See is a ray collides with this tlLine
Returns tlCollisionResult with the results of the collision
You can use this to test for a collision with a ray. Pass the origin of the ray with px and py, and set the direction of the ray with dx and dy.
dx and dy will be normalised and extended infinitely, if maxdistance equals 0 (default), otherwise set maxdistance to how ever far you want the ray
to extend to.