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: 2011-08-08 02:57:06

On 7/08/2011 8:05 PM, Barend Gehrels wrote:
> Why should you do that? Round them and then consider them as 
> duplicate? If they would be duplicate (before rounding), they would 
> not be included (since this is solved).

Hi Barend.
Yes, of course you're right that fractional differences certainly aren't 
duplicates. I'm sorry I implied otherwise.
Having swapped over some time ago to using integers in my Clipper 
library, and now being so used to scaling fractional coordinates into 
integers to manage precision, I'd made the presumption that fractional 
values in these specific tests was unnecessary precision. I now accept 
that some might consider otherwise. Also, I can see now that some of my 
comments may have seemed critical of Ggl and Gtl, and for that I 
apologize. I really do believe each library has it's strengths and 
weaknesses.
Regards
Angus