Marker Files are Different from those provided with Orbiter 2016

[ThChicken]

I have created a waypoint autopilot in Lua that refers to the marker files (*.mkr) found in Config/Earth/Markers. I discovered that the multiple marker files provided in Orbiter 2016 (listed below) are not found in OpenOrbiter (as of build 240105):

Antarctic Stations.mkr
Cities.mkr
Islands.mkr
Impact Features.mkr
Miscellaneous.mkr
Mountains and Volcanos.mkr
Tracking Stations.mkr

In OpenOrbiter 240105 there is only one marker file, and it does not match the name of any of the 2016 marker files:

City.mkr (note Orbiter 2016 has Cities.mkr)

This may not be a bug per se, but I wanted to inquire what was the necessity to altering these files? These marker files resources are the only way to my knowledge to access these station locations within Lua. It will either require Orbiter version checking in the Lua script (not currently available, see Issue #415) or checking of file names and the number of files within the directory (potentially possible but not simple to do in Lua).

[schnepe2]

Generic file i/o should be possible in Lua (at least for OpenOrbiter):
Input and Output Facilities
Operating System Facilities
Whether that's enough is a different question 😉

[ThChicken]

I am aware of Lua file i/o capabilities. The challenge is identifying what files are in a given directory from within Lua. That currently cannot be done in pure Lua without external libraries.

More fundamentally, I'd like to know why this marker file is different from the one provided in Orbiter 2016, and why the other marker files were not included. To my knowledge, these marker files are only utilized to identify bases in the Map MFD function. Did something change in OpenOrbiter with regard to their use?

[schnepe2]

As far as I can remember (long time ago) the Markers have been incorporated into the binary, packed, "Archive" structure in the Textures Folder (for example .\Textures\Earth\Archive\Label.tree)
That "new" format is explained in a technical documentation somewhere.

This has to do with performance considerations as reading those Text-files is not the fastest way to do.

And just before you ask... I will not provide a Lua interface for that 😉