Google Summer of Code 2013

Student Name
Vishal Tiwari

Mentor Name
strk

Project Aim
The aim of the project is as follows:

1. Porting the Voronoi classes from JTS to GEOS: Providing the functionality of constructing Voronoi diagrams to GEOS by porting it from JTS to GEOS.

2. Writing C++ test cases: This will include porting the Voronoi Test file from JTS to GEOS. Furthermore one or two test cases will be written from scratch.

3. Exposing the functions through C-API: It provides a wrapper for the C++ functions. All the reference functions are implemented in geos_ts_c.cpp. (These are the thread safe apis). These functions are also exposed via the non-thread apis that are implemented in geos_c.cpp file. Such wrapper will be provided for the functions/methods that will be ported for Voronoi Class.

4. Writing C test cases: Test cases to test the Voronoi class methods wrapper functions written in geos_ts_c.cpp and geos_c.cpp will be written to test all the methods exposed via the apis.

Week 1 Report

1. Work Done :

• Have ported the methods that are in geos/triangualte/quadedge/QuadEdgeSubdivion.cpp. The methods are as such:
  • getVoronoiDiagram : Gets the cells in the Voronoi diagram for a triangulation.
  • getVoronoiCellPolygons : Gets the polygons for the Voronoi Cells for a triangulation.
  • getVoronoiCellPolygon : Gets the Voronoi cell around a site specified by the origin of a QuadEdge.
  • getVertexUniqueEdges : Gets a collection of QuadEdges whose origin vertices are a unique set which includes all vertices in the subdivision. The frame vertices can be included if required.
• Class TriangleCircumcentreVisitor was also ported.
• More methods like geos::geom::Triangle::circumcentre, and geos::geom::closeRing that were required in the above functions were also ported.

2. Problem Faced :

• I am having some silly problems during compilation which i am working out with strk, it will be solved soon.

3. Work to be done in the next week :

• Solve the errors that are coming as of now.
• Port the classes left, and see the working of the methods ported.
• Start with the port of class VoronoiDiagramBuilder.

Week 2 Report

1. Work Done:

• I have fixed the problems that i was facing the previous week.
• I have ported all the methods and classes that are required for VoronoiDiagramBuilder.
• I have started the port of VoronoiDiagramBuilder class.

2. Problems Faced :

• During the port of one of the methods i was stuck with some C++ STL data structure, which required a different compiler, but it was solved, as i used a different STL data structure.

3. Work to be done in the next week:

• Finish the port of VoronoiDiagramBuilder class.
• Write the testcases for QuadEdgeSubdivision class, and related methods that i have ported earlier.