[vtkusers] vtkAngleWidget and Zoom: Bug or bad integrated into app?

[Martin Raabe]

Hello folks,
I use vtk 5.10.1 for C++ on a PC, where I integrated both widgets:

 - vtkAngleWidget
 - vtkDistanceWidget

When I position both widgets, everything behaves as expected. The angle
and distance are rendered.
When I zoom in or out using the scroll wheel, everything behaves as
expected. The angle and distance are rendered and the cross hairs are
fixed to the world coordinates.

But when I now drag a cross hair, things change, when I zoom in or out:
 - distance: cross hairs stay in place regarding the *world* coordinates
 - *angle*:
   *cross hair NOT dragged* stay in place regarding the *world* coordinates
   *DRAGGED cross hair* stay in place regarding the *display* coordinates

Is this a *known bug* or did I miss something on using it in my application?

Please help me finding out.

Regards

Martin Raabe