[Insight-developers] WrapITK and Transform I/O

[Magnotta, Vincent A]

I have a question about WrapITK and working with the itkTransformFileReader. I am currently testing some functions in Tcl and have come against a wall. I have been able to get the itkTransformFileReader to load an ITK transform to disk. I can get the output of the filter using  GetTransformList. However, I am unable to work with this list because the class std::list<itk::TransformBase::Pointer> is not wrapped. I have  modified SwigExtras.i wrap_SwigExtras.h to include a new template type.

I added the following code to SwigExtras.i

  template<> class list<itk::TransformBase::Pointer> {
    // add specialized typemaps here
  public:
    list();
    unsigned int size() const;
    bool empty() const;
    void clear();
    void push_back(itk::TransformBase::Pointer x); 
    %extend {
      itk::TransformBase::Pointer get(int i) 
        {
        std::list<itk::TransformBase::Pointer>::iterator j = self->begin();
        while(i)
          {
          j++;
          i--;
          }
        return *j;
        }
    }
.
.
.
%template(TransformBaseList) std::list<itk::TransformBase::Pointer>;

and in wrap_SwigExtras.h I added 

typedef std::list<itk::TransformBase::Pointer> TransformBaseList;

in the namespace renames section. When I load InsightToolkit in Tcl I can see the newly wrapped class 

% TransformBaseList
_00e4f90c_p_std__listTitk__TransformBase__Pointer_t

However, when I get an error running the following set of commands
% set tt [itkTransformFileReader_New]
% $tt SetFileName Test.xfm
% $tt Update
% set ts [$tt GetTransformList]
% $ts 
invalid command name "_f4bbf80c_p_std__listTitk__SmartPointerTitk__TransformBase_t_std__allocatorTitk__SmartPointerTitk__TransformBase_t_t_t"

I am assuming that the wrapping of ITK works differently from the SwigExtras code since the Itk wrapping has a itk__SmartPointer within the returned name. Is there a way to wrap the std::list<itk::TransformBase::Pointer> such that the TransformFileReader can be used from the wrapped language?

Thanks,
Vince

----------------------
Assistant Professor 
Department of Radiology 
0453-D JCP 
200 Hawkins Drive 
Iowa City, IA 52242 
E-mail: vincent-magnotta at uiowa.edu 
Phone: 319-356-8255 Fax: 319-353-6275 
Website: http://www.radiology.uiowa.edu