clutter/backend: Stop re-allocating font_options

There is no real need to re-create a new cairo_font_options_t now that
the API is internal. Instead, create the font_options once and just
update it attributes.

Actors already register for the emitted font-changed signal to re-create
a new PangoContext.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4106>

clutter/clutter/clutter-backend-private.h

@@ -100,7 +100,4 @@ gboolean clutter_backend_is_display_server (ClutterBackend *backend);
 CLUTTER_EXPORT
 void clutter_backend_destroy (ClutterBackend *backend);
 
-void clutter_backend_set_font_options (ClutterBackend             *backend,
-                                       const cairo_font_options_t *options);
-
 G_END_DECLS

clutter/clutter/clutter-backend.c

@@ -280,6 +280,13 @@ clutter_backend_init (ClutterBackend *self)
   self->dummy_onscreen = NULL;
 
   self->fallback_resource_scale = 1.f;
+
+  /* Default font options */
+  self->font_options = cairo_font_options_create ();
+  cairo_font_options_set_hint_metrics (self->font_options, CAIRO_HINT_METRICS_ON);
+  cairo_font_options_set_hint_style (self->font_options, CAIRO_HINT_STYLE_NONE);
+  cairo_font_options_set_subpixel_order (self->font_options, CAIRO_SUBPIXEL_ORDER_DEFAULT);
+  cairo_font_options_set_antialias (self->font_options, CAIRO_ANTIALIAS_DEFAULT);
 }
 
 ClutterStageWindow *
@@ -377,41 +384,6 @@ clutter_backend_get_resolution (ClutterBackend *backend)
   return resolution / 1024.0;
 }
 
-/**
- * clutter_backend_set_font_options:
- * @backend: a #ClutterBackend
- * @options: Cairo font options for the backend, or %NULL
- *
- * Sets the new font options for @backend. The #ClutterBackend will
- * copy the #cairo_font_options_t.
- *
- * If @options is %NULL, the first following call to
- * [method@Clutter.Backend.get_font_options] will return the default font
- * options for @backend.
- *
- * This function is intended for actors creating a Pango layout
- * using the PangoCairo API.
- */
-void
-clutter_backend_set_font_options (ClutterBackend             *backend,
-                                  const cairo_font_options_t *options)
-{
-  g_return_if_fail (CLUTTER_IS_BACKEND (backend));
-
-  if (backend->font_options != options)
-    {
-      if (backend->font_options)
-        cairo_font_options_destroy (backend->font_options);
-
-      if (options)
-        backend->font_options = cairo_font_options_copy (options);
-      else
-        backend->font_options = NULL;
-
-      g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
-    }
-}
-
 /**
  * clutter_backend_get_cogl_context:
  * @backend: a #ClutterBackend

clutter/clutter/clutter-settings.c

@@ -120,15 +120,11 @@ clutter_settings_update_font_options (ClutterSettings *self)
   cairo_hint_style_t hint_style = CAIRO_HINT_STYLE_NONE;
   cairo_antialias_t antialias_mode = CAIRO_ANTIALIAS_GRAY;
   cairo_subpixel_order_t subpixel_order = CAIRO_SUBPIXEL_ORDER_DEFAULT;
-  cairo_font_options_t *options;
   const char *clutter_font_hint_style = NULL, *clutter_font_subpixel_order = NULL;
 
   if (self->backend == NULL)
     return;
 
-  options = cairo_font_options_create ();
-  cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_ON);
-
   /* org.gnome.desktop.GDesktopFontAntialiasingMode */
   static const struct
   {
@@ -178,7 +174,7 @@ clutter_settings_update_font_options (ClutterSettings *self)
       hint_style = hintings[i].cairo_hint_style;
       clutter_font_hint_style = hintings[i].clutter_font_hint_style;
     }
-  cairo_font_options_set_hint_style (options, hint_style);
+  cairo_font_options_set_hint_style (self->backend->font_options, hint_style);
 
   i = g_settings_get_enum (settings, "font-rgba-order");
   if (i < G_N_ELEMENTS (rgba_orders))
@@ -186,7 +182,7 @@ clutter_settings_update_font_options (ClutterSettings *self)
       subpixel_order = rgba_orders[i].cairo_subpixel_order;
       clutter_font_subpixel_order = rgba_orders[i].clutter_font_subpixel_order;
     }
-  cairo_font_options_set_subpixel_order (options, subpixel_order);
+  cairo_font_options_set_subpixel_order (self->backend->font_options, subpixel_order);
 
   i = g_settings_get_enum (settings, "font-antialiasing");
   if (i < G_N_ELEMENTS (antialiasings))
@@ -195,7 +191,7 @@ clutter_settings_update_font_options (ClutterSettings *self)
   if (subpixel_order == CAIRO_SUBPIXEL_ORDER_DEFAULT)
     antialias_mode = CAIRO_ANTIALIAS_SUBPIXEL;
 
-  cairo_font_options_set_antialias (options, antialias_mode);
+  cairo_font_options_set_antialias (self->backend->font_options, antialias_mode);
 
   CLUTTER_NOTE (BACKEND, "New font options:\n"
                 " - font-name:  %s\n"
@@ -209,8 +205,7 @@ clutter_settings_update_font_options (ClutterSettings *self)
                 clutter_font_hint_style != NULL ? clutter_font_hint_style : "<null>",
                 clutter_font_subpixel_order != NULL ? clutter_font_subpixel_order : "<null>");
 
-  clutter_backend_set_font_options (self->backend, options);
+  g_signal_emit_by_name (self->backend, "font-changed");
-  cairo_font_options_destroy (options);
 }
 
 static void
@@ -365,18 +360,7 @@ load_initial_settings (ClutterSettings *self)
   schema = g_settings_schema_source_lookup (source, font_settings_path, TRUE);
   if (!schema)
     {
-      cairo_font_options_t *font_options;
-
       g_warning ("Failed to find schema: %s", font_settings_path);
-
-      /* Fallback to the default options */
-      font_options = cairo_font_options_create ();
-      cairo_font_options_set_hint_style (font_options, CAIRO_HINT_STYLE_NONE);
-      cairo_font_options_set_subpixel_order (font_options, CAIRO_SUBPIXEL_ORDER_DEFAULT);
-      cairo_font_options_set_antialias (font_options, CAIRO_ANTIALIAS_DEFAULT);
-      clutter_backend_set_font_options (self->backend, font_options);
-
-      cairo_font_options_destroy (font_options);
     }
   else
     {