Re: GSoC 2017 - Implement boolean operations on polygons

[Juan Pablo Carbajal]

On Fri, Mar 17, 2017 at 7:52 PM, John Swensen <address@hidden> wrote:
>
> On Mar 17, 2017, at 2:56 AM, Juan Pablo Carbajal <address@hidden>
> wrote:
>
> On Fri, Mar 17, 2017 at 9:41 AM, PhilipNienhuis <address@hidden>
> wrote:
>
> Juan Pablo Carbajal-2 wrote
>
> On Thu, Mar 16, 2017 at 9:56 PM, piyushjain &lt;
>
>
> piyushjain1sa@
>
>
> &gt; wrote:
>
> Sir, I went through the current geometry package development and also
> read
> about mkoctfile command, and how to use oct create and use oct-files.
>
> So, can you tell me what are the milestones of the project? I mean,going
> step-wise, what do I need to implement?
>
>
>
> --
> View this message in context:
> http://octave.1599824.n4.nabble.com/GSoC-2017-Implement-boolean-operations-on-polygons-tp4682161p4682435.html
> Sent from the Octave - Maintainers mailing list archive at Nabble.com.
>
> So you know what you want to pursue already?
> 1. Cleanning up the boost interface
> 2. Adding clipper interface, read this
> https://savannah.gnu.org/patch/?func=detailitem&item_id=9000#options
>
>
> From my memory, the Clipper interface should be about done.
> I'm still busy with making it clip polylines (works now) and interpolating Z
> values (got stuck there); but for "ordinary" 2D polygons I think it just
> works as it is.
>
> Philip
>
>
>
> --
>
>
> In that case I suggest you provide patches to integrate Philip work
> into geomtry, following the guidelines described in that savanah
> thread.
> I was planning to do this in Octconf so I will give you quick feedback
> if you provide something beginning of next week.
>
>
> One final comment. I know I pushed the Boost solution because at the time I
> thought it had the most robust solution for self-intersecting polygons,
> polygons with parallel lines, etc. I now feel a little bad that we spent all
> that time and it hasn’t been incorporated into the package. It is quite
> cumbersome to get Boost set up to compile with the version that supports
> self-intersection correction. I think that more work could be done to make
> it a much better solution by making a “Point concept abstraction” that would
> allow it to operate on the Octave variable data in-place without having to
> copy. For larger datasets, this could be a huge memory (and potentially
> performance) improvement over the other solutions where you have to
> transform the Octave data into the format required by the library.
>
> Has anyone ever explored the license for GPC
> (http://www.cs.man.ac.uk/~toby/gpc/)? It says it is free for
> private/hobbyist/education purposes, but I don’t know whether the license is
> compatible with the GPL and Octave. From my experience, GPC is one of the
> fastest and most robust polygon clipper out there. Maybe we overlooked it
> because of its split license and the fact that the license isn’t very well
> defined?
>
> John S.

Hi John,

Do not feel bad, somebody has to start doing something, and you did
it. We should salvage as much as we can from the work done.
Will you be at OctConf?