boost/gil/bit_aligned_pixel_iterator.hpp
/*
Copyright 2005-2007 Adobe Systems Incorporated
Use, modification and distribution are subject to 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).
See http://opensource.adobe.com/gil for most recent version including documentation.
*/
/*************************************************************************************************/
#ifndef GIL_BIT_ALIGNED_PIXEL_ITERATOR_HPP
#define GIL_BIT_ALIGNED_PIXEL_ITERATOR_HPP
////////////////////////////////////////////////////////////////////////////////////////
/// \file
/// \brief A model of a heterogeneous pixel that is not byte aligned. Examples are bitmap (1-bit pixels) or 6-bit RGB (222)
/// \author Lubomir Bourdev and Hailin Jin \n
/// Adobe Systems Incorporated
/// \date 2005-2007 \n Last updated on September 28, 2006
///
////////////////////////////////////////////////////////////////////////////////////////
#include <functional>
#include <boost/iterator/iterator_facade.hpp>
#include "gil_config.hpp"
#include "bit_aligned_pixel_reference.hpp"
#include "pixel_iterator.hpp"
namespace boost { namespace gil {
/// \defgroup PixelIteratorNonAlignedPixelIterator bit_aligned_pixel_iterator
/// \ingroup PixelIteratorModel
/// \brief An iterator over non-byte-aligned pixels. Models PixelIteratorConcept, PixelBasedConcept, MemoryBasedIteratorConcept, HasDynamicXStepTypeConcept
////////////////////////////////////////////////////////////////////////////////////////
/// \brief An iterator over non-byte-aligned pixels. Models PixelIteratorConcept, PixelBasedConcept, MemoryBasedIteratorConcept, HasDynamicXStepTypeConcept
///
/// 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.
///
/// \ingroup PixelIteratorNonAlignedPixelIterator PixelBasedModel
template <typename NonAlignedPixelReference>
struct bit_aligned_pixel_iterator : public iterator_facade<bit_aligned_pixel_iterator<NonAlignedPixelReference>,
typename NonAlignedPixelReference::value_type,
random_access_traversal_tag,
const NonAlignedPixelReference,
typename NonAlignedPixelReference::bit_range_t::difference_type> {
private:
typedef iterator_facade<bit_aligned_pixel_iterator<NonAlignedPixelReference>,
typename NonAlignedPixelReference::value_type,
random_access_traversal_tag,
const NonAlignedPixelReference,
typename NonAlignedPixelReference::bit_range_t::difference_type> parent_t;
template <typename Ref> friend struct bit_aligned_pixel_iterator;
typedef typename NonAlignedPixelReference::bit_range_t bit_range_t;
public:
typedef typename parent_t::difference_type difference_type;
typedef typename parent_t::reference reference;
bit_aligned_pixel_iterator() {}
bit_aligned_pixel_iterator(const bit_aligned_pixel_iterator& p) : _bit_range(p._bit_range) {}
bit_aligned_pixel_iterator& operator=(const bit_aligned_pixel_iterator& p) { _bit_range=p._bit_range; return *this; }
template <typename Ref> bit_aligned_pixel_iterator(const bit_aligned_pixel_iterator<Ref>& p) : _bit_range(p._bit_range) {}
bit_aligned_pixel_iterator(reference* ref) : _bit_range(ref->bit_range()) {}
explicit bit_aligned_pixel_iterator(typename bit_range_t::byte_t* data, int bit_offset=0) : _bit_range(data,bit_offset) {}
/// For some reason operator[] provided by iterator_adaptor returns a custom class that is convertible to reference
/// We require our own reference because it is registered in iterator_traits
reference operator[](difference_type d) const { bit_aligned_pixel_iterator it=*this; it.advance(d); return *it; }
reference operator->() const { return **this; }
const bit_range_t& bit_range() const { return _bit_range; }
bit_range_t& bit_range() { return _bit_range; }
private:
bit_range_t _bit_range;
BOOST_STATIC_CONSTANT(int, bit_size = NonAlignedPixelReference::bit_size);
friend class boost::iterator_core_access;
reference dereference() const { return NonAlignedPixelReference(_bit_range); }
void increment() { ++_bit_range; }
void decrement() { --_bit_range; }
void advance(difference_type d) { _bit_range.bit_advance(d*bit_size); }
difference_type distance_to(const bit_aligned_pixel_iterator& it) const { return _bit_range.bit_distance_to(it._bit_range) / bit_size; }
bool equal(const bit_aligned_pixel_iterator& it) const { return _bit_range==it._bit_range; }
};
template <typename NonAlignedPixelReference>
struct const_iterator_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > {
typedef bit_aligned_pixel_iterator<typename NonAlignedPixelReference::const_reference> type;
};
template <typename NonAlignedPixelReference>
struct iterator_is_mutable<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public mpl::bool_<NonAlignedPixelReference::is_mutable> {};
template <typename NonAlignedPixelReference>
struct is_iterator_adaptor<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public mpl::false_ {};
/////////////////////////////
// PixelBasedConcept
/////////////////////////////
template <typename NonAlignedPixelReference>
struct color_space_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public color_space_type<NonAlignedPixelReference> {};
template <typename NonAlignedPixelReference>
struct channel_mapping_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public channel_mapping_type<NonAlignedPixelReference> {};
template <typename NonAlignedPixelReference>
struct is_planar<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public is_planar<NonAlignedPixelReference> {}; // == false
/////////////////////////////
// MemoryBasedIteratorConcept
/////////////////////////////
template <typename NonAlignedPixelReference>
struct byte_to_memunit<bit_aligned_pixel_iterator<NonAlignedPixelReference> > : public mpl::int_<8> {};
template <typename NonAlignedPixelReference>
inline std::ptrdiff_t memunit_step(const bit_aligned_pixel_iterator<NonAlignedPixelReference>&) {
return NonAlignedPixelReference::bit_size;
}
template <typename NonAlignedPixelReference>
inline std::ptrdiff_t memunit_distance(const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p1, const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p2) {
return (p2.bit_range().current_byte() - p1.bit_range().current_byte())*8 + p2.bit_range().bit_offset() - p1.bit_range().bit_offset();
}
template <typename NonAlignedPixelReference>
inline void memunit_advance(bit_aligned_pixel_iterator<NonAlignedPixelReference>& p, std::ptrdiff_t diff) {
p.bit_range().bit_advance(diff);
}
template <typename NonAlignedPixelReference>
inline bit_aligned_pixel_iterator<NonAlignedPixelReference> memunit_advanced(const bit_aligned_pixel_iterator<NonAlignedPixelReference>& p, std::ptrdiff_t diff) {
bit_aligned_pixel_iterator<NonAlignedPixelReference> ret=p;
memunit_advance(ret, diff);
return ret;
}
template <typename NonAlignedPixelReference> inline
NonAlignedPixelReference memunit_advanced_ref(bit_aligned_pixel_iterator<NonAlignedPixelReference> it, std::ptrdiff_t diff) {
return *memunit_advanced(it,diff);
}
/////////////////////////////
// HasDynamicXStepTypeConcept
/////////////////////////////
template <typename NonAlignedPixelReference>
struct dynamic_x_step_type<bit_aligned_pixel_iterator<NonAlignedPixelReference> > {
typedef memory_based_step_iterator<bit_aligned_pixel_iterator<NonAlignedPixelReference> > type;
};
/////////////////////////////
// iterator_type_from_pixel
/////////////////////////////
template <typename B, typename C, typename L, bool M>
struct iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,false,false,false> {
typedef bit_aligned_pixel_iterator<bit_aligned_pixel_reference<B,C,L,false> > type;
};
template <typename B, typename C, typename L, bool M>
struct iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,false,false,true> {
typedef bit_aligned_pixel_iterator<bit_aligned_pixel_reference<B,C,L,true> > type;
};
template <typename B, typename C, typename L, bool M, bool IsPlanar, bool IsStep, bool IsMutable>
struct iterator_type_from_pixel<bit_aligned_pixel_reference<B,C,L,M>,IsPlanar,IsStep,IsMutable>
: public iterator_type_from_pixel<const bit_aligned_pixel_reference<B,C,L,M>,IsPlanar,IsStep,IsMutable> {};
} } // namespace boost::gil
namespace std {
// It is important to provide an overload of uninitialized_copy for bit_aligned_pixel_iterator. The default STL implementation calls placement new,
// which is not defined for bit_aligned_pixel_iterator.
template <typename NonAlignedPixelReference>
boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> uninitialized_copy(boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> first,
boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> last,
boost::gil::bit_aligned_pixel_iterator<NonAlignedPixelReference> dst) {
return std::copy(first,last,dst);
}
} // namespace std
#endif
