An efficient algorithm for clipping operation based on trapezoidal meshes and sweep-line technique

Abstract

This paper presents an efficient algorithm for clipping points, arcs and polygons, which is a common operation in geographic information system (GIS). By incorporating the sweep-line technique in the proposed algorithm, the involved polygons are decomposed into a collection of trapezoidal meshes. In this way, the clipping operation between the to-be-clipped point, arc, polygon features and the subject polygons is transformed into an operation between points, arcs and the decomposed trapezoidal meshes, which is much easier to implement. Experimental results demonstrate that the algorithm is computational efficient comparing to the existing methods, especially when the input data contain a large number of polygons. In addition, the amount of storage space required is moderate. Furthermore, this algorithm is very flexible and able to handle concave polygons and those with holes.