That’s incredible. I’m always impressed with the utility of the TrueType/open font spec - the flexibility there is really an underappreciated work of engineering genius.
I mean, fonts are Turing-complete [0], so it isn’t surprising that this is possible. Turing-completeness is often by accident rather than by genius [1].
[0] https://litherum.blogspot.com/2019/03/addition-font.html
[1] https://en.wikipedia.org/wiki/Turing_completeness#Unintentio...
Arguably one of those cases where the capability is awesome, but using the capability is wat.
https://www.destroyallsoftware.com/talks/wat