FlightGear wiki - User contributions [en]

Preset Properties

2009-03-08T21:50:53Z

5thDimension: how do you set these presets?

{{stub}}
''This page is great, but can someone please add how to set these presets by both command line options as well as the .fgfsrc file?''

[[FlightGear]] currently uses these properties to set up the [[aircraft]]'s initial situation :

'''/sim/presets/airport-id''' - The ICAO identifier for an airport waypoint, such as "KJFK" or "EGLL". See also the runway property. An airport identifier takes precedence over vor-id , ndb-id , or fix , but is overridden by latitude-deg and longitude-deg .

'''/sim/presets/airspeed-kt'''

'''/sim/presets/altitude-ft''' - If this property has a value greater than -9990, then Flight Gear will use it to set the initial altitude MSL, unless the glideslope-deg property is also set.

'''/sim/presets/carrier'''

'''/sim/presets/fix''' - The identifier for a fix or intersection of some kind. All other waypoints take precedence over a fix. This property should be renamed to fix-id .

'''/sim/presets/heading-deg''' - The aircraft's initial heading in degrees. Flight Gear may also use this property to select a default runway in some situations.

'''/sim/presets/latitude-deg''' - If an explicit longitude and latitude are supplied, Flight Gear will use that; otherwise, it will look for an airport-id , vor-id , ndb-id , fix , and then finally default to KSFO if nothing else is available.

'''/sim/presets/longitude-deg''' - See latitude-deg.

'''/sim/presets/mach'''

'''/sim/presets/ndb-id''' - The identifier for an NDB waypoint, such as "OW" or "YSH". An NDB takes precedence over fix .

'''/sim/presets/onground''' - True if the aircraft should start on the ground, false otherwise.

'''/sim/presets/parkpos'''

'''/sim/presets/pitch-deg'''

'''/sim/presets/roll-deg'''

'''/sim/presets/runway''' - The name of a runway, such as "22" or "11R", for an onground start or an initial approach path. This property makes sense only with the airport-id property. /sim/presets/vor-id The identifier for a VOR waypoint, such as "YOW" or "ART". A VOR takes precedence over ndb-id and fix .

'''/sim/presets/speed-down-fps'''

'''/sim/presets/speed-east-fps'''

'''/sim/presets/speed-north-fps'''

'''/sim/presets/speed-set'''

'''/sim/presets/trim'''

'''/sim/presets/uBody-fps'''

'''/sim/presets/vBody-fps'''

'''/sim/presets/vor-id'''

'''/sim/presets/wBody-fps'''

Preset Properties

2009-03-08T21:49:17Z

5thDimension:

{{stub}}
''This page is great, but can someone please add how to set these presets?''

[[FlightGear]] currently uses these properties to set up the [[aircraft]]'s initial situation :

'''/sim/presets/airport-id''' - The ICAO identifier for an airport waypoint, such as "KJFK" or "EGLL". See also the runway property. An airport identifier takes precedence over vor-id , ndb-id , or fix , but is overridden by latitude-deg and longitude-deg .

'''/sim/presets/airspeed-kt'''

'''/sim/presets/altitude-ft''' - If this property has a value greater than -9990, then Flight Gear will use it to set the initial altitude MSL, unless the glideslope-deg property is also set.

'''/sim/presets/carrier'''

'''/sim/presets/fix''' - The identifier for a fix or intersection of some kind. All other waypoints take precedence over a fix. This property should be renamed to fix-id .

'''/sim/presets/heading-deg''' - The aircraft's initial heading in degrees. Flight Gear may also use this property to select a default runway in some situations.

'''/sim/presets/latitude-deg''' - If an explicit longitude and latitude are supplied, Flight Gear will use that; otherwise, it will look for an airport-id , vor-id , ndb-id , fix , and then finally default to KSFO if nothing else is available.

'''/sim/presets/longitude-deg''' - See latitude-deg.

'''/sim/presets/mach'''

'''/sim/presets/ndb-id''' - The identifier for an NDB waypoint, such as "OW" or "YSH". An NDB takes precedence over fix .

'''/sim/presets/onground''' - True if the aircraft should start on the ground, false otherwise.

'''/sim/presets/parkpos'''

'''/sim/presets/pitch-deg'''

'''/sim/presets/roll-deg'''

'''/sim/presets/runway''' - The name of a runway, such as "22" or "11R", for an onground start or an initial approach path. This property makes sense only with the airport-id property. /sim/presets/vor-id The identifier for a VOR waypoint, such as "YOW" or "ART". A VOR takes precedence over ndb-id and fix .

'''/sim/presets/speed-down-fps'''

'''/sim/presets/speed-east-fps'''

'''/sim/presets/speed-north-fps'''

'''/sim/presets/speed-set'''

'''/sim/presets/trim'''

'''/sim/presets/uBody-fps'''

'''/sim/presets/vBody-fps'''

'''/sim/presets/vor-id'''

'''/sim/presets/wBody-fps'''

Talk:SG LOG

2009-03-03T08:29:20Z

5thDimension: Thanks and clarification on what I was trying to figure out for this page

''Thanks to the person who filled this in--it helps. I was trying to figure out how some of the code worked, and which files were read in, which lead me to see calls to SG_LOG in the code. But I didn't figure out how to activate the logging of those messages. I understood the idea behind it (logging class and level) but not the way to just activate it (for example, I want to be able to turn on logging of messages that are of class SG_GENERAL, and priority SG_INFO. I understand more of it now--so the log is not logging to a file but to the console (wish I knew how to redirect that to a file so I can search it later). I see that to turn it on, I need to run fgfs --log-level=info (for example). Not sure how to select SG_GENERAL as the log class yet. I plan to update this page with my complete understanding when I've figured out what I am trying to figure out. I really opened this page b/c I think it will help others and it needs to be documented. I appreciate the info very much!''

It isn't entirely clear if you are really interested in the SG_LOG facility or more generally in a facility to do logging to a file, however SG_LOG is just a wrapper macro for the SimGear "logstream" class (all output being by default written to the console!). If you are interested in simply logging certain properties to a file at runtime, you may want to use another mechanism - which is more flexible and doesn't require recompilation (see below for more details).

So, the SG_LOG macro just simplifies usage, and is purely meant to be used by programmers/developers, who regularly recompile the source code.
If you just want to log some runtime data to a file, there are several other more flexible ways to do this (possible via networking/scripting or XML).

Basically, the macro allows you to easily associate your debug messages with a "channel" and a "priority".

Which means that you can further specify each log message with a channel (think like a "parent" subsystem, to which the message belongs) and also a priority to indicate if it's a critical/non-critical message.

This mechanism allows users to explicitly enable/subscribe to certain log messages, only - while ignoring others. This can be helpful in order to troubleshoot certain problems.

Logging settings can be modified using the --log-level command line option, detailed help about most available command line options can be obtained from the fgfs executable by calling it with the following arguments: "--help --verbose".

All necessary details can be obtained from the source code (SG & FG) and its documentation/comments:
* http://simgear.org/doxygen/logstream_8hxx.html
* http://simgear.org/doxygen/logstream_8hxx-source.html

So, you just pass a channel and a logging priority/class to the macro, available log channels and priorities can be found here:
* http://simgear.org/doxygen/debug__types_8h.html
* http://simgear.org/doxygen/debug__types_8h-source.html
* http://cvs.flightgear.org/simgear/doxygen/debug__types_8h-source.html

For logging only certain data/properties to a file, you may want to use another logging facility:
* http://cvs.flightgear.org/viewvc/source/src/Main/logger.cxx?revision=1.7&view=markup

Hope this helps

Please note that such and similar questions are usually better discussed on the mailing lists, IRC or forums.

Also, please do feel free to revamp this info and turn it into usable text for your "SG_LOG" article, so that it can hopefully help other users understand the FlightGear logging system.