[mutter/gnome-3-38] feedback-actor: Add API to set and get geometry scale

[Robert Mader <rmader src gnome org>]

commit 989ef121f6a24b9b5b532610dac3b96fab34bbd3
Author: Robert Mader <robert mader posteo de>
Date:   Fri Jan 22 14:14:50 2021 +0100

    feedback-actor: Add API to set and get geometry scale
    
    Analogous to MetaWindowActor. Also take it into account for positioning
    when an anchor is set.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1683>
    
    (cherry picked from commit dfa659b5b55538652cb13abea1ce10978c98904e)

 src/compositor/meta-feedback-actor-private.h |  5 ++++
 src/compositor/meta-feedback-actor.c         | 36 ++++++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 2 deletions(-)
---
diff --git a/src/compositor/meta-feedback-actor-private.h b/src/compositor/meta-feedback-actor-private.h
index 530bb2dc29..86cacb3607 100644
--- a/src/compositor/meta-feedback-actor-private.h
+++ b/src/compositor/meta-feedback-actor-private.h
@@ -62,4 +62,9 @@ void meta_feedback_actor_set_position (MetaFeedbackActor  *self,
 void meta_feedback_actor_update (MetaFeedbackActor  *self,
                                  const ClutterEvent *event);
 
+void meta_feedback_actor_set_geometry_scale (MetaFeedbackActor *self,
+                                             int                geometry_scale);
+
+int meta_feedback_actor_get_geometry_scale (MetaFeedbackActor *self);
+
 #endif /* META_FEEDBACK_ACTOR_PRIVATE_H */
diff --git a/src/compositor/meta-feedback-actor.c b/src/compositor/meta-feedback-actor.c
index c8eb0fcac0..d3277ec3aa 100644
--- a/src/compositor/meta-feedback-actor.c
+++ b/src/compositor/meta-feedback-actor.c
@@ -44,6 +44,8 @@ struct _MetaFeedbackActorPrivate
   float anchor_y;
   float pos_x;
   float pos_y;
+
+  int geometry_scale;
 };
 
 G_DEFINE_TYPE_WITH_PRIVATE (MetaFeedbackActor, meta_feedback_actor, CLUTTER_TYPE_ACTOR)
@@ -65,8 +67,10 @@ meta_feedback_actor_update_position (MetaFeedbackActor *self)
   MetaFeedbackActorPrivate *priv = meta_feedback_actor_get_instance_private (self);
 
   clutter_actor_set_position (CLUTTER_ACTOR (self),
-                              priv->pos_x - priv->anchor_x,
-                              priv->pos_y - priv->anchor_y);
+                              priv->pos_x -
+                              (priv->anchor_x * priv->geometry_scale),
+                              priv->pos_y -
+                              (priv->anchor_y * priv->geometry_scale));
 }
 
 static void
@@ -249,3 +253,31 @@ meta_feedback_actor_update (MetaFeedbackActor  *self,
   clutter_event_get_position (event, &point);
   meta_feedback_actor_set_position (self, point.x, point.y);
 }
+
+void
+meta_feedback_actor_set_geometry_scale (MetaFeedbackActor *self,
+                                        int                geometry_scale)
+{
+  MetaFeedbackActorPrivate *priv =
+    meta_feedback_actor_get_instance_private (self);
+  CoglMatrix child_transform;
+
+  if (priv->geometry_scale == geometry_scale)
+    return;
+
+  priv->geometry_scale = geometry_scale;
+
+  cogl_matrix_init_identity (&child_transform);
+  cogl_matrix_scale (&child_transform, geometry_scale, geometry_scale, 1);
+  clutter_actor_set_child_transform (CLUTTER_ACTOR (self),
+                                     &child_transform);
+}
+
+int
+meta_feedback_actor_get_geometry_scale (MetaFeedbackActor *self)
+{
+  MetaFeedbackActorPrivate *priv =
+    meta_feedback_actor_get_instance_private (self);
+
+  return priv->geometry_scale;
+}