... through 90, 180, and 270 degrees about theorigin and reflections about the lines x =-y and the x-axis are needed. These opera-tions are extremely simple and involve only negation and assignment. ... different polygons, say P and Q, respectively, then we need tomerge these polygons. Let e1 and e2be the top edges for P and f1 and f2, the top edgesfor Q, so that e1 and f1meet in p with ... variables startC0 and startPt, clips the segment [startPt,ith point of polygon], and defines the global variablesstartC, endC – the extended Cohen-Sutherland code for the start and end-point,...