[Insight-users] Wrapping a custom C++ function in Python

[Julien Lamy]

Gaëtan Lehmann a écrit :
> 
> Le 9 juin 09 à 11:44, Julien Lamy a écrit :
> 
>> Gaëtan Lehmann a écrit :
>>> Le 8 juin 09 à 15:12, Julien Lamy a écrit :
>>>>
>>>> I'm trying to wrap a simple C++ function in Python using WrapITK, 
>>>> but the Python script fails with the following traceback :
>>>> TypeError: in method 'test_wrapper', argument 1 of type 'itk::Image< 
>>>> unsigned short,3 > *'
>>>>
>>>> My C++ function is :
>>>>
>>>>   bool test_wrapper(itk::Image<unsigned short, 3>::Pointer input)
>>>>   {
>>>>       std::cout << input->GetRequestedRegion().GetSize() << std::endl;
>>>>   }
>>>>
>>>> My Python script is :
>>>>   import numpy
>>>>   import itk
>>>>   from Wrapper import test_wrapper
>>>>
>>>>   data = numpy.arange(3*5*7, dtype=numpy.uint16).reshape((3,5,7))
>>>>   image_itk = itk.PyBuffer[itk.Image[itk.US, 
>>>> 3]].GetImageFromArray(data)
>>>>   test_wrapper(image_itk)
>>>>
>>>> My SWIG wrapper is :
>>>>
>>>>   %module Wrapper
>>>>   %{
>>>>   #include "test_Wrapper.hpp"
>>>>   %}
>>>>
>>>>   bool test_wrapper(itk::Image<unsigned short, 3> * input);
>>> this last line should be
>>>  bool test_wrapper(itkImageUS3 * input);
>>> and you have to #include Base.includes (located at 
>>> /usr/local/lib/InsightToolkit/WrapITK/Configuration/Typedefs/Base.includes 
>>> on my system), to %include wrap_itkImage.i 
>>> (/usr/local/lib/InsightToolkit/WrapITK/Configuration/Typedefs/wrap_itkImage.i). 
>>>
>>
>> I'm missing both files. There is actually no trace of a 
>> WrapITK/Configuration/Typedefs directory on my system, either in the 
>> source, build or installation directories. I compiled ITK 3.14.0 from 
>> source with the following cmake command :
>> cmake -D BUILD_EXAMPLES=OFF -D BUILD_SHARED_LIBS=ON -D 
>> BUILD_TESTING=OFF \
>>      -D CMAKE_BUILD_TYPE=Release \
>>      -D CMAKE_INSTALL_PREFIX=MY_LOCAL_DIR \
>>      -D ITK_USE_REVIEW=ON \
>>      -D USE_WRAP_ITK=ON \
>>      -D PY_SITE_PACKAGES_PATH=MY_LOCAL_DIR/lib/python2.5/site-packages \
>>      -D WRAP_ITK_JAVA=OFF -D WRAP_ITK_TCL=OFF \
>>      ../InsightToolkit-3.14.0
>>
> 
> Sorry, my mistake.
> I thought you were using wrapitk from google code, because you have 
> listed swig in your programs, but I realize that you are using it only 
> for your own project.
> You can't do that with wrapitk shipped with itk. I think the only way to 
> go is to use an external project.
> 
> 
>> I looked through the CMake options, but I found nothing related to 
>> wrapping and typedefs. I'll give a try to the packages listed on your 
>> code.google.com page and see if I can come up with something.
>>
> 
> Let me know if you found any problem.

I first tried the Ubuntu 9.04 (Jaunty) packages from the repository 
listed on Google Code, but couldn't use them due to the SWIG 1.3.38/ 
Python 2.6 bug. So I got the SVN version (the new version of the 
callbacks is great, btw), and finally achived what I wanted following 
your advice on file inclusion. My SWIG file is now :
%module Wrapper
%{
#include "Base.includes"

#include "test_Wrapper.hpp"
%}

bool test_wrapper(itkImageUS3 * input);

I did not %include wrap_itkImage.i, as this caused errors when running 
the Python script.

Thanks for your help.
-- 
Julien