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    00001 /*
    00002     Copyright 2005-2007 Adobe Systems Incorporated
    00003
    00004     Use, modification and distribution are subject to the Boost Software License,
    00005     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
    00006     http://www.boost.org/LICENSE_1_0.txt).
    00007
    00008     See http://opensource.adobe.com/gil for most recent version including documentation.
    00009 */
    00010
    00011 /*************************************************************************************************/
    00012
    00013 #ifndef GIL_PIXEL_ITERATOR_ADAPTOR_H
    00014 #define GIL_PIXEL_ITERATOR_ADAPTOR_H
    00015
    00024
    00025 #include <iterator>
    00026 #include <boost/iterator/iterator_facade.hpp>
    00027 #include "gil_config.hpp"
    00028 #include "gil_concept.hpp"
    00029 #include "pixel_iterator.hpp"
    00030
    00031 namespace boost { namespace gil {
    00032
    00033
    00037
    00038
    00041
    00042 template <typename Iterator,    // Models Iterator
    00043           typename DFn>  // Models Returns the result of dereferencing a given iterator of type Iterator
    00044 class dereference_iterator_adaptor : public iterator_adaptor<dereference_iterator_adaptor<Iterator,DFn>,
    00045                                                              Iterator,
    00046                                                              typename DFn::value_type,
    00047                                                              use_default,
    00048                                                              typename DFn::reference,
    00049                                                              use_default> {
    00050     DFn _deref_fn;
    00051 public:
    00052     typedef iterator_adaptor<dereference_iterator_adaptor<Iterator,DFn>,
    00053                                     Iterator,
    00054                                     typename DFn::value_type,
    00055                                     use_default,
    00056                                     typename DFn::reference,
    00057                                     use_default> parent_t;
    00058     typedef typename DFn::result_type                         reference;
    00059     typedef typename std::iterator_traits<Iterator>::difference_type difference_type;
    00060     typedef DFn                                               dereference_fn;
    00061
    00062     dereference_iterator_adaptor() {}
    00063     template <typename Iterator1>
    00064     dereference_iterator_adaptor(const dereference_iterator_adaptor<Iterator1,DFn>& dit) : parent_t(dit.base()), _deref_fn(dit._deref_fn) {}
    00065     dereference_iterator_adaptor(Iterator it, DFn deref_fn=DFn()) : parent_t(it), _deref_fn(deref_fn) {}
    00066     template <typename Iterator1, typename DFn1>
    00067     dereference_iterator_adaptor(const dereference_iterator_adaptor<Iterator1,DFn1>& it) : parent_t(it.base()), _deref_fn(it._deref_fn) {}
    00070     reference operator[](difference_type d) const { return *(*this+d);}
    00071
    00072     // although iterator_adaptor defines these, the default implementation computes distance and compares for zero.
    00073     // it is often faster to just apply the relation operator to the base
    00074     bool    operator> (const dereference_iterator_adaptor& p) const { return this->base_reference()> p.base_reference(); }
    00075     bool    operator< (const dereference_iterator_adaptor& p) const { return this->base_reference()< p.base_reference(); }
    00076     bool    operator>=(const dereference_iterator_adaptor& p) const { return this->base_reference()>=p.base_reference(); }
    00077     bool    operator<=(const dereference_iterator_adaptor& p) const { return this->base_reference()<=p.base_reference(); }
    00078     bool    operator==(const dereference_iterator_adaptor& p) const { return this->base_reference()==p.base_reference(); }
    00079     bool    operator!=(const dereference_iterator_adaptor& p) const { return this->base_reference()!=p.base_reference(); }
    00080
    00081     Iterator& base()              { return this->base_reference(); }
    00082     const Iterator& base() const  { return this->base_reference(); }
    00083     const DFn& deref_fn() const { return _deref_fn; }
    00084 private:
    00085     template <typename Iterator1, typename DFn1>
    00086     friend class dereference_iterator_adaptor;
    00087     friend class boost::iterator_core_access;
    00088
    00089     reference dereference() const { return _deref_fn(*(this->base_reference())); }
    00090 };
    00091
    00092 template <typename I, typename DFn>
    00093 struct const_iterator_type<dereference_iterator_adaptor<I,DFn> > {
    00094     typedef dereference_iterator_adaptor<typename const_iterator_type<I>::type,typename DFn::const_t> type;
    00095 };
    00096
    00097 template <typename I, typename DFn>
    00098 struct iterator_is_mutable<dereference_iterator_adaptor<I,DFn> > : public mpl::bool_<DFn::is_mutable> {};
    00099
    00100
    00101 template <typename I, typename DFn>
    00102 struct is_iterator_adaptor<dereference_iterator_adaptor<I,DFn> > : public mpl::true_{};
    00103
    00104 template <typename I, typename DFn>
    00105 struct iterator_adaptor_get_base<dereference_iterator_adaptor<I,DFn> > {
    00106     typedef I type;
    00107 };
    00108
    00109 template <typename I, typename DFn, typename NewBaseIterator>
    00110 struct iterator_adaptor_rebind<dereference_iterator_adaptor<I,DFn>,NewBaseIterator> {
    00111     typedef dereference_iterator_adaptor<NewBaseIterator,DFn> type;
    00112 };
    00113
    00115 //  PixelBasedConcept
    00117
    00118 template <typename I, typename DFn>
    00119 struct color_space_type<dereference_iterator_adaptor<I,DFn> > : public color_space_type<typename DFn::value_type> {};
    00120
    00121 template <typename I, typename DFn>
    00122 struct channel_mapping_type<dereference_iterator_adaptor<I,DFn> > : public channel_mapping_type<typename DFn::value_type> {};
    00123
    00124 template <typename I, typename DFn>
    00125 struct is_planar<dereference_iterator_adaptor<I,DFn> > : public is_planar<typename DFn::value_type> {};
    00126
    00127 template <typename I, typename DFn>
    00128 struct channel_type<dereference_iterator_adaptor<I,DFn> > : public channel_type<typename DFn::value_type> {};
    00129
    00130
    00132 //  MemoryBasedIteratorConcept
    00134
    00135 template <typename Iterator, typename DFn>
    00136 struct byte_to_memunit<dereference_iterator_adaptor<Iterator,DFn> > : public byte_to_memunit<Iterator> {};
    00137
    00138 template <typename Iterator, typename DFn>
    00139 inline typename std::iterator_traits<Iterator>::difference_type
    00140 memunit_step(const dereference_iterator_adaptor<Iterator,DFn>& p) {
    00141     return memunit_step(p.base());
    00142 }
    00143
    00144 template <typename Iterator, typename DFn>
    00145 inline typename std::iterator_traits<Iterator>::difference_type
    00146 memunit_distance(const dereference_iterator_adaptor<Iterator,DFn>& p1,
    00147               const dereference_iterator_adaptor<Iterator,DFn>& p2) {
    00148     return memunit_distance(p1.base(),p2.base());
    00149 }
    00150
    00151 template <typename Iterator, typename DFn>
    00152 inline void memunit_advance(dereference_iterator_adaptor<Iterator,DFn>& p,
    00153                          typename std::iterator_traits<Iterator>::difference_type diff) {
    00154     memunit_advance(p.base(), diff);
    00155 }
    00156
    00157 template <typename Iterator, typename DFn>
    00158 inline dereference_iterator_adaptor<Iterator,DFn>
    00159 memunit_advanced(const dereference_iterator_adaptor<Iterator,DFn>& p,
    00160               typename std::iterator_traits<Iterator>::difference_type diff) {
    00161     return dereference_iterator_adaptor<Iterator,DFn>(memunit_advanced(p.base(), diff), p.deref_fn());
    00162 }
    00163
    00164
    00165 template <typename Iterator, typename DFn>
    00166 inline
    00167 typename std::iterator_traits<dereference_iterator_adaptor<Iterator,DFn> >::reference
    00168 memunit_advanced_ref(const dereference_iterator_adaptor<Iterator,DFn>& p,
    00169                   typename std::iterator_traits<Iterator>::difference_type diff) {
    00170     return *memunit_advanced(p, diff);
    00171 }
    00172
    00174 //  HasDynamicXStepTypeConcept
    00176
    00177 template <typename Iterator, typename DFn>
    00178 struct dynamic_x_step_type<dereference_iterator_adaptor<Iterator,DFn> > {
    00179     typedef dereference_iterator_adaptor<typename dynamic_x_step_type<Iterator>::type,DFn> type;
    00180 };
    00181
    00184 template <typename Iterator, typename Deref>
    00185 struct iterator_add_deref {
    00186     GIL_CLASS_REQUIRE(Deref, boost::gil, PixelDereferenceAdaptorConcept)
    00187
    00188     typedef dereference_iterator_adaptor<Iterator, Deref> type;
    00189
    00190     static type make(const Iterator& it, const Deref& d) { return type(it,d); }
    00191 };
    00192
    00195 template <typename Iterator, typename PREV_DEREF, typename Deref>
    00196 struct iterator_add_deref<dereference_iterator_adaptor<Iterator, PREV_DEREF>,Deref> {
    00197 //    GIL_CLASS_REQUIRE(Deref, boost::gil, PixelDereferenceAdaptorConcept)
    00198
    00199     typedef dereference_iterator_adaptor<Iterator, deref_compose<Deref,PREV_DEREF> > type;
    00200
    00201     static type make(const dereference_iterator_adaptor<Iterator, PREV_DEREF>& it, const Deref& d) {
    00202         return type(it.base(),deref_compose<Deref,PREV_DEREF>(d,it.deref_fn()));
    00203     }
    00204 };
    00205
    00206 } }  // namespace boost::gil
    00207
    00208 #endif