Re: [boost] Formal Review: Boost.Polygon starts today August 24, 2009

Subject: Re: [boost] Formal Review: Boost.Polygon starts today August 24, 2009
From: Jeffrey Hellrung (jhellrung_at_[hidden])
Date: 2009-09-01 02:50:37

Barend Gehrels wrote:
>> The formal review of the Boost.Polygon library by Lucanus Simonson 
>> starts today, August 24, 2009 and will finish September 2, 2009.
...
> Expectations: I think a templated Boost.Polygon library should at least:
> 1) support most of the basic polygon geometry algorithms
> 2) have a performance comparable to other libraries
> 3) support both integer and floating point coordinate types
...
> 3) Boost.Polygon supports integer but does not support double for 
> boolean operations.

+1; I'm generally sympathetic to Barend's concerns, especially the 
(apparent?) lack of direct floating point support.  A generic geometry 
or polygon library could be a component in some fracture simulation 
research software I plan to eventually write, but imprecision associated 
with converting to integer types, and hence the associated inexact 
constructions of intersection points, makes the proposed Boost.Polygon 
unuseable for that purpose, in my opinion.

I would like to see at least a framework to be able to support floating 
point types and exact constructions.  CGAL does this, I believe.  I'm 
not familiar with their framework.

Or a change in the library from Polygon to IntegerPolygon or something 
to indicate it's intended scope, with "Polygon" reserved for a more 
general library encompassing floating point types and a broader class of 
operations.

I'm now interested in comparing the proposed Boost.Polygon with Berand's 
GGL, and in seeing Luke's response to Berand's comments.

That said, I just want to say it looks like Luke's library is very well 
designed toward its intended goals.  I'll try to give a more elaborate 
review saying as much.

- Jeff