Algorithm 1: Function to determine the outcode of the endpoints.

function CODE(x); begin         c := [0000];         if x < $x_{min}$thenc := [1000]                else if x > $x_{max}$thenc := [0100];         if y < $y_{min}$thenc := c lor [1001]                else if y > $y_{max}$thenc := c lor [0010];         CODE := c end [CODE];