Trivial acceptance case of cohen sutherland line clippings
Case 1: it is Trivial acceptance case whether the UDLR bit codes of the end points P, Q of a provided line is 0000 then line is completely visible. Now this is the case as the end points a and b of line l1 are: a (0000), b (0000). The line segment PQ is passed onto Case 2, if this Trival acceptance test is failed.