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