A New Algorithm of Point in-out Polygon Test Based on Monotonicity and Correlative Edges[J]. Journal of Image and Graphics, 2002, 7(6): 595. DOI: 10.11834/jig.200206199.
A New Algorithm of Point in-out Polygon Test Based on Monotonicity and Correlative Edges
Point in-out polygon test is one of the fundamental issues in Computer graphics. In this paper
the fundamental characteristic of the polygon edges-monotonicity is utilized sufficiently. According to the coordinate relations between the points and the edges
the conception of correlative edges is proposed. By integrating monotonicity with correlative edges
a new algorithm of point in-out polygon is put forward. The new algorithm transforms the relationship between a point and a polygon into that between a point and its correlative edges. The operations of intersection are avoided
and the operations of cross product are reduced as far as possible. The efficiency of the algorithm is raised radically. It is proved simply and effectively when the points are at critical positions. Software implementation verifies the high robustness and efficiency of the new algorithm.