Geometry Boost List: [ggl] Re: Problems with the difference between two polygons

Subject: [ggl] Re: Problems with the difference between two polygons
From: Angus Johnson (awj1958)
Date: 2011-08-07 15:34:28

On 7/08/2011 10:29 AM, Simonson, Lucanus J wrote:
> I'm not sure that one choice of rounding can be called more correct 
> than another.

Hi Luke. I hope I didn't call my library "more correct" than the others, 
as that is evidently not the case. However, I was stating that Clipper 
was returning a simpler (while still correct) solution.

> Ggl is most accurate because it uses only machine rounding.

ISTM Ggl doesn't round, but otherwise - yes, fractions *may be* more 
accurate, though Is Ggl still vulnerable to floating point imprecision 
(see 
http://barendgehrels.blogspot.com/2011/01/precision-cause-of-spikes.html )?

A.