Re: [Opengc-devel] multiple data sources?

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

Hmmm... I guess I'm not entirely sure what you're trying to do, so let 
me know if this is any help:

There can only be one data source in a render object; this is because 
it's impossible to override the m_pDataSource member on a per-object 
basis, because it's a static member variable - see the first bit of 
main.cpp, the statics are initialized as:

ogcDataSource* ogcRenderObject::m_pDataSource = 0;

It was designed this way to avoid having to explicitly set the render 
window, data source, and font manager in each subclass of RenderObject, 
since there are so many of them.

Now, there is nothing to prevent you from adding specific network 
functionality to a particular gauge, it would just have to be done 
internally with a different data source name (e.g. m_TCASDataStream). 
You would also probably _not_ want to derive it from the DataSource 
base class, since it's assumed that all data sources are capable of 
providing roughly the same information, and yours provides very 
specific information.

My suggestion would just be to add network socket functionality to your 
version of the nav gauge, that would execute each time a render call 
came through. That way, all of the network traffic occurs locally and 
is only visible to your code.

Does this answer your question?

Cheers,
-Damion-

> I am trying to add another data source, specifically to the
> NavTestGauge, but it isn't working.

---------
Damion Shelton
Carnegie Mellon University, Robotics Institute
A408-o Newell Simon Hall
412.268.3866 (office)
412.818.8829 (cell)
412.268.6436 (fax)
http://www.cs.cmu.edu/~beowulf
---------
I hope that after I die, people will say of me: "That guy sure owed me 
a lot of money."