Btw "rewrite everything" is of course overly dramatic, in reality I need to store all absolute world-space coordinates in fixed-point, make sure all computations are in relative coords, and figure out a few camera-related issues.

Still, that's a lot of rewriting.

I already have fixed-point numbers implemented, and my maths lib is templated on scalar type everywhere, so at least it's an order of magnitude less painful than it could be.