Re: [Pyobjc-dev] VTK bindings

[Carlos P. <ca...@ci...>]

On Dec 3, 2003, at 4:59 AM, Jack Jansen wrote:

>
> On 2 Dec 2003, at 18:38, Ronald Oussoren wrote:
>> The problem is that PyObjCPointer is a not really a wrapped pointer, 
>> when the PyObjCPointer object is created the value pointed-to is 
>> copied into an internal buffer. Most of the time that doesn't work, 
>> vtkRenderer is probably a C++ class and the copied value is invalid.
>>
>> I'll put creation of a real pointer wrapper on my todo-list, a 
>> generic version of the types used to wrapped some other pointer types 
>> (see pointer-support.m).
>
> Isn't cobject what you want here? It just gives you an opaque Python 
> wrapper around a C pointer, but it looks like that could be good 
> engouh.

Actually, ideally I would be able to interact with the C++ objects 
pointed to using the already existing python wrappers. I'm not sure how 
this could be done though.

What I have are objective-c++ files containing objective-c classes with 
methods which take and return pointers to c++ classes. VTK has its own 
python wrappers for these c++ classes. This allows for easy 
construction of rendering pipelines. I could wrap the c++ classes in 
objective-c and then wrap the new objective-c classes in python through 
PyObjC. However, this would not allow me to interact with the c++ 
classes directly in python using VTK python classes which is what I 
want to do.

So ideally I would like to be able to see the c++ classes taken and 
returned by my objective-c classes as VTK python wrapper objects.

Example:
An unwrapped objective-c++ class VTKView has the following method.
-(vtkRenderer *)renderer;

vtkRenderer is a c++ class. There is python wrapper class by the same 
name. I would like to wrap and/or alter VTKView so that I can do the 
following in Python:

v = VTKView.alloc().init()
v.renderer().AddActor(...)

or be able to use v.renderer() as an argument to some python wrapped 
VTK method.