compositor: Don't access use the onscreen framebuffer directly

Instead of assuming there is a single onscreen framebuffer, use the
helper functions for setting the frame callback and getting the frame
counter.

https://bugzilla.gnome.org/show_bug.cgi?id=768976

clutter/clutter/clutter-mutter.h

@@ -36,6 +36,14 @@ void clutter_set_custom_backend_func (ClutterBackend *(* func) (void));
 CLUTTER_AVAILABLE_IN_MUTTER
 gboolean        _clutter_get_sync_to_vblank     (void);
 
+CLUTTER_AVAILABLE_IN_MUTTER
+CoglFrameClosure *clutter_stage_add_frame_callback (ClutterStage     *stage,
+                                                    CoglFrameCallback callback,
+                                                    gpointer          user_data);
+
+CLUTTER_AVAILABLE_IN_MUTTER
+int64_t clutter_stage_get_frame_counter (ClutterStage *stage);
+
 #undef __CLUTTER_H_INSIDE__
 
 #endif /* __CLUTTER_MUTTER_H__ */

clutter/clutter/clutter-stage.c

@@ -4510,3 +4510,25 @@ _clutter_stage_set_scale_factor (ClutterStage *stage,
 
   clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
 }
+
+CoglFrameClosure *
+clutter_stage_add_frame_callback (ClutterStage          *stage,
+                                  CoglFrameCallback      callback,
+                                  gpointer               user_data)
+{
+  ClutterStageWindow *stage_window;
+
+  stage_window = _clutter_stage_get_window (stage);
+  return _clutter_stage_window_set_frame_callback (stage_window,
+                                                   callback,
+                                                   user_data);
+}
+
+int64_t
+clutter_stage_get_frame_counter (ClutterStage          *stage)
+{
+  ClutterStageWindow *stage_window;
+
+  stage_window = _clutter_stage_get_window (stage);
+  return _clutter_stage_window_get_frame_counter (stage_window);
+}

src/compositor/compositor-private.h

@@ -29,7 +29,6 @@ struct _MetaCompositor
   GList                 *windows;
   Window                 output;
 
-  CoglOnscreen          *onscreen;
   CoglFrameClosure      *frame_closure;
   CoglContext           *context;
 

src/compositor/compositor.c

@@ -77,6 +77,7 @@
 #include "meta-sync-ring.h"
 
 #include "backends/x11/meta-backend-x11.h"
+#include "clutter/clutter-mutter.h"
 
 #ifdef HAVE_WAYLAND
 #include "wayland/meta-wayland-private.h"
@@ -1044,13 +1045,12 @@ meta_pre_paint_func (gpointer data)
   MetaWindowActor *top_window;
   MetaCompositor *compositor = data;
 
-  if (compositor->onscreen == NULL)
+  if (!compositor->frame_closure)
     {
-      compositor->onscreen = COGL_ONSCREEN (cogl_get_draw_framebuffer ());
+      compositor->frame_closure =
-      compositor->frame_closure = cogl_onscreen_add_frame_callback (compositor->onscreen,
+        clutter_stage_add_frame_callback (CLUTTER_STAGE (compositor->stage),
-                                                                    frame_callback,
+                                          frame_callback,
-                                                                    compositor,
+                                          compositor);
-                                                                    NULL);
     }
 
   if (compositor->windows == NULL)

src/compositor/meta-window-actor.c

@@ -23,6 +23,7 @@
 #include <meta/meta-enum-types.h>
 #include <meta/meta-shadow-factory.h>
 
+#include "clutter/clutter-mutter.h"
 #include "compositor-private.h"
 #include "meta-shaped-texture-private.h"
 #include "meta-window-actor-private.h"
@@ -659,6 +660,8 @@ static void
 assign_frame_counter_to_frames (MetaWindowActor *self)
 {
   MetaWindowActorPrivate *priv = self->priv;
+  MetaCompositor *compositor = priv->compositor;
+  ClutterStage *stage = CLUTTER_STAGE (compositor->stage);
   GList *l;
 
   /* If the window is obscured, then we're expecting to deal with sending
@@ -672,10 +675,7 @@ assign_frame_counter_to_frames (MetaWindowActor *self)
       FrameData *frame = l->data;
 
       if (frame->frame_counter == -1)
-        {
+        frame->frame_counter = clutter_stage_get_frame_counter (stage);
-          CoglOnscreen *onscreen = COGL_ONSCREEN (cogl_get_draw_framebuffer());
-          frame->frame_counter = cogl_onscreen_get_frame_counter (onscreen);
-        }
     }
 }