clutter: Attach color state information to actors

ClutterColorState, that is a GObject. each ClutterActor would own
such an object, and it'd be set via a GObject property.
It would have an API to get the colorspace, whether the actor
content is in pq or not, and things like that.
if it is NULL, it will default to color state with sRGB colorspace.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2443>

clutter/clutter/clutter-actor.c

@@ -616,6 +616,7 @@
 #include "clutter-action-private.h"
 #include "clutter-actor-meta-private.h"
 #include "clutter-animatable.h"
+#include "clutter-color-state.h"
 #include "clutter-color-static.h"
 #include "clutter-color.h"
 #include "clutter-constraint-private.h"
@@ -755,6 +756,10 @@ struct _ClutterActorPrivate
   /* used when painting, to update the paint volume */
   ClutterEffect *current_effect;
 
+  /* color state contains properties like colorspace for
+   * each clutter actor */
+  ClutterColorState *color_state;
+
   /* This is used to store an effect which needs to be redrawn. A
      redraw can be queued to start from a particular effect. This is
      used by parametrised effects that can cache an image of the
@@ -959,6 +964,8 @@ enum
   PROP_MAGNIFICATION_FILTER,
   PROP_CONTENT_REPEAT,
 
+  PROP_COLOR_STATE,
+
   PROP_LAST
 };
 
@@ -5078,6 +5085,10 @@ clutter_actor_set_property (GObject      *object,
       clutter_actor_set_content_repeat (actor, g_value_get_flags (value));
       break;
 
+    case PROP_COLOR_STATE:
+      clutter_actor_set_color_state (actor, g_value_get_object (value));
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -5527,6 +5538,10 @@ clutter_actor_get_property (GObject    *object,
       g_value_set_flags (value, priv->content_repeat);
       break;
 
+    case PROP_COLOR_STATE:
+      g_value_set_object (value, priv->color_state);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -5574,6 +5589,7 @@ clutter_actor_dispose (GObject *object)
 
   g_clear_object (&priv->pango_context);
   g_clear_object (&priv->actions);
+  g_clear_object (&priv->color_state);
   g_clear_object (&priv->constraints);
   g_clear_object (&priv->effects);
   g_clear_object (&priv->flatten_effect);
@@ -7334,6 +7350,20 @@ clutter_actor_class_init (ClutterActorClass *klass)
                         G_PARAM_STATIC_STRINGS |
                         G_PARAM_EXPLICIT_NOTIFY);
 
+  /**
+   * ClutterActor:color-state:
+   *
+   * The #ClutterColorState contains the properties like colorspace for each
+   * actors.
+   */
+  obj_props[PROP_COLOR_STATE] =
+    g_param_spec_object ("color-state",
+                         P_("ColorState"),
+                         P_("ColorState of the each actors"),
+                         CLUTTER_TYPE_COLOR_STATE,
+                         CLUTTER_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT);
+
   g_object_class_install_properties (object_class, PROP_LAST, obj_props);
 
   /**
@@ -19044,6 +19074,65 @@ clutter_actor_get_content_repeat (ClutterActor *self)
   return self->priv->content_repeat;
 }
 
+static ClutterColorState *
+create_srgb_color_state (ClutterActor *self)
+{
+  ClutterColorState *color_state;
+
+  /* create default sRGB color state */
+  color_state = clutter_color_state_new (CLUTTER_COLORSPACE_SRGB);
+
+  return color_state;
+}
+
+/**
+ * clutter_actor_set_color_state:
+ * @self: a #ClutterActor
+ * @color_state: a #ClutterColorState, or defaults to sRGB if %NULL
+ *
+ * Attaches color state properties to [class@Actor]
+ * default color state representing sRGB.
+ */
+void
+clutter_actor_set_color_state (ClutterActor      *self,
+                               ClutterColorState *color_state)
+{
+  ClutterActorPrivate *priv;
+
+  g_return_if_fail (CLUTTER_IS_ACTOR (self));
+
+  priv = self->priv;
+
+  if (!color_state)
+    color_state = create_srgb_color_state (self);
+  else
+    g_object_ref (color_state);
+
+  g_set_object (&priv->color_state, color_state);
+
+  g_object_unref (color_state);
+
+  g_object_notify_by_pspec (G_OBJECT (self), obj_props[PROP_COLOR_STATE]);
+}
+
+/**
+ * clutter_actor_get_color_state:
+ * @self: a #ClutterActor
+ *
+ * Retrieves the color_state of a [class@Actor] set by
+ * [method@Actor.set_color_state].
+ *
+ * Return value: (transfer full): a pointer to the #ClutterColorState
+ * instance, or %NULL
+ */
+ClutterColorState *
+clutter_actor_get_color_state (ClutterActor *self)
+{
+  g_return_val_if_fail (CLUTTER_IS_ACTOR (self), NULL);
+
+  return self->priv->color_state;
+}
+
 void
 _clutter_actor_handle_event (ClutterActor       *self,
                              ClutterActor       *root,

clutter/clutter/clutter-actor.h

@@ -624,6 +624,13 @@ void                            clutter_actor_set_content_repeat
                                                                                  ClutterContentRepeat        repeat);
 CLUTTER_EXPORT
 ClutterContentRepeat            clutter_actor_get_content_repeat                (ClutterActor               *self);
+
+CLUTTER_EXPORT
+void clutter_actor_set_color_state (ClutterActor      *self,
+                                    ClutterColorState *color_state);
+CLUTTER_EXPORT
+ClutterColorState *clutter_actor_get_color_state (ClutterActor *self);
+
 CLUTTER_EXPORT
 void                            clutter_actor_get_content_box                   (ClutterActor               *self,
                                                                                  ClutterActorBox            *box);

clutter/clutter/clutter-color-state.c

@@ -0,0 +1,182 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Copyright (C) 2022  Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author:
+ *   Naveen Kumar <naveen1.kumar@intel.com>
+ */
+
+/**
+ * ClutterColorState:
+ *
+ * Color state of each ClutterActor
+ *
+ * The #ClutterColorState class contains the colorspace of each color
+ * states (e.g. sRGB colorspace).
+ *
+ * Each [class@Actor] would own such an object.
+ *
+ * A single #ClutterColorState object can be shared by multiple [class@Actor]
+ * or maybe a separate color state for each [class@Actor] (depending on whether
+ * #ClutterColorState would be statefull or stateless).
+ *
+ * #ClutterColorState, if not set during construction, it will default to sRGB
+ * color state
+ *
+ * The #ClutterColorState would have API to get the colorspace, whether the
+ * actor content is in pq or not, and things like that
+ */
+
+#include "clutter-build-config.h"
+
+#include "clutter-color-state.h"
+
+#include "clutter-debug.h"
+#include "clutter-enum-types.h"
+#include "clutter-private.h"
+
+enum
+{
+  PROP_0,
+
+  PROP_COLORSPACE,
+
+  N_PROPS
+};
+
+static GParamSpec *obj_props[N_PROPS];
+
+typedef struct _ClutterColorStatePrivate ClutterColorStatePrivate;
+
+struct _ClutterColorState
+{
+  GObject parent_instance;
+};
+
+struct _ClutterColorStatePrivate
+{
+  ClutterColorspace colorspace;
+};
+
+G_DEFINE_TYPE_WITH_PRIVATE (ClutterColorState,
+                            clutter_color_state,
+                            G_TYPE_OBJECT)
+
+ClutterColorspace
+clutter_color_state_get_colorspace (ClutterColorState *color_state)
+{
+  ClutterColorStatePrivate *priv;
+
+  g_return_val_if_fail (CLUTTER_IS_COLOR_STATE (color_state),
+                        CLUTTER_COLORSPACE_UNKNOWN);
+
+  priv = clutter_color_state_get_instance_private (color_state);
+
+  return priv->colorspace;
+}
+
+static void
+clutter_color_state_set_property (GObject      *object,
+                                  guint         prop_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  ClutterColorState *color_state = CLUTTER_COLOR_STATE (object);
+  ClutterColorStatePrivate *priv;
+
+  priv = clutter_color_state_get_instance_private (color_state);
+
+  switch (prop_id)
+    {
+    case PROP_COLORSPACE:
+      priv->colorspace = g_value_get_enum (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+clutter_color_state_get_property (GObject    *object,
+                                  guint       prop_id,
+                                  GValue     *value,
+                                  GParamSpec *pspec)
+{
+  ClutterColorState *color_state = CLUTTER_COLOR_STATE (object);
+
+  switch (prop_id)
+    {
+    case PROP_COLORSPACE:
+      g_value_set_enum (value,
+                        clutter_color_state_get_colorspace (color_state));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+clutter_color_state_class_init (ClutterColorStateClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gobject_class->set_property = clutter_color_state_set_property;
+  gobject_class->get_property = clutter_color_state_get_property;
+
+  /**
+   * ClutterColorState:colorspace:
+   *
+   * Colorspace information of the each color state,
+   * defaults to sRGB colorspace
+   */
+  obj_props[PROP_COLORSPACE] =
+    g_param_spec_enum ("colorspace",
+                       P_("Colorspace"),
+                       P_("Colorspace information of the color state"),
+                       CLUTTER_TYPE_COLORSPACE,
+                       CLUTTER_COLORSPACE_SRGB,
+                       CLUTTER_PARAM_READWRITE |
+                       G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, obj_props);
+}
+
+static void
+clutter_color_state_init (ClutterColorState *color_state)
+{
+}
+
+/**
+ * clutter_color_state_new:
+ *
+ * Create a new ClutterColorState object.
+ *
+ * Return value: A new ClutterColorState object.
+ **/
+ClutterColorState*
+clutter_color_state_new (ClutterColorspace colorspace)
+{
+  return g_object_new (CLUTTER_TYPE_COLOR_STATE,
+                       "colorspace", colorspace,
+                       NULL);
+}

clutter/clutter/clutter-color-state.h

@@ -0,0 +1,50 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Copyright (C) 2022  Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author:
+ *   Naveen Kumar <naveen1.kumar@intel.com>
+ */
+
+#ifndef CLUTTER_COLOR_STATE_H
+#define CLUTTER_COLOR_STATE_H
+
+#if !defined(__CLUTTER_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <clutter/clutter.h> can be included directly."
+#endif
+
+#include <clutter/clutter-types.h>
+
+G_BEGIN_DECLS
+
+#define CLUTTER_TYPE_COLOR_STATE (clutter_color_state_get_type ())
+CLUTTER_EXPORT
+G_DECLARE_FINAL_TYPE (ClutterColorState, clutter_color_state,
+                      CLUTTER, COLOR_STATE,
+                      GObject)
+
+CLUTTER_EXPORT
+ClutterColorState * clutter_color_state_new (ClutterColorspace colorspace);
+
+CLUTTER_EXPORT
+ClutterColorspace clutter_color_state_get_colorspace (ClutterColorState *color_state);
+
+G_END_DECLS
+
+#endif /* CLUTTER_COLOR_STATE_H */

clutter/clutter/clutter-enums.h

@@ -1424,6 +1424,21 @@ typedef enum
   CLUTTER_REPEAT_BOTH   = CLUTTER_REPEAT_X_AXIS | CLUTTER_REPEAT_Y_AXIS
 } ClutterContentRepeat;
 
+/**
+ * ClutterColorspace:
+ * @CLUTTER_COLORSPACE_UNKNOWN: Unknown colorspace
+ * @CLUTTER_COLORSPACE_SRGB: Default sRGB colorspace
+ * @CLUTTER_COLORSPACE_BT2020: BT2020 colorspace
+ *
+ * Colorspace informations.
+ */
+typedef enum
+{
+  CLUTTER_COLORSPACE_UNKNOWN,
+  CLUTTER_COLORSPACE_SRGB,
+  CLUTTER_COLORSPACE_BT2020
+} ClutterColorspace;
+
 /**
  * ClutterStepMode:
  * @CLUTTER_STEP_MODE_START: The change in the value of a

clutter/clutter/clutter-types.h

@@ -76,6 +76,7 @@ typedef struct _ClutterPathNode                 ClutterPathNode;
 
 typedef struct _ClutterActorBox                 ClutterActorBox;
 typedef struct _ClutterColor                    ClutterColor;
+typedef struct _ClutterColorState               ClutterColorState;
 typedef struct _ClutterKnot                     ClutterKnot;
 typedef struct _ClutterMargin                   ClutterMargin;
 typedef struct _ClutterPerspective              ClutterPerspective;

clutter/clutter/clutter.h

@@ -48,6 +48,7 @@
 #include "clutter-click-action.h"
 #include "clutter-clone.h"
 #include "clutter-color.h"
+#include "clutter-color-state.h"
 #include "clutter-color-static.h"
 #include "clutter-colorize-effect.h"
 #include "clutter-constraint.h"

clutter/clutter/meson.build

@@ -21,6 +21,7 @@ clutter_headers = [
   'clutter-child-meta.h',
   'clutter-click-action.h',
   'clutter-clone.h',
+  'clutter-color-state.h',
   'clutter-color-static.h',
   'clutter-color.h',
   'clutter-colorize-effect.h',
@@ -113,6 +114,7 @@ clutter_sources = [
   'clutter-click-action.c',
   'clutter-clone.c',
   'clutter-color.c',
+  'clutter-color-state.c',
   'clutter-colorize-effect.c',
   'clutter-constraint.c',
   'clutter-container.c',