Boost C++ Libraries: Ticket #9206: intersection of non-closed polygons returns closed polygon

version changed

vschoech@… — Wed, 13 Nov 2013 14:49:50 GMT

version Boost 1.52.0 → Boost 1.55.0

Still reproducible in boost 1.55.0.

attachment set

mkaravel — Fri, 01 Aug 2014 11:56:42 GMT

attachment → ticket_9206.out

output of the ticket_9206.cpp program

mkaravel — Fri, 01 Aug 2014 12:01:58 GMT

I have attached my own stand-alone test program.

First of all I am checking whether the two polygons are valid (new functionality in develop branch and soon in boost 1.56). As you can see the second polygon is reported as invalid. Indeed it is supposed to be counter-clockwise and open, but it is given as clockwise and open.

So after I correct this polygon, I run intersects and display the output in WKT format and using boost::geometry::dsv. I also print the number of points of the output polygon. As you can see, the WKT output "closes" the polygon. This behavior is new in the develop branch and in the upcoming boost 1.56 release: the WKT description of a polygon always reports the polygon as if it were closed. On the other hand the dsv output displays the polygon as open, which is also in sync with what num_points reports: 5 points. So the resulting polygon (at least with my program) is still open, but in order to see that you cannot rely on the WKT output.

status changed; cc, resolution set

mkaravel — Fri, 01 Aug 2014 12:04:06 GMT

cc mkaravel added
status new → closed
resolution → worksforme

status changed; resolution deleted

mkaravel — Fri, 01 Aug 2014 13:48:53 GMT

status closed → reopened
resolution worksforme

status changed; resolution set

mkaravel — Fri, 01 Aug 2014 13:49:03 GMT

status reopened → closed
resolution → invalid

attachment set

mkaravel — Fri, 01 Aug 2014 13:56:30 GMT

attachment → ticket_9206.cpp

stand-alone test program to be used with the BG develop branch