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

Subject: Re: [boost] Progress on the tweener library (with Geometry)
From: Barend Gehrels (barend_at_[hidden])
Date: 2012-07-27 05:06:13

Hi Julien,

On 26-7-2012 7:54, Julien Jorge wrote:
> 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.

Great to hear!

>   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?).

Because I cc this Geometry list now, I copy here your earlier info to 
access the library:

http://lists.boost.org/Archives/boost/2012/07/195216.php

and the first message:

http://lists.boost.org/Archives/boost/2012/07/194979.php

Regards, Barend