about robustness

[fililili]

In this page (http://www.angusj.com/clipper2/Docs/Robustness.htm), it says self-intersection is unavoidable. However, when I study CGAL, I found it has a snap rounding library. And it mentioned a page (Rounding Arrangements Dynamically, Leonidas J. Guibast and David H. Marimont https://dl.acm.org/doi/pdf/10.1145/220279.220300), it provides an algorithm that will not cause self-intersection.

[AngusJohnson]

In this page (http://www.angusj.com/clipper2/Docs/Robustness.htm), it says self-intersection is unavoidable.

Where does it say this? And I'm afraid I don't understand your point?

[fililili]

The paper has provided a snap rouding algorithm. With this algorithm, the arrangement may collapse, but new invert. That means the snap algorithm will never create situations in below picture, so the snap algorithm can avoid self-intersection.

[AngusJohnson]

Again, I'm not seeing an issue here.