| /* |
| 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_POSITION_ITERATOR_HPP |
| #define GIL_POSITION_ITERATOR_HPP |
| |
| //////////////////////////////////////////////////////////////////////////////////////// |
| /// \file |
| /// \brief Locator for virtual image views |
| /// \author Lubomir Bourdev and Hailin Jin \n |
| /// Adobe Systems Incorporated |
| /// \date 2005-2007 \n Last updated on February 12, 2007 |
| /// |
| //////////////////////////////////////////////////////////////////////////////////////// |
| |
| #include <boost/iterator/iterator_facade.hpp> |
| #include "locator.hpp" |
| |
| 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. Models PixelIteratorConcept. Used to create virtual image views. |
| /// Models: StepIteratorConcept, PixelIteratorConcept, PixelBasedConcept, HasDynamicXStepTypeConcept |
| /// \ingroup PixelIteratorModelVirtual PixelBasedModel |
| template <typename Deref, // A function object that given a point returns a pixel reference. Models PixelDereferenceAdaptorConcept |
| int Dim> // the dimension to advance along |
| struct position_iterator : public iterator_facade<position_iterator<Deref,Dim>, |
| typename Deref::value_type, |
| std::random_access_iterator_tag, |
| typename Deref::reference, |
| typename Deref::argument_type::template axis<Dim>::coord_t> { |
| typedef iterator_facade<position_iterator<Deref,Dim>, |
| typename Deref::value_type, |
| std::random_access_iterator_tag, |
| typename Deref::reference, |
| typename Deref::argument_type::template axis<Dim>::coord_t> parent_t; |
| typedef typename parent_t::difference_type difference_type; |
| typedef typename parent_t::reference reference; |
| typedef typename Deref::argument_type point_t; |
| |
| 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 <typename D> position_iterator(const position_iterator<D,Dim>& 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 <typename DE, int DI> 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 <typename Deref,int Dim> |
| struct const_iterator_type<position_iterator<Deref,Dim> > { |
| typedef position_iterator<typename Deref::const_t,Dim> type; |
| }; |
| |
| template <typename Deref,int Dim> |
| struct iterator_is_mutable<position_iterator<Deref,Dim> > : public mpl::bool_<Deref::is_mutable> { |
| }; |
| |
| ///////////////////////////// |
| // PixelBasedConcept |
| ///////////////////////////// |
| |
| template <typename Deref,int Dim> |
| struct color_space_type<position_iterator<Deref,Dim> > : public color_space_type<typename Deref::value_type> {}; |
| |
| template <typename Deref,int Dim> |
| struct channel_mapping_type<position_iterator<Deref,Dim> > : public channel_mapping_type<typename Deref::value_type> {}; |
| |
| template <typename Deref,int Dim> |
| struct is_planar<position_iterator<Deref,Dim> > : public mpl::false_ {}; |
| |
| template <typename Deref,int Dim> |
| struct channel_type<position_iterator<Deref,Dim> > : public channel_type<typename Deref::value_type> {}; |
| |
| ///////////////////////////// |
| // HasDynamicXStepTypeConcept |
| ///////////////////////////// |
| |
| template <typename Deref,int Dim> |
| struct dynamic_x_step_type<position_iterator<Deref,Dim> > { |
| typedef position_iterator<Deref,Dim> type; |
| }; |
| |
| } } // namespace boost::gil |
| |
| #endif |