[Boost-bugs] [Boost C++ Libraries] #11470: Invalid results using convex_hull with unsigned integer points coordinates

Subject: [Boost-bugs] [Boost C++ Libraries] #11470: Invalid results using convex_hull with unsigned integer points coordinates
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-07-10 11:15:12

#11470: Invalid results using convex_hull with unsigned integer points coordinates
-------------------------------------------------+-------------------------
 Reporter:  Eric Noirfalise <eric.noirfalise@…>  |      Owner:
     Type:  Bugs                                 |  barendgehrels
Milestone:  To Be Determined                     |     Status:  new
  Version:  Boost 1.58.0                         |  Component:  geometry
 Keywords:                                       |   Severity:  Problem
-------------------------------------------------+-------------------------
 Hi, I think convex_hull algorithm does not support unsigned integer points
 coordinates.

 The following code works well with signed integer but return a wrong
 result for unsigned version :


 {{{

 #include <boost/geometry.hpp>
 #include <boost/geometry/geometries/point_xy.hpp>
 #include <boost/geometry/geometries/polygon.hpp>
 #include <deque>


 int main()
 {
     typedef boost::geometry::model::d2::point_xy<unsigned int> PointInt;
     typedef boost::geometry::model::polygon<PointInt> polygon_type;

     polygon_type poly1, convPoly1;
     polygon_type poly2, convPoly2;
     boost::geometry::read_wkt("POLYGON((245 143, 243 113, 236 101, 228
 100, 222 106, 217 121, 217 144, 220 155, 227 165, 233 166, 237 163, 245
 143))", poly1);
     boost::geometry::convex_hull(poly1, convPoly1);

     return 0;
 }

 }}}

 Attached file is a representation of input polygon (orange) and output
 result (blue) curve.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11470>
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