[Closed] How does Max know where to put holes in poly'd splines?

Lengthy topic, I know. What I mean is best shown in the picture. There’s a basic spline made of 3 circles. Then i’ve put a Turn to Poly modifier on it. How does it know where to put the hole? I’ve made a script that shoots the selected shape off to Jonathan Richard Shewchuk’s Triangle.exe, that requires a list of edges (verts and indices), and marks holes by having a coordinate that exists in the hole. I don’t know how to do this automatically, yet Max knows how.

http://www.cs.cmu.edu/~quake/triangle.html