Cython - implementing callbacks

Question

I have been working with Cython in an attempt to interface with a library written in c++. So far things are going pretty good, and I can effectively use MOST functions within th

Answer 1

If you can modify the library to define:

typedef void (*Function1)(const uint16_t *data, 
                          unsigned width, unsigned height,
                          void *user_data);
void SetCallBack(Function1, void*);

instead, I fear you are out of luck. If you have the void*, than you define a function that calls a python callable object with correct arguments and SetCallBack with this function and the python callable.

If you can't, but the callback is global (it seems to be), you can create a global variable to store the python object in. Than you'd again create a function to call the python object and pass it to SetCallBack and your PySetCallback would just set the global and ensure proper function is registered.

If the callback is context-specific, but you have no way to pass it a "user data" pointer, I fear you are out of luck here.

I know python and C++, but not cython, so I don't know whether you can create the function in cython, or whether you'd have to write in C++.