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["Sebastien Loriot (GeometryFactory)" <>]

On 04/18/2016 02:53 PM, Frédérik Paradis wrote:
> Hi,
>
> Thank you for your answer. So, before your answer, I reimplemented the
> features I needed from Point_container. The instantiation of the
> Iso_box_d looks like that:
> https://gist.github.com/freud14/88f014742122dc82b9a5a1b87feda5cc Do you
> see anything wrong with that approach?

Never use min and max as variables some versions of MSVC will not compile.
You could have checked that .homogeneous(d) are different for all
the coordinates before doing the product.
BTW, github storage is not so restricted so you can add some comments
in your code ;)

> Also, I looked at the FractionTraits and it seems that the number type
> must be of model ExplicitInteroperable which is not always the case
> when, for instance, the kernel is CGAL::Homogeneous_d<double>. Please
> correct me if I am wrong.

The advantage of this method is that you don't need to loop over
all the points of the rectangle.
IIRC the denominator will be 1 in that case.

Sebastien.

> Thank you.
>
> Frédérik
>
>
> 2016-04-18 3:50 GMT-04:00 Sebastien Loriot (GeometryFactory)
> <
>  
> <mailto:>>:
>
>     Looking at how things are implemented, in the Homogeneous case I think
>     you have no other choice than decomposing each Cartesian coordinate
>     to find a common RT factor.
>     If I have to do it, I would use a functor/function specialized in the
>     Homogeneous case.
>
>     For the specialization you can use the nested Kernel_tag for the Kernel
>     you are using that is either CGAL::Homogeneous_tag or
>     CGAL::Cartesian_tag.
>
>     For the decomposition, you can use Fraction_traits [1] that provides
>     a Decompose functor [2].
>
>     HTH
>
>     Sebastien.
>
>     [1]
>     
> http://doc.cgal.org/latest/Algebraic_foundations/classCGAL_1_1Fraction__traits.html
>
>     [2]
>     
> http://doc.cgal.org/latest/Algebraic_foundations/classFractionTraits___1_1Decompose.html
>
>
>     On 04/16/2016 12:28 AM, Frédérik Paradis wrote:
>
>         HI,
>
>         I am using the class Point_containter to generate and split the
>         bounding
>         box of a point set. I would like to get the bounding box as an
>         Iso_box_d. However, the Point_container class only offers a method
>         bounding_box which return a Kd_tree_rectangle. The only way to
>         retrieve
>         the coordinates of the corners of the rectangle seems to be the
>         methods
>         min_coord and max_coord which both returns the cartesian
>         coordinate for
>         the dimension i with the type FT.
>
>         The problem arises when I'm using the Homogeneous_d kernel with
>         whatever
>         ring type because the ring type and the field type are not the
>         same and
>         thus trigger a compilation error.
>
>         Here is my current code:
>
>                 std::vector<FT> min;
>                 std::vector<FT> max;
>                 const Kd_tree_rectangle<FT, D>& kdbox =
>         container.bounding_box();
>                 for(int i = 0; i < d; i++) {
>                   min.push_back(kdbox.min_coord(i));
>                   max.push_back(kdbox.max_coord(i));
>                 }
>                 bbox = Iso_box_d(Point_d(d, min.begin(), min.end()),
>                                   Point_d(d, max.begin(), max.end()));
>
>         Is there any way to make it work with Point_container or will I
>         have to
>         compute the corners by iterating over all points?
>
>         Thank you.
>
>         Frédérik
>
>
>
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