[geos-devel] GEOS robustness question

Kevin Wiebe Kevin.Wiebe at safe.com
Sat Jun 21 02:27:15 EDT 2003

Hi all,

I have been following JTS development from the beginning, and now also GEOS.

I have been primarily lurking, like many of us I presume, cheering on Yuri and others yet contributing little.

My interest has mostly been around robustness issues.  This is where I have plenty of experience.  I will be interested to do more testing once buffer is completed.

A question I am hoping someone can quickly answer is if there is an isolated method in the code that compares two polylines (line strings with more than two points) to see if they cross over each other.  (Not if they "touch", but if they fully cross over.)

If so, where is this method located?  I would like to see how robust the algorithm, data structures, etc. is, especially with respect to finite precision math.

If you'd like, I'll post my thoughts after I look through it.


p.s.  Here's my contribution today...
The Visual Studio projects that are in CVS are a bit out of date.  They need to include some of the newer exception files.  Also, the projects should include the /GR (RTTI) compiler option, as the code checks object types at runtime in several places.  (AbstractSTRtree.cpp line 122, for example.)  Without this option we will get "unpredictable behaviour".


 Kevin Wiebe     Safe Software Inc.       email:kevinAtsafe.com
      Senior     Surrey, BC, CANADA       phone: (604) 501-9985
   Developer     http://www.safe.com        fax: (604) 501-9965

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