load.hh

// Copyright (C) 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_IO_FLD_LOAD_HH
# define MLN_IO_FLD_LOAD_HH


# include <mln/core/concept/image.hh>
# include <mln/io/fld/header.hh>
# include <mln/io/fld/load_header.hh>
# include <mln/io/fld/max_components.hh>

# include <mln/algebra/vec.hh>
# include <mln/value/rgb.hh>
# include <mln/value/int_u8.hh>

# include <mln/geom/nsites.hh>

# include <fstream>
# include <iostream>

namespace mln
{

  namespace io
  {

    namespace fld
    {

      template <typename I>
      inline
      void
      load(Image<I>& ima_, const char* filename);

# ifndef MLN_INCLUDE_ONLY

      namespace internal
      {

        void
        abort_load(const char* msg, const char* filename)
        {
          std::cerr << "Error: file '" << filename << "'"
                    << "cannot be loaded." << std::endl
                    << "Error description: " << msg << std::endl;
          abort();
        }

        // Read a Milena rgb value (sizeof(int_u8) != 1).
        template <unsigned int n>
        inline
        void read_value(std::ifstream& file, value::rgb<n>& v)
        {
          typedef typename value::int_u<n>::enc E;

          E c;
          file.read((char*)(&c), sizeof(E));
          v.red() = c;
          file.read((char*)(&c), sizeof(E));
          v.green() = c;
          file.read((char*)(&c), sizeof(E));
          v.blue() = c;
        }

        // Read a Milena scalar value (sizeof(int_u8) != 1).
        template <class V>
        inline
        void read_value(std::ifstream& file, value::Scalar<V>& v)
        {
          typedef typename V::enc E;

          E c;
          file.read((char*)(&c), sizeof(E));
          exact(v) = c;
        }

        // Read a builtin scalar value.
        template <typename V>
        inline
        void read_value(std::ifstream& file, V& v)
        {
          V c;
          file.read((char*)(&c), sizeof(V));
          v = c;
        }

        // used when (sizeof(int_u8) != 1)
        template <typename I>
        inline
        void load_raw_uncontiguous(std::ifstream& file, I& ima)
        {
          mln_piter(I) p(ima.domain());
            read_value(file, ima(p));
        }

        // used in g++ > 2.95
        template <typename I>
        inline
        void load_raw_contiguous(std::ifstream& file, I& ima)
        {
          mln_site(I) pmin = ima.domain().pmin();
          mln_site(I) pmax = ima.domain().pmax();

          typedef mln_site(I) P;
          enum { dim = P::dim };

          // The first array index varies most quickly (FORTRAN-style).
          typedef mln_value(I) V;


          std::size_t len = pmax[dim - 1] - pmin[dim - 1] + 1;
          std::size_t n = len * sizeof(V);

          P p = pmin;
          if (dim == 1)
            {
              file.read((char*)(&ima(p)), n);
              return;
            }

          while (true)
            {
              file.read((char*)(&ima(p)), n);
              ++p[dim - 2];

              for (int i = dim - 2; p[i] > pmax[i]; --i)
                {
                  if (i == 0)
                    return;
                  p[i] = pmin[i];
                  ++p[i - 1];
                }
            }
      }

        template <typename I>
        inline
        void load_raw(std::ifstream& file, I& ima)
        {
          if (sizeof(value::int_u8) == 1)
            load_raw_contiguous(file, ima);
          else
            load_raw_uncontiguous(file, ima);
        }

      } // end of mln::io::internal

      template <typename I>
      inline
      void
      load(Image<I>& ima_, const char* filename)
      {
        trace::entering("mln::io::fld::load");

        std::ifstream file(filename);
        if (! file)
          internal::abort_load("Fail to open the file.", filename);

        typedef mln_value(I) V;
        typedef mln_site(I)  P;

        I& ima          = exact(ima_);
        fld_header hder = fld::read_header(file);
        int nspace      = P::dim;
        int veclen      = mln_dim(V);

        if (nspace != hder.nspace)
          internal::abort_load("The dimension of the input does not match the one from the file.", filename);
        if (nspace > 3)
          internal::abort_load("The loader does not handle image dimension greater than three.", filename);
        if (veclen != hder.veclen)
          internal::abort_load("The dimension of the value does not match the one from the file.", filename);
        if (max_component(V ()) != max_component(hder.data))
          internal::abort_load("The data type of the input mismatches the one from the file.", filename);

        box<mln_site(I)> bbox;
        for (int i = 0; i < hder.ndim; ++i)
          {
            bbox.pmin()[i] = hder.min_ext[i];
            bbox.pmax()[i] = hder.max_ext[i];
          }

        ima.init_(bbox);
        internal::load_raw(file, ima);

        file.close();
        trace::exiting("mln::io::fld::load");
      }

# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::io::fld

  } // end of namespace mln::io

} // end of namespace mln

#endif // !MLN_IO_FLD_LOAD_HH

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