float01_.hh

// Copyright (C) 2006, 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation, version 2 of the License.
//
// Olena is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to produce
// an executable, this file does not by itself cause the resulting
// executable to be covered by the GNU General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_VALUE_FLOAT01__HH
# define MLN_VALUE_FLOAT01__HH

# include <iostream>
# include <mln/core/contract.hh>
# include <mln/metal/math/pow.hh>
# include <mln/metal/bexpr.hh>

# include <mln/value/int_u.hh>
# include <mln/value/concept/floating.hh>
# include <mln/value/internal/convert.hh>
# include <mln/value/float01.hh>
# include <mln/trait/value_.hh>



namespace mln
{

  // Fwd decls.
  namespace value {
    class float01;
    template <unsigned n> struct float01_;
  }


  namespace trait
  {

    template <unsigned n>
    struct value_< mln::value::float01_<n> >
    {
      enum constants_ {
        dim = 1,
        nbits = n,
        card  = mln_value_card_from_(nbits)
      };

      typedef trait::value::nature::floating nature;
      typedef trait::value::kind::data       kind;
      typedef mln_value_quant_from_(card)    quant;

      static float min() { return 0.f; }
      static float max() { return 1.f; }
      static float epsilon() { return 0.f; }

      typedef float comp;

      typedef float sum;
    };

  } // end of namespace trait


  namespace value
  {

    template <unsigned n>
    struct float01_

      : public Floating< float01_<n> >,

        public internal::value_like_< float,             // Equivalent. // FIXME: Why not float01?
                                      mln_enc(int_u<n>), // Encoding.
                                      float,             // Interoperation.
                                      float01_<n> >      // Exact.
    {
      float01_();

      float01_(float val);

      float01_(const mln::literal::zero_t&);
      float01_& operator=(const mln::literal::zero_t&);
      float01_(const mln::literal::one_t&);
      float01_& operator=(const mln::literal::one_t&);

      float01_<n>& operator=(float val);

      float value() const;

      void set_ind(unsigned long val);

      operator float() const;

    private:
      typedef mln_enc(int_u<n>) enc_;
    };


    namespace internal
    {

      template <unsigned n>
      struct convert_< float01_<n> >
      {
        static float01_<n> value_at_index(unsigned i)
        {
          float01_<n> tmp;
          tmp.set_ind(i);
          return tmp;
        }

        static unsigned index_of_value(const float01_<n>& v)
        {
          return v.to_enc();
        }
      };
    }


    template <unsigned n>
    std::ostream& operator<<(std::ostream& ostr, const float01_<n>& f);


    template <unsigned n, unsigned m>
    bool approx_equal(const float01_<n>& lhs, const float01_<m>& rhs);

    template <unsigned n>
    bool approx_equal(const float01_<n>& lhs, const float f);



# ifndef MLN_INCLUDE_ONLY

    // Float01_<n>.

    template <unsigned n>
    inline
    float01_<n>::float01_()
    {
    }

    template <unsigned n>
    inline
    float01_<n>::float01_(float val)
    {
      mln_precondition(val >= 0.f);
      mln_precondition(val <= 1.f);
      this->v_ = static_cast<enc_>(val * (float(mln_max(enc_)) - 1.f)); // FIXME
    }

    template <unsigned n>
    inline
    float
    float01_<n>::value() const
    {
      return float(this->v_) / (float(mln_max(enc_)) - 1.f); // FIXME
    }

    template <unsigned n>
    inline
    void
    float01_<n>::set_ind(unsigned long val)
    {
      this->v_ = static_cast<enc_>(val);
    }

    template <unsigned n>
    inline
    float01_<n>::float01_(const mln::literal::zero_t&)
    {
      this->v_ = 0;
    }

    template <unsigned n>
    inline
    float01_<n>&
    float01_<n>::operator=(const mln::literal::zero_t&)
    {
      this->v_ = 0;
      return *this;
    }

    template <unsigned n>
    inline
    float01_<n>::float01_(const mln::literal::one_t&)
    {
      this->v_ = 1;
    }

    template <unsigned n>
    inline
    float01_<n>&
    float01_<n>::operator=(const mln::literal::one_t&)
    {
      this->v_ = 1;
      return *this;
    }

    template <unsigned n>
    inline
    float01_<n>&
    float01_<n>::operator=(float val)
    {
      mln_precondition(val >= 0.f);
      mln_precondition(val <= 1.f);
      this->v_ = static_cast<enc_>(val * (float(mln_max(enc_)) - 1.f)); // FIXME
      return *this;
    }

    template <unsigned n>
    inline
    float01_<n>::operator float() const
    {
      return float(this->v_) / (float(mln_max(enc_)) - 1.f);
    }


    // Operators.

    template <unsigned n>
    inline
    std::ostream& operator<<(std::ostream& ostr, const float01_<n>& f)
    {
      return ostr << f.value();
    }

    template <unsigned n, unsigned m>
    inline
    bool approx_equal(const float01_<n>& lhs, const float01_<m>& rhs)
    {
      return float01(lhs) == float01(rhs);
    }

    template <unsigned n>
    inline
    bool approx_equal(const float01_<n>& lhs, float f)
    {
      return float01(lhs) == float01_<n>(f);
    }


# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::value

} // end of namespace mln

#endif // ! MLN_VALUE_FLOAT01__HH