Addon: Difference between revisions
(Major update and rewrite, mostly based on readme and comments in source files) |
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[[File:Fgaddonslogo202x89.png|right]] | |||
[[File:Fgaddonslogo202x89.png| | To make it easier to create '''addons''' there is since FlightGear 2017.3 a new way to create addons. In essence FlightGear will load an overlay XML into the property tree and start a well known Nasal function.<ref>{{cite web | ||
|url = https://forum.flightgear.org/viewtopic.php?p=314620#p314620 | |||
|title = <nowiki> Re: New Feature: Addon - "API" </nowiki> | |||
|author = <nowiki> Torsten </nowiki> | |||
|date = Jul 19th, 2017 | |||
|added = Jul 19th, 2017 | |||
and | |||
|url = https://forum.flightgear.org/viewtopic.php?p= | |||
|title = <nowiki> Re: | |||
|author = <nowiki> | |||
|date = | |||
|added = | |||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
We now have a simple way to add addons to FlightGear without the need to mess around with <code>FGData/Nasal</code> or <code>FGHome/Nasal</code> directories.<ref name="Forum_announcement">{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p= | |url = https://forum.flightgear.org/viewtopic.php?p=314563#p314563 | ||
|title = <nowiki> | |title = <nowiki> New Feature: Addon - "API" </nowiki> | ||
|author = <nowiki> | |author = <nowiki> Torsten </nowiki> | ||
|date = | |date = Jul 18th, 2017 | ||
}}</ref> | }}</ref> | ||
{{TOC limit|3}} | |||
== Installing and using an addon == | |||
Download and copy the addon to a directory on your computer. | |||
Use the command line switch <code>--addon=/path/to/some/addon</code>.<ref name="Forum_announcement"/> | |||
== Creating an addon == | |||
There is a very simple Skeleton addon available in FGAddon to be used as a template.<ref name="Forum_announcement"/> See {{fgaddon source|path=Addons/Skeleton}}. | |||
=== Minimum configuration === | |||
An addon may be installed in a directory anywhere on your hard disk and need at least two files:<ref name="Forum_announcement"/> | |||
* <code>/config.xml</code> - A standard [[PropertyList XML files|PropertyList XML file]] to be used to populate or modify the [[property tree]]. (Same as to be used in <code>--config=foo.xml</code>) | |||
* <code>/main.nas</code> - The Nasal hook for the logic. This file needs a function called <code>main()</code> which will be called from the global addon initializer (<code>addons.nas</code>) | |||
=== Additional common files === | |||
* <code>/addon-metadata.xml</code> - A PropertyList XML file with metadata about the addon it. | |||
* <code>/addon-menubar-items.xml</code> - A PropertyList XML file describing menus to be added to the FlightGear menu bar. | |||
* <code>/gui/dialogs/<my-foobar-dialog>.xml</code> - PropertyList XML files to create custom dialogs. | |||
The new addon "API" lets you add a addon-config.xml to override the settings in defaults.xml. | === Good to know === | ||
The new addon "API" lets you add a <code>addon-config.xml</code> to override the settings in <code>defaults.xml</code> and other files. | |||
That easily allows to | That easily allows to | ||
* Override key bindings (as in the spoken | * Override key bindings (as in the spoken ATC addon) | ||
* Add or override autopilots and property rules | * Add or override autopilots and property rules | ||
* And of course introduce XML | * And of course introduce XML statemachines | ||
Unless your really want to add/change/remove those at runtime, this should cater for most use cases.<ref>{{cite web | Unless your really want to add/change/remove those at runtime, this should cater for most use cases.<ref>{{cite web | ||
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}}</ref> | }}</ref> | ||
== APIs == | |||
{{hatnote|For more details about these APIs, see the readme file, {{readme file|add-ons}}.}} | |||
=== C++ API === | |||
There is a C++ API on FlightGear's side that handle some on the addon related tasks manly through the <code>AddonManager()</code>, <code>Addon()</code> and <code>AddonVersion()</code> classes. | |||
* [ | == Addon initialization == | ||
* | On initialization fgfs takes care of: | ||
* | * Through {{flightgear source|path=src/Main/options.cxx|text=<code>options.cxx</code>}}:<ref name="Forum_announcement"/> | ||
* [ | ** Creating a property under <code>/addons/addon[n]/path=/path/to/some/addon</code> | ||
* | ** Loading <code>/path/to/some/addon/config.xml</code> into the property tree (same as <code>--config=/path/to/some/addon/config.xml</code>) | ||
** Adding <code>/path/to/some/addon</code> to the list of allowed directories (same as <code>--fg-aircraft=/path/to/some/addon</code>) | |||
* Through {{fgdata source|path=Nasal/addons.nas|text=<code>addons.nas</code>}}: | |||
** Loading <code>/foo/bar/baz/addon-main.nas</code> into namespace <code>__addon[ADDON_ID]__</code> | |||
** Calling <code>main(addonGhost)</code> from <code>/foo/bar/baz/addon-main.nas</code>. | |||
=== Nasal API === | |||
The Nasal add-on API lives in the 'addons' namespace and can for example do queries to <code>AddonManager()</code> and read data from <code>addons.Addon</code> objects. It can for example compare addon versions if there is dependencies. | |||
== Background == | |||
{{See also|Howto:Creating a simple modding framework}} | |||
ATC chatter was removed in 2015, see fgdata commit: [https://sourceforge.net/p/flightgear/fgdata/ci/81607f734e13add9be02816ddaec305d05bc4e47/ 81607f734e13add9be02816ddaec305d05bc4e47] | |||
And the devel list messages referenced in the commit log. | |||
the other relevant commit is this: b60736ba7add2a7cd39af3d8a974d5be3ea46e8b | |||
It would not be very difficult to restore this functionality, or even generalize/improve it significantly (which was the scope of the original discussion on the devel list)<ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p= | |url = https://forum.flightgear.org/viewtopic.php?p=288388#p288388 | ||
|title = <nowiki> Re: Whatever happened to radom radio | |title = <nowiki> Re: Whatever happened to radom radio </nowiki> | ||
|author = <nowiki> Hooray </nowiki> | |author = <nowiki> Hooray </nowiki> | ||
|date = | |date = Jun 11th, 2016 | ||
|added = | |added = Jun 11th, 2016 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
The restored functionality could be distributed as a tarball that is extracted into $FG_ROOT - alternatively, into $FG_HOME, because Nasal files there are treated as overlays, which basically means that you can install user-specific extensions there without having to tamper with $FG_ROOT, it would only take very minor changes to turn the chatter feature into a corresponding "addon" - not unlike fgcamera ...<ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p=288392#p288392 | |||
|title = <nowiki> Re: Whatever happened to radom radio </nowiki> | |||
|author = <nowiki> Hooray </nowiki> | |||
|date = Jun 11th, 2016 | |||
|added = Jun 11th, 2016 | |||
|url = https://forum.flightgear.org/viewtopic.php?p= | |||
|title = <nowiki> | |||
|author = <nowiki> | |||
|date = | |||
|added = | |||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
We should absolutely stop telling anyone to edit preferences.xml in FG_ROOT; any documentation or advice which says to should be changes ASAP. <ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p=192632#p192632 | |||
|title = <nowiki> Re: NavCache:init failed:Sqlite error:Sqlite API abuse </nowiki> | |||
|author = <nowiki> zakalawe </nowiki> | |||
|date = Oct 26th, 2013 | |||
|added = Oct 26th, 2013 | |||
|url = https://forum.flightgear.org/viewtopic.php?p= | |||
|title = <nowiki> Re: | |||
|author = <nowiki> | |||
|date = | |||
|added = | |||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
As of 12/2017, the addon API is in the process of being significantly updated <ref>https://sourceforge.net/p/flightgear/mailman/message/36146017/</ref> <ref>https://sourceforge.net/p/flightgear/mailman/message/36150159/</ref> <ref>https://sourceforge.net/p/flightgear/mailman/message/36150444/</ref> | |||
== List of Addons == | == List of Addons == | ||
You can find the official repository | You can find the official repository at {{fgaddon source|path=Addons}} | ||
* ATC Chatter (ported by Torsten) {{progressbar|100}} | * ATC Chatter (ported by Torsten) {{progressbar|100}} | ||
* | * cockpit-view (work in progress by wkitty42)<ref>{{cite web | ||
|url = https://forum.flightgear.org/viewtopic.php?p= | |url = https://forum.flightgear.org/viewtopic.php?p=316498#p316498 | ||
|title = <nowiki> Re: </nowiki> | |title = <nowiki> Re: </nowiki> | ||
|author = <nowiki> | |author = <nowiki> wkitty42 </nowiki> | ||
|date = | |date = Aug 13th, 2017 | ||
|added = | |added = Aug 13th, 2017 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
* [[ | * [[Earthview#Customization]] - High resolution customization | ||
* [[ | * [[FaceTrackNoIR]] (ported by HHS)<ref>{{cite web | ||
|url = https://sourceforge.net/p/flightgear/mailman/message/36454826/ | |||
|url = https:// | |||
|title = <nowiki> Re: </nowiki> | |title = <nowiki> Re: </nowiki> | ||
|author = <nowiki> | |author = <nowiki> Unknown, HHS</nowiki> | ||
|date = | |date = Nov 1th, 2018 | ||
}}</ref> - An addon to interface this [[Head tracking|head tracker]] with FlightGear | |||
* [[A Failure Management Framework for FlightGear]] | |||
}}</ref> | * [[FGCamera]] (work in progress by Torsten)<ref>{{cite web | ||
* [[FGCamera]] (work in progress by Torsten <ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p=314650#p314650 | |url = https://forum.flightgear.org/viewtopic.php?p=314650#p314650 | ||
|title = <nowiki> Re: Alternative camera control </nowiki> | |title = <nowiki> Re: Alternative camera control </nowiki> | ||
Line 190: | Line 143: | ||
|added = Jul 19th, 2017 | |added = Jul 19th, 2017 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> <ref>{{cite web | }}</ref><ref>{{cite web | ||
|url = https://forum.flightgear.org/viewtopic.php?p=319804#p319804 | |url = https://forum.flightgear.org/viewtopic.php?p=319804#p319804 | ||
|title = <nowiki> Re: New Feature: Addon - "API" </nowiki> | |title = <nowiki> Re: New Feature: Addon - "API" </nowiki> | ||
Line 197: | Line 150: | ||
|added = Oct 2nd, 2017 | |added = Oct 2nd, 2017 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
* [[Ground Services]] (ported by ThomasS<ref>{{cite web | * [[FGPlot]] | ||
* [[Ground Services]] (ported by ThomasS)<ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p=316400#p316400 | |url = https://forum.flightgear.org/viewtopic.php?p=316400#p316400 | ||
|title = <nowiki> Re: </nowiki> | |title = <nowiki> Re: </nowiki> | ||
Line 205: | Line 159: | ||
|added = Aug 12th, 2017 | |added = Aug 12th, 2017 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
* | * [[Landing Rate addon]] [https://forum.flightgear.org/viewtopic.php?f=6&t=33101&p=327787#p327787] | ||
|url = https://forum.flightgear.org/viewtopic.php?p= | * [https://gitlab.com/mdanil/flightgear-hax mdanilov hax!]: landing evaluation and aircraft development tools, TerraSync toggler | ||
* [[Model Cockpit View]] | |||
* [[Oscilloscope addon]] - Allows displaying a property of Nasal function over time | |||
* [[PAR instrument]] - Precision Approach Radar and Ground Controlled Approach | |||
* [[Red Griffin ATC]] - Speaking Air Traffic Controller<ref>{{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?f=6&t=36755 | |||
|title = <nowiki> Re: </nowiki> | |||
|author = <nowiki> RedGriffin </nowiki> | |||
|date = Jan 6th, 2020 | |||
|added = Jan 6th, 2020 | |||
|script_version = 1.0.0 RC2 | |||
}}</ref> | |||
* [[Spoken ATC]] (ported by Torsten<ref>){{cite web | |||
|url = https://forum.flightgear.org/viewtopic.php?p=314095#p314095 | |||
|title = <nowiki> Re: </nowiki> | |title = <nowiki> Re: </nowiki> | ||
|author = <nowiki> | |author = <nowiki> Torsten </nowiki> | ||
|date = | |date = Jul 10th, 2017 | ||
|added = | |added = Jul 10th, 2017 | ||
|script_version = 0.40 | |script_version = 0.40 | ||
}}</ref> | }}</ref> | ||
* [[ | * [[Spoken GCA]] - An offline ground controlled approach (GCA) addon | ||
* [[YASim Development Tools]] (by jsb) | |||
* [[ | |||
== Ideas == | == Ideas == | ||
=== Hooking into features using legacy OpenGL code === | === Hooking into features using legacy OpenGL code === | ||
{{See also|Unifying the 2D rendering backend via canvas}} | {{See also|Unifying the 2D rendering backend via canvas}} | ||
Line 230: | Line 190: | ||
=== Catalog & Package Manager support === | === Catalog & Package Manager support === | ||
if this works with more complex, pre-existing addons such as [[Bombable]], where the file layout is a replica of the old FGData layout, these types of mature addons might be better as SourceForge FlightGear sub-projects rather than being copied into FGAddon. Maybe the config file and nasal script could be used to automate the installation process ?<ref>{{cite web | if this works with more complex, pre-existing addons such as [[Bombable]], where the file layout is a replica of the old FGData layout, these types of mature addons might be better as SourceForge FlightGear sub-projects rather than being copied into FGAddon. Maybe the config file and nasal script could be used to automate the installation process ?<ref>{{cite web | ||
|url = https://sourceforge.net/p/flightgear/mailman/message/35953179/ | |url = https://sourceforge.net/p/flightgear/mailman/message/35953179/ | ||
Line 252: | Line 211: | ||
== References == | == References == | ||
{{Appendix}} | {{Appendix}} | ||
== Related content == | |||
=== Wiki articles === | |||
* [[FlightGear configuration via XML]] | |||
* [[FlightGear configuration via XML#preferences.xml]] | |||
* [[Nasal]] | |||
* [[Property tree]] | |||
* [[Properties persistent between sessions]] | |||
* [[PropertyList XML File]] | |||
=== Forum topics === | |||
* {{forum link|t=32561|title=New Feature: Addon - "API"}} | |||
=== Readme file === | |||
* {{readme file|add-ons}} | |||
=== Source code === | |||
==== FGAddon ==== | |||
* {{fgaddon source|path=Addons/Skeleton}} - Skeleton addon to be used as a template. | |||
==== FGData ==== | |||
* {{fgdata source|path=Nasal/addons.nas}} | |||
==== FlightGear ==== | |||
* {{flightgear source|path=src/Main/options.cxx}} | |||
* {{flightgear source|path=src/Add-ons/}} |
Revision as of 16:08, 10 July 2020
To make it easier to create addons there is since FlightGear 2017.3 a new way to create addons. In essence FlightGear will load an overlay XML into the property tree and start a well known Nasal function.[1]
We now have a simple way to add addons to FlightGear without the need to mess around with FGData/Nasal
or FGHome/Nasal
directories.[2]
Installing and using an addon
Download and copy the addon to a directory on your computer.
Use the command line switch --addon=/path/to/some/addon
.[2]
Creating an addon
There is a very simple Skeleton addon available in FGAddon to be used as a template.[2] See flightgear/fgaddon/trunk/Addons/Skeleton.
Minimum configuration
An addon may be installed in a directory anywhere on your hard disk and need at least two files:[2]
/config.xml
- A standard PropertyList XML file to be used to populate or modify the property tree. (Same as to be used in--config=foo.xml
)/main.nas
- The Nasal hook for the logic. This file needs a function calledmain()
which will be called from the global addon initializer (addons.nas
)
Additional common files
/addon-metadata.xml
- A PropertyList XML file with metadata about the addon it./addon-menubar-items.xml
- A PropertyList XML file describing menus to be added to the FlightGear menu bar./gui/dialogs/<my-foobar-dialog>.xml
- PropertyList XML files to create custom dialogs.
Good to know
The new addon "API" lets you add a addon-config.xml
to override the settings in defaults.xml
and other files.
That easily allows to
- Override key bindings (as in the spoken ATC addon)
- Add or override autopilots and property rules
- And of course introduce XML statemachines
Unless your really want to add/change/remove those at runtime, this should cater for most use cases.[3]
We have some instructions how to use SVN in our wiki. It covers mostly aircraft development but the workflow is pretty much the same for addons.[4]
APIs
C++ API
There is a C++ API on FlightGear's side that handle some on the addon related tasks manly through the AddonManager()
, Addon()
and AddonVersion()
classes.
Addon initialization
On initialization fgfs takes care of:
- Through
options.cxx
:[2]- Creating a property under
/addons/addon[n]/path=/path/to/some/addon
- Loading
/path/to/some/addon/config.xml
into the property tree (same as--config=/path/to/some/addon/config.xml
) - Adding
/path/to/some/addon
to the list of allowed directories (same as--fg-aircraft=/path/to/some/addon
)
- Creating a property under
- Through
addons.nas
:- Loading
/foo/bar/baz/addon-main.nas
into namespace__addon[ADDON_ID]__
- Calling
main(addonGhost)
from/foo/bar/baz/addon-main.nas
.
- Loading
Nasal API
The Nasal add-on API lives in the 'addons' namespace and can for example do queries to AddonManager()
and read data from addons.Addon
objects. It can for example compare addon versions if there is dependencies.
Background
ATC chatter was removed in 2015, see fgdata commit: 81607f734e13add9be02816ddaec305d05bc4e47
And the devel list messages referenced in the commit log. the other relevant commit is this: b60736ba7add2a7cd39af3d8a974d5be3ea46e8b It would not be very difficult to restore this functionality, or even generalize/improve it significantly (which was the scope of the original discussion on the devel list)[5]
The restored functionality could be distributed as a tarball that is extracted into $FG_ROOT - alternatively, into $FG_HOME, because Nasal files there are treated as overlays, which basically means that you can install user-specific extensions there without having to tamper with $FG_ROOT, it would only take very minor changes to turn the chatter feature into a corresponding "addon" - not unlike fgcamera ...[6]
We should absolutely stop telling anyone to edit preferences.xml in FG_ROOT; any documentation or advice which says to should be changes ASAP. [7]
As of 12/2017, the addon API is in the process of being significantly updated [8] [9] [10]
List of Addons
You can find the official repository at flightgear/fgaddon/trunk/Addons
- ATC Chatter (ported by Torsten)
- cockpit-view (work in progress by wkitty42)[11]
- Earthview#Customization - High resolution customization
- FaceTrackNoIR (ported by HHS)[12] - An addon to interface this head tracker with FlightGear
- A Failure Management Framework for FlightGear
- FGCamera (work in progress by Torsten)[13][14]
- FGPlot
- Ground Services (ported by ThomasS)[15]
- Landing Rate addon [1]
- mdanilov hax!: landing evaluation and aircraft development tools, TerraSync toggler
- Model Cockpit View
- Oscilloscope addon - Allows displaying a property of Nasal function over time
- PAR instrument - Precision Approach Radar and Ground Controlled Approach
- Red Griffin ATC - Speaking Air Traffic Controller[16]
- Spoken ATC (ported by Torsten[17]
- Spoken GCA - An offline ground controlled approach (GCA) addon
- YASim Development Tools (by jsb)
Ideas
Hooking into features using legacy OpenGL code
In 09/2018, James suggested that legacy features using raw OpenGL calls (e.g. HUD/2D panels) could be easily replaced via scripted Canvas/Nasal solutions at the mere cost of providing a mechanism to hook into the legacy code implementing these features (namely, the HUD/instrumentation subsystems) [18] [19]
Catalog & Package Manager support
if this works with more complex, pre-existing addons such as Bombable, where the file layout is a replica of the old FGData layout, these types of mature addons might be better as SourceForge FlightGear sub-projects rather than being copied into FGAddon. Maybe the config file and nasal script could be used to automate the installation process ?[20] The Bombable addon is one of the most popular addons out there, and a large number of aircraft in FGAddon have bombable support, so it is worth not forgetting about. Especially if the addon system one day becomes automated through a catalog.xml type system[21]
References
Related content
Wiki articles
- FlightGear configuration via XML
- FlightGear configuration via XML#preferences.xml
- Nasal
- Property tree
- Properties persistent between sessions
- PropertyList XML File
Forum topics
Readme file
- $FG_ROOT/Docs/README.add-ons
Source code
FGAddon
- flightgear/fgaddon/trunk/Addons/Skeleton - Skeleton addon to be used as a template.