Re: [Boost-bugs] [Boost C++ Libraries] #12314: boost::geometry::within for a point in a geographic coordinate system fails

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #12314: boost::geometry::within for a point in a geographic coordinate system fails
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2017-01-03 13:51:34

#12314: boost::geometry::within for a point in a geographic coordinate system fails
-------------------------+-------------------------------------------------
  Reporter:              |      Owner:  barendgehrels
  oleary.simon@…         |     Status:  new
      Type:  Bugs        |  Component:  geometry
 Milestone:  To Be       |   Severity:  Showstopper
  Determined             |   Keywords:  geometry within geographic
   Version:  Boost       |  coordinate system cs
  1.61.0                 |
Resolution:              |
-------------------------+-------------------------------------------------

Comment (by awulkiew):

 In non-cartesian CSes the edges of Polygons are shortest lines between
 points so e.g. the edge: `(0 89, 180 89)` intersects the north pole. In
 the case of the edge `(180 0, 0 0)` I'm not sure what the algorithm
 assumes but this edge is invalid. The reason for that is that there is
 infinite number possible edges connecting these points in spherical and 2
 possible edges in geographic (going through north or south pole). Either
 way I presume this is not what you had in mind.

 You could fix the invalidity by adding additional point between the
 invalid edge, so: `POLYGON((0 89, 180 89, 180 0, 90 0, 0 0, 0 89 ))` but
 this is not what you wanted to do either.

 AFAIU what you wanted to do is to create a "rectangular" region (in
 spherical/geographic having edges being parallels and meridians) and that
 you should use your own rectangle representation adapted to Boost.Geometry
 Box concept or `bg::model::box` for this:

 {{{
 boost::geometry::model::box< wxPoint > box;
 boost::geometry::read_wkt("BOX(0 0, 180 89)", box);
 }}}

 or

 {{{
 boost::geometry::model::box< wxPoint > box(pt1, pt2);
 }}}

 So I don't think this is a bug.

 Does the above explanation make sense and solution work for you?

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12314#comment:1>
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