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