[grishka]

I'm a noob in this kind of stuff but maybe they're using fixed-point math and dynamically redefining the scaling to always have enough precision? But then if you do use fixed point you could as well use integer big numbers. Though I imagine that using any form of big numbers, int or float, is going to hurt the performance more and more as you zoom further. You may also be able to use the rule that you can multiply or divide both sides of an equation by the same number and it will remain valid.