I'm trying to use libfluidsynth with ruby ffi and need to iterate over a soundfont to get all instruments. Specifically, the _fluid_sfont_t struct has iteration_start and iteration_next references that I need to call:
http://fluidsynth.sourceforge.net/api/struct__fluid__sfont__t.html
void (*iteration_start)(fluid_sfont_t* sfont);
I saw in the ffi/ffi documentation how to reference members of a struct where those members were normal types and I saw how to set callbacks in C to point to ruby Procs. However I need to call a function referenced by a function pointer on a struct.
How can this be done?