That advice was specifically meant for people without any Nasal coding experience, because the framework itself has sufficiently evolved to allow such customizations, without having to copy/edit files and change a ton of code.
What you describe would be much more work than simply disregarding the -old- advice not to come up with a custom Airbus ND style now.
It's not that bad, it mainly involves:
- copy the Boeing SVG file
- saving it under a different file name, save it under Airbus.svg
- copying the Boeing style and pasting an identical version named "Airbus"
- changing the SVG file name to your new file
These steps will take ~3 minutes only
That will give a Boeing ND, under the "Airbus" name.
Once that works, you can basically open your Airbus.svg file and change symbols/appearance there.
Likewise, you can remove/add custom symbol animation callbacks from the Airbus styles hash.
Obviously, once you change/add new SVG element IDs, you need to add those to your animation callbacks
The layer changes /additions you describe are trivial to do using MapStructure, those are not "symbols" but actual MapStructure layers - see the MapStructure article for details.
fonts, colors, symbols can be easily customized using MapStructure styles. Extending styling to the ND would not be too difficult either.
A terrain layer is also easy to do, but will have performance implications:
http://wiki.flightgear.org/Canvas_MapStructure_Layershttp://wiki.flightgear.org/MapStructure ... new_LayersRegarding the TAXI view, we already have a taxiways.layer that would only need to be adapted/ported:
Changing colors there would be trivial, it's just a matter of applying MapStructure styles.
The main step is taking taxiways.draw and turning it into a MapStructure symbol file:
http://wiki.flightgear.org/MapStructure ... xml_dialog