Calculating voronoi regions around non axis aligned squares

Question

I'm trying to use SAT for circle-polygon collisions. http://www.metanetsoftware.com/technique/tutorialA.html#section3 suggests voronoi regions to find what axis to test against by finding what VR the circle's centre is in, then use the axis of the side or the vertice take away the circle centre.

How can I calculate this VR? All the polygons are squares, but not necessarily axis aligned. What is an inexpensive method of calculating this

Answer 1

Try this article. There are few examples. http://www.codeproject.com/Articles/413452/Create-a-Voronoi-diagram-2-of-3