Headtracking protocols question for the developers

[stupor-mundi]

I'm trying to improve my headtracking, by plugging FreePIE in between Opentrack and IL-2 Great Battles:

Opentrack -> FreePIE -> IL-2

Until now, I've just used Opentrack with "freetrack 2.0 Enhanced" output, which IL-2 just recognized, no config was necessary.

What I'm trying to do is along the lines of this video https://youtu.be/DREkyWxBJtg  , where FreePIE consumes freetrack output from Opentrack, and produces TrackIR output, like this:

trackIR.y = freeTrack.y

which means in FreePIE there is the opportunity to do some calculations.

I've poked around a bit but I can't make progress because I don't know which headtracking protocol IL-2 prefers if multiple are availble.

Opentrack has multiple output protocols, and FreePIE can handle various input protocols and write to various output protocols.

A limitation of FreePIE seems to be that you can't necessarily

freetrack -> FreePIE -> freetrack

(it's been difficult to find info about this aspect)

I've looked into startup.cfg and found nothing about headtracking. It would be ideal if I could configure IL-2 which headtracking protocol to use, but, failing that, it would help to know which headtracking protocol IL-2 will default to (i.e. read, preferrentially), if multiple of them are present.

Ideally I would set the output of Opentrack to some protocol that IL-2 doesnt recognise, but that FreePIE can use as input, and set the FreePIE output to a protocol that IL-2 will use by default.