In this paper

we introduce a series of algorithms for vector map overlay: We proposed an algorithm for large amounts of points inclusion test

which first preprocesses the polygon and then adopts the ray-crossing idea for each point inclusion test. We proposed an algorithm for large amounts of lines clipping

which builds indexes on the whole line and the segment

and avoids unnecessary intersection-computing. For map overlay on polygons

we use the improved plane sweep algorithm to get all the intersection points

and the complete categories on distribution of segments passing the same point cover all the special cases of intersection points. We record the ID in the process of constructing the result rings

which simplifies the two processes-finding outer ring for holes and attribute propagation. All the geometric algorithms and the corresponding overlay functions are implemented

and the comparisons with the state-of-the-art algorithms and ArcGIS’s function demonstrate its correctness

robustness

efficiency and usability. The above functions have been used in GIS platform and work well.