/* | |
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_H | |
#define GIL_PIXEL_ITERATOR_H | |
//////////////////////////////////////////////////////////////////////////////////////// | |
/// \file | |
/// \brief pixel iterator support | |
/// \author Lubomir Bourdev and Hailin Jin \n | |
/// Adobe Systems Incorporated | |
/// \date 2005-2007 \n May 16, 2006 | |
/// | |
//////////////////////////////////////////////////////////////////////////////////////// | |
#include <cassert> | |
#include <iterator> | |
#include "gil_config.hpp" | |
#include "gil_concept.hpp" | |
#include "utilities.hpp" | |
#include "pixel.hpp" | |
namespace boost { namespace gil { | |
//forwarded declaration (as this file is included in step_iterator.hpp) | |
template <typename Iterator> | |
class memory_based_step_iterator; | |
template <typename Iterator> struct dynamic_x_step_type; | |
/// \brief metafunction predicate determining whether the given iterator is a plain one or an adaptor over another iterator. | |
/// Examples of adaptors are the step iterator and the dereference iterator adaptor. | |
template <typename It> | |
struct is_iterator_adaptor : public mpl::false_{}; | |
/// \brief returns the base iterator for a given iterator adaptor. Provide an specialization when introducing new iterator adaptors | |
template <typename It> | |
struct iterator_adaptor_get_base; | |
/// \brief Changes the base iterator of an iterator adaptor. Provide an specialization when introducing new iterator adaptors | |
template <typename It, typename NewBaseIt> | |
struct iterator_adaptor_rebind; | |
/// \brief Returns the type of an iterator just like the input iterator, except operating over immutable values | |
template <typename It> | |
struct const_iterator_type; | |
// The default implementation when the iterator is a C pointer is to use the standard constness semantics | |
template <typename T> struct const_iterator_type< T*> { typedef const T* type; }; | |
template <typename T> struct const_iterator_type<const T*> { typedef const T* type; }; | |
/// \brief Metafunction predicate returning whether the given iterator allows for changing its values | |
/// \ingroup GILIsMutable | |
template <typename It> | |
struct iterator_is_mutable{}; | |
// The default implementation when the iterator is a C pointer is to use the standard constness semantics | |
template <typename T> struct iterator_is_mutable< T*> : public mpl::true_{}; | |
template <typename T> struct iterator_is_mutable<const T*> : public mpl::false_{}; | |
/// \defgroup PixelIteratorModelInterleavedPtr C pointer to a pixel | |
/// \ingroup PixelIteratorModel | |
/// \brief Iterators over interleaved pixels. | |
/// A C pointer to a model of PixelValueConcept is used as an iterator over interleaved pixels. Models PixelIteratorConcept, HomogeneousPixelBasedConcept, HasDynamicXStepTypeConcept, MemoryBasedIteratorConcept | |
///////////////////////////// | |
// HasDynamicXStepTypeConcept | |
///////////////////////////// | |
/// \ingroup PixelIteratorModelInterleavedPtr | |
template <typename Pixel> | |
struct dynamic_x_step_type<Pixel*> { | |
typedef memory_based_step_iterator<Pixel*> type; | |
}; | |
/// \ingroup PixelIteratorModelInterleavedPtr | |
template <typename Pixel> | |
struct dynamic_x_step_type<const Pixel*> { | |
typedef memory_based_step_iterator<const Pixel*> type; | |
}; | |
///////////////////////////// | |
// PixelBasedConcept | |
///////////////////////////// | |
template <typename Pixel> struct color_space_type< Pixel*> : public color_space_type<Pixel> {}; | |
template <typename Pixel> struct color_space_type<const Pixel*> : public color_space_type<Pixel> {}; | |
template <typename Pixel> struct channel_mapping_type< Pixel*> : public channel_mapping_type<Pixel> {}; | |
template <typename Pixel> struct channel_mapping_type<const Pixel*> : public channel_mapping_type<Pixel> {}; | |
template <typename Pixel> struct is_planar< Pixel*> : public is_planar<Pixel> {}; | |
template <typename Pixel> struct is_planar<const Pixel*> : public is_planar<Pixel> {}; | |
///////////////////////////// | |
// HomogeneousPixelBasedConcept | |
///////////////////////////// | |
template <typename Pixel> struct channel_type<Pixel*> : public channel_type<Pixel> {}; | |
template <typename Pixel> struct channel_type<const Pixel*> : public channel_type<Pixel> {}; | |
//////////////////////////////////////////////////////////////////////////////////////// | |
/// | |
/// Support for pixel iterator movement measured in memory units (bytes or bits) as opposed to pixel type. \n | |
/// Necessary to handle image row alignment and channel plane alignment. | |
/// | |
//////////////////////////////////////////////////////////////////////////////////////// | |
///////////////////////////// | |
// MemoryBasedIteratorConcept | |
///////////////////////////// | |
template <typename T> | |
struct byte_to_memunit : public mpl::int_<1> {}; | |
template <typename P> | |
inline std::ptrdiff_t memunit_step(const P*) { return sizeof(P); } | |
template <typename P> | |
inline std::ptrdiff_t memunit_distance(const P* p1, const P* p2) { | |
return (gil_reinterpret_cast_c<const unsigned char*>(p2)-gil_reinterpret_cast_c<const unsigned char*>(p1)); | |
} | |
template <typename P> | |
inline void memunit_advance(P* &p, std::ptrdiff_t diff) { | |
p=(P*)((unsigned char*)(p)+diff); | |
} | |
template <typename P> | |
inline P* memunit_advanced(const P* p, std::ptrdiff_t diff) { | |
return (P*)((char*)(p)+diff); | |
} | |
// memunit_advanced_ref | |
// (shortcut to advancing a pointer by a given number of memunits and taking the reference in case the compiler is not smart enough) | |
template <typename P> | |
inline P& memunit_advanced_ref(P* p, std::ptrdiff_t diff) { | |
return *memunit_advanced(p,diff); | |
} | |
} } // namespace boost::gil | |
#endif |