Add "closure" operation stubs to GSUB

Filling in.

src/hb-ot-layout-gsub-table.hh

@@ -39,6 +39,13 @@ struct SingleSubstFormat1
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     return (this+coverage) (glyph_id) != NOT_COVERED;
@@ -83,6 +90,13 @@ struct SingleSubstFormat2
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     return (this+coverage) (glyph_id) != NOT_COVERED;
@@ -129,6 +143,16 @@ struct SingleSubst
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c);
+    case 2: return u.format2.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     switch (u.format) {
@@ -172,6 +196,14 @@ struct Sequence
   friend struct MultipleSubstFormat1;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -204,6 +236,13 @@ struct MultipleSubstFormat1
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     return (this+coverage) (glyph_id) != NOT_COVERED;
@@ -244,6 +283,15 @@ struct MultipleSubst
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     switch (u.format) {
@@ -287,6 +335,13 @@ struct AlternateSubstFormat1
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     return (this+coverage) (glyph_id) != NOT_COVERED;
@@ -347,6 +402,15 @@ struct AlternateSubst
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
     switch (u.format) {
@@ -387,6 +451,13 @@ struct Ligature
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t second) const
   {
     return component.len == 2 && component[1] == second;
@@ -482,6 +553,13 @@ struct LigatureSet
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t second) const
   {
     unsigned int num_ligs = ligature.len;
@@ -528,6 +606,13 @@ struct LigatureSubstFormat1
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const
   {
     unsigned int index;
@@ -572,6 +657,15 @@ struct LigatureSubst
 
   private:
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const
   {
     switch (u.format) {
@@ -607,12 +701,20 @@ struct LigatureSubst
 
 
 static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index);
+static inline bool closure_lookup (hb_closure_context_t *c, unsigned int lookup_index);
 
 struct ContextSubst : Context
 {
   friend struct SubstLookupSubTable;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    return Context::closure (c, closure_lookup);
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -625,6 +727,13 @@ struct ChainContextSubst : ChainContext
   friend struct SubstLookupSubTable;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    return ChainContext::closure (c, closure_lookup);
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -646,6 +755,13 @@ struct ExtensionSubst : Extension
     return StructAtOffset<SubstLookupSubTable> (this, offset);
   }
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id) const;
   inline bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const;
 
@@ -662,6 +778,14 @@ struct ReverseChainSingleSubstFormat1
   friend struct ReverseChainSingleSubst;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -728,6 +852,16 @@ struct ReverseChainSingleSubst
   friend struct SubstLookupSubTable;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -774,6 +908,23 @@ struct SubstLookupSubTable
     ReverseChainSingle	= 8
   };
 
+  inline bool closure (hb_closure_context_t *c,
+		       unsigned int    lookup_type) const
+  {
+    TRACE_CLOSURE ();
+    switch (lookup_type) {
+    case Single:		return u.single.closure (c);
+    case Multiple:		return u.multiple.closure (c);
+    case Alternate:		return u.alternate.closure (c);
+    case Ligature:		return u.ligature.closure (c);
+    case Context:		return u.c.closure (c);
+    case ChainContext:		return u.chainContext.closure (c);
+    case Extension:		return u.extension.closure (c);
+    case ReverseChainSingle:	return u.reverseChainContextSingle.closure (c);
+    default:return false;
+    }
+  }
+
   inline bool would_apply (hb_codepoint_t glyph_id,
 			   unsigned int lookup_type) const
   {
@@ -860,6 +1011,15 @@ struct SubstLookup : Lookup
     return lookup_type_is_reverse (type);
   }
 
+  inline bool closure (hb_closure_context_t *c) const
+  {
+    unsigned int lookup_type = get_type ();
+    unsigned int count = get_subtable_count ();
+    bool ret = false;
+    for (unsigned int i = 0; i < count; i++)
+      ret = get_subtable (i).closure (c, lookup_type) || ret;
+    return ret;
+  }
 
   inline bool would_apply (hb_codepoint_t glyph_id) const
   {
@@ -984,6 +1144,10 @@ struct GSUB : GSUBGPOS
   static inline void substitute_start (hb_buffer_t *buffer);
   static inline void substitute_finish (hb_buffer_t *buffer);
 
+  inline bool closure_lookup (hb_closure_context_t *c,
+			      unsigned int          lookup_index) const
+  { return get_lookup (lookup_index).closure (c); }
+
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE ();
     if (unlikely (!GSUBGPOS::sanitize (c))) return false;
@@ -1048,6 +1212,21 @@ inline bool ExtensionSubst::is_reverse (void) const
   return SubstLookup::lookup_type_is_reverse (type);
 }
 
+static inline bool closure_lookup (hb_closure_context_t *c, unsigned int lookup_index)
+{
+  const GSUB &gsub = *(c->face->ot_layout->gsub);
+  const SubstLookup &l = gsub.get_lookup (lookup_index);
+
+  if (unlikely (c->nesting_level_left == 0))
+    return false;
+
+  c->nesting_level_left--;
+  bool ret = l.closure (c);
+  c->nesting_level_left++;
+
+  return ret;
+}
+
 static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index)
 {
   const GSUB &gsub = *(c->face->ot_layout->gsub);

src/hb-ot-layout-gsubgpos-private.hh

@@ -31,6 +31,8 @@
 
 #include "hb-buffer-private.hh"
 #include "hb-ot-layout-gdef-table.hh"
+#include "hb-ot-layout-closure.h"
+
 
 
 /* buffer var allocations */
@@ -45,6 +47,35 @@ static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) {
 
 
 
+#ifndef HB_DEBUG_CLOSURE
+#define HB_DEBUG_CLOSURE (HB_DEBUG+0)
+#endif
+
+#define TRACE_CLOSURE() \
+	hb_auto_trace_t<HB_DEBUG_CLOSURE> trace (&c->debug_depth, "CLOSURE", this, NULL, HB_FUNC);
+
+
+
+struct hb_closure_context_t
+{
+  hb_face_t *face;
+  hb_glyph_map_t *glyphs;
+  unsigned int nesting_level_left;
+  unsigned int debug_depth;
+
+
+  hb_closure_context_t (hb_face_t *face_,
+			hb_glyph_map_t *glyphs_,
+		        unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) :
+			  face (face_), glyphs (glyphs_),
+			  nesting_level_left (nesting_level_left_),
+			  debug_depth (0) {}
+};
+
+typedef bool (*closure_lookup_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
+
+
+
 #ifndef HB_DEBUG_APPLY
 #define HB_DEBUG_APPLY (HB_DEBUG+0)
 #endif
@@ -56,7 +87,6 @@ static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) {
 
 struct hb_apply_context_t
 {
-  unsigned int debug_depth;
   hb_font_t *font;
   hb_face_t *face;
   hb_buffer_t *buffer;
@@ -66,6 +96,7 @@ struct hb_apply_context_t
   unsigned int nesting_level_left;
   unsigned int lookup_props;
   unsigned int property; /* propety of first glyph */
+  unsigned int debug_depth;
 
 
   hb_apply_context_t (hb_font_t *font_,
@@ -81,7 +112,7 @@ struct hb_apply_context_t
 			context_length (context_length_),
 			nesting_level_left (nesting_level_left_),
 			lookup_props (l.get_props ()),
-			property (0) {}
+			property (0), debug_depth (0) {}
 
   hb_apply_context_t (const hb_apply_context_t &c, const Lookup &l) {
     *this = c;
@@ -478,6 +509,14 @@ struct ContextFormat1
   friend struct Context;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -517,6 +556,14 @@ struct ContextFormat2
   friend struct Context;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -562,6 +609,14 @@ struct ContextFormat3
   friend struct Context;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -608,6 +663,18 @@ struct ContextFormat3
 struct Context
 {
   protected:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c, closure_func);
+    case 2: return u.format2.closure (c, closure_func);
+    case 3: return u.format3.closure (c, closure_func);
+    default:return false;
+    }
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -765,6 +832,14 @@ struct ChainContextFormat1
   friend struct ChainContext;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -803,6 +878,14 @@ struct ChainContextFormat2
   friend struct ChainContext;
 
   private:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -864,6 +947,13 @@ struct ChainContextFormat3
 
   private:
 
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    /* TODO FILLME */
+    return false;
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();
@@ -922,6 +1012,18 @@ struct ChainContextFormat3
 struct ChainContext
 {
   protected:
+
+  inline bool closure (hb_closure_context_t *c, closure_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: return u.format1.closure (c, closure_func);
+    case 2: return u.format2.closure (c, closure_func);
+    case 3: return u.format3.closure (c, closure_func);
+    default:return false;
+    }
+  }
+
   inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const
   {
     TRACE_APPLY ();

src/hb-ot-layout.cc

@@ -469,6 +469,14 @@ hb_ot_layout_substitute_finish (hb_buffer_t  *buffer HB_UNUSED)
   GSUB::substitute_finish (buffer);
 }
 
+hb_bool_t
+hb_ot_layout_closure_lookup (hb_face_t      *face,
+			     hb_glyph_map_t *glyphs,
+			     unsigned int    lookup_index)
+{
+  hb_closure_context_t c (face, glyphs);
+  return _get_gsub (face).closure_lookup (&c, lookup_index);
+}
 
 /*
  * GPOS