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 Doré
CTO, Vice President

M: +45 40 53 93 21
P: +45 88 20 20 88
C: Hørsholm, Denmark
W: www.visiopharm.com

 

 

From: Geometry <geometry-bounces@lists.boost.org> On Behalf Of Chris Watts via Geometry
Sent: 31. december 2020 10:32
To: geometry@lists.boost.org
Cc: Chris Watts <Chris@cjwatts.com>
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 easy-to-reproduce 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/boost-point-circle-coming-out-in-weird-shapes/

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