Geometry Boost List: Re: [geometry] Why closure?

Subject: Re: [geometry] Why closure?
From: TONGARI (tongari95_at_[hidden])
Date: 2013-06-20 12:30:19

2013/6/21 Barend Gehrels <barend_at_[hidden]>

> Hi,
>
>
> On 20-6-2013 11:26, TONGARI wrote:
>
>>
>> I'm not quite understand why we need traits::closure for Ring & Polygon,
>> aren't these always closed?
>> What should I expect if the closure is open? Should I see Ring as
>> Linestring then?
>>
>
> No (about the last question).
>
> Apparently the doc about closure should be updated. However, this page
> explains it clearly:
>
> http://www.boost.org/doc/libs/**1_53_0/libs/geometry/doc/html/**
> geometry/reference/**enumerations/closure_selector.**html<http://www.boost.org/doc/libs/1_53_0/libs/geometry/doc/html/geometry/reference/enumerations/closure_selector.html>

Yah, I somewhat missed that page, seems it does contain the info I needed.
Since I'm writing my 2d graphics lib, I always think the lib should close
it anyway for drawing, but I don't know how it matters in the context of
geometry operations...

Thanks.