[Opengc-devel] Re: [Opengc-announce] like to use instruments for my own simulation - where do i start?

[Damion S. <be...@cs...>]

Hi,

> My question to you developer guys is which components do I need from 
> the source code to simply draw a glass cockpit, that is driven with my 
> simulation data ?

This depends on whether you want to have the rendering occur within 
your code or in a separate program. Either way will work, but the 
approach would be different:

Common to either approach - classes derived from ogcDataSource are 
responsible for handling the acquisition of data from the simulator. 
You will need to write a data source that can interface with your 
computer vision code; exactly how this will be done depends on your 
system. I would strongly suggest using network communications (probably 
UDP format) as this will result in the most portable system - any 
computer that can hook up to your vision machine with an ethernet cable 
will be able to read data. Look at the X-Plane data source for an 
example of how UDP programming is done with the Plib library used by 
OpenGC.

Within your code - you need to perform OpenGL window management in a 
way similar to that done in ogcRenderWindow. The gauges are, for the 
most part, coded in pure OpenGL and therefore don't actually care about 
the specifics of window management. Keep in mind that you will need to 
preserve the overall framework of OpenGC. For instance the AppObject 
class allows event messages to be passed between objects, so your code 
would need to replicate this behavior.

Separate program - this is by the far the simplest approach. Write your 
data source in OpenGC to accept UDP network packets that are broadcast 
from you vision machine and translate them to the internal DataSource 
format. This is quite similar to how the existing data sources work. In 
this scheme, OpenGC can be run on any networked machine connected to 
the sim, or even on the sim machine itself with the network configured 
in "loopback" mode.

To summarize: I suggest keeping OpenGC as a separate program, adding 
UDP broadcast to your vision system, and writing a new data source 
(using X-Plane as an example). Keep in mind that the X-Plane data 
source is an example only; it does some slightly strange variable 
casting to deal with the floating point format so don't follow it 
exactly!

If you have any more questions feel free to ask (though I'd suggest 
using the devel instead of announce list).

Cheers,
-Damion-
---------
Damion Shelton
The Open Source Glass Cockpit Project (OpenGC)
Carnegie Mellon University, Robotics Institute
http://www.opengc.org
da...@op...