Your knee-jerk reaction may be that this is not embedded related -- but even embedded designers have to have a hobby -- and I'm currently working on a project that involves twisting tori -- as part of this, I just wrote the first column of a two-part mini-series over on EEJournal.com and I thought I'd share it here for giggles and grins:

Tortuously Topological Toroidal Transformations (a.k.a. Donut Math)
https://www.eejournal.com/article/tortuously-topol...