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- //
- // Copyright 2007-2008 Christian Henning
- //
- // Distributed under the Boost Software License, Version 1.0
- // See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt
- //
- #ifndef BOOST_GIL_IO_SCANLINE_READ_ITERATOR_HPP
- #define BOOST_GIL_IO_SCANLINE_READ_ITERATOR_HPP
- #include <boost/gil/io/error.hpp>
- #include <boost/gil/io/typedefs.hpp>
- #include <boost/iterator/iterator_facade.hpp>
- #include <iterator>
- #include <memory>
- #include <vector>
- namespace boost { namespace gil {
- #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
- #pragma warning(push)
- #pragma warning(disable:4512) //assignment operator could not be generated
- #endif
- /// Input iterator to read images.
- template< typename Reader >
- class scanline_read_iterator : public boost::iterator_facade< scanline_read_iterator< Reader >
- , byte_t*
- , std::input_iterator_tag
- >
- {
- private:
- using base_t = boost::iterator_facade
- <
- scanline_read_iterator<Reader>,
- byte_t*,
- std::input_iterator_tag
- >;
- public:
- scanline_read_iterator( Reader& reader
- , int pos = 0
- )
- : _pos( pos )
- , _read_scanline( true )
- , _skip_scanline( true )
- , _reader( reader )
- {
- _buffer = std::make_shared< buffer_t >( buffer_t( _reader._scanline_length ));
- _buffer_start = &_buffer->front();
- }
- private:
- friend class boost::iterator_core_access;
- void increment()
- {
- if( _skip_scanline == true )
- {
- _reader.skip( _buffer_start
- , _pos
- );
- }
- ++_pos;
- _skip_scanline = true;
- _read_scanline = true;
- }
- bool equal( const scanline_read_iterator& rhs ) const
- {
- return _pos == rhs._pos;
- }
- typename base_t::reference dereference() const
- {
- if( _read_scanline == true )
- {
- _reader.read( _buffer_start
- , _pos
- );
- }
- _skip_scanline = false;
- _read_scanline = false;
- return _buffer_start;
- }
- private:
- Reader& _reader;
- mutable int _pos;
- mutable bool _read_scanline;
- mutable bool _skip_scanline;
- using buffer_t = std::vector<byte_t>;
- using buffer_ptr_t = std::shared_ptr<buffer_t>;
- buffer_ptr_t _buffer;
- mutable byte_t* _buffer_start;
- };
- #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
- #pragma warning(pop)
- #endif
- } // namespace gil
- } // namespace boost
- #endif
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