Concave Containment

I've spent the past couple of months working on an unbreakable algorithm to detect whether a point is inside of a concave shape. Here's what I got so far. CLICK once to create a point and DOUBLE-CLICK to stop adding points. Expect a potential weblog article on this in the future.

The clear Clear Polygon button will clear what you've drawn. On mobile, you may be unable to DOUBLE-CLICK, so you can also press the Stop Drawing button to stop adding vertices.

I have just updated to a new, more efficient version of the algorithm.