Added thirdparty: boost library

thirdparty/include/boost/gil/io/scanline_read_iterator.hpp

@@ -0,0 +1,100 @@
+//
+// 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)
+        : reader_(reader), pos_(pos)
+    {
+        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_)
+        {
+            reader_.skip(buffer_start_, pos_);
+        }
+
+        ++pos_;
+
+        skip_scanline_ = true;
+        read_scanline_ = true;
+    }
+
+    bool equal(scanline_read_iterator const& rhs) const
+    {
+        return pos_ == rhs.pos_;
+    }
+
+    typename base_t::reference dereference() const
+    {
+        if (read_scanline_)
+        {
+            reader_.read(buffer_start_, pos_);
+        }
+        skip_scanline_ = false;
+        read_scanline_ = false;
+
+        return buffer_start_;
+    }
+
+private:
+    Reader& reader_;
+
+    mutable int pos_            = 0;
+    mutable bool read_scanline_ = true;
+    mutable bool skip_scanline_ = true;
+
+    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_ = nullptr;
+};
+
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
+#pragma warning(pop)
+#endif
+
+} // namespace gil
+} // namespace boost
+
+#endif