Bug 337593 – move glyph extents code (and cache) from pangocairo-*font.c

2007-06-09  Behdad Esfahbod  <behdad@gnome.org>

        Bug 337593 – move glyph extents code (and cache) from
        pangocairo-*font.c into pangocairo-font.c

        * pango/pangocairo-fontmap.c:
        * pango/pangocairo-fcfontmap.c:
        Remove per-fontmap renderer.  We've not been using it for a while
        and there is no reason to use it.

        * pango/pangocairo-font.c
        * pango/pangocairo-fcfont.c: 
        Most most code (including glyph extents caching) from fcfont.c to 
        font.c.  Simplifies individual backends a lot. ATSUI and Win32 
        cairo backends should adapt.

        * pango/pangocairo-render.c
        * pango/pangocairo-private.h:
        Update to reflect above changes.


svn path=/trunk/; revision=2335

1 files changed, 439 insertions, 67 deletions

diff --git a/pango/pangocairo-font.c b/pango/pangocairo-font.c
index 2595c0ef..5f439998 100644
--- a/pango/pangocairo-font.c
+++ b/pango/pangocairo-font.c
@@ -29,6 +29,12 @@
 
 PangoCairoWarningHistory _pango_cairo_warning_history = { FALSE };
 
+#define PANGO_CAIRO_FONT_PRIVATE(font)		\
+  ((PangoCairoFontPrivate *)			\
+   (font == NULL ? NULL :			\
+    G_STRUCT_MEMBER_P (font,			\
+    PANGO_CAIRO_FONT_GET_IFACE(PANGO_CAIRO_FONT(font))->cf_priv_offset)))
+
 GType
 pango_cairo_font_get_type (void)
 {
@@ -60,45 +66,86 @@ pango_cairo_font_get_type (void)
   return cairo_font_type;
 }
 
-/**
- * _pango_cairo_font_install:
- * @font: a #PangoCairoFont
- * @cr: a #cairo_t
- *
- * Makes @font the current font for rendering in the specified
- * Cairo context.
- **/
-gboolean
-_pango_cairo_font_install (PangoCairoFont *font,
-			   cairo_t        *cr)
+static PangoCairoFontPrivateScaledFontData *
+_pango_cairo_font_private_scaled_font_data_create (void)
+{
+  return g_slice_new (PangoCairoFontPrivateScaledFontData);
+}
+
+static void
+_pango_cairo_font_private_scaled_font_data_destroy (PangoCairoFontPrivateScaledFontData *data)
 {
-  if (G_UNLIKELY (!PANGO_IS_CAIRO_FONT (font)))
+  cairo_font_options_destroy (data->options);
+  g_slice_free (PangoCairoFontPrivateScaledFontData, data);
+}
+
+cairo_scaled_font_t *
+_pango_cairo_font_private_get_scaled_font (PangoCairoFontPrivate *cf_priv)
+{
+  cairo_font_face_t *font_face;
+
+  if (G_LIKELY (cf_priv->scaled_font))
+    return cf_priv->scaled_font;
+
+  /* need to create it */
+
+  if (G_UNLIKELY (cf_priv->data == NULL))
+    {
+      /* we have tried to create and failed before */
+      return NULL;
+    }
+
+  font_face = (* PANGO_CAIRO_FONT_GET_IFACE (cf_priv->cfont)->create_font_face) (cf_priv->cfont);
+  if (G_UNLIKELY (font_face == NULL))
+    goto done;
+
+  cf_priv->scaled_font = cairo_scaled_font_create (font_face,
+						   &cf_priv->data->font_matrix,
+						   &cf_priv->data->ctm,
+						   cf_priv->data->options);
+
+  cairo_font_face_destroy (font_face);
+
+done:
+  _pango_cairo_font_private_scaled_font_data_destroy (cf_priv->data);
+  cf_priv->data = NULL;
+
+  if (G_UNLIKELY (cf_priv->scaled_font == NULL || cairo_scaled_font_status (cf_priv->scaled_font) != CAIRO_STATUS_SUCCESS))
     {
-      if (!_pango_cairo_warning_history.font_install)
+      PangoFont *font = PANGO_FONT (cf_priv->cfont);
+      static GQuark warned_quark = 0;
+      if (!warned_quark)
+	warned_quark = g_quark_from_static_string ("pangocairo-scaledfont-warned");
+
+      if (!g_object_get_qdata (G_OBJECT (font), warned_quark))
 	{
-	  _pango_cairo_warning_history.font_install = TRUE;
-	  g_warning ("_pango_cairo_font_install called with bad font, expect ugly output");
-	  cairo_set_font_face (cr, NULL);
+	  PangoFontDescription *desc;
+	  char *s;
+
+	  desc = pango_font_describe (font);
+	  s = pango_font_description_to_string (desc);
+	  pango_font_description_free (desc);
+
+	  g_warning ("failed to create cairo %s, expect ugly output. the offending font is '%s'",
+		     font_face ? "scaled font" : "font face",
+		     s);
+
+	  g_free (s);
+
+	  g_object_set_qdata_full (G_OBJECT (font), warned_quark,
+				   GINT_TO_POINTER (1), NULL);
 	}
-      return FALSE;
     }
 
-  return (* PANGO_CAIRO_FONT_GET_IFACE (font)->install) (font, cr);
+  return cf_priv->scaled_font;
 }
 
-cairo_font_face_t *
-_pango_cairo_font_get_font_face (PangoCairoFont *font)
+static cairo_scaled_font_t *
+_pango_cairo_font_get_scaled_font (PangoFont *cfont)
 {
-  g_return_val_if_fail (PANGO_IS_CAIRO_FONT (font), NULL);
-  /* this function will be removed.  don't bother with warning history here */
-
-  return (* PANGO_CAIRO_FONT_GET_IFACE (font)->get_font_face) (font);
-}
+  PangoCairoFontPrivate *cf_priv;
 
-cairo_scaled_font_t *
-_pango_cairo_font_get_scaled_font (PangoCairoFont *font)
-{
-  if (G_UNLIKELY (!PANGO_IS_CAIRO_FONT (font)))
+  if (G_UNLIKELY (!PANGO_IS_CAIRO_FONT (cfont)))
     {
       if (!_pango_cairo_warning_history.font_get_scaled_font)
 	{
@@ -108,27 +155,126 @@ _pango_cairo_font_get_scaled_font (PangoCairoFont *font)
       return NULL;
     }
 
-  return (* PANGO_CAIRO_FONT_GET_IFACE (font)->get_scaled_font) (font);
+  cf_priv = PANGO_CAIRO_FONT_PRIVATE (cfont);
+
+  return _pango_cairo_font_private_get_scaled_font (cf_priv);
 }
 
-static void
-_pango_cairo_hex_box_info_destroy (PangoCairoHexBoxInfo *hbi)
+/**
+ * _pango_cairo_font_install:
+ * @font: a #PangoCairoFont
+ * @cr: a #cairo_t
+ *
+ * Makes @font the current font for rendering in the specified
+ * Cairo context.
+ *
+ * Return value: %TRUE if font was installed successfully, %FALSE otherwise.
+ **/
+gboolean
+_pango_cairo_font_install (PangoFont *font,
+			   cairo_t   *cr)
 {
-  if (hbi)
+  cairo_scaled_font_t *scaled_font = _pango_cairo_font_get_scaled_font (font);
+
+  if (G_UNLIKELY (scaled_font == NULL || cairo_scaled_font_status (scaled_font) != CAIRO_STATUS_SUCCESS))
+    return FALSE;
+
+  cairo_set_scaled_font (cr, scaled_font);
+
+  return TRUE;
+}
+
+
+typedef struct _PangoCairoFontMetricsInfo
+{
+  const char       *sample_str;
+  PangoFontMetrics *metrics;
+} PangoCairoFontMetricsInfo;
+
+PangoFontMetrics *
+_pango_cairo_font_get_metrics (PangoFont     *font,
+			       PangoLanguage *language)
+{
+  PangoCairoFont *cfont = (PangoCairoFont *) font;
+  PangoCairoFontPrivate *cf_priv = PANGO_CAIRO_FONT_PRIVATE (font);
+  PangoCairoFontMetricsInfo *info = NULL; /* Quiet gcc */
+  GSList *tmp_list;
+
+  const char *sample_str = pango_language_get_sample_string (language);
+
+  tmp_list = cf_priv->metrics_by_lang;
+  while (tmp_list)
     {
-      g_object_unref (hbi->font);
-      g_slice_free (PangoCairoHexBoxInfo, hbi);
+      info = tmp_list->data;
+
+      if (info->sample_str == sample_str)    /* We _don't_ need strcmp */
+	break;
+
+      tmp_list = tmp_list->next;
     }
+
+  if (!tmp_list)
+    {
+      PangoContext *context;
+      cairo_font_options_t *font_options;
+      int height, shift;
+
+      info = g_slice_new0 (PangoCairoFontMetricsInfo);
+
+      cf_priv->metrics_by_lang = g_slist_prepend (cf_priv->metrics_by_lang, info);
+
+      info->sample_str = sample_str;
+
+      context = pango_cairo_font_map_create_context ((PangoCairoFontMap *) pango_font_get_font_map (font));
+      pango_context_set_language (context, language);
+      font_options = cairo_font_options_create ();
+      cairo_scaled_font_get_font_options (_pango_cairo_font_private_get_scaled_font (cf_priv), font_options);
+      pango_cairo_context_set_font_options (context, font_options);
+      cairo_font_options_destroy (font_options);
+
+      info->metrics = (* PANGO_CAIRO_FONT_GET_IFACE (font)->create_metrics_for_context) (cfont, context);
+
+      /* We may actually reuse ascent/descent we got from cairo here.  that's
+       * in cf_priv->font_extents.
+       */
+      height = info->metrics->ascent + info->metrics->descent;
+      switch (cf_priv->gravity)
+	{
+	  default:
+	  case PANGO_GRAVITY_AUTO:
+	  case PANGO_GRAVITY_SOUTH:
+	    break;
+	  case PANGO_GRAVITY_NORTH:
+	    info->metrics->ascent = info->metrics->descent;
+	    break;
+	  case PANGO_GRAVITY_EAST:
+	  case PANGO_GRAVITY_WEST:
+	    {
+	      int ascent = height / 2;
+	      if (cf_priv->is_hinted)
+	        ascent = PANGO_UNITS_ROUND (ascent);
+	      info->metrics->ascent = ascent;
+	    }
+	}
+      shift = (height - info->metrics->ascent) - info->metrics->descent;
+      info->metrics->descent += shift;
+      info->metrics->underline_position -= shift;
+      info->metrics->strikethrough_position -= shift;
+      info->metrics->ascent = height - info->metrics->descent;
+
+      g_object_unref (context);
+    }
+
+  return pango_font_metrics_ref (info->metrics);
 }
 
-PangoCairoHexBoxInfo *
-_pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
+static PangoCairoFontHexBoxInfo *
+_pango_cairo_font_private_get_hex_box_info (PangoCairoFontPrivate *cf_priv)
 {
   static const char hexdigits[] = "0123456789ABCDEF";
   char c[2] = {0, 0};
   PangoFont *mini_font;
-  PangoCairoFont *mini_cfont;
-  PangoCairoHexBoxInfo *hbi;
+  PangoCairoFontHexBoxInfo *hbi;
 
   /* for metrics hinting */
   double scale_x = 1., scale_x_inv = 1., scale_y = 1., scale_y_inv = 1.;
@@ -148,24 +294,20 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
   cairo_matrix_t cairo_ctm;
   PangoGravity gravity;
 
-  if (!cfont)
+  if (!cf_priv)
     return NULL;
 
-  hbi = (PangoCairoHexBoxInfo *) g_object_get_data (G_OBJECT (cfont), "hex_box_info");
-  if (hbi)
-    return hbi;
+  if (cf_priv->hbi)
+    return cf_priv->hbi;
 
-  scaled_font = _pango_cairo_font_get_scaled_font (cfont);
-  if (!scaled_font)
-    {
-      g_object_set_data_full (G_OBJECT (cfont), "hex_box_info", NULL, NULL);
-      return NULL;
-    }
+  scaled_font = _pango_cairo_font_private_get_scaled_font (cf_priv);
+  if (G_UNLIKELY (scaled_font == NULL || cairo_scaled_font_status (scaled_font) != CAIRO_STATUS_SUCCESS))
+    return NULL;
+
+  is_hinted = cf_priv->is_hinted;
 
   font_options = cairo_font_options_create ();
-  cairo_scaled_font_get_font_options (scaled_font, font_options);
-  is_hinted = (cairo_font_options_get_hint_metrics(font_options) != CAIRO_HINT_METRICS_OFF);
-  desc = pango_font_describe_with_absolute_size ((PangoFont *)cfont);
+  desc = pango_font_describe_with_absolute_size ((PangoFont *)cf_priv->cfont);
   size = pango_font_description_get_size (desc) / (1.*PANGO_SCALE);
   gravity = pango_font_description_get_gravity (desc);
 
@@ -208,7 +350,7 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
     PangoContext *context;
     PangoFontMap *fontmap;
 
-    fontmap = pango_font_get_font_map ((PangoFont *)cfont);
+    fontmap = pango_font_get_font_map ((PangoFont *)cf_priv->cfont);
 
     /* we inherit most font properties for the mini font.  just
      * change family and size.  means, you get bold hex digits
@@ -233,8 +375,7 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
 	  }
       }
 
-    pango_font_description_set_absolute_size (desc, mini_size * PANGO_SCALE);
-
+    pango_font_description_set_absolute_size (desc, pango_units_from_double (mini_size));
 
     /* load mini_font */
 
@@ -251,8 +392,7 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
   cairo_font_options_destroy (font_options);
 
 
-  mini_cfont = (PangoCairoFont *) mini_font;
-  scaled_mini_font = _pango_cairo_font_get_scaled_font (mini_cfont);
+  scaled_mini_font = _pango_cairo_font_get_scaled_font (mini_font);
 
   for (i = 0 ; i < 16 ; i++)
     {
@@ -274,8 +414,8 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
   pad = (font_extents.ascent + font_extents.descent) / 43;
   pad = MIN (pad, mini_size);
 
-  hbi = g_slice_new (PangoCairoHexBoxInfo);
-  hbi->font = mini_font;
+  hbi = g_slice_new (PangoCairoFontHexBoxInfo);
+  hbi->font = (PangoCairoFont *) mini_font;
   hbi->rows = rows;
 
   hbi->digit_width  = width;
@@ -314,21 +454,114 @@ _pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
        hbi->box_descent = HINT_Y (hbi->box_descent);
     }
 
-  g_object_set_data_full (G_OBJECT (cfont), "hex_box_info", hbi, (GDestroyNotify)_pango_cairo_hex_box_info_destroy);
-
   return hbi;
 }
 
+static void
+_pango_cairo_font_hex_box_info_destroy (PangoCairoFontHexBoxInfo *hbi)
+{
+  if (hbi)
+    {
+      g_object_unref (hbi->font);
+      g_slice_free (PangoCairoFontHexBoxInfo, hbi);
+    }
+}
+
+PangoCairoFontHexBoxInfo *
+_pango_cairo_font_get_hex_box_info (PangoCairoFont *cfont)
+{
+  PangoCairoFontPrivate *cf_priv = PANGO_CAIRO_FONT_PRIVATE (cfont);
+
+  return _pango_cairo_font_private_get_hex_box_info (cf_priv);
+}
+
+void
+_pango_cairo_font_private_initialize (PangoCairoFontPrivate      *cf_priv,
+				      PangoCairoFont             *cfont,
+				      PangoContext               *context,
+				      const PangoFontDescription *desc,
+				      const cairo_matrix_t       *font_matrix)
+{
+  const cairo_font_options_t *font_options;
+  cairo_matrix_t gravity_matrix;
+  const PangoMatrix *pango_ctm;
+
+  cf_priv->cfont = cfont;
+  cf_priv->gravity = pango_font_description_get_gravity (desc);
+
+  cf_priv->data = _pango_cairo_font_private_scaled_font_data_create (); 
+
+  /* first apply gravity rotation, then font_matrix, such that
+   * vertical italic text comes out "correct".  we don't do anything
+   * like baseline adjustment etc though.  should be specially
+   * handled when we support italic correction. */
+  cairo_matrix_init_rotate(&gravity_matrix,
+			   pango_gravity_to_rotation (cf_priv->gravity));
+  cairo_matrix_multiply (&cf_priv->data->font_matrix,
+			 font_matrix,
+			 &gravity_matrix);
+
+  pango_ctm = pango_context_get_matrix (context);
+  if (pango_ctm)
+    cairo_matrix_init (&cf_priv->data->ctm,
+		       pango_ctm->xx,
+		       pango_ctm->yx,
+		       pango_ctm->xy,
+		       pango_ctm->yy,
+		       0., 0.);
+  else
+    cairo_matrix_init_identity (&cf_priv->data->ctm);
+
+  font_options = _pango_cairo_context_get_merged_font_options (context);
+  cf_priv->data->options = cairo_font_options_copy (font_options);
+  cf_priv->is_hinted = cairo_font_options_get_hint_metrics (font_options) != CAIRO_HINT_METRICS_OFF;
+
+  cf_priv->scaled_font = NULL;
+  cf_priv->hbi = NULL;
+  cf_priv->glyph_extents_cache = NULL;
+  cf_priv->metrics_by_lang = NULL;
+}
+
+static void
+free_metrics_info (PangoCairoFontMetricsInfo *info)
+{
+  pango_font_metrics_unref (info->metrics);
+  g_slice_free (PangoCairoFontMetricsInfo, info);
+}
+
 void
-_pango_cairo_get_glyph_extents_missing (PangoCairoFont *cfont,
-					PangoGlyph      glyph,
-					PangoRectangle *ink_rect,
-					PangoRectangle *logical_rect)
+_pango_cairo_font_private_finalize (PangoCairoFontPrivate *cf_priv)
+{
+  _pango_cairo_font_private_scaled_font_data_destroy (cf_priv->data);
+
+  if (cf_priv->scaled_font)
+    cairo_scaled_font_destroy (cf_priv->scaled_font);
+
+  _pango_cairo_font_hex_box_info_destroy (cf_priv->hbi);
+
+  if (cf_priv->glyph_extents_cache)
+    g_free (cf_priv->glyph_extents_cache);
+
+  g_slist_foreach (cf_priv->metrics_by_lang, (GFunc)free_metrics_info, NULL);
+  g_slist_free (cf_priv->metrics_by_lang);
+}
+
+gboolean
+_pango_cairo_font_private_is_metrics_hinted (PangoCairoFontPrivate *cf_priv)
+{
+  return cf_priv->is_hinted;
+}
+
+static void
+_pango_cairo_font_private_get_glyph_extents_missing (PangoCairoFontPrivate *cf_priv,
+						     PangoGlyph             glyph,
+						     PangoRectangle        *ink_rect,
+						     PangoRectangle        *logical_rect)
 {
-  PangoCairoHexBoxInfo *hbi;
+  PangoCairoFontHexBoxInfo *hbi;
   gint rows, cols;
 
-  hbi = _pango_cairo_font_get_hex_box_info (cfont);
+  hbi = _pango_cairo_font_private_get_hex_box_info (cf_priv);
   if (!hbi)
     {
       pango_font_get_glyph_extents (NULL, glyph, ink_rect, logical_rect);
@@ -355,3 +588,142 @@ _pango_cairo_get_glyph_extents_missing (PangoCairoFont *cfont,
     }
 }
 
+#define GLYPH_CACHE_NUM_ENTRIES 256 /* should be power of two */
+#define GLYPH_CACHE_MASK (GLYPH_CACHE_NUM_ENTRIES - 1)
+/* An entry in the fixed-size cache for the glyph->extents mapping.
+ * The cache is indexed by the lower N bits of the glyph (see
+ * GLYPH_CACHE_NUM_ENTRIES).  For scripts with few glyphs,
+ * this should provide pretty much instant lookups.
+ */
+struct _PangoCairoFontGlyphExtentsCacheEntry
+{
+  PangoGlyph     glyph;
+  int            width;
+  PangoRectangle ink_rect;
+};
+
+static gboolean
+_pango_cairo_font_private_glyph_extents_cache_init (PangoCairoFontPrivate *cf_priv)
+{
+  cairo_scaled_font_t *scaled_font = _pango_cairo_font_private_get_scaled_font (cf_priv);
+  cairo_font_extents_t font_extents;
+
+  if (G_UNLIKELY (scaled_font == NULL || cairo_scaled_font_status (scaled_font) != CAIRO_STATUS_SUCCESS))
+    return FALSE;
+
+  cairo_scaled_font_extents (scaled_font, &font_extents);
+
+  cf_priv->font_extents.x = 0;
+  cf_priv->font_extents.width = 0;
+  cf_priv->font_extents.height = pango_units_from_double (font_extents.ascent + font_extents.descent);
+  switch (cf_priv->gravity)
+    {
+      default:
+      case PANGO_GRAVITY_AUTO:
+      case PANGO_GRAVITY_SOUTH:
+	cf_priv->font_extents.y = - pango_units_from_double (font_extents.ascent);
+	break;
+      case PANGO_GRAVITY_NORTH:
+	cf_priv->font_extents.y = - pango_units_from_double (font_extents.descent);
+	break;
+      case PANGO_GRAVITY_EAST:
+      case PANGO_GRAVITY_WEST:
+	{
+	  int ascent = pango_units_from_double (font_extents.ascent + font_extents.descent) / 2;
+	  if (cf_priv->is_hinted)
+	    ascent = PANGO_UNITS_ROUND (ascent);
+	  cf_priv->font_extents.y = - ascent;
+	}
+    }
+
+  cf_priv->glyph_extents_cache = g_new0 (PangoCairoFontGlyphExtentsCacheEntry, GLYPH_CACHE_NUM_ENTRIES);
+  /* Make sure all cache entries are invalid initially */
+  cf_priv->glyph_extents_cache[0].glyph = 1; /* glyph 1 cannot happen in bucket 0 */
+
+  return TRUE;
+}
+
+/* Fills in the glyph extents cache entry
+ */
+static void
+compute_glyph_extents (PangoCairoFontPrivate  *cf_priv,
+		       PangoGlyph              glyph,
+		       PangoCairoFontGlyphExtentsCacheEntry *entry)
+{
+  cairo_text_extents_t extents;
+  cairo_glyph_t cairo_glyph;
+
+  cairo_glyph.index = glyph;
+  cairo_glyph.x = 0;
+  cairo_glyph.y = 0;
+
+  cairo_scaled_font_glyph_extents (_pango_cairo_font_private_get_scaled_font (cf_priv),
+				   &cairo_glyph, 1, &extents);
+
+  entry->glyph = glyph;
+  entry->width = pango_units_from_double (extents.x_advance);
+  entry->ink_rect.x = pango_units_from_double (extents.x_bearing);
+  entry->ink_rect.y = pango_units_from_double (extents.y_bearing);
+  entry->ink_rect.width = pango_units_from_double (extents.width);
+  entry->ink_rect.height = pango_units_from_double (extents.height);
+}
+
+static PangoCairoFontGlyphExtentsCacheEntry *
+_pango_cairo_font_private_get_glyph_extents_cache_entry (PangoCairoFontPrivate  *cf_priv,
+							 PangoGlyph              glyph)
+{
+  PangoCairoFontGlyphExtentsCacheEntry *entry;
+  guint idx;
+
+  idx = glyph & GLYPH_CACHE_MASK;
+  entry = cf_priv->glyph_extents_cache + idx;
+
+  if (entry->glyph != glyph)
+    {
+      compute_glyph_extents (cf_priv, glyph, entry);
+    }
+
+  return entry;
+}
+
+void
+_pango_cairo_font_private_get_glyph_extents (PangoCairoFontPrivate *cf_priv,
+					     PangoGlyph             glyph,
+					     PangoRectangle        *ink_rect,
+					     PangoRectangle        *logical_rect)
+{
+  PangoCairoFontGlyphExtentsCacheEntry *entry;
+
+  if (!cf_priv ||
+      (cf_priv->glyph_extents_cache == NULL &&
+       !_pango_cairo_font_private_glyph_extents_cache_init (cf_priv)))
+    {
+      /* Get generic unknown-glyph extents. */
+      pango_font_get_glyph_extents (NULL, glyph, ink_rect, logical_rect);
+      return;
+    }
+
+  if (glyph == PANGO_GLYPH_EMPTY)
+    {
+      if (ink_rect)
+	ink_rect->x = ink_rect->y = ink_rect->width = ink_rect->height = 0;
+      if (logical_rect)
+	*logical_rect = cf_priv->font_extents;
+      return;
+    }
+  else if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
+    {
+      _pango_cairo_font_private_get_glyph_extents_missing(cf_priv, glyph, ink_rect, logical_rect);
+      return;
+    }
+
+  entry = _pango_cairo_font_private_get_glyph_extents_cache_entry (cf_priv, glyph);
+
+  if (ink_rect)
+    *ink_rect = entry->ink_rect;
+  if (logical_rect)
+    {
+      *logical_rect = cf_priv->font_extents;
+      logical_rect->width = entry->width;
+    }
+}