geometry-challenged

[Brian Yennie]

For the problem at hand, it should suffice to add a little if-logic to 
the beginning.

A line between two non-overlapping objects will always intersect 
exactly one of the sides of each object- you just have to pick the 
right one and _then_ use the intersection function.

With that said, an intersection function should probably error 
gracefully for parallel lines (i.e. non-intersecting).

- Brian

>    I tried the function on two *non*-intersecting lines, and it gave 
> me a "divide by zero" error. Not good. You need to find the 
> mathematical intersection of the infinite lines defined by the two 
> pairs of endpoints, and *then* decide whether or not that intersection 
> point is within *both* of the line *segments* defined by said points.