CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

I am not sure what you use as kernel but simply this should be
the most efficient:

typedef  CGAL::Exact_predicates_exact_constructions_kernel Kernel;
typedef CGAL::Snap_rounding_traits_2<Kernel>      Traits;


Sebastien.

On 10/17/2011 01:14 AM, Graviton wrote:
> I would need to snap round a list of polygons I have, here's my code:
>
>
>
> #include&lt;CGAL/basic.h&gt;
> #include&lt;CGAL/Cartesian.h&gt;
> #include&lt;CGAL/Quotient.h&gt;
> #include&lt;CGAL/MP_Float.h&gt;
> #include&lt;CGAL/Snap_rounding_traits_2.h&gt;
> #include&lt;CGAL/Snap_rounding_2.h&gt;
>
>
> struct Kernel : public CGAL::Exact_predicates_exact_constructions_kernel
> {};
> typedef Kernel::FT                                         Number_type;
>
> //typedef CGAL::Quotient<CGAL::Gmpq>            Number_type;
> typedef CGAL::Cartesian<Number_type>              Kernel;
> typedef CGAL::Snap_rounding_traits_2<Kernel>      Traits;
> typedef Kernel::Segment_2                        Segment_2;
> typedef Kernel::Point_2                          Point_2;
> typedef std::list<Segment_2>                      Segment_list_2;
> typedef std::list<Point_2>                        Polyline_2;
> typedef std::list<Polyline_2>                     Polyline_list_2;
>
> void ComputeSegment(Segment_list_2 seg_list)
> {
>    Polyline_list_2 output_list;
>
>
>
> CGAL::snap_rounding_2&lt;Traits,Segment_list_2::const_iterator,Polyline_list_2&gt;
>      (seg_list.begin(), seg_list.end(), output_list, 10, false, false, 1);
>
>    int counter = 0;
>    Polyline_list_2::const_iterator iter1;
>    for (iter1 = output_list.begin(); iter1 != output_list.end(); ++iter1) {
>      std::cout<<  "Polyline number "<<  ++counter<<  ":\n";
>      Polyline_2::const_iterator iter2;
>      for (iter2 = iter1->begin(); iter2 != iter1->end(); ++iter2)
>        std::cout<<  "    ("<<  iter2->x()<<  ":"<<  iter2->y()<<  ")\n";
>    }
>
>
> }
>
>
>
> My dataset contains about 3000 segments, however, when I run the above code
> it took about 1 second.
>
> I just wonder is there anyway I can further make this code run faster, but
> not at the expense of the accuracy and system stability?
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/Optimize-snap-rounding-operation-tp3911353p3911353.html
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