Change PangoFc font loading API such that PangoContext is not passed down.

2009-01-09  Behdad Esfahbod  <behdad@gnome.org>

        * docs/pango-sections.txt:
        * docs/tmpl/pangofc-fontmap.sgml:
        * docs/tmpl/text-attributes.sgml:
        * pango/pangocairo-fc.h:
        * pango/pangocairo-fcfont.c (get_font_size), (get_gravity_class),
        (get_gravity), (_pango_cairo_fc_font_new):
        * pango/pangocairo-fcfontmap.c
        (pango_cairo_fc_font_map_font_key_substitute),
        (pango_cairo_fc_font_map_create_font),
        (pango_cairo_fc_font_map_class_init):
        * pango/pangofc-font.c (_pango_fc_font_get_font_key),
        (_pango_fc_font_set_font_key):
        * pango/pangofc-fontmap.c (pango_fc_font_key_equal),
        (pango_fc_font_key_hash), (pango_fc_font_key_free),
        (pango_fc_font_key_copy), (get_context_matrix),
        (pango_fc_font_key_init), (pango_fc_font_key_get_pattern),
        (pango_fc_font_key_get_matrix),
        (pango_fc_font_key_get_context_key), (pango_fc_font_map_init),
        (pango_fc_font_map_class_init), (pango_fc_font_map_add),
        (_pango_fc_font_map_remove), (pango_fc_make_pattern),
        (pango_fc_font_map_new_font), (pango_fc_default_substitute),
        (pango_fc_font_map_get_patterns), (pango_fc_font_map_load_fontset):
        * pango/pangofc-fontmap.h:
        * pango/pangofc-private.h:
        Change PangoFc font loading API such that PangoContext is not passed
        down.  We use a new opaque struct called PangoFcFontKey.  This struct
        is in fact our font hash key.  This avoids problems where previously
        we were using context members that were not necessarily considered
        by the pangofc layer when caching.
        This is in preparation for lazy loading of fonts in the pangofc fontmap.

svn path=/trunk/; revision=2804

7 files changed, 288 insertions, 227 deletions

diff --git a/pango/pangocairo-fc.h b/pango/pangocairo-fc.h
index 74f39bab..ea4fccbc 100644
--- a/pango/pangocairo-fc.h
+++ b/pango/pangocairo-fc.h
@@ -44,10 +44,8 @@ struct _PangoCairoFcFontMap
 
 GType pango_cairo_fc_font_map_get_type (void) G_GNUC_CONST;
 
-PangoFcFont *_pango_cairo_fc_font_new (PangoCairoFcFontMap        *cffontmap,
-				       PangoContext               *context,
-				       const PangoFontDescription *desc,
-				       FcPattern	          *pattern);
+PangoFcFont *_pango_cairo_fc_font_new (PangoCairoFcFontMap *cffontmap,
+				       PangoFcFontKey      *key);
 FT_Library   _pango_cairo_fc_font_map_get_library (PangoCairoFcFontMap *fontmap);
 
 G_END_DECLS
diff --git a/pango/pangocairo-fcfont.c b/pango/pangocairo-fcfont.c
index 129fa865..1c9a77aa 100644
--- a/pango/pangocairo-fcfont.c
+++ b/pango/pangocairo-fcfont.c
@@ -169,52 +169,59 @@ pango_cairo_fc_font_init (PangoCairoFcFont *cffont G_GNUC_UNUSED)
  ********************/
 
 static double
-get_font_size (PangoCairoFcFontMap        *cffontmap,
-	       PangoContext               *context,
-	       const PangoFontDescription *desc,
-	       FcPattern                  *pattern)
+get_font_size (const FcPattern *pattern)
 {
   double size;
-
- /* The reason why we read FC_PIXEL_SIZE here rather than just
-  * using the specified size is to support operations like clamping
-  * a font to a minimal readable size in fonts.conf. This is pretty weird,
-  * since it could mean that changing the Cairo CTM doesn't change the
-  * font size, but it's just a more radical version of the non-linear
-  * font scaling we already have due to hinting and due to bitmap
-  * fonts being only available at a few sizes.
-  *
-  * If honoring FC_PIXEL_SIZE gets in the way of more useful features
-  * it should be removed since it only matters in the unusual case
-  * of people doing exotic stuff in fonts.conf.
-  */
+  double dpi;
 
   if (FcPatternGetDouble (pattern, FC_PIXEL_SIZE, 0, &size) == FcResultMatch)
-    return size * PANGO_SCALE / pango_matrix_get_font_scale_factor (pango_context_get_matrix (context));
+    return size * PANGO_SCALE;
 
   /* Just in case FC_PIXEL_SIZE got unset between pango_fc_make_pattern()
-   * and here.
+   * and here.  That would be very weird.
    */
-  if (pango_font_description_get_size_is_absolute (desc))
-    return pango_font_description_get_size (desc);
-  else
-    {
-      double dpi = pango_cairo_context_get_resolution (context);
 
-      if (dpi <= 0)
-	dpi = cffontmap->dpi;
+  if (FcPatternGetDouble (pattern, FC_DPI, 0, &dpi) != FcResultMatch)
+    dpi = 72;
+
+  if (FcPatternGetDouble (pattern, FC_SIZE, 0, &size) == FcResultMatch)
+    return size * dpi / 72.;
+
+  /* Whatever */
+  return 18.;
+}
+
+static gpointer
+get_gravity_class (void)
+{
+  static GEnumClass *class = NULL;
 
-      return dpi * pango_font_description_get_size (desc) / 72.;
+  if (G_UNLIKELY (!class))
+    class = g_type_class_ref (PANGO_TYPE_GRAVITY);
+
+  return class;
+}
+
+static PangoGravity
+get_gravity (const FcPattern *pattern)
+{
+  char *s;
+
+  if (FcPatternGetString (pattern, PANGO_FC_GRAVITY, 0, (FcChar8 **)(void *)&s) == FcResultMatch)
+    {
+      GEnumValue *value = g_enum_get_value_by_nick (get_gravity_class (), s);
+      return value->value;
     }
+
+  return PANGO_GRAVITY_SOUTH;
 }
 
 PangoFcFont *
-_pango_cairo_fc_font_new (PangoCairoFcFontMap        *cffontmap,
-			  PangoContext               *context,
-			  const PangoFontDescription *desc,
-			  FcPattern	             *pattern)
+_pango_cairo_fc_font_new (PangoCairoFcFontMap *cffontmap,
+			  PangoFcFontKey      *key)
 {
   PangoCairoFcFont *cffont;
+  const FcPattern *pattern = pango_fc_font_key_get_pattern (key);
   cairo_matrix_t font_matrix;
   FcMatrix *fc_matrix;
   double size;
@@ -226,7 +233,8 @@ _pango_cairo_fc_font_new (PangoCairoFcFontMap        *cffontmap,
 			 "pattern", pattern,
 			 NULL);
 
-  size = get_font_size (cffontmap, context, desc, pattern);
+  size = get_font_size (pattern) /
+	 pango_matrix_get_font_scale_factor (pango_fc_font_key_get_matrix (key));
 
   if  (FcPatternGetMatrix (pattern,
 			   FC_MATRIX, 0, &fc_matrix) == FcResultMatch)
@@ -244,9 +252,9 @@ _pango_cairo_fc_font_new (PangoCairoFcFontMap        *cffontmap,
 
   _pango_cairo_font_private_initialize (&cffont->cf_priv,
 					(PangoCairoFont *) cffont,
-					pango_font_description_get_gravity (desc),
-					_pango_cairo_context_get_merged_font_options (context),
-					pango_context_get_matrix (context),
+					get_gravity (pattern),
+					pango_fc_font_key_get_context_key (key),
+					pango_fc_font_key_get_matrix (key),
 					&font_matrix);
 
   ((PangoFcFont *)(cffont))->is_hinted = _pango_cairo_font_private_is_metrics_hinted (&cffont->cf_priv);
diff --git a/pango/pangocairo-fcfontmap.c b/pango/pangocairo-fcfontmap.c
index 33e94549..c66602b6 100644
--- a/pango/pangocairo-fcfontmap.c
+++ b/pango/pangocairo-fcfontmap.c
@@ -80,14 +80,14 @@ pango_cairo_fc_font_map_finalize (GObject *object)
 }
 
 static void
-pango_cairo_fc_font_map_context_substitute (PangoFcFontMap *fcfontmap G_GNUC_UNUSED,
-					    PangoContext   *context,
-					    FcPattern      *pattern)
+pango_cairo_fc_font_map_font_key_substitute (PangoFcFontMap *fcfontmap G_GNUC_UNUSED,
+					     PangoFcFontKey *fontkey,
+					     FcPattern      *pattern)
 {
   FcConfigSubstitute (NULL, pattern, FcMatchPattern);
 
-  if (context)
-    cairo_ft_font_options_substitute (_pango_cairo_context_get_merged_font_options (context),
+  if (fontkey)
+    cairo_ft_font_options_substitute (pango_fc_font_key_get_context_key (fontkey),
 				      pattern);
 
   FcDefaultSubstitute (pattern);
@@ -151,13 +151,11 @@ pango_cairo_fc_font_map_context_key_equal (PangoFcFontMap *fcfontmap G_GNUC_UNUS
 }
 
 static PangoFcFont *
-pango_cairo_fc_font_map_create_font (PangoFcFontMap             *fcfontmap,
-				     PangoContext               *context,
-				     const PangoFontDescription *desc,
-				     FcPattern                  *pattern)
+pango_cairo_fc_font_map_create_font (PangoFcFontMap *fcfontmap,
+				     PangoFcFontKey *key)
 {
   return _pango_cairo_fc_font_new ((PangoCairoFcFontMap *) (fcfontmap),
-				   context, desc, pattern);
+				   key);
 }
 
 static void
@@ -168,7 +166,7 @@ pango_cairo_fc_font_map_class_init (PangoCairoFcFontMapClass *class)
 
   gobject_class->finalize  = pango_cairo_fc_font_map_finalize;
 
-  fcfontmap_class->context_substitute = pango_cairo_fc_font_map_context_substitute;
+  fcfontmap_class->font_key_substitute = pango_cairo_fc_font_map_font_key_substitute;
   fcfontmap_class->get_resolution = pango_cairo_fc_font_map_get_resolution_fc;
 
   fcfontmap_class->context_key_get = pango_cairo_fc_font_map_context_key_get;
diff --git a/pango/pangofc-font.c b/pango/pangofc-font.c
index d5f2d57f..64199239 100644
--- a/pango/pangofc-font.c
+++ b/pango/pangofc-font.c
@@ -57,7 +57,7 @@ typedef struct _PangoFcFontPrivate PangoFcFontPrivate;
 struct _PangoFcFontPrivate
 {
   PangoFcDecoder *decoder;
-  gpointer context_key;
+  PangoFcFontKey *key;
   GUnicharToGlyphCacheEntry *char_to_glyph_cache;
 };
 
@@ -855,21 +855,21 @@ _pango_fc_font_set_decoder (PangoFcFont    *font,
     g_object_ref (priv->decoder);
 }
 
-gpointer
-_pango_fc_font_get_context_key (PangoFcFont *fcfont)
+PangoFcFontKey *
+_pango_fc_font_get_font_key (PangoFcFont *fcfont)
 {
   PangoFcFontPrivate *priv = fcfont->priv;
 
-  return priv->context_key;
+  return priv->key;
 }
 
 void
-_pango_fc_font_set_context_key (PangoFcFont *fcfont,
-				gpointer     context_key)
+_pango_fc_font_set_font_key (PangoFcFont    *fcfont,
+			     PangoFcFontKey *key)
 {
   PangoFcFontPrivate *priv = fcfont->priv;
 
-  priv->context_key = context_key;
+  priv->key = key;
 }
 
 static FT_Glyph_Metrics *
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 0d7fe7ee..42cfe01e 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -38,7 +38,6 @@ typedef struct _PangoFcFamily       PangoFcFamily;
 typedef struct _PangoFcPatternSet   PangoFcPatternSet;
 typedef struct _PangoFcFindFuncInfo PangoFcFindFuncInfo;
 typedef struct _FontsetHashKey      FontsetHashKey;
-typedef struct _FontHashKey         FontHashKey;
 
 #define PANGO_FC_TYPE_FAMILY              (pango_fc_family_get_type ())
 #define PANGO_FC_FAMILY(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_FC_TYPE_FAMILY, PangoFcFamily))
@@ -136,6 +135,9 @@ static void          pango_fc_font_map_list_families (PangoFontMap
 						       PangoFontFamily            ***families,
 						       int                          *n_families);
 
+static double pango_fc_font_map_get_resolution (PangoFcFontMap *fcfontmap,
+						PangoContext   *context);
+
 static void pango_fc_font_map_cache_fontset (PangoFcFontMap    *fcfontmap,
 					     PangoFcPatternSet *patterns);
 
@@ -148,72 +150,16 @@ static guint    pango_fc_coverage_key_hash  (PangoFcCoverageKey *key);
 static gboolean pango_fc_coverage_key_equal (PangoFcCoverageKey *key1,
 					      PangoFcCoverageKey *key2);
 
-static guint    font_hash_key_hash  (const FontHashKey *key);
-static gboolean font_hash_key_equal (const FontHashKey *key_a,
-				     const FontHashKey *key_b);
-static void     font_hash_key_free  (FontHashKey       *key);
+static guint    pango_fc_font_key_hash  (const PangoFcFontKey *key);
+static gboolean pango_fc_font_key_equal (const PangoFcFontKey *key_a,
+				     const PangoFcFontKey *key_b);
+static void     pango_fc_font_key_free  (PangoFcFontKey       *key);
 
 static guint    fontset_hash_key_hash  (const FontsetHashKey *key);
 static gboolean fontset_hash_key_equal (const FontsetHashKey *key_a,
 					const FontsetHashKey *key_b);
 static void     fontset_hash_key_free  (FontsetHashKey       *key);
 
-G_DEFINE_ABSTRACT_TYPE (PangoFcFontMap, pango_fc_font_map, PANGO_TYPE_FONT_MAP)
-
-static void
-pango_fc_font_map_init (PangoFcFontMap *fcfontmap)
-{
-  static gboolean registered_modules = FALSE;
-  PangoFcFontMapPrivate *priv;
-
-  priv = fcfontmap->priv = G_TYPE_INSTANCE_GET_PRIVATE (fcfontmap,
-							PANGO_TYPE_FC_FONT_MAP,
-							PangoFcFontMapPrivate);
-
-  if (!registered_modules)
-    {
-      int i;
-
-      registered_modules = TRUE;
-
-      for (i = 0; _pango_included_fc_modules[i].list; i++)
-	pango_module_register (&_pango_included_fc_modules[i]);
-    }
-
-  priv->n_families = -1;
-
-  priv->font_hash = g_hash_table_new_full ((GHashFunc)font_hash_key_hash,
-					   (GEqualFunc)font_hash_key_equal,
-					   (GDestroyNotify)font_hash_key_free,
-					   NULL);
-  priv->fontset_hash = g_hash_table_new_full ((GHashFunc)fontset_hash_key_hash,
-					      (GEqualFunc)fontset_hash_key_equal,
-					      (GDestroyNotify)fontset_hash_key_free,
-					      (GDestroyNotify)pango_fc_pattern_set_free);
-
-  priv->coverage_hash = g_hash_table_new_full ((GHashFunc)pango_fc_coverage_key_hash,
-					       (GEqualFunc)pango_fc_coverage_key_equal,
-					       (GDestroyNotify)g_free,
-					       (GDestroyNotify)pango_coverage_unref);
-  priv->fontset_cache = g_queue_new ();
-  priv->dpi = -1;
-}
-
-static void
-pango_fc_font_map_class_init (PangoFcFontMapClass *class)
-{
-  GObjectClass *object_class = G_OBJECT_CLASS (class);
-  PangoFontMapClass *fontmap_class = PANGO_FONT_MAP_CLASS (class);
-
-  object_class->finalize = pango_fc_font_map_finalize;
-  fontmap_class->load_font = pango_fc_font_map_load_font;
-  fontmap_class->load_fontset = pango_fc_font_map_load_fontset;
-  fontmap_class->list_families = pango_fc_font_map_list_families;
-  fontmap_class->shape_engine_type = PANGO_RENDER_TYPE_FC;
-
-  g_type_class_add_private (object_class, sizeof (PangoFcFontMapPrivate));
-}
-
 static gpointer
 get_gravity_class (void)
 {
@@ -283,10 +229,10 @@ struct _FontsetHashKey {
   gpointer context_key;
 };
 
-struct _FontHashKey {
+struct _PangoFcFontKey {
   PangoFcFontMap *fontmap;
+  const FcPattern *pattern;
   PangoMatrix matrix;
-  FcPattern *pattern;
   gpointer context_key;
 };
 
@@ -378,15 +324,16 @@ fontset_hash_key_copy (FontsetHashKey *old)
   return key;
 }
 
+/*
+ * PangoFcFontKey
+ */
+
 static gboolean
-font_hash_key_equal (const FontHashKey *key_a,
-		     const FontHashKey *key_b)
-{
-  if (key_a->matrix.xx == key_b->matrix.xx &&
-      key_a->matrix.xy == key_b->matrix.xy &&
-      key_a->matrix.yx == key_b->matrix.yx &&
-      key_a->matrix.yy == key_b->matrix.yy &&
-      key_a->pattern == key_b->pattern)
+pango_fc_font_key_equal (const PangoFcFontKey *key_a,
+			 const PangoFcFontKey *key_b)
+{
+  if (key_a->pattern == key_b->pattern &&
+      0 == memcmp (&key_a->matrix, &key_b->matrix, 4 * sizeof (double)))
     {
       if (key_a->context_key && key_b->context_key)
 	return PANGO_FC_FONT_MAP_GET_CLASS (key_a->fontmap)->context_key_equal (key_a->fontmap,
@@ -400,7 +347,7 @@ font_hash_key_equal (const FontHashKey *key_a,
 }
 
 static guint
-font_hash_key_hash (const FontHashKey *key)
+pango_fc_font_key_hash (const PangoFcFontKey *key)
 {
     guint32 hash = FNV1_32_INIT;
 
@@ -417,23 +364,23 @@ font_hash_key_hash (const FontHashKey *key)
 }
 
 static void
-font_hash_key_free (FontHashKey *key)
+pango_fc_font_key_free (PangoFcFontKey *key)
 {
   if (key->context_key)
     PANGO_FC_FONT_MAP_GET_CLASS (key->fontmap)->context_key_free (key->fontmap,
 								  key->context_key);
 
-  g_slice_free (FontHashKey, key);
+  g_slice_free (PangoFcFontKey, key);
 }
 
-static FontHashKey *
-font_hash_key_copy (FontHashKey *old)
+static PangoFcFontKey *
+pango_fc_font_key_copy (PangoFcFontKey *old)
 {
-  FontHashKey *key = g_slice_new (FontHashKey);
+  PangoFcFontKey *key = g_slice_new (PangoFcFontKey);
 
   key->fontmap = old->fontmap;
-  key->matrix = old->matrix;
   key->pattern = old->pattern;
+  key->matrix = old->matrix;
   if (old->context_key)
     key->context_key = PANGO_FC_FONT_MAP_GET_CLASS (key->fontmap)->context_key_copy (key->fontmap,
 										     old->context_key);
@@ -443,6 +390,147 @@ font_hash_key_copy (FontHashKey *old)
   return key;
 }
 
+static void
+get_context_matrix (PangoContext *context,
+		    PangoMatrix *matrix)
+{
+  const PangoMatrix *set_matrix;
+  static const PangoMatrix identity = PANGO_MATRIX_INIT;
+
+  set_matrix = context ? pango_context_get_matrix (context) : NULL;
+  *matrix = set_matrix ? *set_matrix : identity;
+}
+
+static void
+pango_fc_font_key_init (PangoFcFontKey             *key,
+			PangoFcFontMap             *fcfontmap,
+			PangoContext               *context,
+			const FcPattern            *pattern)
+{
+  key->fontmap = fcfontmap;
+  key->pattern = pattern;
+
+  get_context_matrix (context, &key->matrix);
+  key->matrix.x0 = key->matrix.y0 = 0.;
+
+  if (PANGO_FC_FONT_MAP_GET_CLASS (fcfontmap)->context_key_get)
+    key->context_key = (gpointer)PANGO_FC_FONT_MAP_GET_CLASS (fcfontmap)->context_key_get (fcfontmap, context);
+  else
+    key->context_key = NULL;
+}
+
+/* Public API */
+
+/**
+ * pango_fc_font_key_get_pattern:
+ * @key: the font key
+ *
+ * Gets the fontconfig pattern member of @key.
+ *
+ * Returns: the pattern, which is owned by @key and should not be modified.
+ *
+ * Since: 1.24
+ **/
+const FcPattern *
+pango_fc_font_key_get_pattern (const PangoFcFontKey *key)
+{
+  return key->pattern;
+}
+
+/**
+ * pango_fc_font_key_get_matrix:
+ * @key: the font key
+ *
+ * Gets the matrix member of @key.
+ *
+ * Returns: the matrix, which is owned by @key and should not be modified.
+ *
+ * Since: 1.24
+ **/
+const PangoMatrix *
+pango_fc_font_key_get_matrix (const PangoFcFontKey *key)
+{
+  return &key->matrix;
+}
+
+/**
+ * pango_fc_font_key_get_context_key:
+ * @key: the font key
+ *
+ * Gets the context key member of @key.
+ *
+ * Returns: the context key, which is owned by @key and should not be modified.
+ *
+ * Since: 1.24
+ **/
+gpointer
+pango_fc_font_key_get_context_key (const PangoFcFontKey *key)
+{
+  return key->context_key;
+}
+
+
+/*
+ * PangoFcFontMap
+ */
+
+G_DEFINE_ABSTRACT_TYPE (PangoFcFontMap, pango_fc_font_map, PANGO_TYPE_FONT_MAP)
+
+static void
+pango_fc_font_map_init (PangoFcFontMap *fcfontmap)
+{
+  static gboolean registered_modules = FALSE;
+  PangoFcFontMapPrivate *priv;
+
+  priv = fcfontmap->priv = G_TYPE_INSTANCE_GET_PRIVATE (fcfontmap,
+							PANGO_TYPE_FC_FONT_MAP,
+							PangoFcFontMapPrivate);
+
+  if (!registered_modules)
+    {
+      int i;
+
+      registered_modules = TRUE;
+
+      for (i = 0; _pango_included_fc_modules[i].list; i++)
+	pango_module_register (&_pango_included_fc_modules[i]);
+    }
+
+  priv->n_families = -1;
+
+  priv->font_hash = g_hash_table_new_full ((GHashFunc)pango_fc_font_key_hash,
+					   (GEqualFunc)pango_fc_font_key_equal,
+					   (GDestroyNotify)pango_fc_font_key_free,
+					   NULL);
+  priv->fontset_hash = g_hash_table_new_full ((GHashFunc)fontset_hash_key_hash,
+					      (GEqualFunc)fontset_hash_key_equal,
+					      (GDestroyNotify)fontset_hash_key_free,
+					      (GDestroyNotify)pango_fc_pattern_set_free);
+
+  priv->coverage_hash = g_hash_table_new_full ((GHashFunc)pango_fc_coverage_key_hash,
+					       (GEqualFunc)pango_fc_coverage_key_equal,
+					       (GDestroyNotify)g_free,
+					       (GDestroyNotify)pango_coverage_unref);
+  priv->fontset_cache = g_queue_new ();
+  priv->dpi = -1;
+}
+
+static void
+pango_fc_font_map_class_init (PangoFcFontMapClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  PangoFontMapClass *fontmap_class = PANGO_FONT_MAP_CLASS (class);
+
+  object_class->finalize = pango_fc_font_map_finalize;
+  fontmap_class->load_font = pango_fc_font_map_load_font;
+  fontmap_class->load_fontset = pango_fc_font_map_load_fontset;
+  fontmap_class->list_families = pango_fc_font_map_list_families;
+  fontmap_class->shape_engine_type = PANGO_RENDER_TYPE_FC;
+
+  g_type_class_add_private (object_class, sizeof (PangoFcFontMapPrivate));
+}
+
+
 /**
  * pango_fc_font_map_add_decoder_find_func:
  * @fcfontmap: The #PangoFcFontMap to add this method to.
@@ -515,47 +603,14 @@ pango_fc_font_map_finalize (GObject *object)
   G_OBJECT_CLASS (pango_fc_font_map_parent_class)->finalize (object);
 }
 
-static void
-get_context_matrix (PangoContext *context,
-		    PangoMatrix *matrix)
-{
-  const PangoMatrix *set_matrix;
-  static const PangoMatrix identity = PANGO_MATRIX_INIT;
-
-  if (context)
-    set_matrix = pango_context_get_matrix (context);
-  else
-    set_matrix = NULL;
-
-  if (set_matrix)
-    *matrix = *set_matrix;
-  else
-    *matrix = identity;
-}
-
-static void
-font_hash_key_for_context (PangoFcFontMap *fcfontmap,
-			   PangoContext   *context,
-			   FontHashKey    *key)
-{
-  key->fontmap = fcfontmap;
-  get_context_matrix (context, &key->matrix);
-
-  if (PANGO_FC_FONT_MAP_GET_CLASS (fcfontmap)->context_key_get)
-    key->context_key = (gpointer)PANGO_FC_FONT_MAP_GET_CLASS (fcfontmap)->context_key_get (fcfontmap, context);
-  else
-    key->context_key = NULL;
-}
-
 /* Add a mapping from fcfont->font_pattern to fcfont */
 static void
 pango_fc_font_map_add (PangoFcFontMap *fcfontmap,
-		       PangoContext   *context,
+		       PangoFcFontKey *key,
 		       PangoFcFont    *fcfont)
 {
   PangoFcFontMapPrivate *priv = fcfontmap->priv;
-  FontHashKey key;
-  FontHashKey *key_copy;
+  PangoFcFontKey *key_copy;
 
   g_assert (fcfont->fontmap == NULL);
   fcfont->fontmap = (PangoFontMap *) fcfontmap;
@@ -564,46 +619,26 @@ pango_fc_font_map_add (PangoFcFontMap *fcfontmap,
    * here though as PangoFcFontMap already cleans up fcfont->fontmap
    * as part of it's caching scheme. */
 
-  font_hash_key_for_context (fcfontmap, context, &key);
-  key.pattern = fcfont->font_pattern;
-
-  key_copy = font_hash_key_copy (&key);
-  _pango_fc_font_set_context_key (fcfont, key_copy->context_key);
-  fcfont->matrix = key.matrix;
+  key_copy = pango_fc_font_key_copy (key);
+  _pango_fc_font_set_font_key (fcfont, key_copy);
+  fcfont->matrix = key_copy->matrix;
 
   g_hash_table_insert (priv->font_hash, key_copy, fcfont);
 }
 
-static PangoFcFont *
-pango_fc_font_map_lookup (PangoFcFontMap *fcfontmap,
-			  PangoContext   *context,
-			  FcPattern      *pattern)
-{
-  PangoFcFontMapPrivate *priv = fcfontmap->priv;
-  FontHashKey key;
-
-  font_hash_key_for_context (fcfontmap, context, &key);
-  key.pattern = pattern;
-
-  return g_hash_table_lookup (priv->font_hash, &key);
-}
-
 /* Remove mapping from fcfont->font_pattern to fcfont */
 void
 _pango_fc_font_map_remove (PangoFcFontMap *fcfontmap,
 			   PangoFcFont    *fcfont)
 {
   PangoFcFontMapPrivate *priv = fcfontmap->priv;
-  FontHashKey key;
+  PangoFcFontKey *key;
 
-  key.fontmap = fcfontmap;
-  key.matrix = fcfont->matrix;
-  key.pattern = fcfont->font_pattern;
-  key.context_key = _pango_fc_font_get_context_key (fcfont);
+  key = _pango_fc_font_get_font_key (fcfont);
 
-  g_hash_table_remove (priv->font_hash, &key);
+  g_hash_table_remove (priv->font_hash, key);
   fcfont->fontmap = NULL;
-  _pango_fc_font_set_context_key (fcfont, NULL);
+  _pango_fc_font_set_font_key (fcfont, NULL);
 }
 
 static PangoFcFamily *
@@ -832,6 +867,7 @@ pango_fc_make_pattern (const  PangoFontDescription *description,
 #ifdef FC_VERTICAL_LAYOUT
 			    FC_VERTICAL_LAYOUT,  FcTypeBool, vertical,
 #endif
+			    FC_DPI, FcTypeDouble, dpi,
 			    FC_SIZE,  FcTypeDouble,  pixel_size * (72. / dpi),
 			    FC_PIXEL_SIZE,  FcTypeDouble,  pixel_size,
 			    NULL);
@@ -861,7 +897,6 @@ pango_fc_make_pattern (const  PangoFontDescription *description,
 static PangoFont *
 pango_fc_font_map_new_font (PangoFontMap               *fontmap,
 			    PangoContext               *context,
-			    const PangoFontDescription *description,
 			    FcPattern                  *match)
 {
   PangoFcFontMapClass *class;
@@ -870,11 +905,14 @@ pango_fc_font_map_new_font (PangoFontMap               *fontmap,
   FcPattern *pattern;
   PangoFcFont *fcfont;
   GSList *l;
+  PangoFcFontKey key;
 
   if (priv->closed)
     return NULL;
 
-  fcfont = pango_fc_font_map_lookup (fcfontmap, context, match);
+  pango_fc_font_key_init (&key, fcfontmap, context, match);
+
+  fcfont = g_hash_table_lookup (priv->font_hash, &key);
   if (fcfont)
     return g_object_ref (fcfont);
 
@@ -883,9 +921,7 @@ pango_fc_font_map_new_font (PangoFontMap               *fontmap,
   if (class->create_font)
     {
       fcfont = PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->create_font (fcfontmap,
-								   context,
-								   description,
-								   match);
+								   &key);
     }
   else
     {
@@ -922,7 +958,7 @@ pango_fc_font_map_new_font (PangoFontMap               *fontmap,
   if (!fcfont)
     return NULL;
 
-  pango_fc_font_map_add (fcfontmap, context, fcfont);
+  pango_fc_font_map_add (fcfontmap, &key, fcfont);
 
   /*
    * Give any custom decoders a crack at this font now that it's been
@@ -974,16 +1010,16 @@ uniquify_pattern (PangoFcFontMap *fcfontmap,
 
 static void
 pango_fc_default_substitute (PangoFcFontMap    *fontmap,
-			     PangoContext      *context,
+			     PangoFcFontKey    *fontkey,
 			     FcPattern         *pattern)
 {
-  if (PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->context_substitute)
-    PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->context_substitute (fontmap, context, pattern);
+  if (PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->font_key_substitute)
+    PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->font_key_substitute (fontmap, fontkey, pattern);
   else if (PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->default_substitute)
     PANGO_FC_FONT_MAP_GET_CLASS (fontmap)->default_substitute (fontmap, pattern);
 }
 
-static gdouble
+static double
 pango_fc_font_map_get_resolution (PangoFcFontMap *fcfontmap,
 				  PangoContext   *context)
 {
@@ -1064,11 +1100,14 @@ pango_fc_font_map_get_patterns (PangoFontMap               *fontmap,
 
   if (patterns == NULL)
     {
+      PangoFcFontKey fontkey;
+
       pattern = pango_fc_make_pattern (desc, language,
 				       key.scaled_size / 1024.,
 				       pango_fc_font_map_get_resolution (fcfontmap, context));
 
-      pango_fc_default_substitute (fcfontmap, context, pattern);
+      pango_fc_font_key_init (&fontkey, fcfontmap, context, pattern);
+      pango_fc_default_substitute (fcfontmap, &fontkey, pattern);
 
       font_patterns = FcFontSort (NULL, pattern, FcTrue, NULL, &res);
 
@@ -1238,8 +1277,7 @@ pango_fc_font_map_load_fontset (PangoFontMap                 *fontmap,
 	{
 	  PangoFont *font;
 
-	  font = pango_fc_font_map_new_font (fontmap, context, desc,
-					     patterns->patterns[i]);
+	  font = pango_fc_font_map_new_font (fontmap, context, patterns->patterns[i]);
 	  if (font)
 	    pango_fontset_simple_append (simple, font);
 	}
diff --git a/pango/pangofc-fontmap.h b/pango/pangofc-fontmap.h
index fe1e1b5b..6ae73ce2 100644
--- a/pango/pangofc-fontmap.h
+++ b/pango/pangofc-fontmap.h
@@ -29,6 +29,24 @@
 
 G_BEGIN_DECLS
 
+/**
+ * PangoFcFontKey:
+ *
+ * An opaque structure containing all the information needed for
+ * loading a font #PangoFcFont.
+ *
+ * Since: 1.24
+ **/
+typedef struct _PangoFcFontKey        PangoFcFontKey;
+
+const FcPattern   *pango_fc_font_key_get_pattern     (const PangoFcFontKey *key);
+const PangoMatrix *pango_fc_font_key_get_matrix      (const PangoFcFontKey *key);
+gpointer           pango_fc_font_key_get_context_key (const PangoFcFontKey *key);
+
+/*
+ * PangoFcFontMap
+ */
+
 #define PANGO_TYPE_FC_FONT_MAP              (pango_fc_font_map_get_type ())
 #define PANGO_FC_FONT_MAP(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_FC_FONT_MAP, PangoFcFontMap))
 #define PANGO_IS_FC_FONT_MAP(object)        (G_TYPE_CHECK_INSTANCE_TYPE ((object), PANGO_TYPE_FC_FONT_MAP))
@@ -64,7 +82,7 @@ struct _PangoFcFontMap
  * @default_substitute: Substitutes in default values for
  *  unspecified fields in a #FcPattern. This will be called
  *  prior to creating a font for the pattern. May be %NULL.
- *  Deprecated in favor of @context_substitute().
+ *  Deprecated in favor of @font_key_substitute().
  * @new_font: Creates a new #PangoFcFont for the specified
  *  pattern of the appropriate type for this font map. The
  *  @pattern argument must be passed to the "pattern" property
@@ -87,15 +105,18 @@ struct _PangoFcFontMap
  *  @context_key_copy.
  * @context_key_hash: Gets a hash value for a context key
  * @context_key_equal: Compares two context keys for equality.
- * @create_font: Creates a new #PangoFcFont for the specified
- *  pattern of the appropriate type for this font map using
- *  information from the context that is passed in. The
- *  @pattern argument must be passed to the "pattern" property
- *  of #PangoFcFont when you call g_object_new(). Deprecated
- *  in favor of @create_font(). If %NULL, new_font() is used.
- * @context_substitute: Substitutes in default values for
+ * @font_key_substitute: Substitutes in default values for
  *  unspecified fields in a #FcPattern. This will be called
  *  prior to creating a font for the pattern. May be %NULL.
+ *  (Since: 1.24)
+ * @create_font: Creates a new #PangoFcFont for the specified
+ *  pattern of the appropriate type for this font map using
+ *  information from the font key that is passed in. The
+ *  @pattern member of @font_key can be retrieved using
+ *  pango_fc_font_key_get_pattern() and must be passed to
+ *  the "pattern" property of #PangoFcFont when you call
+ *  g_object_new().  If %NULL, new_font() is used.
+ *  (Since: 1.24)
  *
  * Class structure for #PangoFcFontMap.
  **/
@@ -105,7 +126,7 @@ struct _PangoFcFontMapClass
   PangoFontMapClass parent_class;
 
   /*< public >*/
-  /* Deprecated in favor of context_substitute */
+  /* Deprecated in favor of font_key_substitute */
   void         (*default_substitute) (PangoFcFontMap   *fontmap,
 				      FcPattern        *pattern);
   /* Deprecated in favor of create_font */
@@ -127,13 +148,11 @@ struct _PangoFcFontMapClass
 				      gconstpointer               key_a,
 				      gconstpointer               key_b);
 
-  void         (*context_substitute) (PangoFcFontMap             *fontmap,
-				      PangoContext               *context,
+  void         (*font_key_substitute)(PangoFcFontMap             *fontmap,
+				      PangoFcFontKey             *fontkey,
 				      FcPattern                  *pattern);
   PangoFcFont  *(*create_font)       (PangoFcFontMap             *fontmap,
-				      PangoContext               *context,
-				      const PangoFontDescription *desc,
-				      FcPattern                  *pattern);
+				      PangoFcFontKey             *fontkey);
   /*< private >*/
 
   /* Padding for future expansion */
diff --git a/pango/pangofc-private.h b/pango/pangofc-private.h
index a8f3c23c..bc67ffb7 100644
--- a/pango/pangofc-private.h
+++ b/pango/pangofc-private.h
@@ -54,9 +54,9 @@ PangoFcDecoder *_pango_fc_font_get_decoder       (PangoFcFont    *font);
 void            _pango_fc_font_set_decoder       (PangoFcFont    *font,
 						  PangoFcDecoder *decoder);
 
-gpointer        _pango_fc_font_get_context_key   (PangoFcFont    *font);
-void            _pango_fc_font_set_context_key   (PangoFcFont    *font,
-						  gpointer        context_key);
+PangoFcFontKey *_pango_fc_font_get_font_key      (PangoFcFont    *fcfont);
+void            _pango_fc_font_set_font_key      (PangoFcFont    *fcfont,
+						  PangoFcFontKey *key);
 
 void            pango_fc_font_get_raw_extents    (PangoFcFont    *font,
 						  FT_Int32        load_flags,