
Geometry : 
From: Johan DorÃ© (jdh_at_[hidden])
Date: 20210105 09:08:07
Dear All,
We were just compiling Boost Geometry Extension using VS 2017 64 bit and Warning Level 4.
Doing that showed a few warnings regarding size_t to int conversions which you might want to change.
It is in the file:
..\boost\geometry\extensions\algorithms\detail\overlay\dissolver.hpp
Line 436:
int n = boost::size(output_collection);
and Line 580
int size = 0, previous_size = 0;
We assume that both should be size_t.
Thanks a lot for all your hard work
Johan
Best regards,
Johan DorÃ©
CTO, Vice President
[cid:logo_visiopharm_1line_rgb_blk_5b11a6feaf82480b84bec356b54bf0c6.png]
M: +45 40 53 93 21
P: +45 88 20 20 88
C: HÃ¸rsholm, Denmark
W: www.visiopharm.com<http://www.visiopharm.com/>
From: Geometry <geometrybounces_at_[hidden]> On Behalf Of Chris Watts via Geometry
Sent: 31. december 2020 10:32
To: geometry_at_[hidden]
Cc: Chris Watts <Chris_at_[hidden]>
Subject: [geometry] Polygons appear to have serious rounding errors
Hi all,
I've been trying to debug an issue with geographic_point_circle wherein I can't seem to create a circle of radius 10 metres.
The easytoreproduce symptom is that the area of the circle varies greatly with only a small change in latitude or longitude.
See this StackOverflow post for details: https://stackoverflow.com/questions/65493910/boostpointcirclecomingoutinweirdshapes/
In order to produce a suitable circle of that scale, I need to use long double in my point type, but with an epsilon of ~1mm, a regular double ought to work fine. Is there something I'm missing about the implementation of point_circle or bg::area that would imply that this is expected behaviour?
Kind regards,
Chris
Geometry list run by mateusz at loskot.net