[vtk-developers] Changes to the way the pipeline is updated

Sean McBride sean at rogue-research.com
Tue Mar 1 12:39:34 EST 2016


On Fri, 15 Jan 2016 10:57:36 -0500, Berk Geveci said:

>In an effort to address a bug reported on the mailing list, I ended up
>making a change to the way the pipeline is updated. I made a minor change
>to the way update behaves but more importantly, I'd like to make an API
>change that is biggish.

Berk,

After rebuilding my app with VTK master I've run into this.

I just went through the change with git show f020ebb6 and had 2 comments on the code change:

1) Did you mean to commit that commented code in Accelerators/Piston/vtkPistonMapper.cxx ?

2) 

+The following new methods were added:
+
+### vtkAlgorithm:
+
+    int Update(int port, vtkInformationVector* requests);
+    int Update(vtkInformation* requests);
+    int UpdatePiece(int piece, int numPieces, int ghostLevels, int* extents=0);
+    int UpdateExtent(int piece, int numPieces, int ghostLevels, int* extents=0);
+    int UpdateTimeStep(double time,
+        int piece=-1, int numPieces=1, int ghostLevels=0, int* extents=0);

Couldn't those 'extents' params be const?  I know many VTK API are not very const friendly, but seems a shame to perpetuate that with new API.

>Here is how an algorithm is updated currently.
>
>anAlgorithm->Update();
>
>If you want the algorithm to produce a particular subset in space or time,
>you need to do this:
>
>anAlgorithm->UpdateInformation();
>anAlgorithm->SetUpdateExtent(0, 2, 0);
>anAlgorithm->SetUpdateExtent(0, 10, 0, 10, 1, 1);
>anAlgorithm->SetUpdateTimeStep(0.5);
>anAlgorithm->Update();

My app has a few of this pattern:

 slicer->UpdateInformation();
 slicer->SetUpdateExtentToWholeExtent();
 slicer->Update();

do I understand correctly that I can now just do:

 slicer->UpdateWholeExtent();

>Here is the branch that passes all of the tests:
>
>https://gitlab.kitware.com/berkgeveci/vtk/commits/setupdateextent-change

Shame that link is dead just 6 weeks later.  Makes it harder to research what/when changes broke things... :(

Thanks,

-- 
____________________________________________________________
Sean McBride, B. Eng                 sean at rogue-research.com
Rogue Research                        www.rogue-research.com 
Mac Software Developer              Montréal, Québec, Canada




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