FlightGear Newsletter August 2009
Welcome to the second edition of the FlightGear Newsletter.
We're still looking for a permanent (or even a temporary) newsletter editor, so if you'd like to get involved, have a look on the Forums.
What's New in CVS
Tim Moore has committed a significant change to the graphics system that will allow much easier integration of OpenGL shaders within the simulator.
Shaders are small programs that run on your graphics card itself, and allow the simulator to do graphics operations that would otherwise be too computationally expensive. The current FG release (1.9.1) uses shaders for the forests of trees and 3D clouds.
This change represented a lot of work on the infrastructure of the project for long-term benefit. While there aren't any significant graphics changes based on this yet, we can expect a lot in the future, including integration of some nice water effects.
Generic Binary I/O protocol
The input and output code of FlightGear has been very flexible for many years by allowing for communications to (and from) files, serial ports and network sockets just by altering a command-line option.
In conjunction with that FlightGear has had support for a generic ASCII only input-output protocol handler for a number of years now. It is called 'generic' because it allows handling of just about any information in any form by altering a user modifiable xml configuration file. The functionality has been extended further by the possibility to define an offset and a multiplication factor. This approach might not cover every possible scenario but it will probably be good enough for most cases.
With the help of Anders Gidenstam the generic protocol has recently been extended to also support binary input and output. The data will be tightly packed in a packet that contains the requested data described in the configuration file. Supported types are: boolean values (8-bit), integer values (32-bit), floating point values (32-bit) and double precision floating point values (64-bit). Anders also added the option to support network byte ordering (big-endian) or system native byte-ordering which will save some processing time when only one type of system is used. To make it easier to see how the packet will be handled by FlightGear a utility called generic-protocol-analyze has been created which can be found in FlightGear/utils/xmlgrep. It outputs the data offset and size along with it's description.
New Wiki Articles
The wiki provides now a new article for aspiring core developers about extending the built-in Nasal scripting interpreter with custom extension functions: Howto:Extending Nasal. The Nasal documentation itself has been slightly reworked to provide a step by step introduction for users completely new to scripting or programming in general.
In the Hangar
There's a new aircraft in the CVS hangar - the PA 22-160 Tri Pacer. Created by Robert Leda (aka erobo) and Pawel Luchowski, this is a lovely GA aircraft and well worth having a flight in.
The level of detail is very impressive - you must prime to start the engine (making sure the mixture is set), the sound varies depending on whether you've got the window open, and the doors slam shut. All in all, it's a great polished aircraft.
The FG CVS hangar now has a very wide range of Piper aircraft, from the simple Cub, through the Cherokee Warrior II, Comanche 250, to the Seneca II. It is worth noting that the Warrior, Comanche and Seneca are all based on airframes flown by FG contributors in real life.
For those wanting to do some dead reckoning, this CRP5 E6B online calculator may be of interest. Get your stopwatch, chinagraph pencils, ruler and protractor ready!
There are a whole host of funky aviation converters here. Thanks to eeK on the forums for the links.
Check out the cockpit of an Airbus A380 and have a virtual tour here: http://www.airbus.com/store/mm_repository/cockpit_airbusA380/flash/cockpit1.htm
The 2009 edition of the LinuxTag has been concluded and the FlightGear hangar was there full of aircraft and pilots ! You could easily spot our stand since it seemed to me the most popular one, the idea to take a free virtual flight coupled with a free flight instructor was like honey for bears. Furthermore the hardware was impressive, 2 flight stations with 3 big monitors each and real controls were worth a try ! You could even track your flight through a projected mapserver on the wall.
We flew mostly around the Frankfurt area, where a highly detailed airport (still with a high fps rate) was the background of our participants. The favorite aircraft was the SenecaII as it was perfect to be flown with our equipment. Meanwhile in the forward station was easy to see some Eurocopter Bo105 pilot or F-14 Tomcat top gun enjoying carrier approaches.
But it was not just all flying and fun. At the stand you could talk to some code and model developers, discussing new features and wishes. There was a developers section too: Till was hacking an earth and sea textures generator to improve our virtual world terrain painting, applying shaders instead of fixed photos; early results where really interesting and I hope to see them soon in CVS.
The FlightGear guys prove themselves very friendly and always spoke in english in my presence. Martin Spott took care to manage an entrance pass for me and kept me informed prior to LinuxTag via Emails. This means you have no excuses to miss the event next year (At least only if you are not afraid of virtually flight !).
- Francesco Brisa