Collision angle (direction vectors?)

[kcoder]

I've completed some working collision detection code, but now I need to figure out how to compute the angle of collision between two objects with well-behaved bounding squares (the bounding box provided squished down into 2d space). I considered trying to compute direction vectors for both objects along the forward axis, but I'm not sure how to do this. Any ideas?

If you have another method for computing the angle of collision, I'd be happy to hear that, too!