clutter/color-state: Adds an ID to ColorStates

The ID is required for the wayland protocol. In the future we might want
to spend a bit more effort to re-use existing color states when a new
one is requested and also try to re-use IDs instead of just counting up.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3897>

clutter/clutter/clutter-color-manager-private.h

@@ -25,6 +25,8 @@
 #include "clutter/clutter-color-manager.h"
 #include "clutter/clutter-private.h"
 
+unsigned int clutter_color_manager_get_next_id (ClutterColorManager *color_manager);
+
 CoglSnippet * clutter_color_manager_lookup_snippet (ClutterColorManager            *color_manager,
                                                     const ClutterColorTransformKey *key);
 

clutter/clutter/clutter-color-manager.c

@@ -45,6 +45,7 @@ struct _ClutterColorManager
   ClutterContext *context;
 
   GHashTable *snippet_cache;
+  unsigned int id_counter;
 };
 
 G_DEFINE_FINAL_TYPE (ClutterColorManager, clutter_color_manager, G_TYPE_OBJECT)
@@ -133,6 +134,12 @@ clutter_color_manager_init (ClutterColorManager *color_manager)
                            g_object_unref);
 }
 
+unsigned int
+clutter_color_manager_get_next_id (ClutterColorManager *color_manager)
+{
+  return ++color_manager->id_counter;
+}
+
 CoglSnippet *
 clutter_color_manager_lookup_snippet (ClutterColorManager            *color_manager,
                                       const ClutterColorTransformKey *key)

clutter/clutter/clutter-color-state.c

@@ -67,20 +67,19 @@ enum
 
 static GParamSpec *obj_props[N_PROPS];
 
-typedef struct _ClutterColorStatePrivate ClutterColorStatePrivate;
-
 struct _ClutterColorState
 {
   GObject parent_instance;
 };
 
-struct _ClutterColorStatePrivate
+typedef struct _ClutterColorStatePrivate
 {
   ClutterContext *context;
 
+  unsigned int id;
   ClutterColorspace colorspace;
   ClutterTransferFunction transfer_function;
-};
+} ClutterColorStatePrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (ClutterColorState,
                             clutter_color_state,
@@ -160,6 +159,18 @@ clutter_transfer_function_to_string (ClutterTransferFunction transfer_function)
   g_assert_not_reached ();
 }
 
+unsigned int
+clutter_color_state_get_id (ClutterColorState *color_state)
+{
+  ClutterColorStatePrivate *priv;
+
+  g_return_val_if_fail (CLUTTER_IS_COLOR_STATE (color_state), 0);
+
+  priv = clutter_color_state_get_instance_private (color_state);
+
+  return priv->id;
+}
+
 ClutterColorspace
 clutter_color_state_get_colorspace (ClutterColorState *color_state)
 {
@@ -192,8 +203,13 @@ clutter_color_state_constructed (GObject *object)
   ClutterColorState *color_state = CLUTTER_COLOR_STATE (object);
   ClutterColorStatePrivate *priv =
     clutter_color_state_get_instance_private (color_state);
+  ClutterColorManager *color_manager;
 
   g_warn_if_fail (priv->context);
+
+  color_manager = clutter_context_get_color_manager (priv->context);
+
+  priv->id = clutter_color_manager_get_next_id (color_manager);
 }
 
 static void

clutter/clutter/clutter-color-state.h

@@ -43,6 +43,9 @@ ClutterColorState * clutter_color_state_new (ClutterContext          *context,
                                              ClutterColorspace        colorspace,
                                              ClutterTransferFunction  transfer_function);
 
+CLUTTER_EXPORT
+unsigned int clutter_color_state_get_id (ClutterColorState *color_state);
+
 CLUTTER_EXPORT
 ClutterColorspace clutter_color_state_get_colorspace (ClutterColorState *color_state);