// Copyright (c) 2006-2009 Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/trunk/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/shear.h $
// $Id: shear.h 59002 2010-10-04 11:00:27Z lrineau $
// 
//
// Author(s)     : Michael Kerber <mkerber@mpi-inf.mpg.de>
//
// ============================================================================


#ifndef CGAL_ACK_SHEAR_H
#define CGAL_ACK_SHEAR_H 1

#include <CGAL/basic.h>
#include <CGAL/Polynomial_traits_d.h>

#include <utility>
#include <vector>
#include <functional>
#include <iterator>
#include <boost/iterator/transform_iterator.hpp>
#include <boost/iterator/counting_iterator.hpp>

namespace CGAL {

namespace internal {

/*! \ingroup NiX_bivariate_polynomial_hacks
 *  \brief Computes the polynomial f(x+sy,y)
 */ 
template<class NT>
CGAL::Polynomial<CGAL::Polynomial<NT> > 
shear(const CGAL::Polynomial<CGAL::Polynomial<NT> >& f,NT s) {
    typedef CGAL::Polynomial<NT> Poly_1;
    typedef CGAL::Polynomial<Poly_1> Poly_2;

    Poly_1 x(NT(0),NT(1));
    Poly_1 zero(NT(0));
    Poly_1 one(NT(1));
    Poly_2 for_x(x,Poly_1(NT(s)));
    Poly_2 for_y(zero,one);

    std::vector<Poly_2> coeffs;
    coeffs.push_back(for_x);
    coeffs.push_back(for_y);

    return typename CGAL::Polynomial_traits_d<Poly_2>::Substitute()
        (f,coeffs.begin(), coeffs.end());
    
}

} // namespace internal

} //namespace CGAL

#endif // NiX_BIVARIATE_POLYNOMIAL_HACKS_H
// EOF
