Start implementing collect_glyphs() operation

Not functional yet.

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

@@ -52,6 +52,16 @@ struct SingleSubstFormat1
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ()) {
+      hb_codepoint_t glyph_id = iter.get_glyph ();
+      c->input.add (glyph_id);
+      c->output.add ((glyph_id + deltaGlyphID) & 0xFFFF);
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -116,6 +126,15 @@ struct SingleSubstFormat2
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ()) {
+      c->input.add (iter.get_glyph ());
+      c->output.add (substitute[iter.get_coverage ()]);
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -182,6 +201,16 @@ struct SingleSubst
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+    case 1: u.format1.collect_glyphs (c); break;
+    case 2: u.format2.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -261,6 +290,13 @@ struct Sequence
       c->glyphs->add (substitute[i]);
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    unsigned int count = substitute.len;
+    for (unsigned int i = 0; i < count; i++)
+      c->output.add (substitute[i]);
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -316,6 +352,14 @@ struct MultipleSubstFormat1
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    (this+coverage).add_coverage (&c->input);
+    unsigned int count = sequence.len;
+    for (unsigned int i = 0; i < count; i++)
+	(this+sequence[i]).collect_glyphs (c);
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -382,6 +426,14 @@ struct MultipleSubst
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    switch (u.format) {
+    case 1: u.format1.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -455,6 +507,18 @@ struct AlternateSubstFormat1
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ()) {
+      c->input.add (iter.get_glyph ());
+      const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
+      unsigned int count = alt_set.len;
+      for (unsigned int i = 0; i < count; i++)
+	c->output.add (alt_set[i]);
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -539,6 +603,14 @@ struct AlternateSubst
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    switch (u.format) {
+    case 1: u.format1.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -605,6 +677,14 @@ struct Ligature
     c->glyphs->add (ligGlyph);
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    unsigned int count = component.len;
+    for (unsigned int i = 1; i < count; i++)
+      c->input.add (component[i]);
+    c->output.add (ligGlyph);
+  }
+
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     if (c->len != component.len)
@@ -693,6 +773,13 @@ struct LigatureSet
       (this+ligature[i]).closure (c);
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    unsigned int num_ligs = ligature.len;
+    for (unsigned int i = 0; i < num_ligs; i++)
+      (this+ligature[i]).collect_glyphs (c);
+  }
+
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     unsigned int num_ligs = ligature.len;
@@ -767,6 +854,15 @@ struct LigatureSubstFormat1
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    Coverage::Iter iter;
+    for (iter.init (this+coverage); iter.more (); iter.next ()) {
+      c->input.add (iter.get_glyph ());
+      (this+ligatureSet[iter.get_coverage ()]).collect_glyphs (c);
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -844,6 +940,14 @@ struct LigatureSubst
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    switch (u.format) {
+    case 1: u.format1.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -907,6 +1011,7 @@ struct LigatureSubst
 
 static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index);
 static inline void closure_lookup (hb_closure_context_t *c, unsigned int lookup_index);
+static inline void collect_glyphs_lookup (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
 
 struct ContextSubst : Context
 {
@@ -920,6 +1025,11 @@ struct ContextSubst : Context
     return Context::closure (c, closure_lookup);
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    return Context::collect_glyphs (c, collect_glyphs_lookup);
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -939,6 +1049,11 @@ struct ChainContextSubst : ChainContext
     return ChainContext::closure (c, closure_lookup);
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    return ChainContext::collect_glyphs (c, collect_glyphs_lookup);
+  }
+
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY ();
@@ -962,6 +1077,8 @@ struct ExtensionSubst : Extension
 
   inline void closure (hb_closure_context_t *c) const;
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const;
+
   inline const Coverage &get_coverage (void) const;
 
   inline bool would_apply (hb_would_apply_context_t *c) const;
@@ -1005,6 +1122,28 @@ struct ReverseChainSingleSubstFormat1
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
+
+    unsigned int count;
+
+    (this+coverage).add_coverage (&c->input);
+
+    count = backtrack.len;
+    for (unsigned int i = 0; i < count; i++)
+      (this+backtrack[i]).add_coverage (&c->before);
+
+    count = lookahead.len;
+    for (unsigned int i = 0; i < count; i++)
+      (this+lookahead[i]).add_coverage (&c->after);
+
+    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
+    count = substitute.len;
+    for (unsigned int i = 0; i < count; i++)
+      c->output.add (substitute[i]);
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
@@ -1084,6 +1223,14 @@ struct ReverseChainSingleSubst
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    switch (u.format) {
+    case 1: u.format1.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -1155,6 +1302,22 @@ struct SubstLookupSubTable
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c,
+			      unsigned int lookup_type) const
+  {
+    switch (lookup_type) {
+    case Single:		u.single.collect_glyphs (c); break;
+    case Multiple:		u.multiple.collect_glyphs (c); break;
+    case Alternate:		u.alternate.collect_glyphs (c); break;
+    case Ligature:		u.ligature.collect_glyphs (c); break;
+    case Context:		u.context.collect_glyphs (c); break;
+    case ChainContext:		u.chainContext.collect_glyphs (c); break;
+    case Extension:		u.extension.collect_glyphs (c); break;
+    case ReverseChainSingle:	u.reverseChainContextSingle.collect_glyphs (c); break;
+    default:                    break;
+    }
+  }
+
   inline const Coverage &get_coverage (unsigned int lookup_type) const
   {
     switch (lookup_type) {
@@ -1286,6 +1449,14 @@ struct SubstLookup : Lookup
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    unsigned int lookup_type = get_type ();
+    unsigned int count = get_subtable_count ();
+    for (unsigned int i = 0; i < count; i++)
+      get_subtable (i).collect_glyphs (c, lookup_type);
+  }
+
   inline bool would_apply (hb_would_apply_context_t *c, const hb_set_digest_t *digest) const
   {
     if (unlikely (!c->len)) return false;
@@ -1506,6 +1677,11 @@ inline void ExtensionSubst::closure (hb_closure_context_t *c) const
   get_subtable ().closure (c, get_type ());
 }
 
+inline void ExtensionSubst::collect_glyphs (hb_collect_glyphs_context_t *c) const
+{
+  get_subtable ().collect_glyphs (c, get_type ());
+}
+
 inline const Coverage & ExtensionSubst::get_coverage (void) const
 {
   return get_subtable ().get_coverage (get_type ());
@@ -1552,6 +1728,15 @@ static inline void closure_lookup (hb_closure_context_t *c, unsigned int lookup_
   c->nesting_level_left++;
 }
 
+static inline void collect_glyphs_lookup (hb_collect_glyphs_context_t *c, unsigned int lookup_index)
+{
+  const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
+  const SubstLookup &l = gsub.get_lookup (lookup_index);
+
+  /* XXX TODO */
+  l.collect_glyphs (c);
+}
+
 static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index)
 {
   const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);

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

@@ -93,6 +93,40 @@ struct hb_would_apply_context_t
 };
 
 
+
+/* TODO Add TRACE_RETURN annotation to gsub. */
+#ifndef HB_DEBUG_COLLECT_GLYPHS
+#define HB_DEBUG_COLLECT_GLYPHS (HB_DEBUG+0)
+#endif
+
+#define TRACE_COLLECT_GLYPHS() \
+	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS> trace (&c->debug_depth, "COLLECT_GLYPHS", this, HB_FUNC, "");
+
+
+struct hb_collect_glyphs_context_t
+{
+  hb_face_t *face;
+  hb_set_t &before;
+  hb_set_t &input;
+  hb_set_t &after;
+  hb_set_t &output;
+  unsigned int debug_depth;
+
+  hb_collect_glyphs_context_t (hb_face_t *face_,
+			       hb_set_t  *glyphs_before, /* OUT. May be NULL */
+			       hb_set_t  *glyphs_input,  /* OUT. May be NULL */
+			       hb_set_t  *glyphs_after,  /* OUT. May be NULL */
+			       hb_set_t  *glyphs_output  /* OUT. May be NULL */) :
+			      face (face_),
+			      before (glyphs_before ? *glyphs_before : *hb_set_get_empty ()),
+			      input  (glyphs_input  ? *glyphs_input  : *hb_set_get_empty ()),
+			      after  (glyphs_after  ? *glyphs_after  : *hb_set_get_empty ()),
+			      output (glyphs_output ? *glyphs_output : *hb_set_get_empty ()),
+			      debug_depth (0) {};
+};
+
+
+
 #ifndef HB_DEBUG_APPLY
 #define HB_DEBUG_APPLY (HB_DEBUG+0)
 #endif
@@ -341,6 +375,7 @@ struct hb_apply_context_t
 typedef bool (*intersects_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
 typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
 typedef void (*closure_lookup_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
+typedef void (*collect_glyphs_lookup_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
 typedef bool (*apply_lookup_func_t) (hb_apply_context_t *c, unsigned int lookup_index);
 
 struct ContextClosureFuncs
@@ -1105,6 +1140,17 @@ struct Context
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c, collect_glyphs_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+//    case 1: u.format1.collect_glyphs (c); break;
+//    case 2: u.format2.collect_glyphs (c); break;
+//    case 3: u.format2.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {
@@ -1648,6 +1694,17 @@ struct ChainContext
     }
   }
 
+  inline void collect_glyphs (hb_collect_glyphs_context_t *c, collect_glyphs_lookup_func_t closure_func) const
+  {
+    TRACE_CLOSURE ();
+    switch (u.format) {
+//    case 1: u.format1.collect_glyphs (c); break;
+//    case 2: u.format2.collect_glyphs (c); break;
+//    case 3: u.format2.collect_glyphs (c); break;
+    default:                              break;
+    }
+  }
+
   inline const Coverage &get_coverage (void) const
   {
     switch (u.format) {

src/hb-ot-layout.cc

@@ -401,6 +401,35 @@ hb_ot_layout_feature_get_lookups (hb_face_t    *face,
   return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
 }
 
+void
+hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
+				    hb_tag_t      table_tag,
+				    unsigned int  lookup_index,
+				    hb_set_t     *glyphs_before, /* OUT. May be NULL */
+				    hb_set_t     *glyphs_input,  /* OUT. May be NULL */
+				    hb_set_t     *glyphs_after,  /* OUT. May be NULL */
+				    hb_set_t     *glyphs_output  /* OUT. May be NULL */)
+{
+  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return;
+
+  OT::hb_collect_glyphs_context_t c (face, glyphs_before, glyphs_input, glyphs_after, glyphs_output);
+
+  switch (table_tag) {
+    case HB_OT_TAG_GSUB:
+    {
+      const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
+      l.collect_glyphs (&c);
+      return;
+    }
+    case HB_OT_TAG_GPOS:
+    {
+      const OT::PosLookup& l = hb_ot_layout_from_face (face)->gpos->get_lookup (lookup_index);
+//      l.collect_glyphs (&c);
+      return;
+    }
+  }
+}
+
 
 /*
  * OT::GSUB

src/hb-ot-layout.h

@@ -194,16 +194,14 @@ hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
 				  hb_tag_t         table_tag,
 				  hb_set_t        *lookup_indexes /* OUT */);
 
-#ifdef HB_NOT_IMPLEMENTED
 void
-Xhb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
+hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
 				    hb_tag_t      table_tag,
 				    unsigned int  lookup_index,
 				    hb_set_t     *glyphs_before, /* OUT. May be NULL */
 				    hb_set_t     *glyphs_input,  /* OUT. May be NULL */
 				    hb_set_t     *glyphs_after,  /* OUT. May be NULL */
 				    hb_set_t     *glyphs_output  /* OUT. May be NULL */);
-#endif
 
 #ifdef HB_NOT_IMPLEMENTED
 typedef struct