HaxeNME version. Love2d version works equally to this.
Click and drag different parts for interaction.
By user request on Love2d IRC channel, yesterday I've made this nice function to do intersection/collision check between a ray (for clearance, here, a ray is a infinite line with starting point but no end point) and a circle.
Underlying code is fairly simple, though it does not even require understanding to use the function.
Love2d version takes advantage of multi-return values.
Haxe version has slightly longer code due for more optimal implementation of interface.