//
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// Copyright 2005-2007 Adobe Systems Incorporated
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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_BIT_ALIGNED_PIXEL_ITERATOR_HPP
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#define BOOST_GIL_BIT_ALIGNED_PIXEL_ITERATOR_HPP
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#include <boost/gil/bit_aligned_pixel_reference.hpp>
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#include <boost/gil/pixel_iterator.hpp>
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#include <boost/config.hpp>
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#include <boost/iterator/iterator_facade.hpp>
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#include <functional>
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#include <type_traits>
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namespace boost { namespace gil {
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/// A model of a heterogeneous pixel that is not byte aligned.
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/// Examples are bitmap (1-bit pixels) or 6-bit RGB (222).
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/// \defgroup PixelIteratorNonAlignedPixelIterator bit_aligned_pixel_iterator
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/// \ingroup PixelIteratorModel
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/// \brief An iterator over non-byte-aligned pixels. Models PixelIteratorConcept, PixelBasedConcept, MemoryBasedIteratorConcept, HasDynamicXStepTypeConcept
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////////////////////////////////////////////////////////////////////////////////////////
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/// \brief An iterator over non-byte-aligned pixels. Models PixelIteratorConcept, PixelBasedConcept, MemoryBasedIteratorConcept, HasDynamicXStepTypeConcept
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///
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/// An iterator over pixels that correspond to non-byte-aligned bit ranges. Examples of such pixels are single bit grayscale pixel, or a 6-bit RGB 222 pixel.
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///
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/// \ingroup PixelIteratorNonAlignedPixelIterator PixelBasedModel
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template <typename NonAlignedPixelReference>
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struct bit_aligned_pixel_iterator : public iterator_facade<bit_aligned_pixel_iterator<NonAlignedPixelReference>,
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typename NonAlignedPixelReference::value_type,
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std::random_access_iterator_tag,
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const NonAlignedPixelReference,
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typename NonAlignedPixelReference::bit_range_t::difference_type> {
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private:
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using parent_t = iterator_facade<bit_aligned_pixel_iterator<NonAlignedPixelReference>,
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typename NonAlignedPixelReference::value_type,
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std::random_access_iterator_tag,
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const NonAlignedPixelReference,
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typename NonAlignedPixelReference::bit_range_t::difference_type>;
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template <typename Ref> friend struct bit_aligned_pixel_iterator;
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using bit_range_t = typename NonAlignedPixelReference::bit_range_t;
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public:
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using difference_type = typename parent_t::difference_type;
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using reference = typename parent_t::reference;
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bit_aligned_pixel_iterator() {}
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bit_aligned_pixel_iterator(const bit_aligned_pixel_iterator& p) : _bit_range(p._bit_range) {}
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bit_aligned_pixel_iterator& operator=(const bit_aligned_pixel_iterator& p) { _bit_range=p._bit_range; return *this; }
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template <typename Ref> bit_aligned_pixel_iterator(const bit_aligned_pixel_iterator<Ref>& p) : _bit_range(p._bit_range) {}
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bit_aligned_pixel_iterator(reference* ref) : _bit_range(ref->bit_range()) {}
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explicit bit_aligned_pixel_iterator(typename bit_range_t::byte_t* data, int bit_offset=0) : _bit_range(data,bit_offset) {}
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/// For some reason operator[] provided by iterator_adaptor returns a custom class that is convertible to reference
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/// We require our own reference because it is registered in iterator_traits
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reference operator[](difference_type d) const { bit_aligned_pixel_iterator it=*this; it.advance(d); return *it; }
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reference operator->() const { return **this; }
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const bit_range_t& bit_range() const { return _bit_range; }
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bit_range_t& bit_range() { return _bit_range; }
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private:
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bit_range_t _bit_range;
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static constexpr int bit_size = NonAlignedPixelReference::bit_size;
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friend class boost::iterator_core_access;
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reference dereference() const { return NonAlignedPixelReference(_bit_range); }
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void increment() { ++_bit_range; }
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void decrement() { --_bit_range; }
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void advance(difference_type d) { _bit_range.bit_advance(d*bit_size); }
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difference_type distance_to(const bit_aligned_pixel_iterator& it) const { return _bit_range.bit_distance_to(it._bit_range) / bit_size; }
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bool equal(const bit_aligned_pixel_iterator& it) const { return _bit_range==it._bit_range; }
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};
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template <typename NonAlignedPixelReference>
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struct const_iterator_type<bit_aligned_pixel_iterator<NonAlignedPixelReference>>
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{
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using type =
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bit_aligned_pixel_iterator<typename NonAlignedPixelReference::const_reference>;
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};
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template <typename NonAlignedPixelReference>
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struct iterator_is_mutable<bit_aligned_pixel_iterator<NonAlignedPixelReference>>
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: std::integral_constant<bool, NonAlignedPixelReference::is_mutable>
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{};
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template <typename NonAlignedPixelReference>
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struct is_iterator_adaptor<bit_aligned_pixel_iterator<NonAlignedPixelReference>>
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: std::false_type
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{};
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/////////////////////////////
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// PixelBasedConcept
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/////////////////////////////
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template <typename NonAlignedPixelReference>
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struct color_space_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public color_space_type<NonAlignedPixelReference> {};
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template <typename NonAlignedPixelReference>
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struct channel_mapping_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public channel_mapping_type<NonAlignedPixelReference> {};
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template <typename NonAlignedPixelReference>
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struct is_planar<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public is_planar<NonAlignedPixelReference> {}; // == false
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/////////////////////////////
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// MemoryBasedIteratorConcept
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/////////////////////////////
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template <typename NonAlignedPixelReference>
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struct byte_to_memunit<bit_aligned_pixel_iterator<NonAlignedPixelReference>>
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: std::integral_constant<int, 8>
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{};
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template <typename NonAlignedPixelReference>
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inline std::ptrdiff_t memunit_step(const bit_aligned_pixel_iterator<NonAlignedPixelReference>&) {
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return NonAlignedPixelReference::bit_size;
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}
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template <typename NonAlignedPixelReference>
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inline std::ptrdiff_t memunit_distance(const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p1, const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p2) {
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return (p2.bit_range().current_byte() - p1.bit_range().current_byte())*8 + p2.bit_range().bit_offset() - p1.bit_range().bit_offset();
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}
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template <typename NonAlignedPixelReference>
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inline void memunit_advance(bit_aligned_pixel_iterator<NonAlignedPixelReference>& p, std::ptrdiff_t diff) {
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p.bit_range().bit_advance(diff);
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}
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template <typename NonAlignedPixelReference>
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inline bit_aligned_pixel_iterator<NonAlignedPixelReference> memunit_advanced(const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p, std::ptrdiff_t diff) {
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bit_aligned_pixel_iterator<NonAlignedPixelReference> ret=p;
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memunit_advance(ret, diff);
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return ret;
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}
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template <typename NonAlignedPixelReference> inline
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NonAlignedPixelReference memunit_advanced_ref(bit_aligned_pixel_iterator<NonAlignedPixelReference> it, std::ptrdiff_t diff) {
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return *memunit_advanced(it,diff);
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}
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/////////////////////////////
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// HasDynamicXStepTypeConcept
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/////////////////////////////
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template <typename NonAlignedPixelReference>
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struct dynamic_x_step_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > {
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using type = memory_based_step_iterator<bit_aligned_pixel_iterator<NonAlignedPixelReference> >;
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};
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/////////////////////////////
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// iterator_type_from_pixel
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/////////////////////////////
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template <typename B, typename C, typename L, bool M>
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struct iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,false,false,false>
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{
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using type = bit_aligned_pixel_iterator<bit_aligned_pixel_reference<B,C,L,false>> ;
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};
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template <typename B, typename C, typename L, bool M>
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struct iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,false,false,true>
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{
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using type = bit_aligned_pixel_iterator<bit_aligned_pixel_reference<B,C,L,true>>;
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};
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template <typename B, typename C, typename L, bool M, bool IsPlanar, bool IsStep, bool IsMutable>
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struct iterator_type_from_pixel<bit_aligned_pixel_reference<B,C,L,M>,IsPlanar,IsStep,IsMutable>
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: public iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,IsPlanar,IsStep,IsMutable> {};
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} } // namespace boost::gil
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namespace std {
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// It is important to provide an overload of uninitialized_copy for bit_aligned_pixel_iterator. The default STL implementation calls placement new,
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// which is not defined for bit_aligned_pixel_iterator.
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template <typename NonAlignedPixelReference>
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boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> uninitialized_copy(boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> first,
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boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> last,
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boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> dst) {
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return std::copy(first,last,dst);
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}
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} // namespace std
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#endif
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