Geometry Boost List: Re: [geometry] Problems performing boolean operations on polygons with shared edges

Subject: Re: [geometry] Problems performing boolean operations on polygons with shared edges
From: Oleg Evseev (ev.mipt_at_[hidden])
Date: 2016-04-10 16:48:24

> First, the upcoming 1.61 release will have changes in overlay. Please
check there if the problem still appears.

Ok, I will try it, thank you! (Forgot to mention, but I think you had
understand that I'm using 1.60.0 release)

> Second, the JPG's are illustrative, but hard to reproduce the problem.
Could you file a ticket with the WKT representations of two polygons where
the union fails?

I create ticket https://svn.boost.org/trac/boost/ticket/12118

> WKT can easily be generated with the library using std::cout <<
boost::geometry::wkt(input1), etc

I used boost::geometry::dsv before, WKT return floats with more decimals,
but not enough, points that enclose those "almost zero areas" are the same,
so that area is totally empty, not "almost" (it is just an edge).
Is there any way to print floats in WKT representation with more precision?

I wrote in the ticket, but want to repeat here:
I forgot to mention that despite the fact that I use same initial data
(vehicle path) every program restart, boost geometry union_ makes described
problems not in same places.
So WKT representation in the ticket different from pictures in previous
post.

https://pp.vk.me/c631319/v631319687/1f012/2e1MycdOkB8.jpg now in last
program run is what it should to be - only one polygon:
https://pp.vk.me/c633617/v633617687/1cacb/mI45Se8H4OI.jpg

Appended mpolygon is
https://pp.vk.me/c633617/v633617687/1cab7/r_7Ep30w_jc.jpg
And union result now is
https://pp.vk.me/c633617/v633617687/1cac1/bc2qTKY-8Bs.jpg

Thanks, Oleg