| /* |
| 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 |