Re: [boost] Another GGL review

Subject: Re: [boost] Another GGL review
From: Barend Gehrels (barend_at_[hidden])
Date: 2009-11-16 16:36:57

Hi Jose,

Thanks for your interest and for your enthousiastic review.

> The library should incorporate the key extensions that make it useful
> right away, i.e. non-cartesian coordinates.
>   
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

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.

Regards, Barend