[vtkusers] deallocating objects within functions

[Adrian Albert]

Hi


thanks for the tip! I will try this as soon as possible.

Adrian

On Wed, Apr 23, 2008 at 3:14 AM, Mike Jackson <imikejackson at gmail.com>
wrote:

> Look at vtkSmartPointer.h. Basically you use one of these to wrap your
> object and when it goes out of scope your object will get deleted for you.
>
> vtkStructuredPoints* GetField (int index)
> {
> vtkSmartPointer< vtkImageExtractComponents > extr = vtkSmartPointer<
> vtkImageExtractComponents >::New();
>    extr->SetInput (this->GetInputField ());
>    extr->SetComponents (index);
>    extr->Update ();
> vtkStructuredPoints* pts = xtr->GetOutput ();
> pts->Register(NULL)
>    return pts;
> }
>
> Note, that pts will have a ref count of 1 by the time it returns to the
> calling function. When the calling function is done with "pts", it should
> call pts->Delete();.
>
> Hope that helps.
> --
> Mike Jackson   Senior Research Engineer
> Innovative Management & Technology Services
>
>
>
> On Apr 22, 2008, at 6:32 PM, Adrian Albert wrote:
>
>  Dear All,
> >
> > I have a small problem in vtk: I have a class (not derived from any VTK
> > object) that has methods for dealing with vtkImageData in various ways. For
> > example, I am extracting one scalar component from a multi-component
> > vtkImageData object using this function
> >
> > vtkStructuredPoints* GetField (int index)
> > {
> >    vtkImageExtractComponents *extr = vtkImageExtractComponents::New ();
> >    extr->SetInput (this->GetInputField ());
> >    extr->SetComponents (index);
> >    extr->Update ();
> >    return (vtkStructuredPoints*) (extr->GetOutput ());
> > }
> >
> > I am wondering if there is a problem with deallocating the extr object
> > in the above function. I obviously cannot manually call Delete () on it,
> > since I must use it for returning my output. Is the Delete () method
> > automatically called when returning from the function to the calling
> > routine? How 'big' is the extr object? Is it of the same size as the input
> > to the vtkImageExtractComponents filter?
> >
> > Thanks for taking the pain in reading this!
> > Adrian
> > --
> > ---------------------------------------------------
> > Adrian Albert
> > School of Engineering and Science
> > Jacobs University Bremen
> > Germany
> > Tel.: 00494212003258
> > _______________________________________________
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>
>


-- 
---------------------------------------------------
Adrian Albert
School of Engineering and Science
Jacobs University Bremen
Germany
Tel.: 00494212003258
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