--- a/Framework/Viewport/ViewportBase.cpp	Thu Oct 10 14:37:23 2019 +0200
+++ b/Framework/Viewport/ViewportBase.cpp	Thu Oct 10 15:24:48 2019 +0200
@@ -45,10 +45,18 @@
   }
   
 
-  ScenePoint2D ViewportBase::GetPixelCenterCoordinates(int x, int y) const
+  ScenePoint2D ViewportBase::GetPixelCenterCoordinates(int x, int y)
   {
-    return ScenePoint2D(
-      static_cast<double>(x) + 0.5 - static_cast<double>(GetCanvasWidth()) / 2.0,
-      static_cast<double>(y) + 0.5 - static_cast<double>(GetCanvasHeight()) / 2.0);
+    if (HasCompositor())
+    {
+      const ICompositor& compositor = GetCompositor();
+      return ScenePoint2D(
+        static_cast<double>(x) + 0.5 - static_cast<double>(compositor.GetCanvasWidth()) / 2.0,
+        static_cast<double>(y) + 0.5 - static_cast<double>(compositor.GetCanvasHeight()) / 2.0);
+    }
+    else
+    {
+      return ScenePoint2D(0, 0);
+    }
   }
 }