Hey guys.. I am sure someone has come across this before. I'm looking for a library for simple 2D primitives (line, circle, point, polygon) intersection tests. I was about to roll my own, but I thought I'd set an example and see if anyone knew of a good quality one already. I'm mainly after a few key things: Circle/Line intersection (returns collision point, time and normal) Line/Line intersection (same) Swept circle/line Point in/out/on line/poly test I think thats about it. Basically its a mixture of tests for doing really simple 2D scenes. Oh, forgot poly/poly intersection test I guess.. and maybe swept versions of same. Anyone seen such a beast?