Edit: /usr/include/boost/gil/position_iterator.hpp (5005B)
//
// Copyright 2005-2007 Adobe Systems Incorporated
//
// 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_POSITION_ITERATOR_HPP
#define BOOST_GIL_POSITION_ITERATOR_HPP
#include
#include
#include
namespace boost { namespace gil {
/// \defgroup PixelIteratorModelVirtual position_iterator
/// \ingroup PixelIteratorModel
/// \brief An iterator that remembers its current X,Y position and invokes a function object with it upon dereferencing.
/// Models PixelIteratorConcept, PixelBasedConcept, HasDynamicXStepTypeConcept. Used to create virtual image views.
/// \brief An iterator that remembers its current X,Y position and invokes a function object with it upon dereferencing.
/// Used to create virtual image views.
/// Models: StepIteratorConcept, PixelIteratorConcept, PixelBasedConcept, HasDynamicXStepTypeConcept
/// \ingroup PixelIteratorModelVirtual PixelBasedModel
/// \tparam Deref A function object that given a point returns a pixel reference. Models PixelDereferenceAdaptorConcept
/// \tparam Dim Dimension to advance along
template
struct position_iterator : public iterator_facade,
typename Deref::value_type,
std::random_access_iterator_tag,
typename Deref::reference,
typename Deref::argument_type::template axis::coord_t> {
using parent_t = iterator_facade,
typename Deref::value_type,
std::random_access_iterator_tag,
typename Deref::reference,
typename Deref::argument_type::template axis::coord_t>;
using difference_type = typename parent_t::difference_type;
using reference = typename parent_t::reference;
using point_t = typename Deref::argument_type;
position_iterator() {}
position_iterator(const point_t& p, const point_t& step, const Deref& d) : _p(p), _step(step), _d(d) {}
position_iterator(const position_iterator& p) : _p(p._p), _step(p._step), _d(p._d) {}
template position_iterator(const position_iterator& p) : _p(p._p), _step(p._step), _d(p._d) {}
position_iterator& operator=(const position_iterator& p) { _p=p._p; _d=p._d; _step=p._step; return *this; }
const point_t& pos() const { return _p; }
const point_t& step() const { return _step; }
const Deref& deref_fn() const { return _d; }
void set_step(difference_type s) { _step[Dim]=s; }
/// 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 { point_t p=_p; p[Dim]+=d*_step[Dim]; return _d(p); }
private:
point_t _p, _step;
Deref _d;
template friend struct position_iterator;
friend class boost::iterator_core_access;
reference dereference() const { return _d(_p); }
void increment() { _p[Dim]+=_step[Dim]; }
void decrement() { _p[Dim]-=_step[Dim]; }
void advance(difference_type d) { _p[Dim]+=d*_step[Dim]; }
difference_type distance_to(const position_iterator& it) const { return (it._p[Dim]-_p[Dim])/_step[Dim]; }
bool equal(const position_iterator& it) const { return _p==it._p; }
};
template
struct const_iterator_type > {
using type = position_iterator;
};
template
struct iterator_is_mutable>
: std::integral_constant
{
};
/////////////////////////////
// PixelBasedConcept
/////////////////////////////
template
struct color_space_type > : public color_space_type {};
template
struct channel_mapping_type > : public channel_mapping_type {};
template
struct is_planar> : std::false_type {};
template
struct channel_type > : public channel_type {};
/////////////////////////////
// HasDynamicXStepTypeConcept
/////////////////////////////
template
struct dynamic_x_step_type > {
using type = position_iterator;
};
} } // namespace boost::gil
#endif