[Flightgear-devel] GPS/FMS/route-manager changes

[James T. <zak...@ma...>]

I'm planning various enhancements to the GPS and route manager code in  
the next few weeks and months, and would appreciate any feedback or  
criticism people might have, especially from people using the code in  
ways I might not have expected.

In summary, I'm planning to make the route-manager more 'abstract',  
i.e remove the GPS-like functions it currently has (time to next  
waypoint), etc. At the same time I'll make the GPS a mandatory  
instrument, and change the GPS code to use the route manager  
waypoints. This should make the route-manager and GPS code usable in  
far more aircraft to drive a CDI/HSI gauge.

I'm going to update the route-manger to have a 'current waypoint', and  
no longer pop waypoints once they are reached - instead the current  
waypoint will be incremented. This will enable the route-manager to  
drive the leg/flight-plan mode of the GPS more easily, and also permit  
me to show the active route on my work-in-progress NAV display.

Once these basics are done I will extend the GPS with a Nasal  
interface and various standard things it's currently lacking - closest  
VOR tracking, and proper 'direct to' and 'nearest' modes.

Once the above is done I plan to deprecate all of the existing DCLGPS  
code, and re-create the KLN89b as a generic 3D instrument using Nasal.  
I'm happy to work with anyone to create other GPS units - hopefully  
they will all be doable with a Nasal layer on top of the generic GPS  
code, and the Nasal interface can be extended as necessary to make  
this work.

Assuming all the above is done, the next step will be adding even more  
functions to enable a real FMS to be created, again in Nasal with  
support functions in C++.

I would appreciate help on the instrument side - I know Syd has  
created parts of the KLN90 for the B1900, and I'll keep that working  
and hopefully enhance it in parallel with the KLN89B work. The two  
seem to share an awful lot of functionality, so some Nasal reuse is  
probably possible as well.

I've created a wiki page to track the things I'm currently working on:

http://wiki.flightgear.org/index.php/Plan-zakalawe

Regards,
James