[pango/harfbuzz-ng] [HB] Share Extension lookup code between GSUB and GPOS

[Behdad Esfahbod <behdad src gnome org>]

commit fb963a1a1e8f7c337af6b7fee4718c3f65bc8c51
Author: Behdad Esfahbod <behdad behdad org>
Date:   Thu May 21 22:31:33 2009 -0400

    [HB] Share Extension lookup code between GSUB and GPOS
---
 pango/opentype/hb-ot-layout-gpos-private.h     |   64 +++---------------
 pango/opentype/hb-ot-layout-gsub-private.h     |   83 ++++--------------------
 pango/opentype/hb-ot-layout-gsubgpos-private.h |   52 +++++++++++++++
 3 files changed, 77 insertions(+), 122 deletions(-)

diff --git a/pango/opentype/hb-ot-layout-gpos-private.h b/pango/opentype/hb-ot-layout-gpos-private.h
index 15f476b..2e01615 100644
--- a/pango/opentype/hb-ot-layout-gpos-private.h
+++ b/pango/opentype/hb-ot-layout-gpos-private.h
@@ -318,7 +318,6 @@ struct SinglePos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -507,7 +506,6 @@ struct PairPos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -734,7 +732,6 @@ struct CursivePos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -853,7 +850,6 @@ struct MarkBasePos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -943,7 +939,6 @@ struct MarkLigPos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -1061,7 +1056,6 @@ struct MarkMarkPos
   friend struct PosLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -1083,6 +1077,9 @@ static inline bool position_lookup (APPLY_ARG_DEF, unsigned int lookup_index);
 
 struct ContextPos : Context
 {
+  friend struct PosLookupSubTable;
+
+  private:
   inline bool apply (APPLY_ARG_DEF) const
   {
     return Context::apply (APPLY_ARG, position_lookup);
@@ -1092,6 +1089,9 @@ ASSERT_SIZE (ContextPos, 2);
 
 struct ChainContextPos : ChainContext
 {
+  friend struct PosLookupSubTable;
+
+  private:
   inline bool apply (APPLY_ARG_DEF) const
   {
     return ChainContext::apply (APPLY_ARG, position_lookup);
@@ -1100,59 +1100,17 @@ struct ChainContextPos : ChainContext
 ASSERT_SIZE (ChainContextPos, 2);
 
 
-struct ExtensionPosFormat1
-{
-  friend struct ExtensionPos;
-
-  private:
-  inline unsigned int get_type (void) const { return extensionLookupType; }
-  inline unsigned int get_offset (void) const { return (extensionOffset[0] << 16) + extensionOffset[1]; }
-  inline bool apply (APPLY_ARG_DEF) const;
-
-  private:
-  USHORT	format;			/* Format identifier. Set to 1. */
-  USHORT	extensionLookupType;	/* Lookup type of subtable referenced
-					 * by ExtensionOffset (i.e. the
-					 * extension subtable). */
-  USHORT	extensionOffset[2];	/* Offset to the extension subtable,
-					 * of lookup type subtable.
-					 * Defined as two shorts to avoid
-					 * alignment requirements. */
-};
-ASSERT_SIZE (ExtensionPosFormat1, 8);
-
-struct ExtensionPos
+struct ExtensionPos : Extension
 {
-  friend struct PosLookup;
   friend struct PosLookupSubTable;
 
   private:
-
-  inline unsigned int get_type (void) const
-  {
-    switch (u.format) {
-    case 1: return u.format1->get_type ();
-    default:return 0;
-    }
-  }
-
-  inline bool apply (APPLY_ARG_DEF) const
-  {
-    switch (u.format) {
-    case 1: return u.format1->apply (APPLY_ARG);
-    default:return false;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  ExtensionPosFormat1	format1[];
-  } u;
+  inline bool apply (APPLY_ARG_DEF) const;
 };
 ASSERT_SIZE (ExtensionPos, 2);
 
 
+
 /*
  * PosLookup
  */
@@ -1329,14 +1287,14 @@ ASSERT_SIZE (GPOS, 10);
 
 /* Out-of-class implementation for methods recursing */
 
-inline bool ExtensionPosFormat1::apply (APPLY_ARG_DEF) const
+inline bool ExtensionPos::apply (APPLY_ARG_DEF) const
 {
   unsigned int lookup_type = get_type ();
 
   if (HB_UNLIKELY (lookup_type == PosLookupSubTable::Extension))
     return false;
 
-  return ((PosLookupSubTable&)*(((char *) this) + get_offset ())).apply (APPLY_ARG, lookup_type);
+  return ((PosLookupSubTable&) get_subtable ()).apply (APPLY_ARG, lookup_type);
 }
 
 static inline bool position_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
diff --git a/pango/opentype/hb-ot-layout-gsub-private.h b/pango/opentype/hb-ot-layout-gsub-private.h
index cbcdb72..fce4f45 100644
--- a/pango/opentype/hb-ot-layout-gsub-private.h
+++ b/pango/opentype/hb-ot-layout-gsub-private.h
@@ -45,7 +45,6 @@ struct SingleSubstFormat1
   friend struct SingleSubst;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     hb_codepoint_t glyph_id = IN_CURGLYPH ();
@@ -80,7 +79,6 @@ struct SingleSubstFormat2
   friend struct SingleSubst;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     hb_codepoint_t glyph_id = IN_CURGLYPH ();
@@ -119,7 +117,6 @@ struct SingleSubst
   friend struct SubstLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -144,14 +141,6 @@ struct Sequence
   friend struct MultipleSubstFormat1;
 
   private:
-
-  inline void set_glyph_class (hb_ot_layout_t *layout, unsigned int property) const
-  {
-    unsigned int count = substitute.len;
-    for (unsigned int n = 0; n < count; n++)
-      _hb_ot_layout_set_glyph_property (layout, substitute[n], property);
-  }
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     if (HB_UNLIKELY (!substitute.len))
@@ -164,11 +153,12 @@ struct Sequence
     if ( _hb_ot_layout_has_new_glyph_classes (layout) )
     {
       /* this is a guess only ... */
-
       if ( property == HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE )
         property = HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
 
-      set_glyph_class (layout, property);
+      unsigned int count = substitute.len;
+      for (unsigned int n = 0; n < count; n++)
+	_hb_ot_layout_set_glyph_property (layout, substitute[n], property);
     }
 
     return true;
@@ -185,7 +175,6 @@ struct MultipleSubstFormat1
   friend struct MultipleSubst;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
 
@@ -212,7 +201,6 @@ struct MultipleSubst
   friend struct SubstLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -239,7 +227,6 @@ struct AlternateSubstFormat1
   friend struct AlternateSubst;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     hb_codepoint_t glyph_id = IN_CURGLYPH ();
@@ -294,7 +281,6 @@ struct AlternateSubst
   friend struct SubstLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -397,7 +383,6 @@ struct LigatureSet
   friend struct LigatureSubstFormat1;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF, bool is_mark) const
   {
     unsigned int num_ligs = ligature.len;
@@ -423,7 +408,6 @@ struct LigatureSubstFormat1
   friend struct LigatureSubst;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     hb_codepoint_t glyph_id = IN_CURGLYPH ();
@@ -455,7 +439,6 @@ struct LigatureSubst
   friend struct SubstLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -478,6 +461,9 @@ static inline bool substitute_lookup (APPLY_ARG_DEF, unsigned int lookup_index);
 
 struct ContextSubst : Context
 {
+  friend struct SubstLookupSubTable;
+
+  private:
   inline bool apply (APPLY_ARG_DEF) const
   {
     return Context::apply (APPLY_ARG, substitute_lookup);
@@ -487,6 +473,9 @@ ASSERT_SIZE (ContextSubst, 2);
 
 struct ChainContextSubst : ChainContext
 {
+  friend struct SubstLookupSubTable;
+
+  private:
   inline bool apply (APPLY_ARG_DEF) const
   {
     return ChainContext::apply (APPLY_ARG, substitute_lookup);
@@ -495,55 +484,12 @@ struct ChainContextSubst : ChainContext
 ASSERT_SIZE (ChainContextSubst, 2);
 
 
-struct ExtensionSubstFormat1
-{
-  friend struct ExtensionSubst;
-
-  private:
-  inline unsigned int get_type (void) const { return extensionLookupType; }
-  inline unsigned int get_offset (void) const { return (extensionOffset[0] << 16) + extensionOffset[1]; }
-  inline bool apply (APPLY_ARG_DEF) const;
-
-  private:
-  USHORT	format;			/* Format identifier. Set to 1. */
-  USHORT	extensionLookupType;	/* Lookup type of subtable referenced
-					 * by ExtensionOffset (i.e. the
-					 * extension subtable). */
-  USHORT	extensionOffset[2];	/* Offset to the extension subtable,
-					 * of lookup type subtable.
-					 * Defined as two shorts to avoid
-					 * alignment requirements. */
-};
-ASSERT_SIZE (ExtensionSubstFormat1, 8);
-
-struct ExtensionSubst
+struct ExtensionSubst : Extension
 {
-  friend struct SubstLookup;
   friend struct SubstLookupSubTable;
 
   private:
-
-  inline unsigned int get_type (void) const
-  {
-    switch (u.format) {
-    case 1: return u.format1->get_type ();
-    default:return 0;
-    }
-  }
-
-  inline bool apply (APPLY_ARG_DEF) const
-  {
-    switch (u.format) {
-    case 1: return u.format1->apply (APPLY_ARG);
-    default:return false;
-    }
-  }
-
-  private:
-  union {
-  USHORT		format;		/* Format identifier */
-  ExtensionSubstFormat1	format1[];
-  } u;
+  inline bool apply (APPLY_ARG_DEF) const;
 };
 ASSERT_SIZE (ExtensionSubst, 2);
 
@@ -607,7 +553,6 @@ struct ReverseChainSingleSubst
   friend struct SubstLookupSubTable;
 
   private:
-
   inline bool apply (APPLY_ARG_DEF) const
   {
     switch (u.format) {
@@ -815,14 +760,14 @@ ASSERT_SIZE (GSUB, 10);
 
 /* Out-of-class implementation for methods recursing */
 
-inline bool ExtensionSubstFormat1::apply (APPLY_ARG_DEF) const
+inline bool ExtensionSubst::apply (APPLY_ARG_DEF) const
 {
   unsigned int lookup_type = get_type ();
 
-  if (HB_UNLIKELY (lookup_type ==  SubstLookupSubTable::Extension))
+  if (HB_UNLIKELY (lookup_type == SubstLookupSubTable::Extension))
     return false;
 
-  return ((SubstLookupSubTable&)*(((char *) this) + get_offset ())).apply (APPLY_ARG, lookup_type);
+  return ((SubstLookupSubTable&) get_subtable ()).apply (APPLY_ARG, lookup_type);
 }
 
 static inline bool substitute_lookup (APPLY_ARG_DEF, unsigned int lookup_index)
diff --git a/pango/opentype/hb-ot-layout-gsubgpos-private.h b/pango/opentype/hb-ot-layout-gsubgpos-private.h
index 2f5a94b..6028351 100644
--- a/pango/opentype/hb-ot-layout-gsubgpos-private.h
+++ b/pango/opentype/hb-ot-layout-gsubgpos-private.h
@@ -686,6 +686,58 @@ struct ChainContext
 ASSERT_SIZE (ChainContext, 2);
 
 
+struct ExtensionFormat1
+{
+  friend struct Extension;
+
+  private:
+  inline unsigned int get_type (void) const { return extensionLookupType; }
+  inline unsigned int get_offset (void) const { return (extensionOffset[0] << 16) + extensionOffset[1]; }
+  inline const LookupSubTable& get_subtable (void) const
+  {
+    unsigned int offset = get_offset ();
+    if (HB_UNLIKELY (!offset)) return Null(LookupSubTable);
+    return (LookupSubTable&) *(((char *) this) + offset);
+  }
+
+  private:
+  USHORT	format;			/* Format identifier. Set to 1. */
+  USHORT	extensionLookupType;	/* Lookup type of subtable referenced
+					 * by ExtensionOffset (i.e. the
+					 * extension subtable). */
+  USHORT	extensionOffset[2];	/* Offset to the extension subtable,
+					 * of lookup type subtable.
+					 * Defined as two shorts to avoid
+					 * alignment requirements. */
+};
+ASSERT_SIZE (ExtensionFormat1, 8);
+
+struct Extension
+{
+  inline unsigned int get_type (void) const
+  {
+    switch (u.format) {
+    case 1: return u.format1->get_type ();
+    default:return 0;
+    }
+  }
+  inline const LookupSubTable& get_subtable (void) const
+  {
+    switch (u.format) {
+    case 1: return u.format1->get_subtable ();
+    default:return Null(LookupSubTable);
+    }
+  }
+
+  private:
+  union {
+  USHORT		format;		/* Format identifier */
+  ExtensionFormat1	format1[];
+  } u;
+};
+ASSERT_SIZE (Extension, 2);
+
+
 /*
  * GSUB/GPOS Common
  */