Re: [Boost-users] [polygon] Incorrect output from get_trapezoids(..., HORIZONTAL)

Subject: Re: [Boost-users] [polygon] Incorrect output from get_trapezoids(..., HORIZONTAL)
From: Barend Gehrels (barend_at_[hidden])
Date: 2014-10-08 11:40:19

Hi Patrick,

Patrick J. LoPresti wrote On 7-10-2014 21:29:
> I apologize for sending this to the mailing list, but when I tried to
> file a bug report via Trac, it said "Trac thinks your submission might
> be Spam. To prove otherwise please provide a response to the
> following"... And then there was no "following".
>
> Please let me know if there is a better forum to report this sort of issue.
>
> I am using Boost 1.56. The following program uses boost::polygon to
> slice up a figure (with a "hole" cut out of it) into horizontal
> trapezoids. The output I get is:
>
> Output:
> polygon  (4 3) (4 0) (0 0) (0 3) (4 3)
>
> ...which is clearly wrong. I am pretty sure my code is correct,
> because if I replace bg::HORIZONTAL with bg::VERTICAL, I get the
> correct output of a bunch of vertical trapezoids.
>
> For my application, I really want horizontal traps. I suppose I can
> just swap x and y on input and output... But this seemed worth
> reporting.

Thanks for the report, I will look at this soon.

Regards, Barend