Re: [boost] Progress on the tweener library (with Geometry)

Subject: Re: [boost] Progress on the tweener library (with Geometry)
From: Julien Jorge (julien.jorge_at_[hidden])
Date: 2012-07-26 01:54:42

Le Wed, 25 Jul 2012 11:39:05 +0200,
Klaim - Joël Lamotte <mjklaim_at_[hidden]> a écrit :

> On Wed, Jul 25, 2012 at 7:55 AM, Julien Jorge
> <julien.jorge_at_[hidden]>wrote:
> 
> > For the case of the double type, I guess I can find a workaround by
> > providing a specialized implementation for Boost.Geometry and
> > keeping the previous implementation for the general case.
> >
> 
> Oh I see, the Point concept can work with types like double if it is
> wrapped as bg::model::point<double, 1>. Not sure it's the best
> strategy to deal with it but that's a possibility you could use for
> any type that is not accepted by boost geometry, as a last resort
> conversion. I guess you'll have to try different strategies see
> what's efficient.

I finally managed to make the tweeners to work with both Boost.Geometry
and double by selecting the implementation using bg::tag<P>::type. If
the tag is not void, the implementation uses the algorithms of
Boost.Geometry. Otherwise it falls back to the default computation
using the default operators.

However, if the user of the library has a custom coordinate type
that cannot be adapted to bg::point and for which the arithmetic
operators are not defined, then he won't be able to use the
single_tweener as is. There is still the solution for him to use a
tweener_group on each dimension of the type but maybe the library
should provide a way to pass the operators to the tweeners (through
some kind of point_traits?).

Julien Jorge