[bsder]

> You need a method to determine what is sufficiently close to each other to be worthy of a more detailed check.

Your line sweep data structure effectively already does that. I recommend reading the Hobby paper and thinking about how it works. And then you should think about how you differentiate inside from outside when you union/difference your polygons.

Any segments in the line sweep data structure simultaneously have already demonstrated that they need the detailed check.

If you want to argue this, you're going to need to study up on about 40 years of prior art. Given how much money this is worth and how many really smart people went after it (it basically drove the field of Computational Geometry for decades), the probability of you contributing something new to the current algorithms is basically zero.

However, the probability of you contributing something new to parallel DRC algorithms is really quite decent. Nobody I know of has yet come up with "good" parallel algorithms for DRC--most of them are hacks that quite often break down when they hit even common cases.

Being able to handle DRC on a billion VLSI polygons/10 billion line segments in a parallel fashion would be quite an advance, and the field is waiting for it.