Geometry Boost List: Re: [geometry] Fwd: intersection of two polygons

Subject: Re: [geometry] Fwd: intersection of two polygons
From: Barend Gehrels (barend_at_[hidden])
Date: 2012-07-01 14:45:50

Hi Victor,

On 22-6-2012 12:19, Botnev Victor wrote:
> In addition I would specify versions of Boost where this behavior 
> appears. They are 1.48, 1.49 and 1.50beta.
> ---------- Forwarded message ----------
> From: *Botnev Victor* <botnev.victor_at_[hidden] 
> <mailto:botnev.victor_at_[hidden]>>
> Date: 2012/6/21
> Subject: intersection of two polygons
> To: geometry_at_[hidden] <mailto:geometry_at_[hidden]>
>
>
> Hi all, I have found the following problem.
> There are two polygons in binary file in the attachment (One of them 
> contents few thousands of points and their listing would be too long).
> I use Visual Studio 2008 and this file was written by a program which 
> was made by it.
> The code presented in attachment read this file and try to intersect 
> the polygons. The result is wrong. I see it even from analyzing 
> bounding boxes: the bounding box of an intersection should be within 
> (or equal to) the intersection of the bounding boxes of given 
> polygons, but here it is not.

I did have a closer look and can reproduce it, thanks for the versions 
(it indeed occurs still at 1.50).

I can reproduce it also if I simplify it (a tiny bit) and use ttmath, so 
this one is (probably) not a FP-robustness issue.

Hope to fix it soon.

Thanks for the report,
Barend