clutter: Do not check redraw area for pointer repicks

This looks like a relic of glReadPixels-based picking, the pointer
might well be outside redrawn areas, yet still require a device
update (e.g. in order to reflect the actor layout changes in the
"clear area" info).

Instead, always update all devices that are inside the view after
relayouts, the tracking on the need for that update is now done
on each ClutterStageView, instead of globally in the ClutterStage.

This theoretically fixes situations where pointers might miss
updating their "clear area" after the actor tree changed.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2117
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2257>

clutter/clutter/clutter-stage-private.h

@@ -75,7 +75,8 @@ void                _clutter_stage_maybe_setup_viewport  (ClutterStage
                                                           ClutterStageView      *view);
 void                clutter_stage_maybe_relayout         (ClutterActor          *stage);
 void                clutter_stage_maybe_finish_queue_redraws (ClutterStage      *stage);
-GSList *            clutter_stage_find_updated_devices   (ClutterStage          *stage);
+GSList *            clutter_stage_find_updated_devices   (ClutterStage          *stage,
+                                                          ClutterStageView      *view);
 void                clutter_stage_update_devices         (ClutterStage          *stage,
                                                           GSList                *devices);
 void                clutter_stage_finish_layout          (ClutterStage          *stage);

clutter/clutter/clutter-stage-view-private.h

@@ -79,4 +79,6 @@ void clutter_stage_view_notify_presented (ClutterStageView *view,
 CLUTTER_EXPORT
 void clutter_stage_view_notify_ready (ClutterStageView *view);
 
+void clutter_stage_view_invalidate_input_devices (ClutterStageView *view);
+
 #endif /* __CLUTTER_STAGE_VIEW_PRIVATE_H__ */

clutter/clutter/clutter-stage-view.c

@@ -93,6 +93,7 @@ typedef struct _ClutterStageViewPrivate
 
   guint dirty_viewport   : 1;
   guint dirty_projection : 1;
+  guint needs_update_devices : 1;
 } ClutterStageViewPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (ClutterStageView, clutter_stage_view, G_TYPE_OBJECT)
@@ -1176,7 +1177,8 @@ handle_frame_clock_frame (ClutterFrameClock *frame_clock,
 
   clutter_stage_finish_layout (stage);
 
-  devices = clutter_stage_find_updated_devices (stage);
+  if (priv->needs_update_devices)
+    devices = clutter_stage_find_updated_devices (stage, view);
 
   frame = CLUTTER_FRAME_INIT;
 
@@ -1200,6 +1202,7 @@ handle_frame_clock_frame (ClutterFrameClock *frame_clock,
   _clutter_stage_window_finish_frame (stage_window, view, &frame);
 
   clutter_stage_update_devices (stage, devices);
+  priv->needs_update_devices = FALSE;
 
   _clutter_run_repaint_functions (CLUTTER_REPAINT_FLAGS_POST_PAINT);
   clutter_stage_emit_after_update (stage, view);
@@ -1522,3 +1525,12 @@ clutter_stage_view_class_init (ClutterStageViewClass *klass)
 
   g_object_class_install_properties (object_class, PROP_LAST, obj_props);
 }
+
+void
+clutter_stage_view_invalidate_input_devices (ClutterStageView *view)
+{
+  ClutterStageViewPrivate *priv =
+    clutter_stage_view_get_instance_private (view);
+
+  priv->needs_update_devices = TRUE;
+}

clutter/clutter/clutter-stage.c

@@ -127,7 +127,6 @@ struct _ClutterStagePrivate
 
   int update_freeze_count;
 
-  gboolean needs_update_devices;
   gboolean pending_finish_queue_redraws;
 
   GHashTable *pointer_devices;
@@ -785,6 +784,19 @@ clutter_stage_dequeue_actor_relayout (ClutterStage *stage,
     }
 }
 
+static void
+clutter_stage_invalidate_views_devices (ClutterStage *stage)
+{
+  GList *l;
+
+  for (l = clutter_stage_peek_stage_views (stage); l; l = l->next)
+    {
+      ClutterStageView *view = l->data;
+
+      clutter_stage_view_invalidate_input_devices (view);
+    }
+}
+
 void
 clutter_stage_maybe_relayout (ClutterActor *actor)
 {
@@ -832,36 +844,33 @@ clutter_stage_maybe_relayout (ClutterActor *actor)
   CLUTTER_NOTE (ACTOR, "<<< Completed recomputing layout of %d subtrees", count);
 
   if (count)
-    priv->needs_update_devices = TRUE;
+    clutter_stage_invalidate_views_devices (stage);
 }
 
 GSList *
-clutter_stage_find_updated_devices (ClutterStage *stage)
+clutter_stage_find_updated_devices (ClutterStage     *stage,
+                                    ClutterStageView *view)
 {
   ClutterStagePrivate *priv = stage->priv;
   GSList *updating = NULL;
   GHashTableIter iter;
   gpointer value;
 
-  if (!priv->needs_update_devices)
-    return NULL;
-
-  priv->needs_update_devices = FALSE;
-
   g_hash_table_iter_init (&iter, priv->pointer_devices);
   while (g_hash_table_iter_next (&iter, NULL, &value))
     {
       PointerDeviceEntry *entry = value;
-      ClutterStageView *view;
+      ClutterStageView *pointer_view;
-      const cairo_region_t *clip;
 
-      view = clutter_stage_get_view_at (stage, entry->coords.x, entry->coords.y);
+      pointer_view = clutter_stage_get_view_at (stage,
-      if (!view)
+                                                entry->coords.x,
+                                                entry->coords.y);
+      if (!pointer_view)
+        continue;
+      if (pointer_view != view)
         continue;
 
-      clip = clutter_stage_view_peek_redraw_clip (view);
+      updating = g_slist_prepend (updating, entry->device);
-      if (!clip || cairo_region_contains_point (clip, entry->coords.x, entry->coords.y))
-        updating = g_slist_prepend (updating, entry->device);
     }
 
   return updating;