Chris@16: /*
Chris@16:     Copyright 2005-2007 Adobe Systems Incorporated
Chris@16:    
Chris@16:     Use, modification and distribution are subject to the Boost Software License,
Chris@16:     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt).
Chris@16: 
Chris@16:     See http://opensource.adobe.com/gil for most recent version including documentation.
Chris@16: */
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: #ifndef GIL_PIXEL_ITERATOR_ADAPTOR_H
Chris@16: #define GIL_PIXEL_ITERATOR_ADAPTOR_H
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file               
Chris@16: /// \brief pixel step iterator, pixel image iterator and pixel dereference iterator
Chris@16: /// \author Lubomir Bourdev and Hailin Jin \n
Chris@16: ///         Adobe Systems Incorporated
Chris@16: /// \date   2005-2007 \n Last updated on February 16, 2007
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: #include <iterator>
Chris@16: #include <boost/iterator/iterator_facade.hpp>
Chris@16: #include "gil_config.hpp"
Chris@16: #include "gil_concept.hpp"
Chris@16: #include "pixel_iterator.hpp"
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: 
Chris@16: /// \defgroup PixelIteratorModelDerefPtr dereference_iterator_adaptor
Chris@16: /// \ingroup PixelIteratorModel
Chris@16: /// \brief An iterator that invokes a provided function object upon dereference. Models: IteratorAdaptorConcept, PixelIteratorConcept
Chris@16: 
Chris@16: 
Chris@16: /// \ingroup PixelIteratorModelDerefPtr PixelBasedModel
Chris@16: /// \brief An adaptor over an existing iterator that provides for custom filter on dereferencing the object. Models: IteratorAdaptorConcept, PixelIteratorConcept
Chris@16: 
Chris@16: template <typename Iterator,    // Models Iterator
Chris@16:           typename DFn>  // Models Returns the result of dereferencing a given iterator of type Iterator
Chris@16: class dereference_iterator_adaptor : public iterator_adaptor<dereference_iterator_adaptor<Iterator,DFn>,
Chris@16:                                                              Iterator,
Chris@16:                                                              typename DFn::value_type,
Chris@16:                                                              typename std::iterator_traits<Iterator>::iterator_category,
Chris@16:                                                              typename DFn::reference,
Chris@16:                                                              use_default> {
Chris@16:     DFn _deref_fn;
Chris@16: public:
Chris@16:     typedef iterator_adaptor<dereference_iterator_adaptor<Iterator,DFn>,
Chris@16:                                     Iterator,
Chris@16:                                     typename DFn::value_type,
Chris@16:                                     typename std::iterator_traits<Iterator>::iterator_category,
Chris@16:                                     typename DFn::reference,
Chris@16:                                     use_default> parent_t;
Chris@16:     typedef typename DFn::result_type                         reference;
Chris@16:     typedef typename std::iterator_traits<Iterator>::difference_type difference_type;
Chris@16:     typedef DFn                                               dereference_fn;
Chris@16: 
Chris@16:     dereference_iterator_adaptor() {}
Chris@16:     template <typename Iterator1> 
Chris@16:     dereference_iterator_adaptor(const dereference_iterator_adaptor<Iterator1,DFn>& dit) : parent_t(dit.base()), _deref_fn(dit._deref_fn) {}
Chris@16:     dereference_iterator_adaptor(Iterator it, DFn deref_fn=DFn()) : parent_t(it), _deref_fn(deref_fn) {}
Chris@16:     template <typename Iterator1, typename DFn1> 
Chris@16:     dereference_iterator_adaptor(const dereference_iterator_adaptor<Iterator1,DFn1>& it) : parent_t(it.base()), _deref_fn(it._deref_fn) {}
Chris@16:     /// For some reason operator[] provided by iterator_facade returns a custom class that is convertible to reference
Chris@16:     /// We require our own reference because it is registered in iterator_traits
Chris@16:     reference operator[](difference_type d) const { return *(*this+d);}
Chris@16: 
Chris@16:     // although iterator_adaptor defines these, the default implementation computes distance and compares for zero.
Chris@16:     // it is often faster to just apply the relation operator to the base
Chris@16:     bool    operator> (const dereference_iterator_adaptor& p) const { return this->base_reference()> p.base_reference(); }
Chris@16:     bool    operator< (const dereference_iterator_adaptor& p) const { return this->base_reference()< p.base_reference(); }
Chris@16:     bool    operator>=(const dereference_iterator_adaptor& p) const { return this->base_reference()>=p.base_reference(); }
Chris@16:     bool    operator<=(const dereference_iterator_adaptor& p) const { return this->base_reference()<=p.base_reference(); }
Chris@16:     bool    operator==(const dereference_iterator_adaptor& p) const { return this->base_reference()==p.base_reference(); }
Chris@16:     bool    operator!=(const dereference_iterator_adaptor& p) const { return this->base_reference()!=p.base_reference(); }
Chris@16: 
Chris@16:     Iterator& base()              { return this->base_reference(); }
Chris@16:     const Iterator& base() const  { return this->base_reference(); }
Chris@16:     const DFn& deref_fn() const { return _deref_fn; }
Chris@16: private:
Chris@16:     template <typename Iterator1, typename DFn1> 
Chris@16:     friend class dereference_iterator_adaptor;
Chris@16:     friend class boost::iterator_core_access;
Chris@16: 
Chris@16:     reference dereference() const { return _deref_fn(*(this->base_reference())); }
Chris@16: };
Chris@16: 
Chris@16: template <typename I, typename DFn> 
Chris@16: struct const_iterator_type<dereference_iterator_adaptor<I,DFn> > { 
Chris@16:     typedef dereference_iterator_adaptor<typename const_iterator_type<I>::type,typename DFn::const_t> type; 
Chris@16: };
Chris@16: 
Chris@16: template <typename I, typename DFn> 
Chris@16: struct iterator_is_mutable<dereference_iterator_adaptor<I,DFn> > : public mpl::bool_<DFn::is_mutable> {};
Chris@16: 
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct is_iterator_adaptor<dereference_iterator_adaptor<I,DFn> > : public mpl::true_{};
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct iterator_adaptor_get_base<dereference_iterator_adaptor<I,DFn> > {
Chris@16:     typedef I type;
Chris@16: };
Chris@16: 
Chris@16: template <typename I, typename DFn, typename NewBaseIterator>
Chris@16: struct iterator_adaptor_rebind<dereference_iterator_adaptor<I,DFn>,NewBaseIterator> {
Chris@16:     typedef dereference_iterator_adaptor<NewBaseIterator,DFn> type;
Chris@16: };
Chris@16: 
Chris@16: /////////////////////////////
Chris@16: //  PixelBasedConcept
Chris@16: /////////////////////////////
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct color_space_type<dereference_iterator_adaptor<I,DFn> > : public color_space_type<typename DFn::value_type> {};
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct channel_mapping_type<dereference_iterator_adaptor<I,DFn> > : public channel_mapping_type<typename DFn::value_type> {};
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct is_planar<dereference_iterator_adaptor<I,DFn> > : public is_planar<typename DFn::value_type> {};
Chris@16: 
Chris@16: template <typename I, typename DFn>
Chris@16: struct channel_type<dereference_iterator_adaptor<I,DFn> > : public channel_type<typename DFn::value_type> {};
Chris@16: 
Chris@16: 
Chris@16: /////////////////////////////
Chris@16: //  MemoryBasedIteratorConcept
Chris@16: /////////////////////////////
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: struct byte_to_memunit<dereference_iterator_adaptor<Iterator,DFn> > : public byte_to_memunit<Iterator> {};
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: inline typename std::iterator_traits<Iterator>::difference_type 
Chris@16: memunit_step(const dereference_iterator_adaptor<Iterator,DFn>& p) { 
Chris@16:     return memunit_step(p.base());
Chris@16: }
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: inline typename std::iterator_traits<Iterator>::difference_type 
Chris@16: memunit_distance(const dereference_iterator_adaptor<Iterator,DFn>& p1, 
Chris@16:               const dereference_iterator_adaptor<Iterator,DFn>& p2) { 
Chris@16:     return memunit_distance(p1.base(),p2.base()); 
Chris@16: }
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: inline void memunit_advance(dereference_iterator_adaptor<Iterator,DFn>& p, 
Chris@16:                          typename std::iterator_traits<Iterator>::difference_type diff) { 
Chris@16:     memunit_advance(p.base(), diff);
Chris@16: }
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: inline dereference_iterator_adaptor<Iterator,DFn> 
Chris@16: memunit_advanced(const dereference_iterator_adaptor<Iterator,DFn>& p, 
Chris@16:               typename std::iterator_traits<Iterator>::difference_type diff) { 
Chris@16:     return dereference_iterator_adaptor<Iterator,DFn>(memunit_advanced(p.base(), diff), p.deref_fn()); 
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: inline 
Chris@16: typename std::iterator_traits<dereference_iterator_adaptor<Iterator,DFn> >::reference 
Chris@16: memunit_advanced_ref(const dereference_iterator_adaptor<Iterator,DFn>& p, 
Chris@16:                   typename std::iterator_traits<Iterator>::difference_type diff) { 
Chris@16:     return *memunit_advanced(p, diff);
Chris@16: }
Chris@16: 
Chris@16: /////////////////////////////
Chris@16: //  HasDynamicXStepTypeConcept
Chris@16: /////////////////////////////
Chris@16: 
Chris@16: template <typename Iterator, typename DFn>
Chris@16: struct dynamic_x_step_type<dereference_iterator_adaptor<Iterator,DFn> > {
Chris@16:     typedef dereference_iterator_adaptor<typename dynamic_x_step_type<Iterator>::type,DFn> type;
Chris@16: };
Chris@16: 
Chris@16: /// \brief Returns the type (and creates an instance) of an iterator that invokes the given dereference adaptor upon dereferencing
Chris@16: /// \ingroup PixelIteratorModelDerefPtr
Chris@16: template <typename Iterator, typename Deref>
Chris@16: struct iterator_add_deref {
Chris@16:     GIL_CLASS_REQUIRE(Deref, boost::gil, PixelDereferenceAdaptorConcept)
Chris@16: 
Chris@16:     typedef dereference_iterator_adaptor<Iterator, Deref> type;
Chris@16: 
Chris@16:     static type make(const Iterator& it, const Deref& d) { return type(it,d); }
Chris@16: };
Chris@16: 
Chris@16: /// \ingroup PixelIteratorModelDerefPtr
Chris@16: /// \brief For dereference iterator adaptors, compose the new function object after the old one
Chris@16: template <typename Iterator, typename PREV_DEREF, typename Deref>
Chris@16: struct iterator_add_deref<dereference_iterator_adaptor<Iterator, PREV_DEREF>,Deref> {
Chris@16: //    GIL_CLASS_REQUIRE(Deref, boost::gil, PixelDereferenceAdaptorConcept)
Chris@16: 
Chris@16:     typedef dereference_iterator_adaptor<Iterator, deref_compose<Deref,PREV_DEREF> > type;
Chris@16: 
Chris@16:     static type make(const dereference_iterator_adaptor<Iterator, PREV_DEREF>& it, const Deref& d) { 
Chris@16:         return type(it.base(),deref_compose<Deref,PREV_DEREF>(d,it.deref_fn())); 
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: #endif