CGAL users discussion list

[BBB HHH <>]

Hello,

I used the operator() which resolved the problem. But i have another problem. The operator() is given below:

void   operator()(const& Box a, const Box& b)
   {
        Triangles::difference_type index = std::distance(triangles.begin(), box1.handle());
        // Here i want to compute the index of the box a in the list of boxes by finding the distance between the box1.handle() (which is of type         // std::list<Triangle_3>::iterator) and the trinagles.begin() (which is also of the same type). The index allows me to find corresponding   //triangles in my list of triangles and do futher processing.
   }

My program compiles successfully but it crashes when trying to execute the line inside the operator().
I am using Visual Studio 2005 with SP. The error is "list iterators incompatible".

My program is included below.
Thanks in advance
Hichem Barki

#include <iostream>
#include <vector>
#include <list>
#include <CGAL/intersections.h>
#include <CGAL/Bbox_3.h>
#include <CGAL/box_intersection_d.h>
#include <CGAL/function_objects.h>


using std::cout;
using std::cin;
using std::endl;

template <class Kernel>
class My_class
{
public:
    typedef typename Kernel::FT                                            Number_type;
    typedef typename Kernel::Point_2                                    Point_2;
    typedef typename Kernel::Point_3                                    Point_3;
    typedef typename std::list< Triangle_3>                                Triangles;
    typedef typename Triangles::iterator                                            tri_it;
   
   typedef CGAL::Box_intersection_d::Box_with_handle_d<double,3,tri_it> Box;
   
    // Member data
    Triangles                                            triangles;                    // List of the superset triangles
   
    // Constructors
   My_class(...)
    {
        // Fill the list of Triangles
        .....

    }
    void   operator()(const& Box a, const Box& b)
    {
        Triangles::difference_type index = std::distance(triangles.begin(), box1.handle());
    }
    void get_inters_bboxes()
    {
        // Create the corresponding vector of bounding boxes
        std::vector<Box> boxes;
        for (tri_it iter = triangles.begin(); iter != triangles.end(); ++iter)
            boxes.push_back( Box( iter->bbox(), iter));

        // Run the self intersection algorithm with all defaults
        CGAL::box_self_intersection_d(boxes.begin(), boxes.end(), callback, 10, CGAL::Box_intersection_d::HALF_OPEN);
    }
   
   
};

---

De : Pierre Alliez <pierre.alliez@sophia..inria.fr>
À :
Envoyé le : Mercredi, 10 Décembre 2008, 12h14mn 29s
Objet : Re: [cgal-discuss] A problem with iso oriented box intersection package

hi Hichem,

that is tricky indeed -  have already encountered this issue which was solved with the help of Andreas Fabri.

I send you my self_intersect global function, which takes as parameters a CGAL polyhedron, and an output iterator where I write all triangles which interesect. as you can see I can pass to the intersection engine a class Intersect_facets with a parameterized constructor.

the callback function is the operator () of that class.

good luck!

pierre


BBB HHH a écrit :

Hello,

I am working with the CGAL::box_self_intersection_d to detect interrsections in a list of bboxes of triangles. I want to do this in an object oriented manner (inside a class). Some parts of my code are listed below. I can not compile my program since there are several errors in the line using box_self_intersection_d.
I think the error is the use of the callback of box_self_intersection_d. In my program this callback is a class member function. In the examples provided by CGAL. The callback is a global function and the box_self_intersection_d function is called inside main(). Can someone help me to detect the problem (how to put a function object inside a class template and how to use it correctly). I tried a global function as a callback, the compile succeds but i can not acces the member data of my class.

Thanks in advance
Hichem BARKI


#include <iostream>
#include <vector>
#include <list>
#include <CGAL/intersections..h>
#include <CGAL/Bbox_3.h>
#include <CGAL/box_intersection_d.h>
#include <CGAL/function_objects.h>


using std::cout;
using std::cin;
using std::endl;

template <class Kernel>
class My_class
{
public:
    typedef typename Kernel::FT                                            Number_type;
    typedef typename Kernel::Point_2                                    Point_2;
    typedef typename Kernel::Point_3                                    Point_3;
    typedef typename std::list< Triangle_3>                                Triangles;
    typedef typename Triangles::iterator                                            tri_it;
   
   typedef CGAL::Box_intersection_d::Box_with_handle_d<double,3,tri_it> Box;



   
    // Member data
    Triangles                                            triangles;                    // List of the superset triangles
   
    // Constructors
   My_class(...)
    {
        // Fill the list of Triangles
        .....

    }
    void   callback(const& Box a, const Box& b)
    {
        // DO some processing with the member data of My_class
    }
    void get_inters_bboxes()
    {
        // Create the corresponding vector of bounding boxes
        std::vector<Box> boxes;
        for (tri_it iter = triangles.begin(); iter != triangles.end(); ++iter)
            boxes.push_back( Box( iter->bbox(), iter));

        // Run the self intersection algorithm with all defaults
        CGAL::box_self_intersection_d(boxes.begin(), boxes.end(), callback, 10, CGAL::Box_intersection_d::HALF_OPEN);
    }
   
   
};

-- 
Pierre Alliez
INRIA Sophia Antipolis - Mediterranee 
Project-team GEOMETRICA 
http://www-sop.inria.fr/members/Pierre.Alliez/
Tel: +33 4 92 38 76 77
Fax: +33 4 97 15 53 95