metafunctions.hpp

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/*
    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 BOOST_GIL_METAFUNCTIONS_HPP
#define BOOST_GIL_METAFUNCTIONS_HPP


#include <boost/gil/config.hpp>
#include <boost/gil/concept.hpp>
#include <boost/gil/channel.hpp>

#include <boost/mpl/accumulate.hpp>
#include <boost/mpl/back.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/pop_back.hpp>
#include <boost/mpl/push_back.hpp>
#include <boost/mpl/transform.hpp>
#include <boost/mpl/vector_c.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/type_traits.hpp>

#include <iterator>

namespace boost { namespace gil {

// forward declarations
template <typename T, typename L> struct pixel;
template <typename BitField,typename ChannelRefVec,typename Layout> struct packed_pixel;
template <typename T, typename C> struct planar_pixel_reference;
template <typename IC, typename C> struct planar_pixel_iterator;
template <typename I> class memory_based_step_iterator;
template <typename I> class memory_based_2d_locator;
template <typename L> class image_view;
template <typename Pixel, bool IsPlanar, typename Alloc> class image;
template <typename T> struct channel_type;
template <typename T> struct color_space_type;
template <typename T> struct channel_mapping_type;
template <typename It> struct is_iterator_adaptor;
template <typename It> struct iterator_adaptor_get_base;
template <typename BitField, typename ChannelBitSizes, typename Layout, bool IsMutable> struct bit_aligned_pixel_reference;




template <typename PixelRef>        struct pixel_reference_is_basic                     : public mpl::false_ {};
template <typename T,  typename L>  struct pixel_reference_is_basic<      pixel<T,L>&>  : public mpl::true_ {};
template <typename T,  typename L>  struct pixel_reference_is_basic<const pixel<T,L>&>  : public mpl::true_ {};
template <typename TR, typename Cs> struct pixel_reference_is_basic<planar_pixel_reference<TR,Cs> > : public mpl::true_ {};
template <typename TR, typename Cs> struct pixel_reference_is_basic<const planar_pixel_reference<TR,Cs> > : public mpl::true_ {};


template <typename Iterator>
struct iterator_is_basic : public mpl::false_ {};
template <typename T, typename L>  // mutable   interleaved
struct iterator_is_basic<      pixel<T,L>*      > : public mpl::true_ {};
template <typename T, typename L>  // immutable interleaved
struct iterator_is_basic<const pixel<T,L>*      > : public mpl::true_ {};
template <typename T, typename Cs>  // mutable   planar
struct iterator_is_basic<planar_pixel_iterator<      T*,Cs> > : public mpl::true_ {};
template <typename T, typename Cs>    // immutable planar
struct iterator_is_basic<planar_pixel_iterator<const T*,Cs> > : public mpl::true_ {};
template <typename T, typename L>  // mutable   interleaved step
struct iterator_is_basic<memory_based_step_iterator<      pixel<T,L>*> > : public mpl::true_ {};
template <typename T, typename L>  // immutable interleaved step
struct iterator_is_basic<memory_based_step_iterator<const pixel<T,L>*> > : public mpl::true_ {};
template <typename T, typename Cs>  // mutable   planar step
struct iterator_is_basic<memory_based_step_iterator<planar_pixel_iterator<      T*,Cs> > > : public mpl::true_ {};
template <typename T, typename Cs>    // immutable planar step
struct iterator_is_basic<memory_based_step_iterator<planar_pixel_iterator<const T*,Cs> > > : public mpl::true_ {};


template <typename Loc> struct locator_is_basic : public mpl::false_ {};
template <typename Iterator> struct locator_is_basic<memory_based_2d_locator<memory_based_step_iterator<Iterator> > > : public iterator_is_basic<Iterator> {};

template <typename View> struct view_is_basic : public mpl::false_ {};
template <typename Loc> struct view_is_basic<image_view<Loc> > : public locator_is_basic<Loc> {};

template <typename Img> struct image_is_basic : public mpl::false_ {};
template <typename Pixel, bool IsPlanar, typename Alloc> struct image_is_basic<image<Pixel,IsPlanar,Alloc> > : public mpl::true_ {};



template <typename I> struct iterator_is_step;
namespace detail {
    template <typename It, bool IsBase, bool EqualsStepType> struct iterator_is_step_impl;
    // iterator that has the same type as its dynamic_x_step_type must be a step iterator
    template <typename It, bool IsBase> struct iterator_is_step_impl<It,IsBase,true> : public mpl::true_{};

    // base iterator can never be a step iterator
    template <typename It> struct iterator_is_step_impl<It,true,false> : public mpl::false_{};

    // for an iterator adaptor, see if its base is step
    template <typename It> struct iterator_is_step_impl<It,false,false> 
        : public iterator_is_step<typename iterator_adaptor_get_base<It>::type>{};
}

template <typename I> struct iterator_is_step 
    : public detail::iterator_is_step_impl<I, 
        !is_iterator_adaptor<I>::type::value,
        is_same<I,typename dynamic_x_step_type<I>::type>::value >{};

template <typename L> struct locator_is_step_in_x : public iterator_is_step<typename L::x_iterator> {}; 

template <typename L> struct locator_is_step_in_y : public iterator_is_step<typename L::y_iterator> {}; 

template <typename V> struct view_is_step_in_x : public locator_is_step_in_x<typename V::xy_locator> {}; 

template <typename V> struct view_is_step_in_y : public locator_is_step_in_y<typename V::xy_locator> {}; 

template <typename PixelReference>
struct pixel_reference_is_proxy
    : public mpl::not_<is_same<typename remove_const_and_reference<PixelReference>::type,
                               typename remove_const_and_reference<PixelReference>::type::value_type> > {};

template <typename Pixel>
struct pixel_is_reference : public mpl::or_<is_reference<Pixel>, pixel_reference_is_proxy<Pixel> > {};


template <typename R> struct pixel_reference_is_mutable : public mpl::bool_<remove_reference<R>::type::is_mutable> {};
template <typename R> struct pixel_reference_is_mutable<const R&>
    : public mpl::and_<pixel_reference_is_proxy<R>, pixel_reference_is_mutable<R> > {};

template <typename L> struct locator_is_mutable : public iterator_is_mutable<typename L::x_iterator> {};
template <typename V> struct view_is_mutable : public iterator_is_mutable<typename V::x_iterator> {};






template <typename T, typename L, bool IsPlanar=false, bool IsMutable=true> struct pixel_reference_type{};
template <typename T, typename L> struct pixel_reference_type<T,L,false,true > { typedef pixel<T,L>& type; };
template <typename T, typename L> struct pixel_reference_type<T,L,false,false> { typedef const pixel<T,L>& type; };
template <typename T, typename L> struct pixel_reference_type<T,L,true,true> { typedef const planar_pixel_reference<typename channel_traits<T>::reference,typename color_space_type<L>::type> type; };       // TODO: Assert M=identity
template <typename T, typename L> struct pixel_reference_type<T,L,true,false> { typedef const planar_pixel_reference<typename channel_traits<T>::const_reference,typename color_space_type<L>::type> type; };// TODO: Assert M=identity

template <typename Pixel, bool IsPlanar=false, bool IsStep=false, bool IsMutable=true> struct iterator_type_from_pixel{};
template <typename Pixel> struct iterator_type_from_pixel<Pixel,false,false,true > { typedef Pixel* type; };
template <typename Pixel> struct iterator_type_from_pixel<Pixel,false,false,false> { typedef const Pixel* type; };
template <typename Pixel> struct iterator_type_from_pixel<Pixel,true,false,true> { 
    typedef planar_pixel_iterator<typename channel_traits<typename channel_type<Pixel>::type>::pointer,typename color_space_type<Pixel>::type> type; 
};
template <typename Pixel> struct iterator_type_from_pixel<Pixel,true,false,false> { 
    typedef planar_pixel_iterator<typename channel_traits<typename channel_type<Pixel>::type>::const_pointer,typename color_space_type<Pixel>::type> type; 
};
template <typename Pixel, bool IsPlanar, bool IsMutable> struct iterator_type_from_pixel<Pixel,IsPlanar,true,IsMutable> { 
    typedef memory_based_step_iterator<typename iterator_type_from_pixel<Pixel,IsPlanar,false,IsMutable>::type> type; 
};

template <typename T, typename L, bool IsPlanar=false, bool IsStep=false, bool IsMutable=true> struct iterator_type{};
template <typename T, typename L> struct iterator_type<T,L,false,false,true > { typedef pixel<T,L>* type; };
template <typename T, typename L> struct iterator_type<T,L,false,false,false> { typedef const pixel<T,L>* type; };
template <typename T, typename L> struct iterator_type<T,L,true,false,true> { typedef planar_pixel_iterator<T*,typename L::color_space_t> type; };               // TODO: Assert M=identity
template <typename T, typename L> struct iterator_type<T,L,true,false,false> { typedef planar_pixel_iterator<const T*,typename L::color_space_t> type; };        // TODO: Assert M=identity
template <typename T, typename L, bool IsPlanar, bool IsMutable> struct iterator_type<T,L,IsPlanar,true,IsMutable> { 
    typedef memory_based_step_iterator<typename iterator_type<T,L,IsPlanar,false,IsMutable>::type> type; 
};

template <typename XIterator> 
struct type_from_x_iterator {
    typedef memory_based_step_iterator<XIterator>    step_iterator_t;
    typedef memory_based_2d_locator<step_iterator_t> xy_locator_t;
    typedef image_view<xy_locator_t>                     view_t;
};

namespace detail {
    template <typename BitField, typename FirstBit, typename NumBits>
    struct packed_channel_reference_type {
        typedef const packed_channel_reference<BitField,FirstBit::value,NumBits::value,true> type;
    };

    template <typename BitField, typename ChannelBitSizesVector>
    class packed_channel_references_vector_type {
        // If ChannelBitSizesVector is mpl::vector<int,7,7,2>
        // Then first_bits_vector will be mpl::vector<int,0,7,14,16>
        typedef typename mpl::accumulate<ChannelBitSizesVector, mpl::vector1<mpl::int_<0> >, 
            mpl::push_back<mpl::_1, mpl::plus<mpl::back<mpl::_1>, mpl::_2> > >::type first_bits_vector;
    public:
        typedef typename mpl::transform<typename mpl::pop_back<first_bits_vector>::type, ChannelBitSizesVector,
               packed_channel_reference_type<BitField, mpl::_1,mpl::_2> >::type type;
    };

}

template <typename BitField, typename ChannelBitSizeVector, typename Layout>
struct packed_pixel_type {
    typedef packed_pixel<BitField, typename detail::packed_channel_references_vector_type<BitField,ChannelBitSizeVector>::type, Layout> type;
};


template <typename BitField, typename ChannelBitSizeVector, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image_type {
    typedef image<typename packed_pixel_type<BitField,ChannelBitSizeVector,Layout>::type,false,Alloc> type;
};

template <typename BitField, unsigned Size1, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image1_type : public packed_image_type<BitField, mpl::vector1_c<unsigned, Size1>, Layout, Alloc> {};

template <typename BitField, unsigned Size1, unsigned Size2, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image2_type : public packed_image_type<BitField, mpl::vector2_c<unsigned, Size1, Size2>, Layout, Alloc> {};

template <typename BitField, unsigned Size1, unsigned Size2, unsigned Size3, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image3_type : public packed_image_type<BitField, mpl::vector3_c<unsigned, Size1, Size2, Size3>, Layout, Alloc> {};

template <typename BitField, unsigned Size1, unsigned Size2, unsigned Size3, unsigned Size4, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image4_type : public packed_image_type<BitField, mpl::vector4_c<unsigned, Size1, Size2, Size3, Size4>, Layout, Alloc> {};

template <typename BitField, unsigned Size1, unsigned Size2, unsigned Size3, unsigned Size4, unsigned Size5, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct packed_image5_type : public packed_image_type<BitField, mpl::vector5_c<unsigned, Size1, Size2, Size3, Size4, Size5>, Layout, Alloc> {};



template <typename ChannelBitSizeVector, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image_type {
private:
    BOOST_STATIC_CONSTANT(int, bit_size = (mpl::accumulate<ChannelBitSizeVector, mpl::int_<0>, mpl::plus<mpl::_1, mpl::_2> >::type::value));
    typedef typename detail::min_fast_uint<bit_size+7>::type                        bitfield_t;  
    typedef const bit_aligned_pixel_reference<bitfield_t, ChannelBitSizeVector, Layout, true> bit_alignedref_t;
public:
    typedef image<bit_alignedref_t,false,Alloc> type;
};

template <unsigned Size1, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image1_type : public bit_aligned_image_type<mpl::vector1_c<unsigned, Size1>, Layout, Alloc> {};

template <unsigned Size1, unsigned Size2, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image2_type : public bit_aligned_image_type<mpl::vector2_c<unsigned, Size1, Size2>, Layout, Alloc> {};

template <unsigned Size1, unsigned Size2, unsigned Size3, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image3_type : public bit_aligned_image_type<mpl::vector3_c<unsigned, Size1, Size2, Size3>, Layout, Alloc> {};

template <unsigned Size1, unsigned Size2, unsigned Size3, unsigned Size4, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image4_type : public bit_aligned_image_type<mpl::vector4_c<unsigned, Size1, Size2, Size3, Size4>, Layout, Alloc> {};

template <unsigned Size1, unsigned Size2, unsigned Size3, unsigned Size4, unsigned Size5, typename Layout, typename Alloc=std::allocator<unsigned char> >
struct bit_aligned_image5_type : public bit_aligned_image_type<mpl::vector5_c<unsigned, Size1, Size2, Size3, Size4, Size5>, Layout, Alloc> {};



template <typename Channel, typename Layout> 
struct pixel_value_type {
    typedef pixel<Channel,Layout> type;     // by default use gil::pixel. Specializations are provided for 
};

// Specializations for packed channels
template <typename BitField, int NumBits, bool IsMutable, typename Layout> 
struct pixel_value_type<      packed_dynamic_channel_reference<BitField,NumBits,IsMutable>,Layout> :
    public packed_pixel_type<BitField, mpl::vector1_c<unsigned,NumBits>, Layout> {};
template <typename BitField, int NumBits, bool IsMutable, typename Layout> 
struct pixel_value_type<const packed_dynamic_channel_reference<BitField,NumBits,IsMutable>,Layout> :
    public packed_pixel_type<BitField, mpl::vector1_c<unsigned,NumBits>, Layout> {};

template <typename BitField, int FirstBit, int NumBits, bool IsMutable, typename Layout> 
struct pixel_value_type<      packed_channel_reference<BitField,FirstBit,NumBits,IsMutable>,Layout> :
    public packed_pixel_type<BitField, mpl::vector1_c<unsigned,NumBits>, Layout> {};
template <typename BitField, int FirstBit, int NumBits, bool IsMutable, typename Layout> 
struct pixel_value_type<const packed_channel_reference<BitField,FirstBit,NumBits,IsMutable>,Layout> :
    public packed_pixel_type<BitField, mpl::vector1_c<unsigned,NumBits>, Layout> {};

template <int NumBits, typename Layout> 
struct pixel_value_type<packed_channel_value<NumBits>,Layout> :
    public packed_pixel_type<typename detail::min_fast_uint<NumBits>::type, mpl::vector1_c<unsigned,NumBits>, Layout> {};


template <typename T, typename L, bool IsPlanar=false, bool IsStepX=false, bool IsMutable=true> 
struct locator_type {
    typedef typename type_from_x_iterator<typename iterator_type<T,L,IsPlanar,IsStepX,IsMutable>::type>::xy_locator_type type;
};

template <typename T, typename L, bool IsPlanar=false, bool IsStepX=false, bool IsMutable=true> 
struct view_type {
    typedef typename type_from_x_iterator<typename iterator_type<T,L,IsPlanar,IsStepX,IsMutable>::type>::view_t type;
};

template <typename T, typename L, bool IsPlanar=false, typename Alloc=std::allocator<unsigned char> > 
struct image_type {
    typedef image<pixel<T,L>, IsPlanar, Alloc> type;
};

template <typename Pixel, bool IsPlanar=false, bool IsStepX=false, bool IsMutable=true> 
struct view_type_from_pixel {
    typedef typename type_from_x_iterator<typename iterator_type_from_pixel<Pixel,IsPlanar,IsStepX,IsMutable>::type>::view_t type;
};


template <typename Ref, typename T=use_default, typename L=use_default, typename IsPlanar=use_default, typename IsMutable=use_default>
class derived_pixel_reference_type {
    typedef typename remove_reference<Ref>::type pixel_t;
    typedef typename  mpl::if_<is_same<T, use_default>, typename channel_type<pixel_t>::type,     T >::type channel_t;
    typedef typename  mpl::if_<is_same<L, use_default>, 
        layout<typename color_space_type<pixel_t>::type, typename channel_mapping_type<pixel_t>::type>, L>::type           layout_t;
    static const bool mut   =mpl::if_<is_same<IsMutable,use_default>, pixel_reference_is_mutable<Ref>, IsMutable>::type::value;
    static const bool planar=mpl::if_<is_same<IsPlanar,use_default>,  is_planar<pixel_t>,  IsPlanar>::type::value;
public:
    typedef typename pixel_reference_type<channel_t, layout_t, planar, mut>::type type;
};

template <typename Iterator, typename T=use_default, typename L=use_default, typename IsPlanar=use_default, typename IsStep=use_default, typename IsMutable=use_default>
class derived_iterator_type {
    typedef typename  mpl::if_<is_same<T ,use_default>, typename channel_type<Iterator>::type,     T >::type channel_t;
    typedef typename  mpl::if_<is_same<L,use_default>, 
        layout<typename color_space_type<Iterator>::type, typename channel_mapping_type<Iterator>::type>, L>::type layout_t;

    static const bool mut   =mpl::if_<is_same<IsMutable,use_default>, iterator_is_mutable<Iterator>, IsMutable>::type::value;
    static const bool planar=mpl::if_<is_same<IsPlanar,use_default>,         is_planar<Iterator>,  IsPlanar>::type::value;
    static const bool step  =mpl::if_<is_same<IsStep  ,use_default>,  iterator_is_step<Iterator>,    IsStep>::type::value;
public:
    typedef typename iterator_type<channel_t, layout_t, planar, step, mut>::type type;
};

template <typename View, typename T=use_default, typename L=use_default, typename IsPlanar=use_default, typename StepX=use_default, typename IsMutable=use_default>
class derived_view_type {
    typedef typename  mpl::if_<is_same<T ,use_default>, typename channel_type<View>::type, T>::type channel_t;
    typedef typename  mpl::if_<is_same<L,use_default>, 
        layout<typename color_space_type<View>::type, typename channel_mapping_type<View>::type>, L>::type layout_t;
    static const bool mut   =mpl::if_<is_same<IsMutable,use_default>, view_is_mutable<View>, IsMutable>::type::value;
    static const bool planar=mpl::if_<is_same<IsPlanar,use_default>,  is_planar<View>,  IsPlanar>::type::value;
    static const bool step  =mpl::if_<is_same<StepX ,use_default>,  view_is_step_in_x<View>,StepX>::type::value;
public:
    typedef typename view_type<channel_t, layout_t, planar, step, mut>::type type;
};

template <typename Image, typename T=use_default, typename L=use_default, typename IsPlanar=use_default>
class derived_image_type {
    typedef typename  mpl::if_<is_same<T ,use_default>, typename channel_type<Image>::type,     T >::type channel_t;
    typedef typename  mpl::if_<is_same<L,use_default>, 
        layout<typename color_space_type<Image>::type, typename channel_mapping_type<Image>::type>, L>::type layout_t;
    static const bool planar=mpl::if_<is_same<IsPlanar,use_default>,  is_planar<Image>,  IsPlanar>::type::value;
public:
    typedef typename image_type<channel_t, layout_t, planar>::type type;
};

}}  // namespace boost::gil

#endif