wayland: Use weak ref to keep track of buffers

Instead of using a one-shot signal meant to happen then the buffer
is being destroyed.

https://bugzilla.gnome.org/show_bug.cgi?id=782344

clutter/clutter/clutter-actor-private.h

@@ -283,9 +283,6 @@ void                            _clutter_actor_queue_redraw_full
                                                                                          ClutterPaintVolume *volume,
                                                                                          ClutterEffect      *effect);
 
-ClutterPaintVolume *            _clutter_actor_get_queue_redraw_clip                    (ClutterActor       *self);
-void                            _clutter_actor_set_queue_redraw_clip                    (ClutterActor       *self,
-                                                                                         ClutterPaintVolume *clip_volume);
 void                            _clutter_actor_finish_queue_redraw                      (ClutterActor       *self,
                                                                                          ClutterPaintVolume *clip);
 

clutter/clutter/clutter-actor.c

@@ -840,6 +840,7 @@ struct _ClutterActorPrivate
   guint needs_compute_expand        : 1;
   guint needs_x_expand              : 1;
   guint needs_y_expand              : 1;
+  guint needs_paint_volume_update   : 1;
 };
 
 enum
@@ -2619,6 +2620,7 @@ clutter_actor_real_allocate (ClutterActor           *self,
   g_object_freeze_notify (G_OBJECT (self));
 
   changed = clutter_actor_set_allocation_internal (self, box, flags);
+  priv->needs_paint_volume_update = changed;
 
   /* we allocate our children before we notify changes in our geometry,
    * so that people connecting to properties will be able to get valid
@@ -2641,9 +2643,12 @@ clutter_actor_real_allocate (ClutterActor           *self,
 }
 
 static void
-_clutter_actor_signal_queue_redraw (ClutterActor *self,
-                                    ClutterActor *origin)
+_clutter_actor_propagate_queue_redraw (ClutterActor       *self,
+                                       ClutterActor       *origin,
+                                       ClutterPaintVolume *pv)
 {
+  gboolean stop = FALSE;
+
   /* no point in queuing a redraw on a destroyed actor */
   if (CLUTTER_ACTOR_IN_DESTRUCTION (self))
     return;
@@ -2652,27 +2657,33 @@ _clutter_actor_signal_queue_redraw (ClutterActor *self,
    * the actor bas been cloned. In this case the clone will need to
    * receive the signal so it can queue its own redraw.
    */
+  while (self)
+    {
+      _clutter_actor_queue_redraw_on_clones (self);
 
-  _clutter_actor_queue_redraw_on_clones (self);
-
-  /* calls klass->queue_redraw in default handler */
-  if (g_signal_has_handler_pending (self, actor_signals[QUEUE_REDRAW],
+      /* calls klass->queue_redraw in default handler */
+      if (g_signal_has_handler_pending (self, actor_signals[QUEUE_REDRAW],
                                     0, TRUE))
-    {
-      g_signal_emit (self, actor_signals[QUEUE_REDRAW], 0, origin);
-    }
-  else
-    {
-      CLUTTER_ACTOR_GET_CLASS (self)->queue_redraw (self, origin);
+        {
+          g_signal_emit (self, actor_signals[QUEUE_REDRAW], 0, origin, pv, &stop);
+        }
+      else
+        {
+          stop = CLUTTER_ACTOR_GET_CLASS (self)->queue_redraw (self, origin, pv);
+        }
+
+      if (stop)
+        break;
+
+      self = clutter_actor_get_parent (self);
     }
 }
 
-static void
-clutter_actor_real_queue_redraw (ClutterActor *self,
-                                 ClutterActor *origin)
+static gboolean
+clutter_actor_real_queue_redraw (ClutterActor       *self,
+                                 ClutterActor       *origin,
+                                 ClutterPaintVolume *paint_volume)
 {
-  ClutterActor *parent;
-
   CLUTTER_NOTE (PAINT, "Redraw queued on '%s' (from: '%s')",
                 _clutter_actor_get_debug_name (self),
                 origin != NULL ? _clutter_actor_get_debug_name (origin)
@@ -2680,13 +2691,14 @@ clutter_actor_real_queue_redraw (ClutterActor *self,
 
   /* no point in queuing a redraw on a destroyed actor */
   if (CLUTTER_ACTOR_IN_DESTRUCTION (self))
-    return;
+    return TRUE;
 
   /* If the queue redraw is coming from a child then the actor has
      become dirty and any queued effect is no longer valid */
   if (self != origin)
     {
       self->priv->is_dirty = TRUE;
+      self->priv->needs_paint_volume_update = TRUE;
       self->priv->effect_to_redraw = NULL;
     }
 
@@ -2695,7 +2707,7 @@ clutter_actor_real_queue_redraw (ClutterActor *self,
    * won't change so we don't have to propagate up the hierarchy.
    */
   if (!CLUTTER_ACTOR_IS_VISIBLE (self))
-    return;
+    return TRUE;
 
   /* Although we could determine here that a full stage redraw
    * has already been queued and immediately bail out, we actually
@@ -2709,7 +2721,7 @@ clutter_actor_real_queue_redraw (ClutterActor *self,
       ClutterActor *stage = _clutter_actor_get_stage_internal (self);
       if (stage != NULL &&
           _clutter_stage_has_full_redraw_queued (CLUTTER_STAGE (stage)))
-        return;
+        return TRUE;
     }
 
   self->priv->propagated_one_redraw = TRUE;
@@ -2717,12 +2729,7 @@ clutter_actor_real_queue_redraw (ClutterActor *self,
   /* notify parents, if they are all visible eventually we'll
    * queue redraw on the stage, which queues the redraw idle.
    */
-  parent = clutter_actor_get_parent (self);
-  if (parent != NULL)
-    {
-      /* this will go up recursively */
-      _clutter_actor_signal_queue_redraw (parent, origin);
-    }
+  return FALSE;
 }
 
 static void
@@ -8011,10 +8018,12 @@ clutter_actor_class_init (ClutterActorClass *klass)
 		  G_SIGNAL_RUN_LAST |
                   G_SIGNAL_NO_HOOKS,
 		  G_STRUCT_OFFSET (ClutterActorClass, queue_redraw),
-		  NULL, NULL,
-		  _clutter_marshal_VOID__OBJECT,
-		  G_TYPE_NONE, 1,
-                  CLUTTER_TYPE_ACTOR);
+                  g_signal_accumulator_true_handled,
+		  NULL,
+		  _clutter_marshal_BOOLEAN__OBJECT_BOXED,
+		  G_TYPE_BOOLEAN, 2,
+                  CLUTTER_TYPE_ACTOR,
+                  CLUTTER_TYPE_PAINT_VOLUME);
 
   /**
    * ClutterActor::queue-relayout:
@@ -8519,6 +8528,7 @@ clutter_actor_init (ClutterActor *self)
   priv->needs_width_request = TRUE;
   priv->needs_height_request = TRUE;
   priv->needs_allocation = TRUE;
+  priv->needs_paint_volume_update = TRUE;
 
   priv->cached_width_age = 1;
   priv->cached_height_age = 1;
@@ -8612,8 +8622,7 @@ _clutter_actor_finish_queue_redraw (ClutterActor *self,
                                     ClutterPaintVolume *clip)
 {
   ClutterActorPrivate *priv = self->priv;
-  ClutterPaintVolume *pv;
-  gboolean clipped;
+  ClutterPaintVolume *pv = NULL;
 
   /* Remove queue entry early in the process, otherwise a new
      queue_redraw() during signal handling could put back this
@@ -8640,8 +8649,7 @@ _clutter_actor_finish_queue_redraw (ClutterActor *self,
    */
   if (clip)
     {
-      _clutter_actor_set_queue_redraw_clip (self, clip);
-      clipped = TRUE;
+      pv = clip;
     }
   else if (G_LIKELY (priv->last_paint_volume_valid))
     {
@@ -8651,36 +8659,12 @@ _clutter_actor_finish_queue_redraw (ClutterActor *self,
           ClutterActor *stage = _clutter_actor_get_stage_internal (self);
 
           /* make sure we redraw the actors old position... */
-          _clutter_actor_set_queue_redraw_clip (stage,
-                                                &priv->last_paint_volume);
-          _clutter_actor_signal_queue_redraw (stage, stage);
-          _clutter_actor_set_queue_redraw_clip (stage, NULL);
-
-          /* XXX: Ideally the redraw signal would take a clip volume
-           * argument, but that would be an ABI break. Until we can
-           * break the ABI we pass the argument out-of-band
-           */
-
-          /* setup the clip for the actors new position... */
-          _clutter_actor_set_queue_redraw_clip (self, pv);
-          clipped = TRUE;
+          _clutter_actor_propagate_queue_redraw (stage, stage,
+                                                 &priv->last_paint_volume);
         }
-      else
-        clipped = FALSE;
     }
-  else
-    clipped = FALSE;
 
-  _clutter_actor_signal_queue_redraw (self, self);
-
-  /* Just in case anyone is manually firing redraw signals without
-   * using the public queue_redraw() API we are careful to ensure that
-   * our out-of-band clip member is cleared before returning...
-   *
-   * Note: A NULL clip denotes a full-stage, un-clipped redraw
-   */
-  if (G_LIKELY (clipped))
-    _clutter_actor_set_queue_redraw_clip (self, NULL);
+  _clutter_actor_propagate_queue_redraw (self, self, pv);
 }
 
 static void
@@ -8841,8 +8825,7 @@ _clutter_actor_queue_redraw_full (ClutterActor       *self,
         {
           /* NB: NULL denotes an undefined clip which will result in a
            * full redraw... */
-          _clutter_actor_set_queue_redraw_clip (self, NULL);
-          _clutter_actor_signal_queue_redraw (self, self);
+          _clutter_actor_propagate_queue_redraw (self, self, NULL);
           return;
         }
 
@@ -8916,6 +8899,7 @@ _clutter_actor_queue_redraw_full (ClutterActor       *self,
     }
 
   priv->is_dirty = TRUE;
+  priv->needs_paint_volume_update = TRUE;
 }
 
 /**
@@ -12973,6 +12957,7 @@ clutter_actor_add_child_internal (ClutterActor              *self,
       child->priv->needs_width_request = TRUE;
       child->priv->needs_height_request = TRUE;
       child->priv->needs_allocation = TRUE;
+      child->priv->needs_paint_volume_update = TRUE;
 
       /* we only queue a relayout here, because any possible
        * redraw has already been queued either by show() or
@@ -16650,26 +16635,6 @@ clutter_actor_has_pointer (ClutterActor *self)
   return self->priv->has_pointer;
 }
 
-/* XXX: This is a workaround for not being able to break the ABI of
- * the QUEUE_REDRAW signal. It is an out-of-band argument.  See
- * clutter_actor_queue_clipped_redraw() for details.
- */
-ClutterPaintVolume *
-_clutter_actor_get_queue_redraw_clip (ClutterActor *self)
-{
-  return g_object_get_data (G_OBJECT (self),
-                            "-clutter-actor-queue-redraw-clip");
-}
-
-void
-_clutter_actor_set_queue_redraw_clip (ClutterActor       *self,
-                                      ClutterPaintVolume *clip)
-{
-  g_object_set_data (G_OBJECT (self),
-                     "-clutter-actor-queue-redraw-clip",
-                     clip);
-}
-
 /**
  * clutter_actor_has_allocation:
  * @self: a #ClutterActor
@@ -17516,16 +17481,22 @@ _clutter_actor_get_paint_volume_mutable (ClutterActor *self)
   priv = self->priv;
 
   if (priv->paint_volume_valid)
-    clutter_paint_volume_free (&priv->paint_volume);
+    {
+      if (!priv->needs_paint_volume_update)
+        return &priv->paint_volume;
+      clutter_paint_volume_free (&priv->paint_volume);
+    }
 
   if (_clutter_actor_get_paint_volume_real (self, &priv->paint_volume))
     {
       priv->paint_volume_valid = TRUE;
+      priv->needs_paint_volume_update = FALSE;
       return &priv->paint_volume;
     }
   else
     {
       priv->paint_volume_valid = FALSE;
+      priv->needs_paint_volume_update = FALSE;
       return NULL;
     }
 }

clutter/clutter/clutter-actor.h

@@ -236,8 +236,9 @@ struct _ClutterActorClass
   void (* pick)                 (ClutterActor          *actor,
                                  const ClutterColor    *color);
 
-  void (* queue_redraw)         (ClutterActor          *actor,
-                                 ClutterActor          *leaf_that_queued);
+  gboolean (* queue_redraw)     (ClutterActor          *actor,
+                                 ClutterActor          *leaf_that_queued,
+                                 ClutterPaintVolume    *paint_volume);
 
   /* size negotiation */
   void (* get_preferred_width)  (ClutterActor           *self,

clutter/clutter/clutter-marshal.list

@@ -1,6 +1,7 @@
 BOOLEAN:BOXED
 BOOLEAN:BOXED,INT,INT
 BOOLEAN:OBJECT,BOOLEAN
+BOOLEAN:OBJECT,BOXED
 BOOLEAN:OBJECT,BOXED,DOUBLE
 BOOLEAN:OBJECT,DOUBLE
 BOOLEAN:OBJECT,ENUM

clutter/clutter/clutter-paint-volume.c

@@ -1166,6 +1166,21 @@ _clutter_paint_volume_get_stage_paint_box (ClutterPaintVolume *pv,
 
   _clutter_paint_volume_get_bounding_box (&projected_pv, box);
 
+  if (pv->is_2d && pv->actor &&
+      clutter_actor_get_z_position (pv->actor) == 0)
+    {
+      /* If the volume/actor are perfectly 2D, take the bounding box as
+       * good. We won't need to add any extra room for sub-pixel positioning
+       * in this case.
+       */
+      clutter_paint_volume_free (&projected_pv);
+      box->x1 = CLUTTER_NEARBYINT (box->x1);
+      box->y1 = CLUTTER_NEARBYINT (box->y1);
+      box->x2 = CLUTTER_NEARBYINT (box->x2);
+      box->y2 = CLUTTER_NEARBYINT (box->y2);
+      return;
+    }
+
   /* The aim here is that for a given rectangle defined with floating point
    * coordinates we want to determine a stable quantized size in pixels
    * that doesn't vary due to the original box's sub-pixel position.

clutter/clutter/clutter-stage-window.c

@@ -231,19 +231,35 @@ _clutter_stage_window_ignoring_redraw_clips (ClutterStageWindow *window)
   return TRUE;
 }
 
-gboolean
-_clutter_stage_window_get_redraw_clip_bounds (ClutterStageWindow    *window,
-                                              cairo_rectangle_int_t *stage_clip)
+cairo_region_t *
+_clutter_stage_window_get_redraw_clip (ClutterStageWindow *window)
 {
   ClutterStageWindowIface *iface;
 
   g_return_val_if_fail (CLUTTER_IS_STAGE_WINDOW (window), FALSE);
 
   iface = CLUTTER_STAGE_WINDOW_GET_IFACE (window);
-  if (iface->get_redraw_clip_bounds != NULL)
-    return iface->get_redraw_clip_bounds (window, stage_clip);
+  if (iface->get_redraw_clip != NULL)
+    return iface->get_redraw_clip (window);
 
-  return FALSE;
+  return NULL;
+}
+
+gboolean
+_clutter_stage_window_get_redraw_clip_bounds (ClutterStageWindow    *window,
+                                              cairo_rectangle_int_t *stage_clip)
+{
+  cairo_region_t *redraw_clip;
+
+  g_return_val_if_fail (CLUTTER_IS_STAGE_WINDOW (window), FALSE);
+
+  redraw_clip = _clutter_stage_window_get_redraw_clip (window);
+  if (!redraw_clip)
+    return FALSE;
+
+  cairo_region_get_extents (redraw_clip, stage_clip);
+  cairo_region_destroy (redraw_clip);
+  return TRUE;
 }
 
 void

clutter/clutter/clutter-stage-window.h

@@ -68,9 +68,7 @@ struct _ClutterStageWindowIface
                                                  cairo_rectangle_int_t *stage_rectangle);
   gboolean          (* has_redraw_clips)        (ClutterStageWindow    *stage_window);
   gboolean          (* ignoring_redraw_clips)   (ClutterStageWindow    *stage_window);
-  gboolean          (* get_redraw_clip_bounds)  (ClutterStageWindow    *stage_window,
-                                                 cairo_rectangle_int_t *clip);
-
+  cairo_region_t *  (* get_redraw_clip)         (ClutterStageWindow    *stage_window);
 
   void              (* set_accept_focus)        (ClutterStageWindow *stage_window,
                                                  gboolean            accept_focus);
@@ -125,6 +123,7 @@ gboolean          _clutter_stage_window_has_redraw_clips        (ClutterStageWin
 gboolean          _clutter_stage_window_ignoring_redraw_clips   (ClutterStageWindow    *window);
 gboolean          _clutter_stage_window_get_redraw_clip_bounds  (ClutterStageWindow    *window,
                                                                  cairo_rectangle_int_t *clip);
+cairo_region_t *  _clutter_stage_window_get_redraw_clip         (ClutterStageWindow    *window);
 
 void              _clutter_stage_window_set_accept_focus        (ClutterStageWindow *window,
                                                                  gboolean            accept_focus);

clutter/clutter/clutter-stage.c

@@ -1199,45 +1199,44 @@ clutter_stage_real_queue_relayout (ClutterActor *self)
   parent_class->queue_relayout (self);
 }
 
-static void
-clutter_stage_real_queue_redraw (ClutterActor *actor,
-                                 ClutterActor *leaf)
+static gboolean
+clutter_stage_real_queue_redraw (ClutterActor       *actor,
+                                 ClutterActor       *leaf,
+                                 ClutterPaintVolume *redraw_clip)
 {
   ClutterStage *stage = CLUTTER_STAGE (actor);
   ClutterStageWindow *stage_window;
-  ClutterPaintVolume *redraw_clip;
   ClutterActorBox bounding_box;
   ClutterActorBox intersection_box;
   cairo_rectangle_int_t geom, stage_clip;
 
   if (CLUTTER_ACTOR_IN_DESTRUCTION (actor))
-    return;
+    return TRUE;
 
   /* If the backend can't do anything with redraw clips (e.g. it already knows
    * it needs to redraw everything anyway) then don't spend time transforming
    * any clip volume into stage coordinates... */
   stage_window = _clutter_stage_get_window (stage);
   if (stage_window == NULL)
-    return;
+    return TRUE;
 
   if (_clutter_stage_window_ignoring_redraw_clips (stage_window))
     {
       _clutter_stage_window_add_redraw_clip (stage_window, NULL);
-      return;
+      return FALSE;
     }
 
   /* Convert the clip volume into stage coordinates and then into an
    * axis aligned stage coordinates bounding box...
    */
-  redraw_clip = _clutter_actor_get_queue_redraw_clip (leaf);
   if (redraw_clip == NULL)
     {
       _clutter_stage_window_add_redraw_clip (stage_window, NULL);
-      return;
+      return FALSE;
     }
 
   if (redraw_clip->is_empty)
-    return;
+    return TRUE;
 
   _clutter_paint_volume_get_stage_paint_box (redraw_clip,
                                              stage,
@@ -1253,7 +1252,7 @@ clutter_stage_real_queue_redraw (ClutterActor *actor,
   /* There is no need to track degenerate/empty redraw clips */
   if (intersection_box.x2 <= intersection_box.x1 ||
       intersection_box.y2 <= intersection_box.y1)
-    return;
+    return TRUE;
 
   /* when converting to integer coordinates make sure we round the edges of the
    * clip rectangle outwards... */
@@ -1263,6 +1262,7 @@ clutter_stage_real_queue_redraw (ClutterActor *actor,
   stage_clip.height = intersection_box.y2 - stage_clip.y;
 
   _clutter_stage_window_add_redraw_clip (stage_window, &stage_clip);
+  return FALSE;
 }
 
 gboolean
@@ -1315,6 +1315,31 @@ clutter_stage_get_redraw_clip_bounds (ClutterStage          *stage,
     }
 }
 
+cairo_region_t *
+clutter_stage_get_redraw_clip (ClutterStage *stage)
+{
+  ClutterStagePrivate *priv;
+  cairo_rectangle_int_t clip;
+  cairo_region_t *region;
+
+  g_return_val_if_fail (CLUTTER_IS_STAGE (stage), NULL);
+
+  priv = stage->priv;
+
+  region = _clutter_stage_window_get_redraw_clip (priv->impl);
+  if (region)
+    return region;
+
+  if (!region)
+    {
+      /* Set clip to the full extents of the stage */
+      _clutter_stage_window_get_geometry (priv->impl, &clip);
+      region = cairo_region_create_rectangle (&clip);
+    }
+
+  return region;
+}
+
 static void
 read_pixels_to_file (char *filename_stem,
                      int   x,

clutter/clutter/clutter-stage.h

@@ -245,6 +245,9 @@ guchar *        clutter_stage_read_pixels                       (ClutterStage
 CLUTTER_AVAILABLE_IN_ALL
 void            clutter_stage_get_redraw_clip_bounds            (ClutterStage          *stage,
                                                                  cairo_rectangle_int_t *clip);
+CLUTTER_AVAILABLE_IN_MUTTER
+cairo_region_t * clutter_stage_get_redraw_clip                  (ClutterStage          *stage);
+
 CLUTTER_AVAILABLE_IN_ALL
 void            clutter_stage_ensure_viewport                   (ClutterStage          *stage);
 CLUTTER_AVAILABLE_IN_ALL

clutter/clutter/cogl/clutter-stage-cogl.c

@@ -54,7 +54,7 @@ typedef struct _ClutterStageViewCoglPrivate
   /* Stores a list of previous damaged areas in the stage coordinate space */
 #define DAMAGE_HISTORY_MAX 16
 #define DAMAGE_HISTORY(x) ((x) & (DAMAGE_HISTORY_MAX - 1))
-  cairo_rectangle_int_t damage_history[DAMAGE_HISTORY_MAX];
+  cairo_region_t * damage_history[DAMAGE_HISTORY_MAX];
   unsigned int damage_index;
 } ClutterStageViewCoglPrivate;
 
@@ -246,13 +246,10 @@ clutter_stage_cogl_has_redraw_clips (ClutterStageWindow *stage_window)
   /* NB: at the start of each new frame there is an implied clip that
    * clips everything (i.e. nothing would be drawn) so we need to make
    * sure we return True in the un-initialized case here.
-   *
-   * NB: a clip width of 0 means a full stage redraw has been queued
-   * so we effectively don't have any redraw clips in that case.
    */
   if (!stage_cogl->initialized_redraw_clip ||
       (stage_cogl->initialized_redraw_clip &&
-       stage_cogl->bounding_redraw_clip.width != 0))
+       stage_cogl->redraw_clip))
     return TRUE;
   else
     return FALSE;
@@ -263,9 +260,9 @@ clutter_stage_cogl_ignoring_redraw_clips (ClutterStageWindow *stage_window)
 {
   ClutterStageCogl *stage_cogl = CLUTTER_STAGE_COGL (stage_window);
 
-  /* NB: a clip width of 0 means a full stage redraw is required */
+  /* NB: a NULL clip means a full stage redraw is required */
   if (stage_cogl->initialized_redraw_clip &&
-      stage_cogl->bounding_redraw_clip.width == 0)
+      !stage_cogl->redraw_clip)
     return TRUE;
   else
     return FALSE;
@@ -296,11 +293,11 @@ clutter_stage_cogl_add_redraw_clip (ClutterStageWindow    *stage_window,
     return;
 
   /* A NULL stage clip means a full stage redraw has been queued and
-   * we keep track of this by setting a zero width
-   * stage_cogl->bounding_redraw_clip */
+   * we keep track of this by setting a NULL redraw_clip.
+   */
   if (stage_clip == NULL)
     {
-      stage_cogl->bounding_redraw_clip.width = 0;
+      g_clear_pointer (&stage_cogl->redraw_clip, cairo_region_destroy);
       stage_cogl->initialized_redraw_clip = TRUE;
       return;
     }
@@ -309,34 +306,27 @@ clutter_stage_cogl_add_redraw_clip (ClutterStageWindow    *stage_window,
   if (stage_clip->width == 0 || stage_clip->height == 0)
     return;
 
-  if (!stage_cogl->initialized_redraw_clip)
+  if (!stage_cogl->redraw_clip)
     {
-      stage_cogl->bounding_redraw_clip = *stage_clip;
+      stage_cogl->redraw_clip = cairo_region_create_rectangle (stage_clip);
     }
-  else if (stage_cogl->bounding_redraw_clip.width > 0)
+  else
     {
-      _clutter_util_rectangle_union (&stage_cogl->bounding_redraw_clip,
-                                     stage_clip,
-                                     &stage_cogl->bounding_redraw_clip);
+      cairo_region_union_rectangle (stage_cogl->redraw_clip, stage_clip);
     }
 
   stage_cogl->initialized_redraw_clip = TRUE;
 }
 
-static gboolean
-clutter_stage_cogl_get_redraw_clip_bounds (ClutterStageWindow    *stage_window,
-                                           cairo_rectangle_int_t *stage_clip)
+static cairo_region_t *
+clutter_stage_cogl_get_redraw_clip (ClutterStageWindow *stage_window)
 {
   ClutterStageCogl *stage_cogl = CLUTTER_STAGE_COGL (stage_window);
 
-  if (stage_cogl->using_clipped_redraw)
-    {
-      *stage_clip = stage_cogl->bounding_redraw_clip;
+  if (stage_cogl->using_clipped_redraw && stage_cogl->redraw_clip)
+    return cairo_region_copy (stage_cogl->redraw_clip);
 
-      return TRUE;
-    }
-
-  return FALSE;
+  return NULL;
 }
 
 static inline gboolean
@@ -414,37 +404,51 @@ swap_framebuffer (ClutterStageWindow    *stage_window,
 static void
 paint_stage (ClutterStageCogl            *stage_cogl,
              ClutterStageView            *view,
-             const cairo_rectangle_int_t *clip)
+             cairo_region_t              *clip)
 {
   ClutterStage *stage = stage_cogl->wrapper;
+  cairo_rectangle_int_t clip_rect;
+
+  cairo_region_get_extents (clip, &clip_rect);
 
   _clutter_stage_maybe_setup_viewport (stage, view);
-  _clutter_stage_paint_view (stage, view, clip);
+  _clutter_stage_paint_view (stage, view, &clip_rect);
 
   if (clutter_stage_view_get_onscreen (view) !=
       clutter_stage_view_get_framebuffer (view))
     {
-      clutter_stage_view_blit_offscreen (view, clip);
+      clutter_stage_view_blit_offscreen (view, &clip_rect);
     }
 }
 
 static void
-fill_current_damage_history_and_step (ClutterStageView *view)
+fill_current_damage_history (ClutterStageView *view,
+                             cairo_region_t   *damage)
 {
   ClutterStageViewCogl *view_cogl = CLUTTER_STAGE_VIEW_COGL (view);
   ClutterStageViewCoglPrivate *view_priv =
     clutter_stage_view_cogl_get_instance_private (view_cogl);
-  cairo_rectangle_int_t view_rect;
-  cairo_rectangle_int_t *current_damage;
+  cairo_region_t **current_damage;
 
   current_damage =
     &view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index)];
-  clutter_stage_view_get_layout (view, &view_rect);
 
-  *current_damage = view_rect;
+  g_clear_pointer (current_damage, cairo_region_destroy);
+  *current_damage = cairo_region_copy (damage);
   view_priv->damage_index++;
 }
 
+static void
+fill_current_damage_history_rectangle (ClutterStageView            *view,
+                                       const cairo_rectangle_int_t *rect)
+{
+  cairo_region_t *damage;
+
+  damage = cairo_region_create_rectangle (rect);
+  fill_current_damage_history (view, damage);
+  cairo_region_destroy (damage);
+}
+
 static void
 transform_swap_region_to_onscreen (ClutterStageView      *view,
                                    cairo_rectangle_int_t *swap_region)
@@ -499,9 +503,11 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
   gboolean do_swap_buffer;
   gboolean swap_with_damage;
   ClutterActor *wrapper;
-  cairo_rectangle_int_t redraw_clip;
+  cairo_region_t *redraw_clip;
+  cairo_region_t *clip_region;
   cairo_rectangle_int_t swap_region;
-  cairo_rectangle_int_t clip_region;
+  cairo_rectangle_int_t clip_rect;
+  cairo_rectangle_int_t redraw_rect;
   gboolean clip_region_empty;
   int fb_scale;
 
@@ -517,20 +523,19 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
     cogl_is_onscreen (fb) &&
     cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_BUFFER_AGE);
 
-  /* NB: a zero width redraw clip == full stage redraw */
-  if (stage_cogl->bounding_redraw_clip.width == 0)
+  /* NB: a NULL redraw clip == full stage redraw */
+  if (!stage_cogl->redraw_clip)
     have_clip = FALSE;
   else
     {
-      redraw_clip = stage_cogl->bounding_redraw_clip;
-      _clutter_util_rectangle_intersection (&redraw_clip,
-                                            &view_rect,
-                                            &redraw_clip);
+      cairo_region_t *view_region;
+      redraw_clip = cairo_region_copy (stage_cogl->redraw_clip);
 
-      have_clip = !(redraw_clip.x == view_rect.x &&
-                    redraw_clip.y == view_rect.y &&
-                    redraw_clip.width == view_rect.width &&
-                    redraw_clip.height == view_rect.height);
+      view_region = cairo_region_create_rectangle (&view_rect);
+      cairo_region_intersect (redraw_clip, view_region);
+
+      have_clip = !cairo_region_equal (redraw_clip, view_region);
+      cairo_region_destroy (view_region);
     }
 
   may_use_clipped_redraw = FALSE;
@@ -542,11 +547,12 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
       cogl_onscreen_get_frame_counter (COGL_ONSCREEN (fb)) > 3)
     {
       may_use_clipped_redraw = TRUE;
-      clip_region = redraw_clip;
+      clip_region = cairo_region_reference (redraw_clip);
     }
   else
     {
-      clip_region = (cairo_rectangle_int_t){ 0 };
+      clip_region = cairo_region_create ();
+      redraw_clip = cairo_region_reference (clip_region);
     }
 
   if (may_use_clipped_redraw &&
@@ -555,7 +561,7 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
   else
     use_clipped_redraw = FALSE;
 
-  clip_region_empty = may_use_clipped_redraw && clip_region.width == 0;
+  clip_region_empty = may_use_clipped_redraw && cairo_region_is_empty (clip_region);
 
   fb_scale = clutter_stage_view_get_scale (view);
 
@@ -565,34 +571,26 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
       if (use_clipped_redraw && !clip_region_empty)
         {
           int age, i;
-          cairo_rectangle_int_t *current_damage =
-            &view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index++)];
 
           age = cogl_onscreen_get_buffer_age (COGL_ONSCREEN (fb));
 
           if (valid_buffer_age (view_cogl, age))
             {
-              *current_damage = clip_region;
+              fill_current_damage_history (view, clip_region);
 
               for (i = 1; i <= age; i++)
                 {
-                  cairo_rectangle_int_t *damage =
-                    &view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index - i - 1)];
-
-                  _clutter_util_rectangle_union (&clip_region, damage, &clip_region);
+                  cairo_region_t *damage =
+                    view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index - i - 1)];
+                  cairo_region_union (clip_region, damage);
                 }
 
-              /* Update the bounding redraw clip state with the extra damage. */
-              _clutter_util_rectangle_union (&stage_cogl->bounding_redraw_clip,
-                                             &clip_region,
-                                             &stage_cogl->bounding_redraw_clip);
+              /* Update the redraw clip state with the extra damage. */
+              cairo_region_union (stage_cogl->redraw_clip, clip_region);
 
-              CLUTTER_NOTE (CLIPPING, "Reusing back buffer(age=%d) - repairing region: x=%d, y=%d, width=%d, height=%d\n",
+              CLUTTER_NOTE (CLIPPING, "Reusing back buffer(age=%d) - repairing region: num rects: %d\n",
                             age,
-                            clip_region.x,
-                            clip_region.y,
-                            clip_region.width,
-                            clip_region.height);
+                            cairo_region_num_rectangles (clip_region));
 
               swap_with_damage = TRUE;
             }
@@ -600,15 +598,17 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
             {
               CLUTTER_NOTE (CLIPPING, "Invalid back buffer(age=%d): forcing full redraw\n", age);
               use_clipped_redraw = FALSE;
-              *current_damage = view_rect;
+              fill_current_damage_history_rectangle (view, &view_rect);
             }
         }
       else if (!use_clipped_redraw)
         {
-          fill_current_damage_history_and_step (view);
+          fill_current_damage_history_rectangle (view, &view_rect);
         }
     }
 
+  cairo_region_get_extents (clip_region, &clip_rect);
+
   cogl_push_framebuffer (fb);
   if (use_clipped_redraw && clip_region_empty)
     {
@@ -621,21 +621,21 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
 
       CLUTTER_NOTE (CLIPPING,
                     "Stage clip pushed: x=%d, y=%d, width=%d, height=%d\n",
-                    clip_region.x,
-                    clip_region.y,
-                    clip_region.width,
-                    clip_region.height);
+                    clip_rect.x,
+                    clip_rect.y,
+                    clip_rect.width,
+                    clip_rect.height);
 
       stage_cogl->using_clipped_redraw = TRUE;
 
-      scissor_x = (clip_region.x - view_rect.x) * fb_scale;
-      scissor_y = (clip_region.y - view_rect.y) * fb_scale;
+      scissor_x = (clip_rect.x - view_rect.x) * fb_scale;
+      scissor_y = (clip_rect.y - view_rect.y) * fb_scale;
       cogl_framebuffer_push_scissor_clip (fb,
                                           scissor_x,
                                           scissor_y,
-                                          clip_region.width * fb_scale,
-                                          clip_region.height * fb_scale);
-      paint_stage (stage_cogl, view, &clip_region);
+                                          clip_rect.width * fb_scale,
+                                          clip_rect.height * fb_scale);
+      paint_stage (stage_cogl, view, clip_region);
       cogl_framebuffer_pop_clip (fb);
 
       stage_cogl->using_clipped_redraw = FALSE;
@@ -645,7 +645,7 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
       CLUTTER_NOTE (CLIPPING, "Unclipped stage paint\n");
 
       /* If we are trying to debug redraw issues then we want to pass
-       * the bounding_redraw_clip so it can be visualized */
+       * the redraw_clip so it can be visualized */
       if (G_UNLIKELY (clutter_paint_debug_flags & CLUTTER_DEBUG_DISABLE_CLIPPED_REDRAWS) &&
           may_use_clipped_redraw &&
           !clip_region_empty)
@@ -653,31 +653,39 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
           int scissor_x;
           int scissor_y;
 
-          scissor_x = (clip_region.x - view_rect.x) * fb_scale;;
-          scissor_y = (clip_region.y - view_rect.y) * fb_scale;
+          scissor_x = (clip_rect.x - view_rect.x) * fb_scale;;
+          scissor_y = (clip_rect.y - view_rect.y) * fb_scale;
           cogl_framebuffer_push_scissor_clip (fb,
                                               scissor_x,
                                               scissor_y,
-                                              clip_region.width * fb_scale,
-                                              clip_region.height * fb_scale);
-          paint_stage (stage_cogl, view, &clip_region);
+                                              clip_rect.width * fb_scale,
+                                              clip_rect.height * fb_scale);
+          paint_stage (stage_cogl, view, clip_region);
           cogl_framebuffer_pop_clip (fb);
         }
       else
-        paint_stage (stage_cogl, view, &view_rect);
+        {
+          cairo_region_t *view_region;
+
+          view_region = cairo_region_create_rectangle (&view_rect);
+          paint_stage (stage_cogl, view, view_region);
+          cairo_region_destroy (view_region);
+        }
     }
   cogl_pop_framebuffer ();
 
+  cairo_region_get_extents (redraw_clip, &redraw_rect);
+
   if (may_use_clipped_redraw &&
       G_UNLIKELY ((clutter_paint_debug_flags & CLUTTER_DEBUG_REDRAWS)))
     {
       CoglContext *ctx = cogl_framebuffer_get_context (fb);
       static CoglPipeline *outline = NULL;
       ClutterActor *actor = CLUTTER_ACTOR (wrapper);
-      float x_1 = redraw_clip.x;
-      float x_2 = redraw_clip.x + redraw_clip.width;
-      float y_1 = redraw_clip.y;
-      float y_2 = redraw_clip.y + redraw_clip.height;
+      float x_1 = redraw_rect.x;
+      float x_2 = redraw_rect.x + redraw_rect.width;
+      float y_1 = redraw_rect.y;
+      float y_2 = redraw_rect.y + redraw_rect.height;
       CoglVertexP2 quad[4] = {
         { x_1, y_1 },
         { x_2, y_1 },
@@ -724,10 +732,10 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
       else if (use_clipped_redraw)
         {
           swap_region = (cairo_rectangle_int_t) {
-            .x = (clip_region.x - view_rect.x) * fb_scale,
-            .y = (clip_region.y - view_rect.y) * fb_scale,
-            .width = clip_region.width * fb_scale,
-            .height = clip_region.height * fb_scale,
+            .x = (clip_rect.x - view_rect.x) * fb_scale,
+            .y = (clip_rect.y - view_rect.y) * fb_scale,
+            .width = clip_rect.width * fb_scale,
+            .height = clip_rect.height * fb_scale,
           };
           g_assert (swap_region.width > 0);
           do_swap_buffer = TRUE;
@@ -749,6 +757,11 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
       do_swap_buffer = TRUE;
     }
 
+  if (redraw_clip)
+    cairo_region_destroy (redraw_clip);
+  if (clip_region)
+    cairo_region_destroy (clip_region);
+
   if (do_swap_buffer)
     {
       if (clutter_stage_view_get_onscreen (view) !=
@@ -796,6 +809,7 @@ clutter_stage_cogl_redraw (ClutterStageWindow *stage_window)
 
   /* reset the redraw clipping for the next paint... */
   stage_cogl->initialized_redraw_clip = FALSE;
+  g_clear_pointer (&stage_cogl->redraw_clip, cairo_region_destroy);
 
   stage_cogl->frame_count++;
 }
@@ -810,7 +824,7 @@ clutter_stage_cogl_get_dirty_pixel (ClutterStageWindow *stage_window,
   gboolean has_buffer_age =
     cogl_is_onscreen (framebuffer) &&
     cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_BUFFER_AGE);
-  cairo_rectangle_int_t *rect;
+  cairo_rectangle_int_t rect;
 
   if (!has_buffer_age)
     {
@@ -823,12 +837,18 @@ clutter_stage_cogl_get_dirty_pixel (ClutterStageWindow *stage_window,
       ClutterStageViewCoglPrivate *view_priv =
         clutter_stage_view_cogl_get_instance_private (view_cogl);
       cairo_rectangle_int_t view_layout;
+      cairo_region_t *damage;
 
       clutter_stage_view_get_layout (view, &view_layout);
 
-      rect = &view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index - 1)];
-      *x = rect->x - view_layout.x;
-      *y = rect->y - view_layout.y;
+      damage = view_priv->damage_history[DAMAGE_HISTORY (view_priv->damage_index - 1)];
+      if (damage)
+        cairo_region_get_rectangle (damage, 0, &rect);
+      else
+        rect.x = rect.y = 0;
+
+      *x = rect.x - view_layout.x;
+      *y = rect.y - view_layout.y;
     }
 }
 
@@ -847,7 +867,7 @@ clutter_stage_window_iface_init (ClutterStageWindowIface *iface)
   iface->add_redraw_clip = clutter_stage_cogl_add_redraw_clip;
   iface->has_redraw_clips = clutter_stage_cogl_has_redraw_clips;
   iface->ignoring_redraw_clips = clutter_stage_cogl_ignoring_redraw_clips;
-  iface->get_redraw_clip_bounds = clutter_stage_cogl_get_redraw_clip_bounds;
+  iface->get_redraw_clip = clutter_stage_cogl_get_redraw_clip;
   iface->redraw = clutter_stage_cogl_redraw;
   iface->get_dirty_pixel = clutter_stage_cogl_get_dirty_pixel;
 }

clutter/clutter/cogl/clutter-stage-cogl.h

@@ -59,7 +59,7 @@ struct _ClutterStageCogl
    * junk frames to start with. */
   unsigned int frame_count;
 
-  cairo_rectangle_int_t bounding_redraw_clip;
+  cairo_region_t *redraw_clip;
 
   guint initialized_redraw_clip : 1;
 

cogl/cogl/cogl-framebuffer-private.h

@@ -193,6 +193,11 @@ struct _CoglFramebuffer
   CoglFramebufferBits bits;
 
   int                 samples_per_pixel;
+
+  /* Whether the depth buffer was enabled for this framebuffer,
+   * usually means it needs to be cleared before being reused next.
+   */
+  CoglBool            depth_buffer_clear_needed;
 };
 
 typedef enum {

cogl/cogl/cogl-framebuffer.c

@@ -117,6 +117,7 @@ _cogl_framebuffer_init (CoglFramebuffer *framebuffer,
   framebuffer->viewport_age_for_scissor_workaround = -1;
   framebuffer->dither_enabled = TRUE;
   framebuffer->depth_writing_enabled = TRUE;
+  framebuffer->depth_buffer_clear_needed = TRUE;
 
   framebuffer->modelview_stack = cogl_matrix_stack_new (ctx);
   framebuffer->projection_stack = cogl_matrix_stack_new (ctx);
@@ -268,6 +269,13 @@ cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
   int scissor_y1;
   CoglBool saved_viewport_scissor_workaround;
 
+  if (!framebuffer->depth_buffer_clear_needed &&
+      (buffers & COGL_BUFFER_BIT_DEPTH))
+    buffers &= ~(COGL_BUFFER_BIT_DEPTH);
+
+  if (buffers == 0)
+    return;
+
   _cogl_clip_stack_get_bounds (clip_stack,
                                &scissor_x0, &scissor_y0,
                                &scissor_x1, &scissor_y1);
@@ -415,6 +423,9 @@ cleared:
   _cogl_framebuffer_mark_mid_scene (framebuffer);
   _cogl_framebuffer_mark_clear_clip_dirty (framebuffer);
 
+  if (buffers & COGL_BUFFER_BIT_DEPTH)
+    framebuffer->depth_buffer_clear_needed = FALSE;
+
   if (buffers & COGL_BUFFER_BIT_COLOR && buffers & COGL_BUFFER_BIT_DEPTH)
     {
       /* For our fast-path for reading back a single pixel of simple

cogl/cogl/driver/gl/cogl-pipeline-opengl.c

@@ -418,7 +418,11 @@ flush_depth_state (CoglContext *ctx,
   if (ctx->depth_test_enabled_cache != depth_state->test_enabled)
     {
       if (depth_state->test_enabled == TRUE)
-        GE (ctx, glEnable (GL_DEPTH_TEST));
+        {
+          GE (ctx, glEnable (GL_DEPTH_TEST));
+          if (ctx->current_draw_buffer)
+            ctx->current_draw_buffer->depth_buffer_clear_needed = TRUE;
+        }
       else
         GE (ctx, glDisable (GL_DEPTH_TEST));
       ctx->depth_test_enabled_cache = depth_state->test_enabled;

src/compositor/meta-shadow-factory.c

@@ -220,11 +220,7 @@ meta_shadow_paint (MetaShadow     *shadow,
   int dest_x[4];
   int dest_y[4];
   int n_x, n_y;
-
-  cogl_pipeline_set_color4ub (shadow->pipeline,
-                              opacity, opacity, opacity, opacity);
-
-  cogl_set_source (shadow->pipeline);
+  gboolean source_updated = FALSE;
 
   if (shadow->scale_width)
     {
@@ -300,6 +296,17 @@ meta_shadow_paint (MetaShadow     *shadow,
           else
             overlap = CAIRO_REGION_OVERLAP_IN;
 
+          if (overlap == CAIRO_REGION_OVERLAP_OUT)
+            continue;
+
+          if (!source_updated)
+            {
+              cogl_pipeline_set_color4ub (shadow->pipeline,
+                                          opacity, opacity, opacity, opacity);
+              cogl_set_source (shadow->pipeline);
+              source_updated = TRUE;
+            }
+
           /* There's quite a bit of overhead from allocating a new
            * region in order to find an exact intersection and
            * generating more geometry - we make the assumption that

src/compositor/meta-surface-actor.c

@@ -35,7 +35,6 @@ G_DEFINE_ABSTRACT_TYPE_WITH_CODE (MetaSurfaceActor, meta_surface_actor, CLUTTER_
                                   G_IMPLEMENT_INTERFACE (META_TYPE_CULLABLE, cullable_iface_init));
 
 enum {
-  REPAINT_SCHEDULED,
   SIZE_CHANGED,
 
   LAST_SIGNAL,
@@ -121,13 +120,6 @@ meta_surface_actor_class_init (MetaSurfaceActorClass *klass)
   object_class->dispose = meta_surface_actor_dispose;
   actor_class->pick = meta_surface_actor_pick;
 
-  signals[REPAINT_SCHEDULED] = g_signal_new ("repaint-scheduled",
-                                             G_TYPE_FROM_CLASS (object_class),
-                                             G_SIGNAL_RUN_LAST,
-                                             0,
-                                             NULL, NULL, NULL,
-                                             G_TYPE_NONE, 0);
-
   signals[SIZE_CHANGED] = g_signal_new ("size-changed",
                                         G_TYPE_FROM_CLASS (object_class),
                                         G_SIGNAL_RUN_LAST,
@@ -201,8 +193,7 @@ meta_surface_actor_update_area (MetaSurfaceActor *self,
 {
   MetaSurfaceActorPrivate *priv = self->priv;
 
-  if (meta_shaped_texture_update_area (priv->texture, x, y, width, height))
-    g_signal_emit (self, signals[REPAINT_SCHEDULED], 0);
+  meta_shaped_texture_update_area (priv->texture, x, y, width, height);
 }
 
 gboolean

src/compositor/meta-window-actor.c

@@ -82,7 +82,6 @@ struct _MetaWindowActorPrivate
   guint             send_frame_messages_timer;
   gint64            frame_drawn_time;
 
-  guint             repaint_scheduled_id;
   guint             size_changed_id;
 
   /*
@@ -194,6 +193,18 @@ frame_data_free (FrameData *frame)
   g_slice_free (FrameData, frame);
 }
 
+static gboolean
+meta_window_actor_queue_redraw (ClutterActor       *actor,
+                                ClutterActor       *leaf,
+                                ClutterPaintVolume *paint_volume)
+{
+  MetaWindowActor *self = META_WINDOW_ACTOR (actor);
+  MetaWindowActorPrivate *priv = self->priv;
+
+  priv->repaint_scheduled = TRUE;
+  return CLUTTER_ACTOR_CLASS (meta_window_actor_parent_class)->queue_redraw (actor, leaf, paint_volume);
+}
+
 static void
 meta_window_actor_class_init (MetaWindowActorClass *klass)
 {
@@ -211,6 +222,7 @@ meta_window_actor_class_init (MetaWindowActorClass *klass)
 
   actor_class->paint = meta_window_actor_paint;
   actor_class->get_paint_volume = meta_window_actor_get_paint_volume;
+  actor_class->queue_redraw = meta_window_actor_queue_redraw;
 
   /**
    * MetaWindowActor::first-frame:
@@ -297,16 +309,6 @@ surface_size_changed (MetaSurfaceActor *actor,
   meta_window_actor_update_shape (self);
 }
 
-static void
-surface_repaint_scheduled (MetaSurfaceActor *actor,
-                           gpointer          user_data)
-{
-  MetaWindowActor *self = META_WINDOW_ACTOR (user_data);
-  MetaWindowActorPrivate *priv = self->priv;
-
-  priv->repaint_scheduled = TRUE;
-}
-
 static gboolean
 is_argb32 (MetaWindowActor *self)
 {
@@ -396,9 +398,7 @@ set_surface (MetaWindowActor  *self,
 
   if (priv->surface)
     {
-      g_signal_handler_disconnect (priv->surface, priv->repaint_scheduled_id);
       g_signal_handler_disconnect (priv->surface, priv->size_changed_id);
-      priv->repaint_scheduled_id = 0;
       clutter_actor_remove_child (CLUTTER_ACTOR (self), CLUTTER_ACTOR (priv->surface));
       g_object_unref (priv->surface);
     }
@@ -408,8 +408,6 @@ set_surface (MetaWindowActor  *self,
   if (priv->surface)
     {
       g_object_ref_sink (priv->surface);
-      priv->repaint_scheduled_id = g_signal_connect (priv->surface, "repaint-scheduled",
-                                                     G_CALLBACK (surface_repaint_scheduled), self);
       priv->size_changed_id = g_signal_connect (priv->surface, "size-changed",
                                                 G_CALLBACK (surface_size_changed), self);
       clutter_actor_add_child (CLUTTER_ACTOR (self), CLUTTER_ACTOR (priv->surface));
@@ -717,6 +715,7 @@ meta_window_actor_paint (ClutterActor *actor)
       cairo_rectangle_int_t shape_bounds;
       cairo_region_t *clip = priv->shadow_clip;
       MetaWindow *window = priv->window;
+      gboolean partially_drawn = FALSE;
 
       meta_window_actor_get_shape_bounds (self, &shape_bounds);
       meta_window_actor_get_shadow_params (self, appears_focused, &params);
@@ -734,6 +733,17 @@ meta_window_actor_paint (ClutterActor *actor)
 
           cairo_region_subtract (clip, frame_bounds);
         }
+      else if (clip)
+        {
+          cairo_rectangle_int_t shadow_bounds;
+          cairo_region_t *shadow_region;
+
+          meta_window_actor_get_shadow_bounds (self, appears_focused, &shadow_bounds);
+          shadow_region = cairo_region_create_rectangle (&shadow_bounds);
+          cairo_region_intersect (shadow_region, clip);
+          partially_drawn = !cairo_region_is_empty (shadow_region);
+          cairo_region_destroy (shadow_region);
+        }
 
       meta_shadow_paint (shadow,
                          params.x_offset + shape_bounds.x,
@@ -742,7 +752,7 @@ meta_window_actor_paint (ClutterActor *actor)
                          shape_bounds.height,
                          (clutter_actor_get_paint_opacity (actor) * params.opacity * window->opacity) / (255 * 255),
                          clip,
-                         clip_shadow_under_window (self)); /* clip_strictly - not just as an optimization */
+                         clip_shadow_under_window (self) || partially_drawn);
 
       if (clip && clip != priv->shadow_clip)
         cairo_region_destroy (clip);

src/compositor/meta-window-group.c

@@ -57,7 +57,7 @@ meta_window_group_paint (ClutterActor *actor)
 {
   cairo_region_t *clip_region;
   cairo_region_t *unobscured_region;
-  cairo_rectangle_int_t visible_rect, clip_rect;
+  cairo_rectangle_int_t visible_rect;
   int paint_x_origin, paint_y_origin;
   int screen_width, screen_height;
 
@@ -109,11 +109,7 @@ meta_window_group_paint (ClutterActor *actor)
    * sizes, we could intersect this with an accurate union of the
    * monitors to avoid painting shadows that are visible only in the
    * holes. */
-  clutter_stage_get_redraw_clip_bounds (CLUTTER_STAGE (stage),
-                                        &clip_rect);
-
-  clip_region = cairo_region_create_rectangle (&clip_rect);
-
+  clip_region = clutter_stage_get_redraw_clip (CLUTTER_STAGE (stage));
   cairo_region_translate (clip_region, -paint_x_origin, -paint_y_origin);
 
   meta_cullable_cull_out (META_CULLABLE (window_group), unobscured_region, clip_region);

src/wayland/meta-wayland-surface.c

@@ -470,14 +470,6 @@ queue_surface_actor_frame_callbacks (MetaWaylandSurface      *surface,
   wl_list_init (&pending->frame_callback_list);
 }
 
-static void
-pending_buffer_resource_destroyed (MetaWaylandBuffer       *buffer,
-                                   MetaWaylandPendingState *pending)
-{
-  g_signal_handler_disconnect (buffer, pending->buffer_destroy_handler_id);
-  pending->buffer = NULL;
-}
-
 static void
 pending_state_init (MetaWaylandPendingState *state)
 {
@@ -510,8 +502,9 @@ pending_state_destroy (MetaWaylandPendingState *state)
   g_clear_pointer (&state->opaque_region, cairo_region_destroy);
 
   if (state->buffer)
-    g_signal_handler_disconnect (state->buffer,
-                                 state->buffer_destroy_handler_id);
+    g_object_remove_weak_pointer (G_OBJECT (state->buffer),
+                                  (gpointer *) &state->buffer);
+
   wl_list_for_each_safe (cb, next, &state->frame_callback_list, link)
     wl_resource_destroy (cb->resource);
 }
@@ -528,7 +521,10 @@ move_pending_state (MetaWaylandPendingState *from,
                     MetaWaylandPendingState *to)
 {
   if (from->buffer)
-    g_signal_handler_disconnect (from->buffer, from->buffer_destroy_handler_id);
+    {
+      g_object_remove_weak_pointer (G_OBJECT (from->buffer),
+                                    (gpointer *) &from->buffer);
+    }
 
   to->newly_attached = from->newly_attached;
   to->buffer = from->buffer;
@@ -554,10 +550,8 @@ move_pending_state (MetaWaylandPendingState *from,
 
   if (to->buffer)
     {
-      to->buffer_destroy_handler_id =
-        g_signal_connect (to->buffer, "resource-destroyed",
-                          G_CALLBACK (pending_buffer_resource_destroyed),
-                          to);
+      g_object_add_weak_pointer (G_OBJECT (to->buffer),
+                                 (gpointer *) &to->buffer);
     }
 
   pending_state_init (from);
@@ -913,8 +907,8 @@ wl_surface_attach (struct wl_client *client,
 
   if (surface->pending->buffer)
     {
-      g_signal_handler_disconnect (surface->pending->buffer,
-                                   surface->pending->buffer_destroy_handler_id);
+      g_object_remove_weak_pointer (G_OBJECT (surface->pending->buffer),
+                                    (gpointer *) &surface->pending->buffer);
     }
 
   surface->pending->newly_attached = TRUE;
@@ -924,10 +918,8 @@ wl_surface_attach (struct wl_client *client,
 
   if (buffer)
     {
-      surface->pending->buffer_destroy_handler_id =
-        g_signal_connect (buffer, "resource-destroyed",
-                          G_CALLBACK (pending_buffer_resource_destroyed),
-                          surface->pending);
+      g_object_add_weak_pointer (G_OBJECT (surface->pending->buffer),
+                                 (gpointer *) &surface->pending->buffer);
     }
 }
 

src/wayland/meta-wayland-surface.h

@@ -123,7 +123,6 @@ struct _MetaWaylandPendingState
   /* wl_surface.attach */
   gboolean newly_attached;
   MetaWaylandBuffer *buffer;
-  gulong buffer_destroy_handler_id;
   int32_t dx;
   int32_t dy;