Re: [boost] Another GGL review

Subject: Re: [boost] Another GGL review
From: Jose (jmalv04_at_[hidden])
Date: 2009-11-17 03:48:38

On Mon, Nov 16, 2009 at 10:36 PM, Barend Gehrels <barend_at_[hidden]> wrote:
> As I've a GIS-background myself too I'm glad to read this. The reasons for
> moving it to extension were:
> - the kernel should be geometry and not GIS
> - there is one thing still to be incorporated in the design of the
> GIS-extension (this is: the earth model, it is referred to in distance and
> in projections, and it should be shared)
> - the library is large and projections should make much it larger, and we
> didn't write the maths ourselves

Moving it to extensions make sense. My point is that the extensions
necessary to make the library useful for GIS should be part of the
core library rather than a separate extension that the user has to
find.

> One question, do you mean with key-extension:
> - the geographic coordinate system
> - or also the projections?
>
> The first is small, a few sources and distance calculations, and they were
> included in the distribution because they nicely show how to work with BGL
> (and GIS/SVG).
> The projections is more, ~90 complex math sources
>
>> I think the problem with the PROJ dependency could be handled similary
>> to the MPI library, that provides bindings to the C library.
>>
>
> That is an option, but we converted PROJ to C++ style, that alone gives
> already some %'s performance gain. Besides that we want to be able to use
> GMP numbers (optionally), so we don't want to mingle them into existing
> (heavily macro's) C sources.

The first one is key, the second one you would need feedback from more
reviewers. If there is no PROJ dependency then it's even easier to
include it.

regards
jose