From 963413fc5454d92621ae83a8d9c9324e404b8166 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Sun, 26 Aug 2018 00:47:55 -0700
Subject: [PATCH] WIP

---
 src/hb-ot-cmap-table.hh        |  1 -
 src/hb-ot-face.hh              | 22 ----------------------
 src/hb-ot-layout-gpos-table.hh |  2 ++
 src/hb-ot-layout-gsub-table.hh |  2 ++
 src/hb-ot-layout-gsubgpos.hh   | 31 ++++++++++++++++++++++++++++++-
 src/hb-ot-layout.hh            | 18 +++++++++++++++++-
 6 files changed, 51 insertions(+), 25 deletions(-)

diff --git a/src/hb-ot-cmap-table.hh b/src/hb-ot-cmap-table.hh
index cdf67f1..c357714 100644
--- a/src/hb-ot-cmap-table.hh
+++ b/src/hb-ot-cmap-table.hh
@@ -1018,7 +1018,6 @@ struct cmap
   {
     inline void init (hb_face_t *face)
     {
-      /* TODO Switch to using table from face->ot.table. */
       this->blob = hb_sanitize_context_t().reference_table<cmap> (face);
       const cmap *table = this->blob->as<cmap> ();
       const CmapSubtableFormat14 *subtable_uvs = nullptr;
diff --git a/src/hb-ot-face.hh b/src/hb-ot-face.hh
index bbbc6e2..1466f11 100644
--- a/src/hb-ot-face.hh
+++ b/src/hb-ot-face.hh
@@ -32,7 +32,6 @@
 #include "hb.hh"
 
 #include "hb-machinery.hh"
-#include "hb-set-digest.hh"
 
 #include "hb-ot-cmap-table.hh"
 #include "hb-ot-glyf-table.hh"
@@ -46,27 +45,6 @@
  * hb_ot_face_data_t
  */
 
-struct hb_ot_layout_lookup_accelerator_t
-{
-  template <typename TLookup>
-  inline void init (const TLookup &lookup)
-  {
-    digest.init ();
-    lookup.add_coverage (&digest);
-  }
-
-  inline void fini (void)
-  {
-  }
-
-  inline bool may_have (hb_codepoint_t g) const {
-    return digest.may_have (g);
-  }
-
-  private:
-  hb_set_digest_t digest;
-};
-
 /* Most of these tables are NOT needed for shaping.  But we need to hook them *somewhere*.
  * This is as good as any place. */
 #define HB_OT_LAYOUT_TABLES \
diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index 66767df..e1a4050 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -1522,6 +1522,8 @@ struct GPOS : GSUBGPOS
     const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
     return_trace (list.sanitize (c, this));
   }
+
+  typedef GSUBGPOS::accelerator_t<GPOS> accelerator_t;
 };
 
 
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index d2c1fb9..59e8a43 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -1317,6 +1317,8 @@ struct GSUB : GSUBGPOS
     const OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
     return_trace (list.sanitize (c, this));
   }
+
+  typedef GSUBGPOS::accelerator_t<GSUB> accelerator_t;
 };
 
 
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh
index d21c3de..44b595a 100644
--- a/src/hb-ot-layout-gsubgpos.hh
+++ b/src/hb-ot-layout-gsubgpos.hh
@@ -988,7 +988,6 @@ struct LookupRecord
   DEFINE_SIZE_STATIC (4);
 };
 
-
 template <typename context_t>
 static inline void recurse_lookups (context_t *c,
 				    unsigned int lookupCount,
@@ -2382,6 +2381,36 @@ struct GSUBGPOS
 		  (version.to_int () < 0x00010001u || featureVars.sanitize (c, this)));
   }
 
+  template <typename T>
+  struct accelerator_t
+  {
+    inline void init (hb_face_t *face)
+    {
+      this->blob = hb_sanitize_context_t().reference_table<T> (face);
+      const T &table = *this->blob->as<T> ();
+
+      this->lookup_count = table.get_lookup_count ();
+
+      this->accels = (hb_ot_layout_lookup_accelerator_t *) calloc (this->lookup_count, sizeof (hb_ot_layout_lookup_accelerator_t));
+      if (unlikely (!this->accels))
+        this->lookup_count = 0;
+
+      for (unsigned int i = 0; i < this->lookup_count; i++)
+	this->accels[i].init (table.get_lookup (i));
+    }
+
+    inline void fini (void)
+    {
+      hb_blob_destroy (this->blob);
+      free (accels);
+    }
+
+    private:
+      hb_blob_t *blob;
+      unsigned int lookup_count;
+      hb_ot_layout_lookup_accelerator_t *accels;
+  };
+
   protected:
   FixedVersion<>version;	/* Version of the GSUB/GPOS table--initially set
 				 * to 0x00010000u */
diff --git a/src/hb-ot-layout.hh b/src/hb-ot-layout.hh
index fcc0998..02c8c7b 100644
--- a/src/hb-ot-layout.hh
+++ b/src/hb-ot-layout.hh
@@ -34,6 +34,7 @@
 #include "hb-font.hh"
 #include "hb-buffer.hh"
 #include "hb-open-type.hh"
+#include "hb-set-digest.hh"
 
 
 /* Private API corresponding to hb-ot-layout.h: */
@@ -86,7 +87,22 @@ hb_ot_layout_substitute_start (hb_font_t    *font,
 			       hb_buffer_t  *buffer);
 
 
-struct hb_ot_layout_lookup_accelerator_t;
+struct hb_ot_layout_lookup_accelerator_t
+{
+  template <typename TLookup>
+  inline void init (const TLookup &lookup)
+  {
+    digest.init ();
+    lookup.add_coverage (&digest);
+  }
+  inline void fini (void) {}
+
+  inline bool may_have (hb_codepoint_t g) const
+  { return digest.may_have (g); }
+
+  private:
+  hb_set_digest_t digest;
+};
 
 namespace OT {
   struct hb_ot_apply_context_t;
-- 
2.7.4