image_write.hh

// Copyright (C) 2001, 2002, 2003, 2004  EPITA Research and Development Laboratory
//
// This file is part of the Olena Library.  This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License version 2 as published by the
// Free Software Foundation.
//
// This library 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 this library; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
// MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free
// software library 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 OLENA_IO_IMAGE_WRITE_HH
# define OLENA_IO_IMAGE_WRITE_HH

# include <mlc/bool.hh>

# include <oln/config/system.hh>
# include <oln/core/abstract/image_with_dim.hh>
# include <oln/core/image2d.hh>
# include <oln/core/image1d.hh>

# include <oln/io/image_base.hh>
# include <oln/io/pnm_write_2d.hh>
# include <oln/io/pnm_write_3d.hh>
# include <oln/io/stream_wrapper.hh>
# include <oln/io/utils.hh>

# include <list>
# include <iostream>

namespace oln {

  namespace io {

    namespace internal {

      template< writer_id W, typename T >
      struct try_writers
      {
        static bool
        by_extension(const T& input, std::ostream& out, const std::string& ext)
        {
          if (image_writer<W,T>::knows_ext(ext))
            if (image_writer<W,T>::write(out, input))
              return true;
          return try_writers<writer_id(unsigned(W)-1), T>
                   ::by_extension(input, out, ext);
        }

        static bool
        by_data(const T& input, std::ostream& out, const std::string& ext)
        {
          if (image_writer<W,T>::write(out, input))
            {
              // std::clog << "[ambiguous extension '" << ext
              //        << "' wrote as " << image_writer<W,T>::name() << "] "
              //        << std::flush;
              return true;
            }
          return try_writers<writer_id(unsigned(W)-1), T>
                   ::by_data(input, out, ext);
        }
      };


      template< typename T >
      struct try_writers<WriteNone, T>
      {
        static bool
        by_extension(const T&, std::ostream&, const std::string&)
        {
          return false;
        }

        static bool
        by_data(const T&, std::ostream&, const std::string&)
        {
          return false;
        }
      };

      struct writers_trier
      {
        template <class T>
        static bool
        doit(const T& input, std::ostream& out, const std::string ext)
        {
          bool result = try_writers<WriteAny,T>::by_extension(input, out, ext);
          if (!result)
            result = try_writers<WriteAny,T>::by_data(input, out, ext);
          return result;
        }
      };


      template <class E, unsigned N>
      inline bool
      write(const abstract::image_with_dim<N, E>& input,
            const std::string& name)
      {
        mlc::is_true<N == 2 || N == 3>::ensure();

        typedef try_stream_wrappers_out<StreamAny, E, writers_trier>
          stream_trier;

        std::string ext = utils::extension(name);

        if (stream_trier::by_extension(input.exact(), name, ext))
          return true;
        // std::clog << "[unable to write '" << name << "'] " << std::endl;
        return false;
      }

      template <class E>
      inline bool
      write(const abstract::image_with_dim<1, E>& input,
            const std::string& name)
      {
        image2d<oln_value_type(E)> tmp(1, input.ncols());
        oln_iter_type(image1d<oln_value_type(E) > ) it(input);
        for_all(it)
          tmp(0, it.col()) = input[it];
        if (!write(tmp, name))
          return false;
        return true;
      }

    } // end of namespace internal

  } // end of namespace io

} // end of namespace oln

#endif // ! OLENA_IO_IMAGE_WRITE_HH

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