[Opengc-devel] code refactoring progress

[Damion S. <da...@op...>]

Hi,

A quick update as to where I am on the "rewrite", and how things are 
shaping up.

1) The CMake build process has been extensively overhauled. The paths 
to the various external libraries are now either determined 
automatically, or are prompted for in the GUI/TUI presented by CMake. 
This means that you no longer have to hack the CMakeLists.txt file to 
set library paths, making it easier to keep in sync with the CVS 
version.

2) OpenGC is now built as a series of libraries; at the moment, this 
includes OpenGCBase, OpenGCDataSources, and OpenGCNav. The data source 
and nav libraries are actually useful in their own right, so developers 
who want _just_ data collection (for creating motion platforms, steam 
gauges, etc.) can obtain that functionality without dragging the rest 
of OpenGC along for the ride. The gauges have been reorganized by 
aircraft type and will eventually be rolled into a library as well.

3) The OpenGC executable code has been moved to a separate 
"Applications" directory; in addition to still being the public face of 
OpenGC, it also serves as an example of how to write a standalone app 
that links against the libraries. I will probably GPL the current 
application and continue development of it as the "lite" version of 
OpenGC. My understanding is that it's ok to use non-GPL code in a GPL 
application, but the reverse is not true. Can anyone verify this? In 
other words, although the core of the toolkit will not be GPL after the 
rewrite is finished, it's perfectly fine to distribute add-on bits that 
work with it which _are_ GPL...(?)

4) Any code that was (a) in the GPL'd OpenGC and (b) the author/s wish 
to keep as GPL will be placed in an "unsupported" directory; there will 
be a build flag that will allow you to turn on/off the creation of the 
OpenGCUnsupported library. If you link against code in this library, 
your application may be subject to commercial restrictions per the GPL 
or other open source license. If you link against any of the other 
libraries you are free to develop commercial products subject only to 
the copyright notice restriction. Obviously, if you are only interested 
in developing open source code, this shouldn't really affect you.

5) New code contributions can fall into one of two categories: official 
or unsupported. Official code will be released under the new VTK 
(BSD-like) license, and will be supported with automated build testing, 
Doxygen documentation, and CVSweb browsing. Unsupported code can be 
released under any of the licenses permitted by Sourceforge.net will be 
included in the toolkit and built per (4). I would encourage potential 
developers to consider releasing their work "officially".

Finally, none of these changes have been committed to the CVS 
repository. I will give plenty of advance notice prior to committing 
anything... If you have questions or comments please let me know.

Cheers,
-Damion-

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