_data () const { return this != &Null (OS2V2Tail); }
+
+  const OS2V2Tail * operator -> () const { return this; }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -113,9 +117,9 @@ struct OS2
     OBLIQUE		= 1u<<9
   };
 
-  bool is_italic () const       { return fsSelection & ITALIC; }
-  bool is_oblique () const      { return fsSelection & OBLIQUE; }
-  bool is_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; }
+  bool is_italic () const        { return fsSelection & ITALIC; }
+  bool is_oblique () const       { return fsSelection & OBLIQUE; }
+  bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; }
 
   enum width_class_t {
     FWIDTH_ULTRA_CONDENSED	= 1, /* 50% */
@@ -192,13 +196,14 @@ struct OS2
   }
 
   static void find_min_and_max_codepoint (const hb_set_t *codepoints,
-						 uint16_t *min_cp, /* OUT */
-						 uint16_t *max_cp  /* OUT */)
+					  uint16_t *min_cp, /* OUT */
+					  uint16_t *max_cp  /* OUT */)
   {
     *min_cp = codepoints->get_min ();
     *max_cp = codepoints->get_max ();
   }
 
+  /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 */
   enum font_page_t {
     HEBREW_FONT_PAGE		= 0xB100, // Hebrew Windows 3.1 font page
     SIMP_ARABIC_FONT_PAGE	= 0xB200, // Simplified Arabic Windows 3.1 font page
@@ -208,8 +213,6 @@ struct OS2
     TRAD_FARSI_FONT_PAGE	= 0xBB00, // Traditional Farsi Windows 3.1 font page
     THAI_FONT_PAGE		= 0xDE00  // Thai Windows 3.1 font page
   };
-
-  // https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681
   font_page_t get_font_page () const
   { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); }
 
diff --git a/src/hb-ot-post-table.hh b/src/hb-ot-post-table.hh
index 720e03bac..fb826cd35 100644
--- a/src/hb-ot-post-table.hh
+++ b/src/hb-ot-post-table.hh
@@ -178,6 +178,8 @@ struct post
       return false;
     }
 
+    hb_blob_ptr_t<post> table;
+
     protected:
 
     unsigned int get_glyph_count () const
@@ -237,7 +239,6 @@ struct post
     }
 
     private:
-    hb_blob_ptr_t<post> table;
     uint32_t version;
     const ArrayOf<HBUINT16> *glyphNameIndex;
     hb_vector_t<uint32_t> index_to_offset;
@@ -245,6 +246,8 @@ struct post
     hb_atomic_ptr_t<uint16_t *> gids_sorted_by_name;
   };
 
+  bool has_data () const { return version.to_int (); }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
diff --git a/src/hb-ot.h b/src/hb-ot.h
index db784694c..d00ee80ae 100644
--- a/src/hb-ot.h
+++ b/src/hb-ot.h
@@ -35,6 +35,7 @@
 #include "hb-ot-font.h"
 #include "hb-ot-layout.h"
 #include "hb-ot-math.h"
+#include "hb-ot-metrics.h"
 #include "hb-ot-name.h"
 #include "hb-ot-shape.h"
 #include "hb-ot-var.h"
diff --git a/src/hb-unicode.hh b/src/hb-unicode.hh
index 9b181c11c..0c355f111 100644
--- a/src/hb-unicode.hh
+++ b/src/hb-unicode.hh
@@ -105,9 +105,6 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
   unsigned int
   modified_combining_class (hb_codepoint_t u)
   {
-    /* XXX This hack belongs to the Myanmar shaper. */
-    if (unlikely (u == 0x1037u)) u = 0x103Au;
-
     /* XXX This hack belongs to the USE shaper (for Tai Tham):
      * Reorder SAKOT to ensure it comes after any tone marks. */
     if (unlikely (u == 0x1A60u)) return 254;
diff --git a/src/hb-uniscribe.cc b/src/hb-uniscribe.cc
index b113ed4cf..289a3477f 100644
--- a/src/hb-uniscribe.cc
+++ b/src/hb-uniscribe.cc
@@ -58,13 +58,6 @@
  * Functions for using HarfBuzz with the Windows fonts.
  **/
 
-
-static inline uint16_t hb_uint16_swap (const uint16_t v)
-{ return (v >> 8) | (v << 8); }
-static inline uint32_t hb_uint32_swap (const uint32_t v)
-{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
-
-
 typedef HRESULT (WINAPI *SIOT) /*ScriptItemizeOpenType*/(
   const WCHAR *pwcInChars,
   int cInChars,
diff --git a/src/hb.hh b/src/hb.hh
index f8b5e70a8..8dcd5aa88 100644
--- a/src/hb.hh
+++ b/src/hb.hh
@@ -318,7 +318,8 @@ extern "C" void  hb_free_impl(void *ptr);
 #  define HB_FALLTHROUGH /* FALLTHROUGH */
 #endif
 
-#ifdef __clang__
+/* https://github.com/harfbuzz/harfbuzz/issues/1852 */
+#if defined(__clang__) && !(defined(_AIX) && (defined(__IBMCPP__) || defined(__ibmxl__)))
 /* Disable certain sanitizer errors. */
 /* https://github.com/harfbuzz/harfbuzz/issues/1247 */
 #define HB_NO_SANITIZE_SIGNED_INTEGER_OVERFLOW __attribute__((no_sanitize("signed-integer-overflow")))
@@ -476,6 +477,11 @@ static_assert ((sizeof (hb_var_int_t) == 4), "");
 /* Size signifying variable-sized array */
 #define VAR 1
 
+/* Endian swap, used in Windows related backends */
+static inline uint16_t hb_uint16_swap (const uint16_t v)
+{ return (v >> 8) | (v << 8); }
+static inline uint32_t hb_uint32_swap (const uint32_t v)
+{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
 
 /*
  * Big-endian integers.  Here because fundamental.
diff --git a/test/api/Makefile.am b/test/api/Makefile.am
index 85f2f6fd1..b95d8c9ac 100644
--- a/test/api/Makefile.am
+++ b/test/api/Makefile.am
@@ -90,6 +90,7 @@ TEST_PROGS += \
 	test-ot-color \
 	test-ot-ligature-carets \
 	test-ot-name \
+	test-ot-metrics \
 	test-ot-tag \
 	test-ot-extents-cff \
 	test-ot-metrics-tt-var \
diff --git a/test/api/test-ot-color.c b/test/api/test-ot-color.c
index c0cbd77b9..d646f7371 100644
--- a/test/api/test-ot-color.c
+++ b/test/api/test-ot-color.c
@@ -426,9 +426,9 @@ test_hb_ot_color_png (void)
   g_assert (strncmp (data + 1, "PNG", 3) == 0);
   hb_font_get_glyph_extents (sbix_font, 1, &extents);
   g_assert_cmpint (extents.x_bearing, ==, 0);
-  g_assert_cmpint (extents.y_bearing, ==, 0);
+  g_assert_cmpint (extents.y_bearing, ==, 800);
   g_assert_cmpint (extents.width, ==, 800);
-  g_assert_cmpint (extents.height, ==, 800);
+  g_assert_cmpint (extents.height, ==, -800);
   hb_blob_destroy (blob);
   hb_font_destroy (sbix_font);
 
diff --git a/test/api/test-ot-metrics.c b/test/api/test-ot-metrics.c
new file mode 100644
index 000000000..91dd7f5e1
--- /dev/null
+++ b/test/api/test-ot-metrics.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright © 2018  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#include "hb-test.h"
+
+#include <hb-ot.h>
+
+#include <math.h>
+
+/* Unit tests for hb-ot-metrics.h */
+
+static void
+test_ot_metrics_get (void)
+{
+  hb_face_t *face = hb_test_open_font_file ("fonts/cpal-v0.ttf");
+  hb_font_t *font = hb_font_create (face);
+  hb_position_t value;
+  g_assert (hb_ot_metrics_get_position (font, HB_OT_METRICS_HORIZONTAL_ASCENDER, &value));
+  g_assert_cmpint (value, ==, 1000);
+  g_assert_cmpint (hb_ot_metrics_get_x_variation (font, HB_OT_METRICS_HORIZONTAL_ASCENDER), ==, 0);
+  g_assert_cmpint (hb_ot_metrics_get_y_variation (font, HB_OT_METRICS_HORIZONTAL_ASCENDER), ==, 0);
+  // g_assert_cmpint ((int) hb_ot_metrics_get_variation (font, HB_OT_METRICS_HORIZONTAL_ASCENDER), ==, 0);
+  hb_font_destroy (font);
+  hb_face_destroy (face);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+  hb_test_add (test_ot_metrics_get);
+  return hb_test_run ();
+}
diff --git a/test/fuzzing/run-shape-fuzzer-tests.py b/test/fuzzing/run-shape-fuzzer-tests.py
index ba480dd52..6d36c2cfe 100755
--- a/test/fuzzing/run-shape-fuzzer-tests.py
+++ b/test/fuzzing/run-shape-fuzzer-tests.py
@@ -5,41 +5,41 @@ from __future__ import print_function, division, absolute_import
 import sys, os, subprocess, tempfile, threading
 
 
-def which(program):
+def which (program):
 	# https://stackoverflow.com/a/377028
-	def is_exe(fpath):
-		return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
+	def is_exe (fpath):
+		return os.path.isfile (fpath) and os.access (fpath, os.X_OK)
 
-	fpath, _ = os.path.split(program)
+	fpath, _ = os.path.split (program)
 	if fpath:
-		if is_exe(program):
+		if is_exe (program):
 			return program
 	else:
-		for path in os.environ["PATH"].split(os.pathsep):
-			exe_file = os.path.join(path, program)
-			if is_exe(exe_file):
+		for path in os.environ["PATH"].split (os.pathsep):
+			exe_file = os.path.join (path, program)
+			if is_exe (exe_file):
 				return exe_file
 
 	return None
 
 
-def cmd(command):
+def cmd (command):
 	# https://stackoverflow.com/a/4408409
 	# https://stackoverflow.com/a/10012262
-	with tempfile.TemporaryFile() as tempf:
+	with tempfile.TemporaryFile () as tempf:
 		p = subprocess.Popen (command, stderr=tempf)
 		is_killed = {'value': False}
 
-		def timeout(p, is_killed):
+		def timeout (p, is_killed):
 			is_killed['value'] = True
-			p.kill()
+			p.kill ()
 		timer = threading.Timer (2, timeout, [p, is_killed])
 
 		try:
 			timer.start()
 			p.wait ()
 			tempf.seek (0)
-			text = tempf.read().decode ("utf-8").strip ()
+			text = tempf.read ().decode ("utf-8").strip ()
 			returncode = p.returncode
 		finally:
 			timer.cancel()
@@ -67,9 +67,9 @@ please provide it as the first argument to the tool""")
 print ('hb_shape_fuzzer:', hb_shape_fuzzer)
 fails = 0
 
-libtool = os.environ.get('LIBTOOL')
+libtool = os.environ.get ('LIBTOOL')
 valgrind = None
-if os.environ.get('RUN_VALGRIND', ''):
+if os.environ.get ('RUN_VALGRIND', ''):
 	valgrind = which ('valgrind')
 	if valgrind is None:
 		print ("""Valgrind requested but not found.""")
@@ -80,7 +80,7 @@ if os.environ.get('RUN_VALGRIND', ''):
 
 parent_path = os.path.join (srcdir, "fonts")
 for file in os.listdir (parent_path):
-	path = os.path.join(parent_path, file)
+	path = os.path.join (parent_path, file)
 
 	if valgrind:
 		text, returncode = cmd (libtool.split(' ') + ['--mode=execute', valgrind + ' --leak-check=full --error-exitcode=1', '--', hb_shape_fuzzer, path])
@@ -89,7 +89,7 @@ for file in os.listdir (parent_path):
 		if 'error' in text:
 			returncode = 1
 
-	if not valgrind and text.strip ():
+	if (not valgrind or returncode) and text.strip ():
 		print (text)
 
 	if returncode != 0:
diff --git a/test/shaping/data/in-house/fonts/fcbaa518d3cce441ed37ae3b1fed6a19e9b54efd.ttf b/test/shaping/data/in-house/fonts/fcbaa518d3cce441ed37ae3b1fed6a19e9b54efd.ttf
new file mode 100644
index 000000000..b1a8a33e9
Binary files /dev/null and b/test/shaping/data/in-house/fonts/fcbaa518d3cce441ed37ae3b1fed6a19e9b54efd.ttf differ
diff --git a/test/shaping/data/in-house/tests/color-fonts.tests b/test/shaping/data/in-house/tests/color-fonts.tests
index b325d78c1..bf0005c67 100644
--- a/test/shaping/data/in-house/tests/color-fonts.tests
+++ b/test/shaping/data/in-house/tests/color-fonts.tests
@@ -1 +1,2 @@
 ../fonts/ee39587d13b2afa5499cc79e45780aa79293bbd4.ttf:--font-funcs=ot --show-extents:U+1F42F:[gid1=0+2963<0,2179,2963,-2789>]
+../fonts/fcbaa518d3cce441ed37ae3b1fed6a19e9b54efd.ttf:--font-funcs=ot --show-extents:U+1F600:[gid4=0+2550<0,1898,2555,-2405>]