Re: [Boost-bugs] [Boost C++ Libraries] #10108: boost::geometry::intersection fails for triangle-triangle intersection

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10108: boost::geometry::intersection fails for triangle-triangle intersection
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-10-22 11:36:00

#10108: boost::geometry::intersection fails for triangle-triangle intersection
-------------------------------------+-------------------------------------
  Reporter:  Raffael Casagrande      |      Owner:  barendgehrels
  <raffael@…>                        |     Status:  new
      Type:  Bugs                    |  Component:  geometry
 Milestone:  To Be Determined        |   Severity:  Problem
   Version:  Boost 1.56.0            |   Keywords:  intersection, triangle,
Resolution:                          |  robustness
-------------------------------------+-------------------------------------

Comment (by dgb@…):

 Hi,

 I have a strikingly similar problem that persists from Boos 1.47 through
 1.56: When intersecting two adjacent polygons (fourangles in my case) that
 share part of an edge, in some cases one of the inputs is erroneously
 returned as the output.

 Trying to attach the image
 'IntersectionReturnsFourangleBInsteadOfIntersection.png' to visualize the
 situation.

 {{{
 typedef
 boost::geometry::model::polygon<boost::geometry::model::d2::point_xy<double>
 > polygon;
 polygon red, green;
 boost::geometry::read_wkt("POLYGON((818.61020100991334 686.40744987236633,
 818.94520828641623 714.37814489343316, 857.67308553468195
 713.83138513092547, 857.33807828316174 685.94987141847253,
 818.61020100991334 686.40744987236633))", red);
   boost::geometry::read_wkt("POLYGON((857.33807828316174
 685.94987141847253, 857.64395373587263 711.40684463430682,
 910.49336536223325 710.67130033421233, 910.18750000000000
 685.32544378698219, 857.33807828316174 685.94987141847253))", green);

 --> intersect returns 'green' polygon
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10108#comment:2>
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