mini.cpp

#include <CGAL/leda_real.h>
#include <CGAL/CORE_Expr.h>
#include <CGAL/Lazy_exact_nt.h>
#include <CGAL/Simple_cartesian.h>

#include <iostream>



template <class Segment_2, class FT>
void compute_supporting_line(const Segment_2& s,
                             FT& a, FT& b, FT& c)
{
  a = s.source().y() - s.target().y();
  b = s.target().x() - s.source().x();
  c = s.source().x() * s.target().y() - s.target().x() * s.source().y();
}

template <class FT>
void bug()
{
  typedef CGAL::Simple_cartesian<FT> K;
  typedef typename K::Point_2 Point_2;
  typedef typename K::Segment_2 Segment_2;
  
  Point_2 ip(0.3080532378, 0.1282279698),
          iq(0.3080629044, 0.1282376364),
          ir(0.3080725711, 0.1282473031);
  
  Segment_2 sq(ip,iq);
  Segment_2 sr(iq,ir);
  Point_2 pp=ip;
    
  FT a1, b1, c1, a2, b2, c2;
  compute_supporting_line(sq, a1, b1, c1);
  compute_supporting_line(sr, a2, b2, c2);

  FT c1_ = a1 * pp.x() + b1 * pp.y() + c1;
  FT c2_ = a2 * pp.x() + b2 * pp.y() + c2;

  c1_ = FT(0);

  FT n1 = CGAL::square(a1) + CGAL::square(b1);
  FT n2 = CGAL::square(a2) + CGAL::square(b2);

  FT D1D2 = n1 * n2;

  FT uz = -a1 * a2 - b1 * b2 + CGAL::sqrt(D1D2);

  // the homogeneous coordinates of the Voronoi vertex are:
  //       (J + pp.x() * uz, uy = I + pp.y() * uz, uz)
  if (uz==0)
  {
    std::cout << std::setprecision(17);  
    std::cout << "CGAL::sqrt(D1D2)==a1 * a2 + b1 * b2 : " << (CGAL::sqrt(D1D2)==a1 * a2 + b1 * b2) << "\n";
    std::cout << "a1*b2==b1*a2 : " << (a1*b2==b1*a2) << "\n";
    std::cout << "D1D2==CGAL::square(a1 * a2 + b1 * b2) : " << (D1D2==CGAL::square(a1 * a2 + b1 * b2)) << "\n";
    std::cout << "CGAL::square(CGAL::sqrt(D1D2))==CGAL::square(a1 * a2 + b1 * b2) : " << (CGAL::square(CGAL::sqrt(D1D2))==CGAL::square(a1 * a2 + b1 * b2)) << "\n";
  }
  CGAL_assertion(uz!=0);
}

int main()
{
  std::cout << "testing leda::real\n";
  bug<leda::real>();
  std::cout << "testing CGAL::Lazy_exact_nt<CORE::Expr>\n";
  bug<CGAL::Lazy_exact_nt<CORE::Expr> >();
  std::cout << "testing CORE::Expr\n";
  bug<CORE::Expr >();
  return 0;
}