have a "property" mode as well as the original "binary" mode. The property mode
will allow the remote module to request any set of properties, and it will send
those properties each frame. The remote module can reply with a list of arbitrary
property name/value pairs to update on the FlightGear side.
This is a first stab, so it's not the cleanest, most well concieved code, but it
allows an external module (communicating via a pipe) to have a huge amount of
flexibility in the data in can access and update.
I have added a fledgling replay system that records flight data and control
positions during the flight.
I have added an internal command called "replay" which will trigger a replay
of the entire saved flight data set. This could be bound to a keyboard or
menu command, in fact this entire module is screaming for someone to build
a gui to control playback speed, amount of playback, etc.
This is the initial version so there are kinks that still need to be worked
out, please be patient.
FGExternalPipe is destructed.) This leaves the name pipe hanging around
even after flightgear exits, but assuming we put the files in /tmp that
shouldn't be a big deal.
ExternalNet interface:
- allows a much more closely coupled execution. A remote network FDM will run
at it's own rate, and maybe a particular data packets will come, maybe it
won't. This makes it very hard to control timing and keep the animation
smooth. There are also cpu scheduling issues with running multiple
processes on a single machine. The linux scheduler by default runs at
100hz. If an FDM process uses a sleep/alarm system to avoid wasting
CPU, it will be forced to run at 100hz, 50hz, 25hz, 20hz, etc. This
makes it *impossible* to serve a display system running at 60hz without
dropping frames.
- the downside is that the FDM process must now run on the same machine as
the master flightgear process.
