Hey Joel,
Its not currently possible to create a UAna ChuGin, though
this is something we are definitely considering for the
future. If it were me doing this right now I would buffer FFT
frames internally in a UGen and spit out pitches from a member
function or variable as they become available. You would
probably have to write your own FFT (or use code/a library
from somewhere else), which is sort of lame/inefficient from a
software design perspective, given that ChucK already has its
own FFT implementation built-in.
That being said, I think a dependable, go-to pitch tracker
would be a great addition to ChucK's chugin library, so please
keep us posted on your work and we would be happy to help with
any general guidance or specific questions. This is the kind
of use case we want to make easy, or at least not
unnecessarily cumbersome.
Im planning to write a solid chugin tutorial some time in
the next month or so, but for now, yes, the paper and the
source code are the primary documentation. A good portion of
ChucK's internal ugens/libraries use the ChuGin-style API (but
are compiled in statically of course). So the ChucK source
tends to have more breadth in showing how the system works
than most of the existing chugins, which are generally pretty
simple.
spencer