x , y

1 1

x , y

2 2

Possible Cases Line parallel to a boundary

completely outside the Area

but within the parallel boundaries

Min(Ut1

, -, 1) = Ut1

Max(Us1

, -, 0) = 0

end = Ut = Ut1

ini = Us = 0

Us > Ut Outside box

Us1

Us2

Ut1

Ut2

Are ‘inﬁnite’, there’s no way this line will

ever touch both the parallel boundaries

goes in

goes in

goes out

goes out

nx , ny

1 1

nx , ny

2 2

x , y

2 2

= =

x , y

1 1

0

1