From 156852991e18e5ac256ee4d6b2916931cc274977 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Thu, 25 Sep 2014 17:45:49 +0300
Subject: [PATCH] [ot-font] Add hb_ot_face_cmap_accelerator_t

---
 src/hb-ot-font.cc | 113 +++++++++++++++++++++++++++-------------------
 1 file changed, 66 insertions(+), 47 deletions(-)

diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 91df5ca53..2af2f54a7 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -91,14 +91,72 @@ struct hb_ot_face_metrics_accelerator_t
   }
 };
 
+struct hb_ot_face_cmap_accelerator_t
+{
+  const OT::CmapSubtable *table;
+  const OT::CmapSubtable *uvs_table;
+  hb_blob_t *blob;
+
+  inline void init (hb_face_t *face)
+  {
+    this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
+    const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob);
+    const OT::CmapSubtable *subtable = NULL;
+    const OT::CmapSubtable *subtable_uvs = NULL;
+
+    /* 32-bit subtables. */
+    if (!subtable) subtable = cmap->find_subtable (3, 10);
+    if (!subtable) subtable = cmap->find_subtable (0, 6);
+    if (!subtable) subtable = cmap->find_subtable (0, 4);
+    /* 16-bit subtables. */
+    if (!subtable) subtable = cmap->find_subtable (3, 1);
+    if (!subtable) subtable = cmap->find_subtable (0, 3);
+    if (!subtable) subtable = cmap->find_subtable (0, 2);
+    if (!subtable) subtable = cmap->find_subtable (0, 1);
+    if (!subtable) subtable = cmap->find_subtable (0, 0);
+    /* Meh. */
+    if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
+
+    /* UVS subtable. */
+    if (!subtable_uvs) subtable_uvs = cmap->find_subtable (0, 5);
+    /* Meh. */
+    if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtable);
+
+    this->table = subtable;
+    this->uvs_table = subtable_uvs;
+  }
+
+  inline void fini (void)
+  {
+    hb_blob_destroy (this->blob);
+  }
+
+  inline bool get_glyph (hb_codepoint_t  unicode,
+			 hb_codepoint_t  variation_selector,
+			 hb_codepoint_t *glyph) const
+  {
+    if (unlikely (variation_selector))
+    {
+      switch (this->uvs_table->get_glyph_variant (unicode,
+						  variation_selector,
+						  glyph))
+      {
+	case OT::GLYPH_VARIANT_NOT_FOUND:	return false;
+	case OT::GLYPH_VARIANT_FOUND:		return true;
+	case OT::GLYPH_VARIANT_USE_DEFAULT:	break;
+      }
+    }
+
+    return this->table->get_glyph (unicode, glyph);
+  }
+};
+
+
 struct hb_ot_font_t
 {
+  hb_ot_face_cmap_accelerator_t cmap;
   hb_ot_face_metrics_accelerator_t h_metrics;
   hb_ot_face_metrics_accelerator_t v_metrics;
-
-  const OT::CmapSubtable *cmap;
-  const OT::CmapSubtable *cmap_uvs;
-  hb_blob_t *cmap_blob;
 };
 
 
@@ -113,35 +171,9 @@ _hb_ot_font_create (hb_font_t *font)
 
   unsigned int upem = face->get_upem ();
 
+  ot_font->cmap.init (face);
   ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, upem>>1);
-  /* TODO Can we do this lazily? */
-  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem);
-
-  ot_font->cmap_blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
-  const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (ot_font->cmap_blob);
-  const OT::CmapSubtable *subtable = NULL;
-  const OT::CmapSubtable *subtable_uvs = NULL;
-
-  /* 32-bit subtables. */
-  if (!subtable) subtable = cmap->find_subtable (3, 10);
-  if (!subtable) subtable = cmap->find_subtable (0, 6);
-  if (!subtable) subtable = cmap->find_subtable (0, 4);
-  /* 16-bit subtables. */
-  if (!subtable) subtable = cmap->find_subtable (3, 1);
-  if (!subtable) subtable = cmap->find_subtable (0, 3);
-  if (!subtable) subtable = cmap->find_subtable (0, 2);
-  if (!subtable) subtable = cmap->find_subtable (0, 1);
-  if (!subtable) subtable = cmap->find_subtable (0, 0);
-  /* Meh. */
-  if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
-
-  /* UVS subtable. */
-  if (!subtable_uvs) subtable_uvs = cmap->find_subtable (0, 5);
-  /* Meh. */
-  if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtable);
-
-  ot_font->cmap = subtable;
-  ot_font->cmap_uvs = subtable_uvs;
+  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem); /* TODO Can we do this lazily? */
 
   return ot_font;
 }
@@ -149,7 +181,7 @@ _hb_ot_font_create (hb_font_t *font)
 static void
 _hb_ot_font_destroy (hb_ot_font_t *ot_font)
 {
-  hb_blob_destroy (ot_font->cmap_blob);
+  ot_font->cmap.fini ();
   ot_font->h_metrics.fini ();
   ot_font->v_metrics.fini ();
 
@@ -167,20 +199,7 @@ hb_ot_get_glyph (hb_font_t *font HB_UNUSED,
 
 {
   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
-
-  if (unlikely (variation_selector))
-  {
-    switch (ot_font->cmap_uvs->get_glyph_variant (unicode,
-						  variation_selector,
-						  glyph))
-    {
-      case OT::GLYPH_VARIANT_NOT_FOUND:		return false;
-      case OT::GLYPH_VARIANT_FOUND:		return true;
-      case OT::GLYPH_VARIANT_USE_DEFAULT:	break;
-    }
-  }
-
-  return ot_font->cmap->get_glyph (unicode, glyph);
+  return ot_font->cmap.get_glyph (unicode, variation_selector, glyph);
 }
 
 static hb_position_t