Re: [Boost-bugs] [Boost C++ Libraries] #10976: Problem with polygon library versions 1.56 and 1.57

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10976: Problem with polygon library versions 1.56 and 1.57
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-06-30 10:50:14

#10976: Problem with polygon library versions 1.56 and 1.57
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  Reporter:  Uwe Keller <Uwe.Keller@…>  |      Owner:  asydorchuk
      Type:  Bugs                       |     Status:  closed
 Milestone:  Boost 1.58.0               |  Component:  polygon
   Version:  Boost 1.56.0               |   Severity:  Problem
Resolution:  fixed                      |   Keywords:
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Comment (by mhilferink@…):

 Note that  ''insert_vertex_sequence()'' calls ''insert_clean(elem)'' which
 has ''is_hole'' as a second optional parameter and already has code to
 reverse the orientation. It would be cleaner to pass ''is_hole'' to
 ''insert_clean'' and avoid scattering the orientation logic around.

 BTW, why is on various places the orientation reversed if a edge is
 horizontal or vertical? I can see that intersected segments can have a
 reversed order of first and second point due to round off, making a
 vertical (S<-N) segment from an (NW->SE) edge, or a (S->N) segment from a
 (SE<-NW) edge. But reversing on specific directions such as in
 validate_scan, independent of whether point order did change or the points
 were actually swapped, seems something that is attempted to be compensated
 elsewhere, such as in _processEvent.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10976#comment:7>
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