[HB] Port ot-layout to new public API

14 files changed, 485 insertions, 436 deletions

diff --git a/pango/opentype/TODO b/pango/opentype/TODO
index badfa645..997de7cd 100644
--- a/pango/opentype/TODO
+++ b/pango/opentype/TODO
@@ -1,3 +1,4 @@
+- Get rid of custom GSUB/GPOS table type enum?
 - Test OpenType 1.6 mark filtering sets
 - When sanitizing, have to do a second round to make sure no toe-stepping
 - HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH vs LookupType::... mess
diff --git a/pango/opentype/hb-common.h b/pango/opentype/hb-common.h
index 011e8650..de94fb2f 100644
--- a/pango/opentype/hb-common.h
+++ b/pango/opentype/hb-common.h
@@ -45,6 +45,7 @@ typedef uint32_t hb_tag_t;
 				((const char *) s)[1], \
 				((const char *) s)[2], \
 				((const char *) s)[3]))
+#define HB_TAG_NONE HB_TAG(0,0,0,0)
 
 typedef uint32_t hb_codepoint_t;
 typedef int32_t hb_position_t;
diff --git a/pango/opentype/hb-font.c b/pango/opentype/hb-font.c
index 2397d77c..dbe82baf 100644
--- a/pango/opentype/hb-font.c
+++ b/pango/opentype/hb-font.c
@@ -314,6 +314,15 @@ hb_font_destroy (hb_font_t *font)
   free (font);
 }
 
+hb_face_t *
+hb_font_get_face (hb_font_t *font)
+{
+  if (HB_OBJECT_IS_INERT (font))
+    return &_hb_face_nil;
+
+  return font->face;
+}
+
 void
 hb_font_set_scale (hb_font_t *font,
 		   hb_16dot16_t x_scale,
diff --git a/pango/opentype/hb-font.h b/pango/opentype/hb-font.h
index deab22e6..71f7eb7d 100644
--- a/pango/opentype/hb-font.h
+++ b/pango/opentype/hb-font.h
@@ -176,6 +176,9 @@ hb_font_get_reference_count (hb_font_t *font);
 void
 hb_font_destroy (hb_font_t *font);
 
+hb_face_t *
+hb_font_get_face (hb_font_t *font);
+
 /*
  * XXX
  * should we decompose this to units_per_EM and font-size?
diff --git a/pango/opentype/hb-ot-layout-gdef-private.h b/pango/opentype/hb-ot-layout-gdef-private.h
index a463a41b..0ed74a8d 100644
--- a/pango/opentype/hb-ot-layout-gdef-private.h
+++ b/pango/opentype/hb-ot-layout-gdef-private.h
@@ -90,10 +90,10 @@ struct CaretValueFormat1
   friend struct CaretValue;
 
   private:
-  inline int get_caret_value (hb_ot_layout_t *layout, hb_codepoint_t glyph_id) const
+  inline int get_caret_value (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id) const
   {
     /* XXX vertical */
-    return layout->gpos_info.x_scale * coordinate / 0x10000;
+    return context->font->x_scale * coordinate / 0x10000;
   }
 
   private:
@@ -107,7 +107,7 @@ struct CaretValueFormat2
   friend struct CaretValue;
 
   private:
-  inline int get_caret_value (hb_ot_layout_t *layout, hb_codepoint_t glyph_id) const
+  inline int get_caret_value (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id) const
   {
     return /* TODO contour point */ 0;
   }
@@ -122,11 +122,11 @@ struct CaretValueFormat3
 {
   friend struct CaretValue;
 
-  inline int get_caret_value (hb_ot_layout_t *layout, hb_codepoint_t glyph_id) const
+  inline int get_caret_value (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id) const
   {
     /* XXX vertical */
-    return layout->gpos_info.x_scale * coordinate / 0x10000 +
-	   (this+deviceTable).get_delta (layout->gpos_info.x_ppem) << 6;
+    return context->font->x_scale * coordinate / 0x10000 +
+	   (this+deviceTable).get_delta (context->font->x_ppem) << 6;
   }
 
   private:
@@ -142,12 +142,12 @@ ASSERT_SIZE (CaretValueFormat3, 6);
 struct CaretValue
 {
   /* XXX  we need access to a load-contour-point vfunc here */
-  int get_caret_value (hb_ot_layout_t *layout, hb_codepoint_t glyph_id) const
+  int get_caret_value (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id) const
   {
     switch (u.format) {
-    case 1: return u.format1->get_caret_value (layout, glyph_id);
-    case 2: return u.format2->get_caret_value (layout, glyph_id);
-    case 3: return u.format3->get_caret_value (layout, glyph_id);
+    case 1: return u.format1->get_caret_value (context, glyph_id);
+    case 2: return u.format2->get_caret_value (context, glyph_id);
+    case 3: return u.format3->get_caret_value (context, glyph_id);
     default:return 0;
     }
   }
@@ -164,7 +164,7 @@ ASSERT_SIZE (CaretValue, 2);
 
 struct LigGlyph
 {
-  inline void get_lig_carets (hb_ot_layout_t *layout,
+  inline void get_lig_carets (hb_ot_layout_context_t *context,
 			      hb_codepoint_t glyph_id,
 			      unsigned int *caret_count /* IN/OUT */,
 			      int *caret_array /* OUT */) const
@@ -172,7 +172,7 @@ struct LigGlyph
 
     unsigned int count = MIN (carets.len, *caret_count);
     for (unsigned int i = 0; i < count; i++)
-      caret_array[i] = (this+carets[i]).get_caret_value (layout, glyph_id);
+      caret_array[i] = (this+carets[i]).get_caret_value (context, glyph_id);
 
     *caret_count = carets.len;
   }
@@ -187,7 +187,7 @@ ASSERT_SIZE (LigGlyph, 2);
 
 struct LigCaretList
 {
-  inline bool get_lig_carets (hb_ot_layout_t *layout,
+  inline bool get_lig_carets (hb_ot_layout_context_t *context,
 			      hb_codepoint_t glyph_id,
 			      unsigned int *caret_count /* IN/OUT */,
 			      int *caret_array /* OUT */) const
@@ -199,7 +199,7 @@ struct LigCaretList
       return false;
     }
     const LigGlyph &lig_glyph = this+ligGlyph[index];
-    lig_glyph.get_lig_carets (layout, glyph_id, caret_count, caret_array);
+    lig_glyph.get_lig_carets (context, glyph_id, caret_count, caret_array);
     return true;
   }
 
@@ -279,11 +279,11 @@ struct GDEF
   { return (this+attachList).get_attach_points (glyph_id, point_count, point_array); }
 
   inline bool has_lig_carets () const { return ligCaretList != 0; }
-  inline bool get_lig_carets (hb_ot_layout_t *layout,
+  inline bool get_lig_carets (hb_ot_layout_context_t *context,
 			      hb_codepoint_t glyph_id,
 			      unsigned int *caret_count /* IN/OUT */,
 			      int *caret_array /* OUT */) const
-  { return (this+ligCaretList).get_lig_carets (layout, glyph_id, caret_count, caret_array); }
+  { return (this+ligCaretList).get_lig_carets (context, glyph_id, caret_count, caret_array); }
 
   inline bool has_mark_sets () const { return version >= 0x00010002 && markGlyphSetsDef[0] != 0; }
   inline bool mark_set_covers (unsigned int set_index, hb_codepoint_t glyph_id) const
diff --git a/pango/opentype/hb-ot-layout-gpos-private.h b/pango/opentype/hb-ot-layout-gpos-private.h
index dafd7d76..8bb3f95a 100644
--- a/pango/opentype/hb-ot-layout-gpos-private.h
+++ b/pango/opentype/hb-ot-layout-gpos-private.h
@@ -55,7 +55,7 @@ struct ValueFormat : USHORT
   inline unsigned int get_len () const
   { return _hb_popcount32 ((unsigned int) *this); }
 
-  const void apply_value (hb_ot_layout_t      *layout,
+  const void apply_value (hb_ot_layout_context_t *context,
 			  const char          *base,
 			  const Value         *values,
 			  hb_internal_glyph_position_t *glyph_pos) const
@@ -97,8 +97,8 @@ struct ValueRecord {
 };
 #endif
 
-    x_scale = layout->gpos_info.x_scale;
-    y_scale = layout->gpos_info.y_scale;
+    x_scale = context->font->x_scale;
+    y_scale = context->font->y_scale;
     /* design units -> fractional pixel */
     if (format & xPlacement)
       glyph_pos->x_pos += x_scale * *(SHORT*)values++ / 0x10000;
@@ -109,8 +109,8 @@ struct ValueRecord {
     if (format & yAdvance)
       glyph_pos->y_advance += y_scale * *(SHORT*)values++ / 0x10000;
 
-    x_ppem = layout->gpos_info.x_ppem;
-    y_ppem = layout->gpos_info.y_ppem;
+    x_ppem = context->font->x_ppem;
+    y_ppem = context->font->y_ppem;
     /* pixel -> fractional pixel */
     if (format & xPlaDevice) {
       if (x_ppem)
@@ -146,11 +146,11 @@ struct AnchorFormat1
   friend struct Anchor;
 
   private:
-  inline void get_anchor (hb_ot_layout_t *layout, hb_codepoint_t glyph_id,
+  inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id,
 			  hb_position_t *x, hb_position_t *y) const
   {
-      *x = layout->gpos_info.x_scale * xCoordinate / 0x10000;
-      *y = layout->gpos_info.y_scale * yCoordinate / 0x10000;
+      *x = context->font->x_scale * xCoordinate / 0x10000;
+      *y = context->font->y_scale * yCoordinate / 0x10000;
   }
 
   private:
@@ -165,12 +165,12 @@ struct AnchorFormat2
   friend struct Anchor;
 
   private:
-  inline void get_anchor (hb_ot_layout_t *layout, hb_codepoint_t glyph_id,
+  inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id,
 			  hb_position_t *x, hb_position_t *y) const
   {
       /* TODO Contour */
-      *x = layout->gpos_info.x_scale * xCoordinate / 0x10000;
-      *y = layout->gpos_info.y_scale * yCoordinate / 0x10000;
+      *x = context->font->x_scale * xCoordinate / 0x10000;
+      *y = context->font->y_scale * yCoordinate / 0x10000;
   }
 
   private:
@@ -186,16 +186,16 @@ struct AnchorFormat3
   friend struct Anchor;
 
   private:
-  inline void get_anchor (hb_ot_layout_t *layout, hb_codepoint_t glyph_id,
+  inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id,
 			  hb_position_t *x, hb_position_t *y) const
   {
-      *x = layout->gpos_info.x_scale * xCoordinate / 0x10000;
-      *y = layout->gpos_info.y_scale * yCoordinate / 0x10000;
+      *x = context->font->x_scale * xCoordinate / 0x10000;
+      *y = context->font->y_scale * yCoordinate / 0x10000;
 
-      if (layout->gpos_info.x_ppem)
-	*x += (this+xDeviceTable).get_delta (layout->gpos_info.x_ppem) << 6;
-      if (layout->gpos_info.y_ppem)
-	*y += (this+yDeviceTable).get_delta (layout->gpos_info.y_ppem) << 6;
+      if (context->font->x_ppem)
+	*x += (this+xDeviceTable).get_delta (context->font->x_ppem) << 6;
+      if (context->font->y_ppem)
+	*y += (this+yDeviceTable).get_delta (context->font->y_ppem) << 6;
   }
 
   private:
@@ -215,15 +215,15 @@ ASSERT_SIZE (AnchorFormat3, 10);
 
 struct Anchor
 {
-  inline void get_anchor (hb_ot_layout_t *layout, hb_codepoint_t glyph_id,
+  inline void get_anchor (hb_ot_layout_context_t *context, hb_codepoint_t glyph_id,
 			  hb_position_t *x, hb_position_t *y) const
   {
     *x = *y = 0;
     switch (u.format) {
-    case 1: u.format1->get_anchor (layout, glyph_id, x, y); return;
-    case 2: u.format2->get_anchor (layout, glyph_id, x, y); return;
-    case 3: u.format3->get_anchor (layout, glyph_id, x, y); return;
-    default:						    return;
+    case 1: u.format1->get_anchor (context, glyph_id, x, y); return;
+    case 2: u.format2->get_anchor (context, glyph_id, x, y); return;
+    case 3: u.format3->get_anchor (context, glyph_id, x, y); return;
+    default:						     return;
     }
   }
 
@@ -275,7 +275,7 @@ struct SinglePosFormat1
     if (HB_LIKELY (index == NOT_COVERED))
       return false;
 
-    valueFormat.apply_value (layout, (const char *) this, values, CURPOSITION ());
+    valueFormat.apply_value (context, (const char *) this, values, CURPOSITION ());
 
     buffer->in_pos++;
     return true;
@@ -308,7 +308,7 @@ struct SinglePosFormat2
     if (HB_LIKELY (index >= valueCount))
       return false;
 
-    valueFormat.apply_value (layout, (const char *) this,
+    valueFormat.apply_value (context, (const char *) this,
 			     values + index * valueFormat.get_len (),
 			     CURPOSITION ());
 
@@ -394,7 +394,7 @@ struct PairPosFormat1
       return false;
 
     unsigned int j = buffer->in_pos + 1;
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (j == end))
 	return false;
@@ -413,8 +413,8 @@ struct PairPosFormat1
     {
       if (IN_GLYPH (j) == record->secondGlyph)
       {
-	valueFormat1.apply_value (layout, (const char *) this, record->values, CURPOSITION ());
-	valueFormat2.apply_value (layout, (const char *) this, record->values + len1, POSITION (j));
+	valueFormat1.apply_value (context, (const char *) this, record->values, CURPOSITION ());
+	valueFormat2.apply_value (context, (const char *) this, record->values + len1, POSITION (j));
 	if (len2)
 	  j++;
 	buffer->in_pos = j;
@@ -459,7 +459,7 @@ struct PairPosFormat2
       return false;
 
     unsigned int j = buffer->in_pos + 1;
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (j == end))
 	return false;
@@ -476,8 +476,8 @@ struct PairPosFormat2
       return false;
 
     const Value *v = values + record_len * (klass1 * class2Count + klass2);
-    valueFormat1.apply_value (layout, (const char *) this, v, CURPOSITION ());
-    valueFormat2.apply_value (layout, (const char *) this, v + len1, POSITION (j));
+    valueFormat1.apply_value (context, (const char *) this, v, CURPOSITION ());
+    valueFormat2.apply_value (context, (const char *) this, v + len1, POSITION (j));
 
     if (len2)
       j++;
@@ -677,7 +677,7 @@ struct CursivePosFormat1
        Since horizontal advance widths or vertical advance heights
        can be used alone but not together, no ambiguity occurs.        */
 
-    struct hb_ot_layout_t::gpos_info_t *gpi = &layout->gpos_info;
+    struct hb_ot_layout_context_t::info_t::gpos_t *gpi = &context->info.gpos;
     hb_codepoint_t last_pos = gpi->last;
     gpi->last = HB_OT_LAYOUT_GPOS_NO_LAST;
 
@@ -695,7 +695,7 @@ struct CursivePosFormat1
       goto end;
 
     hb_position_t entry_x, entry_y;
-    (this+record.entryAnchor).get_anchor (layout, IN_CURGLYPH (), &entry_x, &entry_y);
+    (this+record.entryAnchor).get_anchor (context, IN_CURGLYPH (), &entry_x, &entry_y);
 
     /* TODO vertical */
 
@@ -725,7 +725,7 @@ struct CursivePosFormat1
     if (record.exitAnchor)
     {
       gpi->last = buffer->in_pos;
-      (this+record.exitAnchor).get_anchor (layout, IN_CURGLYPH (), &gpi->anchor_x, &gpi->anchor_y);
+      (this+record.exitAnchor).get_anchor (context, IN_CURGLYPH (), &gpi->anchor_x, &gpi->anchor_y);
     }
 
     buffer->in_pos++;
@@ -794,7 +794,7 @@ struct MarkBasePosFormat1
     /* now we search backwards for a non-mark glyph */
     unsigned int count = buffer->in_pos;
     unsigned int i = 1, j = count - 1;
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), LookupFlag::IgnoreMarks, &property))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), LookupFlag::IgnoreMarks, &property))
     {
       if (HB_UNLIKELY (i == count))
 	return false;
@@ -821,9 +821,9 @@ struct MarkBasePosFormat1
 
     hb_position_t mark_x, mark_y, base_x, base_y;
 
-    mark_anchor.get_anchor (layout, IN_CURGLYPH (), &mark_x, &mark_y);
+    mark_anchor.get_anchor (context, IN_CURGLYPH (), &mark_x, &mark_y);
     unsigned int index = base_index * classCount + mark_class;
-    (&base_array+base_array.matrix[index]).get_anchor (layout, IN_GLYPH (j), &base_x, &base_y);
+    (&base_array+base_array.matrix[index]).get_anchor (context, IN_GLYPH (j), &base_x, &base_y);
 
     hb_internal_glyph_position_t *o = POSITION (buffer->in_pos);
     o->x_pos     = base_x - mark_x;
@@ -912,7 +912,7 @@ struct MarkLigPosFormat1
     /* now we search backwards for a non-mark glyph */
     unsigned int count = buffer->in_pos;
     unsigned int i = 1, j = count - 1;
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), LookupFlag::IgnoreMarks, &property))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), LookupFlag::IgnoreMarks, &property))
     {
       if (HB_UNLIKELY (i == count))
 	return false;
@@ -958,9 +958,9 @@ struct MarkLigPosFormat1
 
     hb_position_t mark_x, mark_y, lig_x, lig_y;
 
-    mark_anchor.get_anchor (layout, IN_CURGLYPH (), &mark_x, &mark_y);
+    mark_anchor.get_anchor (context, IN_CURGLYPH (), &mark_x, &mark_y);
     unsigned int index = comp_index * classCount + mark_class;
-    (&lig_attach+lig_attach.matrix[index]).get_anchor (layout, IN_GLYPH (j), &lig_x, &lig_y);
+    (&lig_attach+lig_attach.matrix[index]).get_anchor (context, IN_GLYPH (j), &lig_x, &lig_y);
 
     hb_internal_glyph_position_t *o = POSITION (buffer->in_pos);
     o->x_pos     = lig_x - mark_x;
@@ -1043,7 +1043,7 @@ struct MarkMarkPosFormat1
     /* now we search backwards for a suitable mark glyph until a non-mark glyph */
     unsigned int count = buffer->in_pos;
     unsigned int i = 1, j = count - 1;
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), lookup_flag, &property))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), lookup_flag, &property))
     {
       if (HB_UNLIKELY (i == count))
 	return false;
@@ -1073,9 +1073,9 @@ struct MarkMarkPosFormat1
 
     hb_position_t mark1_x, mark1_y, mark2_x, mark2_y;
 
-    mark1_anchor.get_anchor (layout, IN_CURGLYPH (), &mark1_x, &mark1_y);
+    mark1_anchor.get_anchor (context, IN_CURGLYPH (), &mark1_x, &mark1_y);
     unsigned int index = mark2_index * classCount + mark1_class;
-    (&mark2_array+mark2_array.matrix[index]).get_anchor (layout, IN_GLYPH (j), &mark2_x, &mark2_y);
+    (&mark2_array+mark2_array.matrix[index]).get_anchor (context, IN_GLYPH (j), &mark2_x, &mark2_y);
 
     hb_internal_glyph_position_t *o = POSITION (buffer->in_pos);
     o->x_pos     = mark2_x - mark1_x;
@@ -1243,7 +1243,7 @@ struct PosLookup : Lookup
     return type;
   }
 
-  inline bool apply_once (hb_ot_layout_t *layout,
+  inline bool apply_once (hb_ot_layout_context_t *context,
 			  hb_buffer_t    *buffer,
 			  unsigned int    context_length,
 			  unsigned int    nesting_level_left) const
@@ -1252,7 +1252,7 @@ struct PosLookup : Lookup
     unsigned int lookup_flag = get_flag ();
     unsigned int property;
 
-    if (!_hb_ot_layout_check_glyph_property (layout, IN_CURINFO (), lookup_flag, &property))
+    if (!_hb_ot_layout_check_glyph_property (context->layout, IN_CURINFO (), lookup_flag, &property))
       return false;
 
     for (unsigned int i = 0; i < get_subtable_count (); i++)
@@ -1262,7 +1262,7 @@ struct PosLookup : Lookup
     return false;
   }
 
-  bool apply_string (hb_ot_layout_t *layout,
+  bool apply_string (hb_ot_layout_context_t *context,
 		     hb_buffer_t    *buffer,
 		     hb_ot_layout_feature_mask_t mask) const
   {
@@ -1271,7 +1271,7 @@ struct PosLookup : Lookup
     if (HB_UNLIKELY (!buffer->in_length))
       return false;
 
-    layout->gpos_info.last = HB_OT_LAYOUT_GPOS_NO_LAST; /* no last valid glyph for cursive pos. */
+    context->info.gpos.last = HB_OT_LAYOUT_GPOS_NO_LAST; /* no last valid glyph for cursive pos. */
 
     buffer->in_pos = 0;
     while (buffer->in_pos < buffer->in_length)
@@ -1279,7 +1279,7 @@ struct PosLookup : Lookup
       bool done;
       if (~IN_PROPERTIES (buffer->in_pos) & mask)
       {
-	  done = apply_once (layout, buffer, NO_CONTEXT, MAX_NESTING_LEVEL);
+	  done = apply_once (context, buffer, NO_CONTEXT, MAX_NESTING_LEVEL);
 	  ret |= done;
       }
       else
@@ -1287,7 +1287,7 @@ struct PosLookup : Lookup
           done = false;
 	  /* Contrary to properties defined in GDEF, user-defined properties
 	     will always stop a possible cursive positioning.                */
-	  layout->gpos_info.last = HB_OT_LAYOUT_GPOS_NO_LAST;
+	  context->info.gpos.last = HB_OT_LAYOUT_GPOS_NO_LAST;
       }
 
       if (!done)
@@ -1314,11 +1314,11 @@ struct GPOS : GSUBGPOS
   inline const PosLookup& get_lookup (unsigned int i) const
   { return (const PosLookup&) GSUBGPOS::get_lookup (i); }
 
-  inline bool position_lookup (hb_ot_layout_t *layout,
+  inline bool position_lookup (hb_ot_layout_context_t *context,
 			       hb_buffer_t    *buffer,
 			       unsigned int    lookup_index,
 			       hb_ot_layout_feature_mask_t  mask) const
-  { return get_lookup (lookup_index).apply_string (layout, buffer, mask); }
+  { return get_lookup (lookup_index).apply_string (context, buffer, mask); }
 
 };
 ASSERT_SIZE (GPOS, 10);
@@ -1338,7 +1338,7 @@ inline bool ExtensionPos::apply (APPLY_ARG_DEF) const
 
 static inline bool position_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
 {
-  const GPOS &gpos = *(layout->gpos);
+  const GPOS &gpos = *(context->layout->gpos);
   const PosLookup &l = gpos.get_lookup (lookup_index);
 
   if (HB_UNLIKELY (nesting_level_left == 0))
@@ -1348,7 +1348,7 @@ static inline bool position_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
   if (HB_UNLIKELY (context_length < 1))
     return false;
 
-  return l.apply_once (layout, buffer, context_length, nesting_level_left);
+  return l.apply_once (context, buffer, context_length, nesting_level_left);
 }
 
 
diff --git a/pango/opentype/hb-ot-layout-gsub-private.h b/pango/opentype/hb-ot-layout-gsub-private.h
index 14f69e48..e4c3afb9 100644
--- a/pango/opentype/hb-ot-layout-gsub-private.h
+++ b/pango/opentype/hb-ot-layout-gsub-private.h
@@ -46,8 +46,8 @@ struct SingleSubstFormat1
     _hb_buffer_replace_glyph (buffer, glyph_id);
 
     /* We inherit the old glyph class to the substituted glyph */
-    if (_hb_ot_layout_has_new_glyph_classes (layout))
-      _hb_ot_layout_set_glyph_property (layout, glyph_id, property);
+    if (_hb_ot_layout_has_new_glyph_classes (context->layout))
+      _hb_ot_layout_set_glyph_property (context->layout, glyph_id, property);
 
     return true;
   }
@@ -81,8 +81,8 @@ struct SingleSubstFormat2
     _hb_buffer_replace_glyph (buffer, glyph_id);
 
     /* We inherit the old glyph class to the substituted glyph */
-    if (_hb_ot_layout_has_new_glyph_classes (layout))
-      _hb_ot_layout_set_glyph_property (layout, glyph_id, property);
+    if (_hb_ot_layout_has_new_glyph_classes (context->layout))
+      _hb_ot_layout_set_glyph_property (context->layout, glyph_id, property);
 
     return true;
   }
@@ -137,14 +137,14 @@ struct Sequence
 				  0xFFFF, 0xFFFF);
 
     /* This is a guess only ... */
-    if (_hb_ot_layout_has_new_glyph_classes (layout))
+    if (_hb_ot_layout_has_new_glyph_classes (context->layout))
     {
       if (property == HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE)
         property = HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
 
       unsigned int count = substitute.len;
       for (unsigned int n = 0; n < count; n++)
-	_hb_ot_layout_set_glyph_property (layout, substitute[n], property);
+	_hb_ot_layout_set_glyph_property (context->layout, substitute[n], property);
     }
 
     return true;
@@ -229,8 +229,8 @@ struct AlternateSubstFormat1
     unsigned int alt_index = 0;
 
     /* XXX callback to user to choose alternate
-    if (layout->altfunc)
-      alt_index = (layout->altfunc)(layout, buffer,
+    if (context->layout->altfunc)
+      alt_index = (context->layout->altfunc)(context->layout, buffer,
 				    buffer->out_pos, glyph_id,
 				    alt_set.len, alt_set.array);
 				   */
@@ -243,8 +243,8 @@ struct AlternateSubstFormat1
     _hb_buffer_replace_glyph (buffer, glyph_id);
 
     /* We inherit the old glyph class to the substituted glyph */
-    if (_hb_ot_layout_has_new_glyph_classes (layout))
-      _hb_ot_layout_set_glyph_property (layout, glyph_id, property);
+    if (_hb_ot_layout_has_new_glyph_classes (context->layout))
+      _hb_ot_layout_set_glyph_property (context->layout, glyph_id, property);
 
     return true;
   }
@@ -297,7 +297,7 @@ struct Ligature
 
     for (i = 1, j = buffer->in_pos + 1; i < count; i++, j++)
     {
-      while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), lookup_flag, &property))
+      while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), lookup_flag, &property))
       {
 	if (HB_UNLIKELY (j + count - i == end))
 	  return false;
@@ -311,10 +311,10 @@ struct Ligature
         return false;
     }
     /* This is just a guess ... */
-    if (_hb_ot_layout_has_new_glyph_classes (layout))
-      hb_ot_layout_set_glyph_class (layout, ligGlyph,
-				    is_mark ? HB_OT_LAYOUT_GLYPH_CLASS_MARK
-					    : HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE);
+    if (_hb_ot_layout_has_new_glyph_classes (context->layout))
+      _hb_ot_layout_set_glyph_class (context->layout, ligGlyph,
+				     is_mark ? HB_OT_LAYOUT_GLYPH_CLASS_MARK
+					     : HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE);
 
     if (j == buffer->in_pos + i) /* No input glyphs skipped */
       /* We don't use a new ligature ID if there are no skipped
@@ -338,7 +338,7 @@ struct Ligature
 
       for ( i = 1; i < count; i++ )
       {
-	while (_hb_ot_layout_skip_mark (layout, IN_CURINFO (), lookup_flag, NULL))
+	while (_hb_ot_layout_skip_mark (context->layout, IN_CURINFO (), lookup_flag, NULL))
 	  _hb_buffer_add_output_glyph (buffer, IN_CURGLYPH (), i - 1, lig_id);
 
 	(buffer->in_pos)++;
@@ -627,7 +627,7 @@ struct SubstLookup : Lookup
   inline bool is_reverse (void) const
   { return HB_UNLIKELY (get_effective_type () == SubstLookupSubTable::ReverseChainSingle); }
 
-  inline bool apply_once (hb_ot_layout_t *layout,
+  inline bool apply_once (hb_ot_layout_context_t *context,
 			  hb_buffer_t    *buffer,
 			  unsigned int    context_length,
 			  unsigned int    nesting_level_left) const
@@ -636,7 +636,7 @@ struct SubstLookup : Lookup
     unsigned int lookup_flag = get_flag ();
     unsigned int property;
 
-    if (!_hb_ot_layout_check_glyph_property (layout, IN_CURINFO (), lookup_flag, &property))
+    if (!_hb_ot_layout_check_glyph_property (context->layout, IN_CURINFO (), lookup_flag, &property))
       return false;
 
     for (unsigned int i = 0; i < get_subtable_count (); i++)
@@ -646,7 +646,7 @@ struct SubstLookup : Lookup
     return false;
   }
 
-  bool apply_string (hb_ot_layout_t *layout,
+  bool apply_string (hb_ot_layout_context_t *context,
 		     hb_buffer_t    *buffer,
 		     hb_ot_layout_feature_mask_t mask) const
   {
@@ -663,7 +663,7 @@ struct SubstLookup : Lookup
 	while (buffer->in_pos < buffer->in_length)
 	{
 	  if ((~IN_PROPERTIES (buffer->in_pos) & mask) &&
-	      apply_once (layout, buffer, NO_CONTEXT, MAX_NESTING_LEVEL))
+	      apply_once (context, buffer, NO_CONTEXT, MAX_NESTING_LEVEL))
 	    ret = true;
 	  else
 	    _hb_buffer_next_glyph (buffer);
@@ -681,7 +681,7 @@ struct SubstLookup : Lookup
 	do
 	{
 	  if ((~IN_PROPERTIES (buffer->in_pos) & mask) &&
-	      apply_once (layout, buffer, NO_CONTEXT, MAX_NESTING_LEVEL))
+	      apply_once (context, buffer, NO_CONTEXT, MAX_NESTING_LEVEL))
 	    ret = true;
 	  else
 	    buffer->in_pos--;
@@ -710,11 +710,11 @@ struct GSUB : GSUBGPOS
   inline const SubstLookup& get_lookup (unsigned int i) const
   { return (const SubstLookup&) GSUBGPOS::get_lookup (i); }
 
-  inline bool substitute_lookup (hb_ot_layout_t *layout,
+  inline bool substitute_lookup (hb_ot_layout_context_t *context,
 				 hb_buffer_t    *buffer,
 			         unsigned int    lookup_index,
 				 hb_ot_layout_feature_mask_t  mask) const
-  { return get_lookup (lookup_index).apply_string (layout, buffer, mask); }
+  { return get_lookup (lookup_index).apply_string (context, buffer, mask); }
 
 };
 ASSERT_SIZE (GSUB, 10);
@@ -734,7 +734,7 @@ inline bool ExtensionSubst::apply (APPLY_ARG_DEF) const
 
 static inline bool substitute_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
 {
-  const GSUB &gsub = *(layout->gsub);
+  const GSUB &gsub = *(context->layout->gsub);
   const SubstLookup &l = gsub.get_lookup (lookup_index);
 
   if (HB_UNLIKELY (nesting_level_left == 0))
@@ -744,7 +744,7 @@ static inline bool substitute_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
   if (HB_UNLIKELY (context_length < 1))
     return false;
 
-  return l.apply_once (layout, buffer, context_length, nesting_level_left);
+  return l.apply_once (context, buffer, context_length, nesting_level_left);
 }
 
 
diff --git a/pango/opentype/hb-ot-layout-gsubgpos-private.h b/pango/opentype/hb-ot-layout-gsubgpos-private.h
index ccbbeb86..35d8f8cb 100644
--- a/pango/opentype/hb-ot-layout-gsubgpos-private.h
+++ b/pango/opentype/hb-ot-layout-gsubgpos-private.h
@@ -32,14 +32,14 @@
 
 
 #define APPLY_ARG_DEF \
-	hb_ot_layout_t *layout, \
+	hb_ot_layout_context_t *context, \
 	hb_buffer_t    *buffer, \
 	unsigned int    context_length HB_GNUC_UNUSED, \
 	unsigned int    nesting_level_left HB_GNUC_UNUSED, \
 	unsigned int    lookup_flag, \
 	unsigned int    property HB_GNUC_UNUSED /* propety of first glyph */
 #define APPLY_ARG \
-	layout, \
+	context, \
 	buffer, \
 	context_length, \
 	nesting_level_left, \
@@ -89,7 +89,7 @@ static inline bool match_input (APPLY_ARG_DEF,
 
   for (i = 1, j = buffer->in_pos + 1; i < count; i++, j++)
   {
-    while (_hb_ot_layout_skip_mark (layout, IN_INFO (j), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_INFO (j), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (j + count - i == end))
 	return false;
@@ -116,7 +116,7 @@ static inline bool match_backtrack (APPLY_ARG_DEF,
 
   for (unsigned int i = 0, j = buffer->out_pos - 1; i < count; i++, j--)
   {
-    while (_hb_ot_layout_skip_mark (layout, OUT_INFO (j), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, OUT_INFO (j), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (j + 1 == count - i))
 	return false;
@@ -144,7 +144,7 @@ static inline bool match_lookahead (APPLY_ARG_DEF,
 
   for (i = 0, j = buffer->in_pos + offset; i < count; i++, j++)
   {
-    while (_hb_ot_layout_skip_mark (layout, OUT_INFO (j), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, OUT_INFO (j), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (j + count - i == end))
 	return false;
@@ -182,7 +182,7 @@ static inline bool apply_lookup (APPLY_ARG_DEF,
    *      Should be easy for in_place ones at least. */
   for (unsigned int i = 0; i < count; i++)
   {
-    while (_hb_ot_layout_skip_mark (layout, IN_CURINFO (), lookup_flag, NULL))
+    while (_hb_ot_layout_skip_mark (context->layout, IN_CURINFO (), lookup_flag, NULL))
     {
       if (HB_UNLIKELY (buffer->in_pos == end))
 	return true;
diff --git a/pango/opentype/hb-ot-layout-private.h b/pango/opentype/hb-ot-layout-private.h
index 3fdd4283..447c7504 100644
--- a/pango/opentype/hb-ot-layout-private.h
+++ b/pango/opentype/hb-ot-layout-private.h
@@ -31,11 +31,18 @@
 
 #include "hb-ot-layout.h"
 
+#include "hb-font-private.h"
 #include "hb-buffer-private.h"
 
 
 typedef unsigned int hb_ot_layout_class_t;
 
+/*
+ * hb_ot_layout_t
+ */
+
+typedef struct _hb_ot_layout_t hb_ot_layout_t;
+
 struct _hb_ot_layout_t
 {
   const struct GDEF *gdef;
@@ -47,17 +54,23 @@ struct _hb_ot_layout_t
     unsigned char *klasses;
     unsigned int len;
   } new_gdef;
+};
 
-  /* TODO full-matrix transformation? */
-  struct gpos_info_t
-  {
-    unsigned int x_ppem, y_ppem;
-    hb_16dot16_t x_scale, y_scale;
+typedef struct _hb_ot_layout_context_t hb_ot_layout_context_t;
+struct _hb_ot_layout_context_t
+{
+  hb_ot_layout_t *layout;
+  hb_font_t *font;
 
-    unsigned int last;        /* the last valid glyph--used with cursive positioning */
-    hb_position_t anchor_x;   /* the coordinates of the anchor point */
-    hb_position_t anchor_y;   /* of the last valid glyph */
-  } gpos_info;
+  union info_t
+  {
+    struct gpos_t
+    {
+      unsigned int last;        /* the last valid glyph--used with cursive positioning */
+      hb_position_t anchor_x;   /* the coordinates of the anchor point */
+      hb_position_t anchor_y;   /* of the last valid glyph */
+    } gpos;
+  } info;
 };
 
 
@@ -79,6 +92,11 @@ _hb_ot_layout_set_glyph_property (hb_ot_layout_t *layout,
 				  hb_codepoint_t  glyph,
 				  unsigned int    property);
 
+HB_INTERNAL void
+_hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
+			       hb_codepoint_t              glyph,
+			       hb_ot_layout_glyph_class_t  klass);
+
 HB_INTERNAL hb_bool_t
 _hb_ot_layout_check_glyph_property (hb_ot_layout_t  *layout,
 				    hb_internal_glyph_info_t *ginfo,
diff --git a/pango/opentype/hb-ot-layout.cc b/pango/opentype/hb-ot-layout.cc
index 03f7c560..a1fcdbed 100644
--- a/pango/opentype/hb-ot-layout.cc
+++ b/pango/opentype/hb-ot-layout.cc
@@ -40,30 +40,16 @@
 #include <string.h>
 
 
-hb_ot_layout_t *
-hb_ot_layout_create (void)
+void
+_hb_ot_layout_init (hb_ot_layout_t *layout,
+		    hb_face_t      *face)
 {
-  hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
-
   layout->gdef = &Null(GDEF);
   layout->gsub = &Null(GSUB);
   layout->gpos = &Null(GPOS);
-
-  return layout;
-}
-
-hb_bool_t
-hb_ot_layout_has_substitution (hb_ot_layout_t *layout)
-{
-  return layout->gsub != &Null(GSUB);
-}
-
-hb_bool_t
-hb_ot_layout_has_positioning (hb_ot_layout_t *layout)
-{
-  return layout->gpos != &Null(GPOS);
 }
 
+#if 0
 hb_ot_layout_t *
 hb_ot_layout_create_for_data (const char *font_data,
 			      int         face_index)
@@ -91,42 +77,32 @@ hb_ot_layout_create_for_tables (const char *gdef_data,
 				const char *gpos_data)
 {
   hb_ot_layout_t *layout;
-  
+
   if (HB_UNLIKELY (gdef_data == NULL && gsub_data == NULL && gpos_data == NULL))
     return hb_ot_layout_create ();
-  
+
   layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
-  
+
   layout->gdef = &GDEF::get_for_data (gdef_data);
   layout->gsub = &GSUB::get_for_data (gsub_data);
   layout->gpos = &GPOS::get_for_data (gpos_data);
-  
-  return layout;
-}
 
-void
-hb_ot_layout_destroy (hb_ot_layout_t *layout)
-{
-  free (layout);
+  return layout;
 }
+#endif
 
 void
-hb_ot_layout_set_scale (hb_ot_layout_t *layout,
-			hb_16dot16_t x_scale, hb_16dot16_t y_scale)
+_hb_ot_layout_fini (hb_ot_layout_t *layout,
+		    hb_face_t      *face)
 {
-  layout->gpos_info.x_scale = x_scale;
-  layout->gpos_info.y_scale = y_scale;
 }
 
-void
-hb_ot_layout_set_ppem (hb_ot_layout_t *layout,
-		       unsigned int x_ppem, unsigned int y_ppem)
+static hb_ot_layout_t *
+_hb_ot_face_get_layout (hb_face_t *face)
 {
-  layout->gpos_info.x_ppem = x_ppem;
-  layout->gpos_info.y_ppem = y_ppem;
+  return NULL; /* XXX */
 }
 
-
 /*
  * GDEF
  */
@@ -134,8 +110,9 @@ hb_ot_layout_set_ppem (hb_ot_layout_t *layout,
 /* TODO the public class_t is a mess */
 
 hb_bool_t
-hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout)
+hb_ot_layout_has_font_glyph_classes (hb_face_t *face)
 {
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
   return layout->gdef->has_glyph_classes ();
 }
 
@@ -243,21 +220,9 @@ _hb_ot_layout_skip_mark (hb_ot_layout_t  *layout,
 }
 
 HB_INTERNAL void
-_hb_ot_layout_set_glyph_property (hb_ot_layout_t *layout,
-				  hb_codepoint_t  glyph,
-				  unsigned int    property)
-{ hb_ot_layout_set_glyph_class (layout, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }
-
-
-hb_ot_layout_glyph_class_t
-hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
-			      hb_codepoint_t  glyph)
-{ return (hb_ot_layout_glyph_class_t) (_hb_ot_layout_get_glyph_property (layout, glyph) & 0xff); }
-
-void
-hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
-			      hb_codepoint_t              glyph,
-			      hb_ot_layout_glyph_class_t  klass)
+_hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
+			       hb_codepoint_t              glyph,
+			       hb_ot_layout_glyph_class_t  klass)
 {
   /* TODO optimize this? similar to old harfbuzz code for example */
 
@@ -299,13 +264,39 @@ hb_ot_layout_set_glyph_class (hb_ot_layout_t             *layout,
   return;
 }
 
+HB_INTERNAL void
+_hb_ot_layout_set_glyph_property (hb_ot_layout_t *layout,
+				  hb_codepoint_t  glyph,
+				  unsigned int    property)
+{ _hb_ot_layout_set_glyph_class (layout, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }
+
+
+hb_ot_layout_glyph_class_t
+hb_ot_layout_get_glyph_class (hb_face_t      *face,
+			      hb_codepoint_t  glyph)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  return (hb_ot_layout_glyph_class_t) (_hb_ot_layout_get_glyph_property (layout, glyph) & 0xff);
+}
+
 void
-hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
+hb_ot_layout_set_glyph_class (hb_face_t                 *face,
+			      hb_codepoint_t             glyph,
+			      hb_ot_layout_glyph_class_t klass)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  _hb_ot_layout_set_glyph_class (layout, glyph, klass);
+}
+
+void
+hb_ot_layout_build_glyph_classes (hb_face_t      *face,
 				  uint16_t        num_total_glyphs,
 				  hb_codepoint_t *glyphs,
 				  unsigned char  *klasses,
 				  uint16_t        count)
 {
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+
   if (HB_UNLIKELY (!count || !glyphs || !klasses))
     return;
 
@@ -315,25 +306,30 @@ hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
   }
 
   for (unsigned int i = 0; i < count; i++)
-    hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
+    _hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
 }
 
 hb_bool_t
-hb_ot_layout_get_attach_points (hb_ot_layout_t *layout,
+hb_ot_layout_get_attach_points (hb_face_t      *face,
 				hb_codepoint_t  glyph,
 				unsigned int   *point_count /* IN/OUT */,
 				unsigned int   *point_array /* OUT */)
 {
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
   return layout->gdef->get_attach_points (glyph, point_count, point_array);
 }
 
 hb_bool_t
-hb_ot_layout_get_lig_carets (hb_ot_layout_t *layout,
+hb_ot_layout_get_lig_carets (hb_face_t      *face,
+			     hb_font_t      *font,
 			     hb_codepoint_t  glyph,
 			     unsigned int   *caret_count /* IN/OUT */,
 			     int            *caret_array /* OUT */)
 {
-  return layout->gdef->get_lig_carets (layout, glyph, caret_count, caret_array);
+  hb_ot_layout_context_t context;
+  context.font = font;
+  context.layout = _hb_ot_face_get_layout (face);
+  return context.layout->gdef->get_lig_carets (&context, glyph, caret_count, caret_array);
 }
 
 /*
@@ -341,44 +337,47 @@ hb_ot_layout_get_lig_carets (hb_ot_layout_t *layout,
  */
 
 static const GSUBGPOS&
-get_gsubgpos_table (hb_ot_layout_t            *layout,
-		    hb_ot_layout_table_type_t  table_type)
+get_gsubgpos_table (hb_ot_layout_t *layout,
+		    hb_tag_t        table_tag)
 {
-  switch (table_type) {
-    case HB_OT_LAYOUT_TABLE_TYPE_GSUB: return *(layout->gsub);
-    case HB_OT_LAYOUT_TABLE_TYPE_GPOS: return *(layout->gpos);
-    default:                           return Null(GSUBGPOS);
+  switch (table_tag) {
+    case HB_OT_TAG_GSUB: return *(layout->gsub);
+    case HB_OT_TAG_GPOS: return *(layout->gpos);
+    default:             return Null(GSUBGPOS);
   }
 }
 
 
 unsigned int
-hb_ot_layout_table_get_script_count (hb_ot_layout_t            *layout,
-				     hb_ot_layout_table_type_t  table_type)
+hb_ot_layout_table_get_script_count (hb_face_t *face,
+				     hb_tag_t   table_tag)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   return g.get_script_count ();
 }
 
 hb_tag_t
-hb_ot_layout_table_get_script_tag (hb_ot_layout_t            *layout,
-				   hb_ot_layout_table_type_t  table_type,
-				   unsigned int               script_index)
+hb_ot_layout_table_get_script_tag (hb_face_t    *face,
+				   hb_tag_t      table_tag,
+				   unsigned int  script_index)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   return g.get_script_tag (script_index);
 }
 
 hb_bool_t
-hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
-				hb_ot_layout_table_type_t  table_type,
-				hb_tag_t                   script_tag,
-				unsigned int              *script_index)
+hb_ot_layout_table_find_script (hb_face_t    *face,
+				hb_tag_t      table_tag,
+				hb_tag_t      script_tag,
+				unsigned int *script_index)
 {
   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   if (g.find_script_index (script_tag, script_index))
     return TRUE;
@@ -396,32 +395,35 @@ hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
 }
 
 unsigned int
-hb_ot_layout_table_get_feature_count (hb_ot_layout_t            *layout,
-				      hb_ot_layout_table_type_t  table_type)
+hb_ot_layout_table_get_feature_count (hb_face_t *face,
+				      hb_tag_t   table_tag)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   return g.get_feature_count ();
 }
 
 hb_tag_t
-hb_ot_layout_table_get_feature_tag (hb_ot_layout_t            *layout,
-				    hb_ot_layout_table_type_t  table_type,
-				    unsigned int               feature_index)
+hb_ot_layout_table_get_feature_tag (hb_face_t    *face,
+				    hb_tag_t      table_tag,
+				    unsigned int  feature_index)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   return g.get_feature_tag (feature_index);
 }
 
 hb_bool_t
-hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
-				 hb_ot_layout_table_type_t  table_type,
-				 hb_tag_t                   feature_tag,
-				 unsigned int              *feature_index)
+hb_ot_layout_table_find_feature (hb_face_t    *face,
+				 hb_tag_t      table_tag,
+				 hb_tag_t      feature_tag,
+				 unsigned int *feature_index)
 {
   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   if (g.find_feature_index (feature_tag, feature_index))
     return TRUE;
@@ -431,45 +433,49 @@ hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
 }
 
 unsigned int
-hb_ot_layout_table_get_lookup_count (hb_ot_layout_t            *layout,
-				     hb_ot_layout_table_type_t  table_type)
+hb_ot_layout_table_get_lookup_count (hb_face_t *face,
+				     hb_tag_t   table_tag)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
 
   return g.get_lookup_count ();
 }
 
 
 unsigned int
-hb_ot_layout_script_get_language_count (hb_ot_layout_t            *layout,
-					hb_ot_layout_table_type_t  table_type,
-					unsigned int               script_index)
+hb_ot_layout_script_get_language_count (hb_face_t    *face,
+					hb_tag_t      table_tag,
+					unsigned int  script_index)
 {
-  const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const Script &s = get_gsubgpos_table (layout, table_tag).get_script (script_index);
 
   return s.get_lang_sys_count ();
 }
 
 hb_tag_t
-hb_ot_layout_script_get_language_tag (hb_ot_layout_t            *layout,
-				      hb_ot_layout_table_type_t  table_type,
-				      unsigned int               script_index,
-				      unsigned int               language_index)
+hb_ot_layout_script_get_language_tag (hb_face_t    *face,
+				      hb_tag_t      table_tag,
+				      unsigned int  script_index,
+				      unsigned int  language_index)
 {
-  const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const Script &s = get_gsubgpos_table (layout, table_tag).get_script (script_index);
 
   return s.get_lang_sys_tag (language_index);
 }
 
 hb_bool_t
-hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
-				   hb_ot_layout_table_type_t  table_type,
-				   unsigned int               script_index,
-				   hb_tag_t                   language_tag,
-				   unsigned int              *language_index)
+hb_ot_layout_script_find_language (hb_face_t    *face,
+				   hb_tag_t      table_tag,
+				   unsigned int  script_index,
+				   hb_tag_t      language_tag,
+				   unsigned int *language_index)
 {
   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
-  const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const Script &s = get_gsubgpos_table (layout, table_tag).get_script (script_index);
 
   if (s.find_lang_sys_index (language_tag, language_index))
     return TRUE;
@@ -483,13 +489,14 @@ hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
 }
 
 hb_bool_t
-hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *layout,
-						  hb_ot_layout_table_type_t  table_type,
-						  unsigned int               script_index,
-						  unsigned int               language_index,
-						  unsigned int              *feature_index)
+hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
+						  hb_tag_t      table_tag,
+						  unsigned int  script_index,
+						  unsigned int  language_index,
+						  unsigned int *feature_index)
 {
-  const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const LangSys &l = get_gsubgpos_table (layout, table_tag).get_script (script_index).get_lang_sys (language_index);
 
   if (feature_index) *feature_index = l.get_required_feature_index ();
 
@@ -497,37 +504,40 @@ hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *lay
 }
 
 unsigned int
-hb_ot_layout_language_get_feature_count (hb_ot_layout_t            *layout,
-					 hb_ot_layout_table_type_t  table_type,
-					 unsigned int               script_index,
-					 unsigned int               language_index)
+hb_ot_layout_language_get_feature_count (hb_face_t    *face,
+					 hb_tag_t      table_tag,
+					 unsigned int  script_index,
+					 unsigned int  language_index)
 {
-  const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const LangSys &l = get_gsubgpos_table (layout, table_tag).get_script (script_index).get_lang_sys (language_index);
 
   return l.get_feature_count ();
 }
 
 unsigned int
-hb_ot_layout_language_get_feature_index (hb_ot_layout_t            *layout,
-					 hb_ot_layout_table_type_t  table_type,
-					 unsigned int               script_index,
-					 unsigned int               language_index,
-					 unsigned int               num_feature)
-{
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+hb_ot_layout_language_get_feature_index (hb_face_t    *face,
+					 hb_tag_t      table_tag,
+					 unsigned int  script_index,
+					 unsigned int  language_index,
+					 unsigned int  num_feature)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 
   return l.get_feature_index (num_feature);
 }
 
 hb_tag_t
-hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               script_index,
-				       unsigned int               language_index,
-				       unsigned int               num_feature)
-{
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+hb_ot_layout_language_get_feature_tag (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  script_index,
+				       unsigned int  language_index,
+				       unsigned int  num_feature)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
   unsigned int feature_index = l.get_feature_index (num_feature);
 
@@ -536,15 +546,16 @@ hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
 
 
 hb_bool_t
-hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
-				    hb_ot_layout_table_type_t  table_type,
-				    unsigned int               script_index,
-				    unsigned int               language_index,
-				    hb_tag_t                   feature_tag,
-				    unsigned int              *feature_index)
+hb_ot_layout_language_find_feature (hb_face_t    *face,
+				    hb_tag_t      table_tag,
+				    unsigned int  script_index,
+				    unsigned int  language_index,
+				    hb_tag_t      feature_tag,
+				    unsigned int *feature_index)
 {
   ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
   const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
 
   unsigned int num_features = l.get_feature_count ();
@@ -562,23 +573,25 @@ hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
 }
 
 unsigned int
-hb_ot_layout_feature_get_lookup_count (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               feature_index)
+hb_ot_layout_feature_get_lookup_count (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  feature_index)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
   const Feature &f = g.get_feature (feature_index);
 
   return f.get_lookup_count ();
 }
 
 unsigned int
-hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               feature_index,
-				       unsigned int               num_lookup)
+hb_ot_layout_feature_get_lookup_index (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  feature_index,
+				       unsigned int  num_lookup)
 {
-  const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  const GSUBGPOS &g = get_gsubgpos_table (layout, table_tag);
   const Feature &f = g.get_feature (feature_index);
 
   return f.get_lookup_index (num_lookup);
@@ -589,12 +602,22 @@ hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
  */
 
 hb_bool_t
-hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
+hb_ot_layout_has_substitution (hb_face_t *face)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  return layout->gsub != &Null(GSUB);
+}
+
+hb_bool_t
+hb_ot_layout_substitute_lookup (hb_face_t                   *face,
 				hb_buffer_t                 *buffer,
-			        unsigned int                 lookup_index,
+				unsigned int                 lookup_index,
 				hb_ot_layout_feature_mask_t  mask)
 {
-  return layout->gsub->substitute_lookup (layout, buffer, lookup_index, mask);
+  hb_ot_layout_context_t context;
+  context.font = NULL;
+  context.layout = _hb_ot_face_get_layout (face);
+  return context.layout->gsub->substitute_lookup (&context, buffer, lookup_index, mask);
 }
 
 /*
@@ -602,10 +625,21 @@ hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
  */
 
 hb_bool_t
-hb_ot_layout_position_lookup   (hb_ot_layout_t              *layout,
+hb_ot_layout_has_positioning (hb_face_t *face)
+{
+  hb_ot_layout_t *layout = _hb_ot_face_get_layout (face);
+  return layout->gpos != &Null(GPOS);
+}
+
+hb_bool_t
+hb_ot_layout_position_lookup   (hb_face_t                   *face,
+				hb_font_t                   *font,
 				hb_buffer_t                 *buffer,
-			        unsigned int                 lookup_index,
+				unsigned int                 lookup_index,
 				hb_ot_layout_feature_mask_t  mask)
 {
-  return layout->gpos->position_lookup (layout, buffer, lookup_index, mask);
+  hb_ot_layout_context_t context;
+  context.font = font;
+  context.layout = _hb_ot_face_get_layout (font->face);
+  return context.layout->gpos->position_lookup (&context, buffer, lookup_index, mask);
 }
diff --git a/pango/opentype/hb-ot-layout.h b/pango/opentype/hb-ot-layout.h
index d19f558a..889a2bd2 100644
--- a/pango/opentype/hb-ot-layout.h
+++ b/pango/opentype/hb-ot-layout.h
@@ -29,40 +29,13 @@
 
 #include "hb-common.h"
 #include "hb-buffer.h"
+#include "hb-font.h"
 
 HB_BEGIN_DECLS
 
-/*
- * hb_ot_layout_t
- */
-
-typedef struct _hb_ot_layout_t hb_ot_layout_t;
-
-hb_ot_layout_t *
-hb_ot_layout_create (void);
-
-hb_ot_layout_t *
-hb_ot_layout_create_for_data (const char *font_data,
-			      int         face_index);
-
-hb_ot_layout_t *
-hb_ot_layout_create_for_tables (const char *gdef_data,
-				const char *gsub_data,
-				const char *gpos_data);
-
-void
-hb_ot_layout_destroy (hb_ot_layout_t *layout);
-
-void
-hb_ot_layout_set_scale (hb_ot_layout_t *layout,
-			hb_16dot16_t x_scale, hb_16dot16_t y_scale);
-
-void
-hb_ot_layout_set_ppem (hb_ot_layout_t *layout,
-		       unsigned int x_ppem, unsigned int y_ppem);
-
-/* TODO sanitizing API/constructor (make_writable_func_t) */
-/* TODO get_table_func_t constructor */
+#define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
+#define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
+#define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
 
 /*
  * GDEF
@@ -76,33 +49,37 @@ typedef enum {
   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT	= 0x0010
 } hb_ot_layout_glyph_class_t;
 
+/* XXX These should eventually be removed as we move synthesized glyph
+ * classes in harfbuzz. */
+
 hb_bool_t
-hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout);
+hb_ot_layout_has_font_glyph_classes (hb_face_t *face);
 
 hb_ot_layout_glyph_class_t
-hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
+hb_ot_layout_get_glyph_class (hb_face_t      *face,
 			      hb_codepoint_t  glyph);
 
 void
-hb_ot_layout_set_glyph_class (hb_ot_layout_t            *layout,
+hb_ot_layout_set_glyph_class (hb_face_t                 *face,
 			      hb_codepoint_t             glyph,
 			      hb_ot_layout_glyph_class_t klass);
 
 void
-hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
-				  uint16_t        num_total_glyphs,
-				  hb_codepoint_t *glyphs,
-				  unsigned char  *klasses,
-				  uint16_t        count);
+hb_ot_layout_build_glyph_classes (hb_face_t      *face,
+				uint16_t        num_total_glyphs,
+				hb_codepoint_t *glyphs,
+				unsigned char  *klasses,
+				uint16_t        count);
 
 hb_bool_t
-hb_ot_layout_get_attach_points (hb_ot_layout_t *layout,
+hb_ot_layout_get_attach_points (hb_face_t      *face,
 				hb_codepoint_t  glyph,
 				unsigned int   *point_count /* IN/OUT */,
 				unsigned int   *point_array /* OUT */);
 
 hb_bool_t
-hb_ot_layout_get_lig_carets (hb_ot_layout_t *layout,
+hb_ot_layout_get_lig_carets (hb_face_t      *face,
+			     hb_font_t      *font,
 			     hb_codepoint_t  glyph,
 			     unsigned int   *caret_count /* IN/OUT */,
 			     int            *caret_array /* OUT */);
@@ -111,12 +88,6 @@ hb_ot_layout_get_lig_carets (hb_ot_layout_t *layout,
  * GSUB/GPOS
  */
 
-typedef enum {
-  HB_OT_LAYOUT_TABLE_TYPE_GSUB,
-  HB_OT_LAYOUT_TABLE_TYPE_GPOS,
-  HB_OT_LAYOUT_TABLE_TYPE_NONE
-} hb_ot_layout_table_type_t;
-
 typedef uint32_t hb_ot_layout_feature_mask_t;
 
 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX		((unsigned int) 0xFFFF)
@@ -126,114 +97,115 @@ typedef uint32_t hb_ot_layout_feature_mask_t;
 #define HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE	HB_TAG ('d', 'f', 'l', 't')
 
 unsigned int
-hb_ot_layout_table_get_script_count (hb_ot_layout_t            *layout,
-				     hb_ot_layout_table_type_t  table_type);
+hb_ot_layout_table_get_script_count (hb_face_t *face,
+				     hb_tag_t   table_tag);
 
 hb_tag_t
-hb_ot_layout_table_get_script_tag (hb_ot_layout_t            *layout,
-				   hb_ot_layout_table_type_t  table_type,
-				   unsigned int               script_index);
+hb_ot_layout_table_get_script_tag (hb_face_t    *face,
+				   hb_tag_t      table_tag,
+				   unsigned int  script_index);
 
 hb_bool_t
-hb_ot_layout_table_find_script (hb_ot_layout_t            *layout,
-				hb_ot_layout_table_type_t  table_type,
-				hb_tag_t                   script_tag,
-				unsigned int              *script_index);
+hb_ot_layout_table_find_script (hb_face_t    *face,
+				hb_tag_t      table_tag,
+				hb_tag_t      script_tag,
+				unsigned int *script_index);
 
 unsigned int
-hb_ot_layout_table_get_feature_count (hb_ot_layout_t            *layout,
-				      hb_ot_layout_table_type_t  table_type);
+hb_ot_layout_table_get_feature_count (hb_face_t *face,
+				      hb_tag_t   table_tag);
 
 hb_tag_t
-hb_ot_layout_table_get_feature_tag (hb_ot_layout_t            *layout,
-				    hb_ot_layout_table_type_t  table_type,
-				    unsigned int               feature_index);
+hb_ot_layout_table_get_feature_tag (hb_face_t    *face,
+				    hb_tag_t      table_tag,
+				    unsigned int  feature_index);
 
 hb_bool_t
-hb_ot_layout_table_find_feature (hb_ot_layout_t            *layout,
-				 hb_ot_layout_table_type_t  table_type,
-				 hb_tag_t                   feature_tag,
-				 unsigned int              *feature_index);
+hb_ot_layout_table_find_feature (hb_face_t    *face,
+				 hb_tag_t      table_tag,
+				 hb_tag_t      feature_tag,
+				 unsigned int *feature_index);
 
 unsigned int
-hb_ot_layout_table_get_lookup_count (hb_ot_layout_t            *layout,
-				     hb_ot_layout_table_type_t  table_type);
+hb_ot_layout_table_get_lookup_count (hb_face_t  *face,
+				     hb_tag_t    table_tag);
 
 unsigned int
-hb_ot_layout_script_get_language_count (hb_ot_layout_t            *layout,
-					hb_ot_layout_table_type_t  table_type,
-					unsigned int               script_index);
+hb_ot_layout_script_get_language_count (hb_face_t    *face,
+					hb_tag_t      table_tag,
+					unsigned int  script_index);
 
 hb_tag_t
-hb_ot_layout_script_get_language_tag (hb_ot_layout_t            *layout,
-				      hb_ot_layout_table_type_t  table_type,
-				      unsigned int               script_index,
-				      unsigned int               language_index);
+hb_ot_layout_script_get_language_tag (hb_face_t    *face,
+				      hb_tag_t      table_tag,
+				      unsigned int  script_index,
+				      unsigned int  language_index);
 
 hb_bool_t
-hb_ot_layout_script_find_language (hb_ot_layout_t            *layout,
-				   hb_ot_layout_table_type_t  table_type,
-				   unsigned int               script_index,
-				   hb_tag_t                   language_tag,
-				   unsigned int              *language_index);
+hb_ot_layout_script_find_language (hb_face_t    *face,
+				   hb_tag_t      table_tag,
+				   unsigned int  script_index,
+				   hb_tag_t      language_tag,
+				   unsigned int *language_index);
 
 hb_bool_t
-hb_ot_layout_language_get_required_feature_index (hb_ot_layout_t            *layout,
-						  hb_ot_layout_table_type_t  table_type,
-						  unsigned int               script_index,
-						  unsigned int               language_index,
-						  unsigned int              *feature_index);
+hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
+						  hb_tag_t      table_tag,
+						  unsigned int  script_index,
+						  unsigned int  language_index,
+						  unsigned int *feature_index);
 
 unsigned int
-hb_ot_layout_language_get_feature_count (hb_ot_layout_t            *layout,
-					 hb_ot_layout_table_type_t  table_type,
-					 unsigned int               script_index,
-					 unsigned int               language_index);
+hb_ot_layout_language_get_feature_count (hb_face_t    *face,
+					 hb_tag_t      table_tag,
+					 unsigned int  script_index,
+					 unsigned int  language_index);
 
 unsigned int
-hb_ot_layout_language_get_feature_index (hb_ot_layout_t            *layout,
-				         hb_ot_layout_table_type_t  table_type,
-				         unsigned int               script_index,
-				         unsigned int               language_index,
-				         unsigned int               num_feature);
+hb_ot_layout_language_get_feature_index (hb_face_t    *face,
+					 hb_tag_t      table_tag,
+					 unsigned int  script_index,
+					 unsigned int  language_index,
+					 unsigned int  num_feature);
 
 hb_tag_t
-hb_ot_layout_language_get_feature_tag (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               script_index,
-				       unsigned int               language_index,
-				       unsigned int               num_feature);
+hb_ot_layout_language_get_feature_tag (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  script_index,
+				       unsigned int  language_index,
+				       unsigned int  num_feature);
 
 hb_bool_t
-hb_ot_layout_language_find_feature (hb_ot_layout_t            *layout,
-				    hb_ot_layout_table_type_t  table_type,
-				    unsigned int               script_index,
-				    unsigned int               language_index,
-				    hb_tag_t                   feature_tag,
-				    unsigned int              *feature_index);
+hb_ot_layout_language_find_feature (hb_face_t    *face,
+				    hb_tag_t      table_tag,
+				    unsigned int  script_index,
+				    unsigned int  language_index,
+				    hb_tag_t      feature_tag,
+				    unsigned int *feature_index);
 
 unsigned int
-hb_ot_layout_feature_get_lookup_count (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               feature_index);
+hb_ot_layout_feature_get_lookup_count (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  feature_index);
 
 unsigned int
-hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t            *layout,
-				       hb_ot_layout_table_type_t  table_type,
-				       unsigned int               feature_index,
-				       unsigned int               num_lookup);
+hb_ot_layout_feature_get_lookup_index (hb_face_t    *face,
+				       hb_tag_t      table_tag,
+				       unsigned int  feature_index,
+				       unsigned int  num_lookup);
 
 /*
  * GSUB
  */
 
 hb_bool_t
-hb_ot_layout_has_substitution (hb_ot_layout_t *layout);
+hb_ot_layout_has_substitution (hb_face_t *face);
 
+/* GSUB is not font-size dependent, so we apply on face */
 hb_bool_t
-hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
+hb_ot_layout_substitute_lookup (hb_face_t                   *face,
 				hb_buffer_t                 *buffer,
-			        unsigned int                 lookup_index,
+				unsigned int                 lookup_index,
 				hb_ot_layout_feature_mask_t  mask);
 
 /*
@@ -241,12 +213,13 @@ hb_ot_layout_substitute_lookup (hb_ot_layout_t              *layout,
  */
 
 hb_bool_t
-hb_ot_layout_has_positioning (hb_ot_layout_t *layout);
+hb_ot_layout_has_positioning (hb_face_t *face);
 
 hb_bool_t
-hb_ot_layout_position_lookup   (hb_ot_layout_t              *layout,
+hb_ot_layout_position_lookup   (hb_face_t                   *face,
+				hb_font_t                   *font,
 				hb_buffer_t                 *buffer,
-			        unsigned int                 lookup_index,
+				unsigned int                 lookup_index,
 				hb_ot_layout_feature_mask_t  mask);
 
 
diff --git a/pango/pango-ot-buffer.c b/pango/pango-ot-buffer.c
index f42dc3e8..a4aacc3a 100644
--- a/pango/pango-ot-buffer.c
+++ b/pango/pango-ot-buffer.c
@@ -327,7 +327,7 @@ pango_ot_buffer_output (const PangoOTBuffer *buffer,
 			PangoGlyphString    *glyphs)
 {
   FT_Face face;
-  hb_ot_layout_t *layout;
+  hb_face_t *hb_face;
   unsigned int i;
   int last_cluster;
 
@@ -359,7 +359,7 @@ pango_ot_buffer_output (const PangoOTBuffer *buffer,
       last_cluster = glyphs->log_clusters[i];
     }
 
-  layout = _pango_ot_info_get_layout (pango_ot_info_get (face));
+  hb_face = _pango_ot_info_get_hb_face (pango_ot_info_get (face));
 
   /* Apply default positioning */
   for (i = 0; i < (unsigned int)glyphs->num_glyphs; i++)
@@ -369,7 +369,7 @@ pango_ot_buffer_output (const PangoOTBuffer *buffer,
 	  PangoRectangle logical_rect;
 
 	  if (buffer->zero_width_marks &&
-	      hb_ot_layout_get_glyph_class (layout, glyphs->glyphs[i].glyph) == HB_OT_LAYOUT_GLYPH_CLASS_MARK)
+	      hb_ot_layout_get_glyph_class (hb_face, glyphs->glyphs[i].glyph) == HB_OT_LAYOUT_GLYPH_CLASS_MARK)
 	    {
 	      glyphs->glyphs[i].geometry.width = 0;
 	    }
diff --git a/pango/pango-ot-info.c b/pango/pango-ot-info.c
index f3c2fc3f..1eaa67f3 100644
--- a/pango/pango-ot-info.c
+++ b/pango/pango-ot-info.c
@@ -74,8 +74,8 @@ pango_ot_info_finalize (GObject *object)
 {
   PangoOTInfo *info = PANGO_OT_INFO (object);
 
-  if (info->layout)
-    hb_ot_layout_destroy (info->layout);
+  if (info->hb_face)
+    hb_face_destroy (info->hb_face);
 
   parent_class->finalize (object);
 }
@@ -117,23 +117,30 @@ pango_ot_info_get (FT_Face face)
 
       if (FT_IS_SFNT (face))
         {
-	  /* XXX handle face->stream->base == NULL better */
-	  info->layout = hb_ot_layout_create_for_data ((const char *) face->stream->base, face->face_index);
+	  hb_blob_t *blob;
 
-	  if (!hb_ot_layout_has_font_glyph_classes (info->layout))
+	  /* XXX handle face->stream->base == NULL better */
+	  blob = hb_blob_create ((const char *) face->stream->base,
+				 (unsigned int) face->stream->size,
+				 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITEABLE,
+				 NULL, NULL);
+	  info->hb_face = hb_face_create_for_data (blob, face->face_index);
+	  hb_blob_destroy (blob);
+
+	  if (!hb_ot_layout_has_font_glyph_classes (info->hb_face))
 	    synthesize_class_def (info);
 	}
       else
-        info->layout = hb_ot_layout_create ();
+        info->hb_face = hb_face_create_for_data (NULL, 0);
     }
 
   return info;
 }
 
-hb_ot_layout_t *
-_pango_ot_info_get_layout (PangoOTInfo *info)
+hb_face_t *
+_pango_ot_info_get_hb_face (PangoOTInfo *info)
 {
-  return info->layout;
+  return info->hb_face;
 }
 
 typedef struct _GlyphInfo GlyphInfo;
@@ -263,7 +270,7 @@ synthesize_class_def (PangoOTInfo *info)
 
   g_array_free (glyph_infos, TRUE);
 
-  hb_ot_layout_build_glyph_classes (info->layout, info->face->num_glyphs,
+  hb_ot_layout_build_glyph_classes (info->hb_face, info->face->num_glyphs,
 				    glyph_indices, classes, j);
 
   g_free (glyph_indices);
@@ -273,13 +280,13 @@ synthesize_class_def (PangoOTInfo *info)
     FT_Set_Charmap (info->face, old_charmap);
 }
 
-static hb_ot_layout_table_type_t
+static hb_tag_t
 get_hb_table_type (PangoOTTableType table_type)
 {
   switch (table_type) {
-    case PANGO_OT_TABLE_GSUB: return HB_OT_LAYOUT_TABLE_TYPE_GSUB;
-    case PANGO_OT_TABLE_GPOS: return HB_OT_LAYOUT_TABLE_TYPE_GPOS;
-    default:                  return (hb_ot_layout_table_type_t) -1;
+    case PANGO_OT_TABLE_GSUB: return HB_OT_TAG_GSUB;
+    case PANGO_OT_TABLE_GPOS: return HB_OT_TAG_GPOS;
+    default:                  return HB_TAG_NONE;
   }
 }
 
@@ -308,9 +315,9 @@ pango_ot_info_find_script (PangoOTInfo      *info,
 			   PangoOTTag        script_tag,
 			   guint            *script_index)
 {
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
 
-  return hb_ot_layout_table_find_script (info->layout, tt,
+  return hb_ot_layout_table_find_script (info->hb_face, tt,
 					 script_tag,
 					 script_index);
 }
@@ -346,15 +353,15 @@ pango_ot_info_find_language (PangoOTInfo      *info,
 {
   gboolean ret;
   unsigned l_index;
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
 
-  ret = hb_ot_layout_script_find_language (info->layout, tt,
+  ret = hb_ot_layout_script_find_language (info->hb_face, tt,
 					   script_index,
 					   language_tag,
 					   &l_index);
   if (language_index) *language_index = l_index;
 
-  hb_ot_layout_language_get_required_feature_index (info->layout, tt,
+  hb_ot_layout_language_get_required_feature_index (info->hb_face, tt,
 						    script_index,
 						    l_index,
 						    required_feature_index);
@@ -392,9 +399,9 @@ pango_ot_info_find_feature  (PangoOTInfo      *info,
 			     guint             language_index,
 			     guint            *feature_index)
 {
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
 
-  return hb_ot_layout_language_find_feature (info->layout, tt,
+  return hb_ot_layout_language_find_feature (info->hb_face, tt,
 					     script_index,
 					     language_index,
 					     feature_tag,
@@ -415,16 +422,16 @@ PangoOTTag *
 pango_ot_info_list_scripts (PangoOTInfo      *info,
 			    PangoOTTableType  table_type)
 {
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
   PangoOTTag *result;
   unsigned int count, i;
 
-  count = hb_ot_layout_table_get_script_count (info->layout, tt);
+  count = hb_ot_layout_table_get_script_count (info->hb_face, tt);
 
   result = g_new (PangoOTTag, count + 1);
 
   for (i = 0; i < count; i++)
-    result[i] = hb_ot_layout_table_get_script_tag (info->layout, tt, i);
+    result[i] = hb_ot_layout_table_get_script_tag (info->hb_face, tt, i);
 
   result[i] = 0;
 
@@ -449,17 +456,17 @@ pango_ot_info_list_languages (PangoOTInfo      *info,
 			      guint             script_index,
 			      PangoOTTag        language_tag G_GNUC_UNUSED)
 {
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
   PangoOTTag *result;
   unsigned int count, i;
 
-  count = hb_ot_layout_script_get_language_count (info->layout, tt,
+  count = hb_ot_layout_script_get_language_count (info->hb_face, tt,
 						  script_index);
 
   result = g_new (PangoOTTag, count + 1);
 
   for (i = 0; i < count; i++)
-    result[i] = hb_ot_layout_script_get_language_tag (info->layout, tt,
+    result[i] = hb_ot_layout_script_get_language_tag (info->hb_face, tt,
 						      script_index,
 						      i);
 
@@ -490,18 +497,18 @@ pango_ot_info_list_features  (PangoOTInfo      *info,
 			      guint             script_index,
 			      guint             language_index)
 {
-  hb_ot_layout_table_type_t tt = get_hb_table_type (table_type);
+  hb_tag_t tt = get_hb_table_type (table_type);
   PangoOTTag *result;
   unsigned int count, i;
 
-  count = hb_ot_layout_language_get_feature_count (info->layout, tt,
+  count = hb_ot_layout_language_get_feature_count (info->hb_face, tt,
 						   script_index,
 						   language_index);
 
   result = g_new (PangoOTTag, count + 1);
 
   for (i = 0; i < count; i++)
-    result[i] = hb_ot_layout_language_get_feature_tag (info->layout, tt,
+    result[i] = hb_ot_layout_language_get_feature_tag (info->hb_face, tt,
 						       script_index,
 						       language_index,
 						       i);
@@ -528,19 +535,19 @@ _pango_ot_info_substitute  (const PangoOTInfo    *info,
 	continue;
 
       mask = rule->property_bit;
-      lookup_count = hb_ot_layout_feature_get_lookup_count (info->layout,
-							    HB_OT_LAYOUT_TABLE_TYPE_GSUB,
+      lookup_count = hb_ot_layout_feature_get_lookup_count (info->hb_face,
+							    HB_OT_TAG_GSUB,
 							    rule->feature_index);
 
       for (j = 0; j < lookup_count; j++)
         {
 	  unsigned int lookup_index;
 
-	  lookup_index = hb_ot_layout_feature_get_lookup_index (info->layout,
-								HB_OT_LAYOUT_TABLE_TYPE_GSUB,
+	  lookup_index = hb_ot_layout_feature_get_lookup_index (info->hb_face,
+								HB_OT_TAG_GSUB,
 								rule->feature_index,
 								j);
-	  hb_ot_layout_substitute_lookup (info->layout,
+	  hb_ot_layout_substitute_lookup (info->hb_face,
 					  buffer->buffer,
 					  lookup_index,
 					  rule->property_bit);
@@ -554,19 +561,20 @@ _pango_ot_info_position    (const PangoOTInfo    *info,
 			    PangoOTBuffer        *buffer)
 {
   unsigned int i;
+  gboolean is_hinted;
+  hb_font_t *hb_font;
 
   hb_buffer_clear_positions (buffer->buffer);
 
-  hb_ot_layout_set_scale (info->layout,
-			  info->face->size->metrics.x_scale,
-			  info->face->size->metrics.y_scale);
-
-  if (buffer->font->is_hinted)
-    hb_ot_layout_set_ppem (info->layout,
-			   info->face->size->metrics.x_ppem,
-			   info->face->size->metrics.y_ppem);
-  else
-    hb_ot_layout_set_ppem (info->layout, 0, 0);
+  /* XXX reuse hb_font */
+  hb_font = hb_font_create (info->hb_face);
+  hb_font_set_scale (hb_font,
+		     info->face->size->metrics.x_scale,
+		     info->face->size->metrics.y_scale);
+  is_hinted = buffer->font->is_hinted;
+  hb_font_set_ppem (hb_font,
+		    is_hinted ? info->face->size->metrics.x_ppem : 0,
+		    is_hinted ? info->face->size->metrics.y_ppem : 0);
 
   for (i = 0; i < ruleset->rules->len; i++)
     {
@@ -578,19 +586,19 @@ _pango_ot_info_position    (const PangoOTInfo    *info,
 	continue;
 
       mask = rule->property_bit;
-      lookup_count = hb_ot_layout_feature_get_lookup_count (info->layout,
-							    HB_OT_LAYOUT_TABLE_TYPE_GPOS,
+      lookup_count = hb_ot_layout_feature_get_lookup_count (info->hb_face,
+							    HB_OT_TAG_GPOS,
 							    rule->feature_index);
 
       for (j = 0; j < lookup_count; j++)
         {
 	  unsigned int lookup_index;
 
-	  lookup_index = hb_ot_layout_feature_get_lookup_index (info->layout,
-								HB_OT_LAYOUT_TABLE_TYPE_GPOS,
+	  lookup_index = hb_ot_layout_feature_get_lookup_index (info->hb_face,
+								HB_OT_TAG_GPOS,
 								rule->feature_index,
 								j);
-	  hb_ot_layout_position_lookup (info->layout,
+	  hb_ot_layout_position_lookup (info->hb_face, hb_font,
 					buffer->buffer,
 					lookup_index,
 					rule->property_bit);
@@ -621,4 +629,6 @@ _pango_ot_info_position    (const PangoOTInfo    *info,
 	  positions[j].y_pos += positions[j - positions[j].cursive_chain].y_pos;
       }
     }
+
+  hb_font_destroy (hb_font);
 }
diff --git a/pango/pango-ot-private.h b/pango/pango-ot-private.h
index 6d3d1cf4..9b0f84ef 100644
--- a/pango/pango-ot-private.h
+++ b/pango/pango-ot-private.h
@@ -25,7 +25,7 @@
 #include <glib-object.h>
 
 #include <pango/pango-ot.h>
-#include "opentype/hb-ot-layout.h"
+#include "opentype/hb-ot.h"
 
 G_BEGIN_DECLS
 
@@ -39,7 +39,7 @@ struct _PangoOTInfo
 
   FT_Face face;
 
-  hb_ot_layout_t *layout;
+  hb_face_t *hb_face;
 };
 
 struct _PangoOTInfoClass
@@ -87,7 +87,7 @@ struct _PangoOTBuffer
   guint applied_gpos : 1;
 };
 
-hb_ot_layout_t *_pango_ot_info_get_layout (PangoOTInfo *info);
+hb_face_t *_pango_ot_info_get_hb_face (PangoOTInfo *info);
 void _pango_ot_info_substitute  (const PangoOTInfo    *info,
 				 const PangoOTRuleset *ruleset,
 				 PangoOTBuffer        *buffer);