Use paint nodes to set up the stage

This allows to set a Content on a stage, and consolidates the paint
code where it belongs.

https://bugzilla.gnome.org/show_bug.cgi?id=704625

clutter/clutter-actor.c

@@ -3563,23 +3563,51 @@ clutter_actor_paint_node (ClutterActor     *actor,
                           ClutterPaintNode *root)
 {
   ClutterActorPrivate *priv = actor->priv;
+  ClutterActorBox box;
+  ClutterColor bg_color;
 
   if (root == NULL)
     return FALSE;
 
-  if (priv->bg_color_set &&
-      !clutter_color_equal (&priv->bg_color, CLUTTER_COLOR_Transparent))
-    {
-      ClutterPaintNode *node;
-      ClutterColor bg_color;
-      ClutterActorBox box;
-
   box.x1 = 0.f;
   box.y1 = 0.f;
   box.x2 = clutter_actor_box_get_width (&priv->allocation);
   box.y2 = clutter_actor_box_get_height (&priv->allocation);
 
   bg_color = priv->bg_color;
+
+  if (CLUTTER_ACTOR_IS_TOPLEVEL (actor))
+    {
+      ClutterPaintNode *node;
+      CoglFramebuffer *fb;
+      CoglBufferBit clear_flags;
+
+      fb = _clutter_stage_get_active_framebuffer (CLUTTER_STAGE (actor));
+
+      if (clutter_stage_get_use_alpha (CLUTTER_STAGE (actor)))
+        {
+          bg_color.alpha = clutter_actor_get_paint_opacity_internal (actor)
+                         * priv->bg_color.alpha
+                         / 255;
+        }
+      else
+        bg_color.alpha = 255;
+
+      clear_flags = COGL_BUFFER_BIT_DEPTH;
+      if (!clutter_stage_get_no_clear_hint (CLUTTER_STAGE (actor)))
+        clear_flags |= COGL_BUFFER_BIT_COLOR;
+
+      node = _clutter_root_node_new (fb, &bg_color, clear_flags);
+      clutter_paint_node_set_name (node, "stageClear");
+      clutter_paint_node_add_rectangle (node, &box);
+      clutter_paint_node_add_child (root, node);
+      clutter_paint_node_unref (node);
+    }
+  else if (priv->bg_color_set &&
+           !clutter_color_equal (&priv->bg_color, CLUTTER_COLOR_Transparent))
+    {
+      ClutterPaintNode *node;
+
       bg_color.alpha = clutter_actor_get_paint_opacity_internal (actor)
                      * priv->bg_color.alpha
                      / 255;

clutter/clutter-stage.c

@@ -679,6 +679,8 @@ _clutter_stage_do_paint (ClutterStage                *stage,
   clutter_stage_invoke_paint_callback (stage);
 }
 
+#if 0
+/* the Stage is cleared in clutter_actor_paint_node() */
 static void
 clutter_stage_paint (ClutterActor *self)
 {
@@ -725,6 +727,7 @@ clutter_stage_paint (ClutterActor *self)
   while (clutter_actor_iter_next (&iter, &child))
     clutter_actor_paint (child);
 }
+#endif
 
 static void
 clutter_stage_pick (ClutterActor       *self,
@@ -1915,7 +1918,6 @@ clutter_stage_class_init (ClutterStageClass *klass)
   actor_class->allocate = clutter_stage_allocate;
   actor_class->get_preferred_width = clutter_stage_get_preferred_width;
   actor_class->get_preferred_height = clutter_stage_get_preferred_height;
-  actor_class->paint = clutter_stage_paint;
   actor_class->pick = clutter_stage_pick;
   actor_class->get_paint_volume = clutter_stage_get_paint_volume;
   actor_class->realize = clutter_stage_realize;

examples/image-content.c

@@ -49,7 +49,7 @@ on_tap (ClutterTapAction *action,
 int
 main (int argc, char *argv[])
 {
-  ClutterActor *stage, *box, *text;
+  ClutterActor *stage, *text;
   ClutterContent *image;
   ClutterAction *action;
   GdkPixbuf *pixbuf;
@@ -63,17 +63,12 @@ main (int argc, char *argv[])
   clutter_stage_set_title (CLUTTER_STAGE (stage), "Content Box");
   clutter_stage_set_user_resizable (CLUTTER_STAGE (stage), TRUE);
   g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
+  clutter_actor_set_margin_top (stage, 12);
+  clutter_actor_set_margin_right (stage, 12);
+  clutter_actor_set_margin_bottom (stage, 12);
+  clutter_actor_set_margin_left (stage, 12);
   clutter_actor_show (stage);
 
-  box = clutter_actor_new ();
-  clutter_actor_set_name (box, "Image");
-  clutter_actor_set_margin_top (box, 12);
-  clutter_actor_set_margin_right (box, 12);
-  clutter_actor_set_margin_bottom (box, 12);
-  clutter_actor_set_margin_left (box, 12);
-  clutter_actor_add_constraint (box, clutter_bind_constraint_new (stage, CLUTTER_BIND_SIZE, 0.0));
-  clutter_actor_add_child (stage, box);
-
   pixbuf = gdk_pixbuf_new_from_file (TESTS_DATADIR G_DIR_SEPARATOR_S "redhand.png", NULL);
   image = clutter_image_new ();
   clutter_image_set_data (CLUTTER_IMAGE (image),
@@ -87,11 +82,11 @@ main (int argc, char *argv[])
                           NULL);
   g_object_unref (pixbuf);
 
-  clutter_actor_set_content_scaling_filters (box,
+  clutter_actor_set_content_scaling_filters (stage,
                                              CLUTTER_SCALING_FILTER_TRILINEAR,
                                              CLUTTER_SCALING_FILTER_LINEAR);
-  clutter_actor_set_content_gravity (box, gravities[n_gravities - 1].gravity);
+  clutter_actor_set_content_gravity (stage, gravities[n_gravities - 1].gravity);
-  clutter_actor_set_content (box, image);
+  clutter_actor_set_content (stage, image);
   g_object_unref (image);
 
   str = g_strconcat ("Content gravity: ",
@@ -107,8 +102,7 @@ main (int argc, char *argv[])
 
   action = clutter_tap_action_new ();
   g_signal_connect (action, "tap", G_CALLBACK (on_tap), text);
-  clutter_actor_set_reactive (box, TRUE);
+  clutter_actor_add_action (stage, action);
-  clutter_actor_add_action (box, action);
 
   clutter_main ();