Modified trivial rejection criteria in Cohen-Sutherland line clipping algorithm

Abstract

In the line clipping procedures if the line is not completely inside the clipping window then we have no option but to divide the line into segments at the intersections of the line and clipping window edges and then identify which segment is inside and which segment is outside the clipping window. But if the line is completely outside the clipping window, the line is eligible for total clipping or trivial rejection. There exist total 26 possible cases for trivial rejection of a line. Out of these 26 cases only 12 cases were solved without dividing the line into segments in the Cohen-Sutherland line clipping algorithm. Remaining 14 cases were solved by dividing the line into segments. But if the line is totally outside the clipping window, we don't require any segmentation. This paper presents the mechanism by which the remaining 14 cases can be solved without dividing the line into segments. © 2011 Springer-Verlag Berlin Heidelberg.