diff --git a/src/compositor/clutter-utils.c b/src/compositor/clutter-utils.c
index 86d788562..95839c2df 100644
--- a/src/compositor/clutter-utils.c
+++ b/src/compositor/clutter-utils.c
@@ -69,8 +69,7 @@ gboolean
 meta_actor_vertices_are_untransformed (graphene_point3d_t *verts,
                                        float               widthf,
                                        float               heightf,
-                                       int                *x_origin,
-                                       int                *y_origin)
+                                       MetaTransforms     *out_transforms)
 {
   int width, height;
   int v0x, v0y, v1x, v1y, v2x, v2y, v3x, v3y;
@@ -90,6 +89,14 @@ meta_actor_vertices_are_untransformed (graphene_point3d_t *verts,
   x = v0x >> 8;
   y = v0y >> 8;
 
+  if (out_transforms)
+    {
+      out_transforms->x_origin = x;
+      out_transforms->y_origin = y;
+      out_transforms->x_scale = (v1x - v0x) / (float) width;
+      out_transforms->y_scale = (v2y - v0y) / (float) height;
+    }
+
   /* At integral coordinates? */
   if (x * 256 != v0x || y * 256 != v0y)
     return FALSE;
@@ -103,11 +110,6 @@ meta_actor_vertices_are_untransformed (graphene_point3d_t *verts,
       v3x != v1x || v3y != v2y)
     return FALSE;
 
-  if (x_origin)
-    *x_origin = x;
-  if (y_origin)
-    *y_origin = y;
-
   return TRUE;
 }
 
@@ -137,8 +139,7 @@ meta_actor_painting_untransformed (CoglFramebuffer *fb,
                                    int              paint_height,
                                    int              sample_width,
                                    int              sample_height,
-                                   int             *x_origin,
-                                   int             *y_origin)
+                                   MetaTransforms  *out_transforms)
 {
   graphene_matrix_t modelview, projection, modelview_projection;
   graphene_point3d_t vertices[4];
@@ -183,6 +184,6 @@ meta_actor_painting_untransformed (CoglFramebuffer *fb,
 
   return meta_actor_vertices_are_untransformed (vertices,
                                                 sample_width, sample_height,
-                                                x_origin, y_origin);
+                                                out_transforms);
 }
 
diff --git a/src/compositor/clutter-utils.h b/src/compositor/clutter-utils.h
index 8ed0e2a4d..921551aaf 100644
--- a/src/compositor/clutter-utils.h
+++ b/src/compositor/clutter-utils.h
@@ -23,18 +23,21 @@
 
 #include "clutter/clutter.h"
 
+typedef struct {
+  int x_origin, y_origin;
+  float x_scale, y_scale;
+} MetaTransforms;
+
 gboolean meta_actor_vertices_are_untransformed (graphene_point3d_t *verts,
                                                 float               widthf,
                                                 float               heightf,
-                                                int                *x_origin,
-                                                int                *y_origin);
+                                                MetaTransforms     *out_transforms);
 
 gboolean meta_actor_painting_untransformed (CoglFramebuffer *fb,
                                             int              paint_width,
                                             int              paint_height,
                                             int              sample_widthf,
                                             int              sample_heightf,
-                                            int             *x_origin,
-                                            int             *y_origin);
+                                            MetaTransforms  *out_transforms);
 
 #endif /* __META_CLUTTER_UTILS_H__ */
diff --git a/src/compositor/meta-background-content.c b/src/compositor/meta-background-content.c
index 2e8c923b4..e472c3c5d 100644
--- a/src/compositor/meta-background-content.c
+++ b/src/compositor/meta-background-content.c
@@ -548,7 +548,7 @@ setup_pipeline (MetaBackgroundContent *self,
                                          actor_pixel_rect->height,
                                          self->texture_width,
                                          self->texture_height,
-                                         NULL, NULL))
+                                         NULL))
     {
       min_filter = COGL_PIPELINE_FILTER_NEAREST;
       mag_filter = COGL_PIPELINE_FILTER_NEAREST;
diff --git a/src/compositor/meta-cullable.c b/src/compositor/meta-cullable.c
index 6f38c5e47..e306c56e2 100644
--- a/src/compositor/meta-cullable.c
+++ b/src/compositor/meta-cullable.c
@@ -175,7 +175,7 @@ meta_cullable_default_is_untransformed (MetaCullable *cullable)
   clutter_actor_get_abs_allocation_vertices (CLUTTER_ACTOR (cullable), verts);
 
   return meta_actor_vertices_are_untransformed (verts, width, height,
-                                                NULL, NULL);
+                                                NULL);
 }
 
 static void
diff --git a/src/compositor/meta-shaped-texture.c b/src/compositor/meta-shaped-texture.c
index d7cba799e..29a6b1c90 100644
--- a/src/compositor/meta-shaped-texture.c
+++ b/src/compositor/meta-shaped-texture.c
@@ -712,7 +712,7 @@ do_paint_content (MetaShapedTexture   *stex,
   if (meta_actor_painting_untransformed (framebuffer,
                                          dst_width, dst_height,
                                          sample_width, sample_height,
-                                         NULL, NULL))
+                                         NULL))
     filter = COGL_PIPELINE_FILTER_NEAREST;
   else
     filter = COGL_PIPELINE_FILTER_LINEAR;
diff --git a/src/compositor/meta-surface-actor.c b/src/compositor/meta-surface-actor.c
index c2bf6696a..fcd94b86d 100644
--- a/src/compositor/meta-surface-actor.c
+++ b/src/compositor/meta-surface-actor.c
@@ -331,7 +331,7 @@ meta_surface_actor_is_untransformed (MetaCullable *cullable)
   return meta_actor_vertices_are_untransformed (verts,
                                                 width * geometry_scale,
                                                 height * geometry_scale,
-                                                NULL, NULL);
+                                                NULL);
 }
 
 static void
diff --git a/src/compositor/meta-window-group.c b/src/compositor/meta-window-group.c
index 16ff2db09..c6af609ae 100644
--- a/src/compositor/meta-window-group.c
+++ b/src/compositor/meta-window-group.c
@@ -92,6 +92,7 @@ meta_window_group_paint (ClutterActor        *actor,
     {
       CoglFramebuffer *fb;
       ClutterStageView *view;
+      MetaTransforms trans;
 
       fb = clutter_paint_context_get_framebuffer (paint_context);
       view = clutter_paint_context_get_stage_view (paint_context);
@@ -102,13 +103,15 @@ meta_window_group_paint (ClutterActor        *actor,
                                               screen_height,
                                               screen_width,
                                               screen_height,
-                                              &paint_x_origin,
-                                              &paint_y_origin) ||
+                                              &trans) ||
           !meta_cullable_is_untransformed (META_CULLABLE (actor)))
         {
           parent_actor_class->paint (actor, paint_context);
           return;
         }
+
+      paint_x_origin = trans.x_origin;
+      paint_y_origin = trans.y_origin;
     }
   else
     {