[NTG-context] What was that 'rounding paths' metafun(?) function again?

I think I saw a function in MetaFun somehwre that you could give a ‘hard’ path, i.e. (0,0) -- (0,1) — (1,1) and it would become a path with nicely rounded (part of a circle) corners (still straight lines), but I can’t find it anymore. I wrote my own, but it is giving me headaches so I’d like to find something that is better than what I produce. G