Hello!
It is great to see nearly the hole map on the screen when you play the game on a 4k monitor, but on the other hand everything that needs to be read needs to be read with magnifying glasses. ;)
On Linux, most programs understand some sort of scaling argument, passed as an environment variable, like
GDK_SCALE=2 program
How do I scale the Simutrans GUI when starting the game?
Simutrans supports GUI theme (https://simutrans-germany.com/wiki/wiki/en_ThemeDef?page_ref_id=1696) and font size since version 120.0.1.
The font can be changed via Settings/Display. Another theme ( Simutrans (large size) ) can also be selected there.
The GUI changed over the theme tab files in the folder simutrans/themes.
The large Simutrans theme is still pretty small, especially since there are no dedicated larger buttons. I use the theme of pak192.comic on my 4k -> https://github.com/Flemmbrav/Pak192.Comic/releases (you only need themes.zip)
You'll also need to change the font, since the normal game font does not scale. Even then the font size is restricted (19 is max), therefore it's best to use a font that's naturally bold - eg. Impact - for best readability. Fitting with Comic pak, I personally use Chewy ->https://fonts.google.com/specimen/Chewy
I don't think you can change the GUI from outside the game, but once it's changed, the game always starts with the most recent configuration.
There is the -autodpi switch on commandline, which will scale most buttons by default and select a larger zoom level at start up. The font is currently work in progress, since this is difficult among systems.
The "-autodpi" option really eases the stress on the eyes. Thanks:)
Now I still need to find a font that looks good and that is big enough on a hidpi screen when using the package German 128. Any suggestions?
In principle any TTF font should do. I use the "Bahnschrift" which is the font of German railway signs, in 19 pt on my 11" 2k display (which also needs scaling badly).