[vtkusers] Changes in class hierarchy 4.0 - 4.2

[Roman Putanowicz]

Hi,

I tried to compile my old program written for VTK 4.0 and compilation 
failed. I have found out that this is related to the change
in class hierarchy, specifically to the class vtkSampleFunction.
In VTK 4.0 vtkSampleFunction is  derived from vtkStructuredPointsSource
and in VTK4.2 it is derived from vtkImageSource.

Because of the above there is a change in the return type of the
method GetOutput. In the 4.0 it is vtkStructuredPoints and
in 4.2 it is vtkImageData.

I looked to the FAQ but did not find the change in the section
related the the differences between 4.0 and 4.2.
Is this the exceptional change or are more changes of this sort
in 4.2?
I found some posting related to the change of vtkSampleFunction API
http://public.kitware.com/pipermail/vtk-developers/2002-June/001645.html
but it does not explain the above.

What are the reasons behind that change ?

Romek


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    _/_/_/       _/     _/       _/_/_/_/_/    Roman Putanowicz 
  _/            _/     _/           _/         Inst.Comp.Meth.Civ.Eng.
 _/            _/     _/           _/          tel +48 12  628 2569
 _/_/_/racow   _/_/_/niversity of _/echnology  putanowr at twins.pk.edu.pl