[aat] First sketch at using hb_set_digest_t

They are not cached in an accelerator yet.

src/hb-aat-layout-common.hh

@@ -95,6 +95,13 @@ struct LookupFormat0
     return &arrayZ[glyph_id];
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs, unsigned num_glyphs) const
+  {
+    for (unsigned int i = 0; i < num_glyphs; i++)
+      glyphs.add (i);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -123,6 +130,12 @@ struct LookupSegmentSingle
   int cmp (hb_codepoint_t g) const
   { return g < first ? -1 : g <= last ? 0 : +1 ; }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    glyphs.add_range (first, last);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -153,6 +166,14 @@ struct LookupFormat2
     return v ? &v->value : nullptr;
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    unsigned count = segments.get_length ();
+    for (unsigned int i = 0; i < count; i++)
+      segments[i].collect_glyphs (glyphs);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -184,6 +205,12 @@ struct LookupSegmentArray
     return first <= glyph_id && glyph_id <= last ? &(base+valuesZ)[glyph_id - first] : nullptr;
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    glyphs.add_range (first, last);
+  }
+
   int cmp (hb_codepoint_t g) const
   { return g < first ? -1 : g <= last ? 0 : +1; }
 
@@ -226,6 +253,14 @@ struct LookupFormat4
     return v ? v->get_value (glyph_id, this) : nullptr;
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    unsigned count = segments.get_length ();
+    for (unsigned i = 0; i < count; i++)
+      segments[i].collect_glyphs (glyphs);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -254,6 +289,12 @@ struct LookupSingle
 
   int cmp (hb_codepoint_t g) const { return glyph.cmp (g); }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    glyphs.add (glyph);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -283,6 +324,14 @@ struct LookupFormat6
     return v ? &v->value : nullptr;
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    unsigned count = entries.get_length ();
+    for (unsigned i = 0; i < count; i++)
+      entries[i].collect_glyphs (glyphs);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -314,6 +363,14 @@ struct LookupFormat8
 	   &valueArrayZ[glyph_id - firstGlyph] : nullptr;
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs) const
+  {
+    if (unlikely (!glyphCount))
+      return;
+    glyphs.add_range (firstGlyph, firstGlyph + glyphCount - 1);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -406,6 +463,19 @@ struct Lookup
     }
   }
 
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs, unsigned int num_glyphs) const
+  {
+    switch (u.format) {
+    case 0: u.format0.collect_glyphs (glyphs, num_glyphs); return;
+    case 2: u.format2.collect_glyphs (glyphs); return;
+    case 4: u.format4.collect_glyphs (glyphs); return;
+    case 6: u.format6.collect_glyphs (glyphs); return;
+    case 8: u.format8.collect_glyphs (glyphs); return;
+    default:return;
+    }
+  }
+
   typename T::type get_class (hb_codepoint_t glyph_id,
 			      unsigned int num_glyphs,
 			      unsigned int outOfRange) const
@@ -535,9 +605,19 @@ struct StateTable
   int new_state (unsigned int newState) const
   { return Types::extended ? newState : ((int) newState - (int) stateArrayTable) / (int) nClasses; }
 
-  unsigned int get_class (hb_codepoint_t glyph_id, unsigned int num_glyphs) const
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs, unsigned num_glyphs) const
+  {
+    (this+classTable).collect_glyphs (glyphs, num_glyphs);
+  }
+
+  template <typename set_t>
+  unsigned int get_class (hb_codepoint_t glyph_id,
+			  unsigned int num_glyphs,
+			  const set_t &glyphs) const
   {
     if (unlikely (glyph_id == DELETED_GLYPH)) return CLASS_DELETED_GLYPH;
+    if (!glyphs[glyph_id]) return CLASS_OUT_OF_BOUNDS;
     return (this+classTable).get_class (glyph_id, num_glyphs, 1);
   }
 
@@ -690,6 +770,14 @@ struct ClassTable
   {
     return get_class (glyph_id, outOfRange);
   }
+
+  template <typename set_t>
+  void collect_glyphs (set_t &glyphs, HB_UNUSED unsigned num_glyphs) const
+  {
+    for (unsigned int i = 0; i < classArray.len; i++)
+      glyphs.add (i + firstGlyph);
+  }
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -815,9 +903,12 @@ struct StateTableDriver
 		    hb_face_t *face_) :
 	      machine (machine_),
 	      buffer (buffer_),
-	      num_glyphs (face_->get_num_glyphs ()) {}
+	      num_glyphs (face_->get_num_glyphs ())
+  {
+    machine.collect_glyphs (glyph_set, num_glyphs);
+  }
 
-  template <typename context_t>
+  template <typename context_t, typename set_t = hb_set_digest_t>
   void drive (context_t *c, hb_aat_apply_context_t *ac)
   {
     if (!c->in_place)
@@ -855,7 +946,7 @@ struct StateTableDriver
       }
 
       unsigned int klass = buffer->idx < buffer->len ?
-			   machine.get_class (buffer->cur().codepoint, num_glyphs) :
+			   machine.get_class (buffer->cur().codepoint, num_glyphs, glyph_set) :
 			   (unsigned) StateTableT::CLASS_END_OF_TEXT;
       DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx);
       const EntryT &entry = machine.get_entry (state, klass);
@@ -946,6 +1037,7 @@ struct StateTableDriver
   const StateTableT &machine;
   hb_buffer_t *buffer;
   unsigned int num_glyphs;
+  hb_set_digest_t glyph_set;
 };
 
 

src/hb-aat-layout-kerx-table.hh

@@ -30,6 +30,7 @@
 
 #include "hb-kern.hh"
 #include "hb-aat-layout-ankr-table.hh"
+#include "hb-set-digest.hh"
 
 /*
  * kerx -- Extended Kerning
@@ -82,7 +83,7 @@ struct KernPair
     return_trace (c->check_struct (this));
   }
 
-  protected:
+  public:
   HBGlyphID16	left;
   HBGlyphID16	right;
   FWORD		value;
@@ -122,13 +123,31 @@ struct KerxSubTableFormat0
   {
     const KerxSubTableFormat0 &table;
     hb_aat_apply_context_t *c;
+    hb_set_digest_t left_set, right_set;
+
+    template <typename set_t>
+    void collect_glyphs (set_t &left, set_t &right)
+    {
+      for (const KernPair& pair : table.pairs)
+      {
+        left_set.add (pair.left);
+        right_set.add (pair.right);
+      }
+    }
 
     accelerator_t (const KerxSubTableFormat0 &table_,
 		   hb_aat_apply_context_t *c_) :
-		     table (table_), c (c_) {}
+		     table (table_), c (c_)
+    {
+      collect_glyphs (left_set, right_set);
+    }
 
     int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
-    { return table.get_kerning (left, right, c); }
+    {
+      if (!left_set[left] || !right_set[right])
+        return 0;
+      return table.get_kerning (left, right, c);
+    }
   };