An efficient algorithm to clip a 2D-polygon against a rectangular clip window

Abstract

Polygon clipping is of great importance in computer graphics. One of the popular algorithms to clip a polygon is Cohan—Sutherland Hodgeman algorithm which is based on line clipping. Cohan—Sutherland Hodgeman algorithm clips the polygon against the given rectangular clip window with the help of line clipping method. Cohan—Sutherland algorithm requires traversing the polygon in anti clockwise direction (positive orientation). In this work we propose an efficient polygon clipping algorithm against a rectangular clip window. Proposed algorithm uses parametric representation of polygon edges. Using the concept of point clipping, we can find required intersection points of edges of polygon with clip window boundaries. Well suited numerical illustrations are used to explain the proposed polygon clipping method. The proposed algorithm is computationally less expensive and comprehensive.