Re: [Swig-user] OpenCV + my C++ code --> usable from Python

[Guy K. K. <G....@ma...>]

On Friday 27 April 2007 7:11:50 am John Lenz wrote:
> I don't really understand all the details you are explaining, but I
> suspect you are looking for typemaps.
>
> See, the way a pointer to some C++ class is stored in a python object is
> probably different between SWIG and the native cv. =A0It might be encoded
> inside a python integer inside some class, or embedded into a string or
> something.

That's why I'm eager to use the existing OpenCV SWIG binding interfaces. If=
 I=20
use them (correctly), then I shouldn't have any problem in accessing/passin=
g=20
the types as they should undergo the same type of mapping.

> So by default, SWIG assumes the pointer is encoded in its own format.
> This is done by the functions SWIG_Python_NewPointerObj and
> SWIG_Python_MustGetPtr, which appear near the top of a _wrap.cxx output
> file.
>
> What I think you will need to do is write a typemap that extracts the
> C++ pointer from the python format cv uses.

Well, I don't want to re-solve the problem that has been solved initially=20
creating those OpenCV bindings already.

Maybe the question could be re-phrased:

"""
I've got an already SWIG-wrapped (to Python) library libfoo I'm also using =
in=20
native C++ code, which presents custom types.

How can I expose self created functions/methods using these types as=20
parameters or return values consistently to python, preferably using the=20
existing SWIG interfaces?
"""

Guy

=2D-=20
Guy K. Kloss
Institute of Information and Mathematical Sciences
Room 2.63, Quad Block A Building
Massey University, Auckland, Albany
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