//Part 2. Chapter 13. Exercise 8
//------------------------------------------------------------------------------
 
struct Hexagon : Shape {
 
        Hexagon(Point Center, double radius)
                :       rCircumCircle(radius)
        {
                add(Center);
        }
       
        void draw_lines() const;
 
private:
        double rCircumCircle;
};
 
//------------------------------------------------------------------------------
 
//------------------------------------------------------------------------------
 
void Hexagon::draw_lines() const {
 
        if (fill_color().visibility()) {
                       
                fl_color(fill_color().as_int());
                fl_begin_complex_polygon();
 
                for (int i = 0; i < 6; i++)
                        fl_vertex(point(0).x + rCircumCircle*cos(2*M_PI*i/6),
                        point(0).y + rCircumCircle*sin(2*M_PI*i/6));
               
                       
                fl_end_complex_polygon();
                fl_color(color().as_int());    // reset color
                       
        }
 
        if (color().visibility()) {
                fl_color(color().as_int());
                for (int i = 0; i < 6; i++) {
                        int p;
                        if (i < 5) p = i + 1;
                        else p = 0;
                       
                        fl_line(point(0).x + rCircumCircle*cos(2*M_PI*i/6),
                        point(0).y + rCircumCircle*sin(2*M_PI*i/6),
                        point(0).x + rCircumCircle*cos(2*M_PI*p/6),
                        point(0).y + rCircumCircle*sin(2*M_PI*p/6));
                }
        }
}
 
//------------------------------------------------------------------------------