What an interesting piece!

Robust Arithmetic in Computational Geometry / Volodymyr Agafonkin | Observable

Every developer should know that floating point numbers implement approximations.

During my master thesys in Civil Enginineering (twenty years ago!) I learned that professor Jonathan R Shewchuk wrote almost perfect C code about this, and used in its Delaunay triangulation. At that time I hadn’t the time to really study it as it seemed to me a little like magic.

Now this page in its exact test is using robust-predicates, a modern JavaScript, a port of Jonathan Shewchuk’s robust predicates code.

Wow.