[dsnyozep] Convex circular polygon

One can generalize a convex polygon to have circular arcs as edges.  The area is the intersection of the interiors or exteriors of a collection of circles.  A straight edge is a circle of infinite radius.

If we permit unions, then non-convex is possible.  Reminiscent of constructive solid geometry.

It is easy to test if a point is inside or outside an edge (circle), and how far inside or outside.