CGAL users discussion list

[skhiat <>]

Hello
I am a new user with CGAL I would like extrude many polygon_2 joined with 
union
operation and extrude it in y axis. And with a Polyhedron_3 generated I would
like add intersection plan (y = k) on my Polyhedron_3.
I am here to ask you how I can do it ?

I tried to work on first part of my program : boolean operation with 
polygon_2.
I was code function to do primitive polygon :

Polygon_2 doCircle(double R, unsigned short k)
{
    Point_2 tmp_p;
    Polygon_2 p;
    double da = double(2.0*3.1415926535897932)/double(k);
    for (unsigned int i = 0; i < k; i++)
    {
        tmp_p = Point_2(R*cos(double(i)*da), R*sin(double(i)*da));
        p.push_back(tmp_p);
    }
    return p;
}

Polygon_2 doEllipse(double Rx, double Ry, unsigned short k)
{
    Point_2 tmp_p;
    Polygon_2 p;
    double da = double(2.0*3.1415926535897932)/double(k);
    for (unsigned int i = 0; i < k; i++)
    {
        tmp_p = Point_2(Rx*cos(double(i)*da), Ry*sin(double(i)*da));
        p.push_back(tmp_p);
    }
    return p;
}

Polygon_2 doSquare(double cc)
{
    Point_2 tmp_p;
    Polygon_2 p;
    double c = cc/2.0;
    p.push_back(Point_2( c,  c));
    p.push_back(Point_2(-c,  c));
    p.push_back(Point_2(-c, -c));
    p.push_back(Point_2( c, -c));
    return p;
}

And to join my polygon I do :
Polygon_set_2 S;
Polygon_2 Circ = doCircle(6.0, 10);
Polygon_2 Squa = doSquare(10.0);
Polygon_2 Elli = doEllipse(1.0, 10.0, 48);
S.insert (Circ);
S.join (Squa);
S.join (Elli);

I don't know if my method is a good solution but I don't not how do otherwise.
And to draw it I do :
glBegin(GL_TRIANGLE_STRIP);
    for (it_vrtx it = arr.vertices_begin(); it != arr.vertices_end(); it++)
        glVertex3d(it->point().x(), it->point().y(), 0.0);
glEnd();

I have a Bad renderer because I can't get faces I try to se in
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/Partition_2/Chapter_main.html
but I not understand how I can do it.

And for my others part I don't know how I can do it like :
extrusion and cutting my polygon extruded.

Thank you for you future answer

PS : sorry for my bad english (I'm frensh speaker)
--