Intersection area Circle - Rect

Question

Hi guys,
I'm trying to compute the intersecting area of a circle and a rect. I've already searched the web for ages and found some good stuff like this: [Area of intersection between circle and rectangle|http://stackoverflow.com/questions/622287/area-of-intersection-between-circle-and-rectangle], but my problem is, that I don't now how to compute the intersection points of a circle and a rect.
Is there any way to compute the area easier (e.g. with a java lib)? And how do I compute the intersecting points?
Thx for any help in advance! Greetings.

Answer 1

A rectangle and a circle can intersect each other in many ways:
1) no intersection because one is completely contained by the other or both are completely disjunct;
2) intersect one edge of the rectangle; there are two intersection points
3) intersect two adjacent edges of the rectangle; there are four intersection points;
4) intersect two opposite edges of the rectangle; there are four intersection points;
5) intersect three edges of the rectangle; there are six intersection points;
6) intersect all edges of the rectangle; there are eight intersection points.
Note that some of the points in all cases where both intersect can be identical. You have to figure out each and every situation one by one.
kind regards,
Jos