/*

    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_ALGORITHM_HPP

#define GIL_ALGORITHM_HPP



#include <cassert>

#include <cstddef>

#include <algorithm>

#include <iterator>

#include <memory>

#include "gil_config.hpp"

#include "gil_concept.hpp"

#include "color_base_algorithm.hpp"

#include "image_view.hpp"

#include "image_view_factory.hpp"

#include "bit_aligned_pixel_iterator.hpp"



////////////////////////////////////////////////////////////////////////////////////////

/// \file               

/// \brief Some basic STL-style algorithms when applied to image views

/// \author Lubomir Bourdev and Hailin Jin \n

///         Adobe Systems Incorporated

/// \date   2005-2007 \n Last updated on May 6, 2007

///

////////////////////////////////////////////////////////////////////////////////////////



//#ifdef _MSC_VER

//#pragma warning(push)

//#pragma warning(disable : 4244)     // conversion from 'gil::image<V,Alloc>::coord_t' to 'int', possible loss of data (visual studio compiler doesn't realize that the two types are the same)

//#endif



namespace boost { namespace gil {



//forward declarations

template <typename ChannelPtr, typename ColorSpace>

struct planar_pixel_iterator;

template <typename Iterator>

class memory_based_step_iterator;

template <typename StepIterator>

class memory_based_2d_locator;



// a tag denoting incompatible arguments

struct error_t {};



/// \defgroup ImageViewSTLAlgorithms STL-like Algorithms

/// \ingroup ImageViewAlgorithm

/// \brief Image view-equivalents of STL algorithms

///

/// Image views provide 1D iteration of their pixels via \p begin() and \p end() methods,

/// which makes it possible to use STL algorithms with them. However, using nested loops

/// over X and Y is in many cases more efficient. The algorithms in this section resemble

/// STL algorithms, but they abstract away the nested loops and take views (as opposed to ranges) as input.

///

/// Most algorithms check whether the image views are 1D-traversable. A 1D-traversable image view has no gaps

/// at the end of the rows. In other words, if an x_iterator of that view is advanced past the last pixel in a row

/// it will move to the first pixel of the next row. When image views are 1D-traversable, the algorithms use

/// a single loop and run more efficiently. If one or more of the input views are not 1D-traversable, the algorithms

/// fall-back to an X-loop nested inside a Y-loop.

///

/// The algorithms typically delegate the work to their corresponding STL algorithms. For example, \p copy_pixels calls

/// \p std::copy either for each row, or, when the images are 1D-traversable, once for all pixels.

///

/// In addition, overloads are sometimes provided for the STL algorithms. For example, std::copy for planar iterators

/// is overloaded to perform \p std::copy for each of the planes. \p std::copy over bitwise-copiable pixels results in

/// std::copy over unsigned char, which STL typically implements via \p memmove.

///

/// As a result \p copy_pixels may result in a single call to \p memmove for interleaved 1D-traversable views, 

/// or one per each plane of planar 1D-traversable views, or one per each row of interleaved non-1D-traversable images, etc.





/// \defgroup STLOptimizations  Performance overloads of STL algorithms

/// \ingroup ImageViewAlgorithm

/// \brief overloads of STL algorithms allowing more efficient implementation when used with GIL constructs



/// \brief A generic binary operation on views

/// \ingroup ImageViewSTLAlgorithms

///

/// Use this class as a convenience superclass when defining an operation for any image views.

/// Many operations have different behavior when the two views are compatible. This class checks

/// for compatibility and invokes apply_compatible(V1,V2) or apply_incompatible(V1,V2) of the subclass.

/// You must provide apply_compatible(V1,V2) method in your subclass, but apply_incompatible(V1,V2)

/// is not required and the default throws std::bad_cast.

template <typename Derived, typename Result=void>

struct binary_operation_obj {

    typedef Result result_type;



    template <typename V1, typename V2> GIL_FORCEINLINE

    result_type operator()(const std::pair<const V1*,const V2*>& p) const {

        return apply(*p.first, *p.second, typename views_are_compatible<V1,V2>::type());

    }



    template <typename V1, typename V2> GIL_FORCEINLINE

    result_type operator()(const V1& v1, const V2& v2) const {

        return apply(v1, v2, typename views_are_compatible<V1,V2>::type());

    }



    result_type operator()(const error_t&) const { throw std::bad_cast(); }

private:



    // dispatch from apply overload to a function with distinct name

    template <typename V1, typename V2>

    GIL_FORCEINLINE result_type apply(const V1& v1, const V2& v2, mpl::false_) const {

        return ((const Derived*)this)->apply_incompatible(v1,v2);

    }



    // dispatch from apply overload to a function with distinct name

    template <typename V1, typename V2>

    GIL_FORCEINLINE result_type apply(const V1& v1, const V2& v2, mpl::true_) const {

        return ((const Derived*)this)->apply_compatible(v1,v2);

    }



    // function with distinct name - it can be overloaded by subclasses

    template <typename V1, typename V2>

    GIL_FORCEINLINE result_type apply_incompatible(const V1& v1, const V2& v2) const {

        throw std::bad_cast();

    }

};

} }  // namespace boost::gil



//////////////////////////////////////////////////////////////////////////////////////

///

/// std::copy and gil::copy_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsCopyPixels copy_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::copy for image views



namespace std {



/// \ingroup STLOptimizations

/// \brief Copy when both src and dst are interleaved and of the same type can be just memmove

template<typename T, typename Cs> 

GIL_FORCEINLINE boost::gil::pixel<T,Cs>* 

copy(boost::gil::pixel<T,Cs>* first, boost::gil::pixel<T,Cs>* last, 

     boost::gil::pixel<T,Cs>* dst) { 

    return (boost::gil::pixel<T,Cs>*)std::copy((unsigned char*)first,(unsigned char*)last, (unsigned char*)dst);

}



/// \ingroup STLOptimizations

/// \brief Copy when both src and dst are interleaved and of the same type can be just memmove

template<typename T, typename Cs> 

GIL_FORCEINLINE boost::gil::pixel<T,Cs>* 

copy(const boost::gil::pixel<T,Cs>* first, const boost::gil::pixel<T,Cs>* last, 

     boost::gil::pixel<T,Cs>* dst) { 

    return (boost::gil::pixel<T,Cs>*)std::copy((unsigned char*)first,(unsigned char*)last, (unsigned char*)dst);

}

} // namespace std



namespace boost { namespace gil {

namespace detail {

template <typename I, typename O> struct copy_fn { 

    GIL_FORCEINLINE I operator()(I first, I last, O dst) const { return std::copy(first,last,dst); } 

};

} // namespace detail

} }  // namespace boost::gil



namespace std {

/// \ingroup STLOptimizations

/// \brief Copy when both src and dst are planar pointers is copy for each channel

template<typename Cs, typename IC1, typename IC2> GIL_FORCEINLINE

boost::gil::planar_pixel_iterator<IC2,Cs> copy(boost::gil::planar_pixel_iterator<IC1,Cs> first, boost::gil::planar_pixel_iterator<IC1,Cs> last, boost::gil::planar_pixel_iterator<IC2,Cs> dst) { 

    boost::gil::gil_function_requires<boost::gil::ChannelsCompatibleConcept<typename std::iterator_traits<IC1>::value_type,typename std::iterator_traits<IC2>::value_type> >();

    static_for_each(first,last,dst,boost::gil::detail::copy_fn<IC1,IC2>());

    return dst+(last-first);

}

} // namespace std



namespace boost { namespace gil {

namespace detail {

/// Does a copy-n. If the inputs contain image iterators, performs a copy at each row using the row iterators

/// \ingroup CopyPixels

template <typename I, typename O>

struct copier_n {

    GIL_FORCEINLINE void operator()(I src, typename std::iterator_traits<I>::difference_type n, O dst) const { std::copy(src,src+n, dst); }

};



/// Source range is delimited by image iterators

template <typename IL, typename O>  // IL Models ConstPixelLocatorConcept, O Models PixelIteratorConcept

struct copier_n<iterator_from_2d<IL>,O> {

    typedef typename std::iterator_traits<iterator_from_2d<IL> >::difference_type diff_t;

    GIL_FORCEINLINE void operator()(iterator_from_2d<IL> src, diff_t n, O dst) const {

        gil_function_requires<PixelLocatorConcept<IL> >();

        gil_function_requires<MutablePixelIteratorConcept<O> >();

        while (n>0) {

            typedef typename iterator_from_2d<IL>::difference_type diff_t;

            diff_t l=src.width()-src.x_pos();

            diff_t numToCopy=(n<l ? n:l);

            detail::copy_n(src.x(), numToCopy, dst);

            dst+=numToCopy;

            src+=numToCopy;

            n-=numToCopy;

        }

    }

};



/// Destination range is delimited by image iterators

template <typename I, typename OL> // I Models ConstPixelIteratorConcept, OL Models PixelLocatorConcept

struct copier_n<I,iterator_from_2d<OL> > {

    typedef typename std::iterator_traits<I>::difference_type diff_t;

    GIL_FORCEINLINE void operator()(I src, diff_t n, iterator_from_2d<OL> dst) const {

        gil_function_requires<PixelIteratorConcept<I> >();

        gil_function_requires<MutablePixelLocatorConcept<OL> >();

        while (n>0) {

            diff_t l=dst.width()-dst.x_pos();

            diff_t numToCopy=(n<l ? n:l);

            detail::copy_n(src, numToCopy, dst.x());

            dst+=numToCopy;

            src+=numToCopy;

            n-=numToCopy;

        }

    }

};



/// Both source and destination ranges are delimited by image iterators

template <typename IL, typename OL>

struct copier_n<iterator_from_2d<IL>,iterator_from_2d<OL> > {

   typedef typename iterator_from_2d<IL>::difference_type diff_t;

   GIL_FORCEINLINE void operator()(iterator_from_2d<IL> src, diff_t n, iterator_from_2d<OL> dst) const {

        gil_function_requires<PixelLocatorConcept<IL> >();

        gil_function_requires<MutablePixelLocatorConcept<OL> >();

        if (src.x_pos()!=dst.x_pos() || src.width()!=dst.width()) {

            while(n-->0) {

                *dst++=*src++;

            }

        }

        while (n>0) {

            diff_t l=dst.width()-dst.x_pos();

            diff_t numToCopy=(n<l ? n : l);

            detail::copy_n(src.x(), numToCopy, dst.x());

            dst+=numToCopy;

            src+=numToCopy;

            n-=numToCopy;

        }

    }

};



template <typename SrcIterator, typename DstIterator>

GIL_FORCEINLINE DstIterator copy_with_2d_iterators(SrcIterator first, SrcIterator last, DstIterator dst) {

    typedef typename SrcIterator::x_iterator src_x_iterator;

    typedef typename DstIterator::x_iterator dst_x_iterator;



    typename SrcIterator::difference_type n = last - first;



    if (first.is_1d_traversable()) {

        if (dst.is_1d_traversable())

            copier_n<src_x_iterator,dst_x_iterator>()(first.x(),n, dst.x());

        else

            copier_n<src_x_iterator,DstIterator >()(first.x(),n, dst);

    } else {

        if (dst.is_1d_traversable())

            copier_n<SrcIterator,dst_x_iterator>()(first,n, dst.x());

        else

            copier_n<SrcIterator,DstIterator>()(first,n,dst);

    }

    return dst+n;

}



} // namespace detail

} }  // namespace boost::gil



namespace std {

/// \ingroup STLOptimizations

/// \brief  std::copy(I1,I1,I2) with I1 and I2 being a iterator_from_2d

template <typename IL, typename OL>

GIL_FORCEINLINE boost::gil::iterator_from_2d<OL> copy1(boost::gil::iterator_from_2d<IL> first, boost::gil::iterator_from_2d<IL> last, boost::gil::iterator_from_2d<OL> dst) {

    return boost::gil::detail::copy_with_2d_iterators(first,last,dst);

}



} // namespace std



namespace boost { namespace gil {





/// \ingroup ImageViewSTLAlgorithmsCopyPixels

/// \brief std::copy for image views

template <typename View1, typename View2> GIL_FORCEINLINE

void copy_pixels(const View1& src, const View2& dst) { 

    assert(src.dimensions()==dst.dimensions());

    detail::copy_with_2d_iterators(src.begin(),src.end(),dst.begin());

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// copy_and_convert_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsCopyAndConvertPixels copy_and_convert_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief copies src view into dst view, color converting if necessary.

///

/// Versions taking static and runtime views are provided. Versions taking user-defined color convered are provided.



namespace detail {

template <typename CC>

class copy_and_convert_pixels_fn : public binary_operation_obj<copy_and_convert_pixels_fn<CC> > {

private:

    CC _cc;

public:

    typedef typename binary_operation_obj<copy_and_convert_pixels_fn<CC> >::result_type result_type;

    copy_and_convert_pixels_fn() {}

    copy_and_convert_pixels_fn(CC cc_in) : _cc(cc_in) {}

   // when the two color spaces are incompatible, a color conversion is performed

    template <typename V1, typename V2> GIL_FORCEINLINE 

    result_type apply_incompatible(const V1& src, const V2& dst) const {

        copy_pixels(color_converted_view<typename V2::value_type>(src,_cc),dst);

    }



    // If the two color spaces are compatible, copy_and_convert is just copy

    template <typename V1, typename V2> GIL_FORCEINLINE 

    result_type apply_compatible(const V1& src, const V2& dst) const {

         copy_pixels(src,dst);

    }

};

} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsCopyAndConvertPixels

template <typename V1, typename V2,typename CC> 

GIL_FORCEINLINE 

void copy_and_convert_pixels(const V1& src, const V2& dst,CC cc) { 

    detail::copy_and_convert_pixels_fn<CC> ccp(cc);

    ccp(src,dst);

}



struct default_color_converter;



/// \ingroup ImageViewSTLAlgorithmsCopyAndConvertPixels

template <typename View1, typename View2> 

GIL_FORCEINLINE 

void copy_and_convert_pixels(const View1& src, const View2& dst) { 

    detail::copy_and_convert_pixels_fn<default_color_converter> ccp;

    ccp(src,dst);

}



} }  // namespace boost::gil



//////////////////////////////////////////////////////////////////////////////////////

//

// std::fill and gil::fill_pixels

//

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsFillPixels fill_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::fill for image views





namespace std {

/// \ingroup STLOptimizations

/// \brief std::fill(I,I,V) with I being a iterator_from_2d

///

/// Invoked when one calls std::fill(I,I,V) with I being a iterator_from_2d (which is

/// a 1D iterator over the pixels in an image). For contiguous images (i.e. images that have

/// no alignment gap at the end of each row) it is more efficient to use the underlying 

/// pixel iterator that does not check for the end of rows. For non-contiguous images fill

/// resolves to fill of each row using the underlying pixel iterator, which is still faster

template <typename IL, typename V>

void fill(boost::gil::iterator_from_2d<IL> first, boost::gil::iterator_from_2d<IL> last, const V& val) {

    boost::gil::gil_function_requires<boost::gil::MutablePixelLocatorConcept<IL> >();

    if (first.is_1d_traversable()) {

        std::fill(first.x(), last.x(), val);

    } else {

        // fill row by row

        std::ptrdiff_t n=last-first;

        while (n>0) {

            std::ptrdiff_t numToDo=std::min<const std::ptrdiff_t>(n,(std::ptrdiff_t)(first.width()-first.x_pos()));

            fill_n(first.x(), numToDo, val);

            first+=numToDo;

            n-=numToDo;

        }

    }

} 

} // namespace std



namespace boost { namespace gil {



namespace detail {

/// struct to do std::fill

struct std_fill_t {

    template <typename It, typename P>

    void operator()(It first, It last, const P& p_in) {

        std::fill(first,last,p_in);

    }

};

/// std::fill for planar iterators

template <typename It, typename P>

GIL_FORCEINLINE 

void fill_aux(It first, It last, const P& p, mpl::true_) {

    static_for_each(first,last,p,std_fill_t());

}

/// std::fill for interleaved iterators

template <typename It, typename P>

GIL_FORCEINLINE 

void fill_aux(It first, It last, const P& p,mpl::false_) {

    std::fill(first,last,p);

}

} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsFillPixels

/// \brief std::fill for image views

template <typename View, typename Value> GIL_FORCEINLINE 

void fill_pixels(const View& img_view, const Value& val) {

    if (img_view.is_1d_traversable())

        detail::fill_aux(img_view.begin().x(), img_view.end().x(), 

                 val,is_planar<View>());

    else

        for (std::ptrdiff_t y=0; y<img_view.height(); ++y)

            detail::fill_aux(img_view.row_begin(y),img_view.row_end(y),

                     val,is_planar<View>());

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// destruct_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsDestructPixels destruct_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief invokes the destructor on every pixel of an image view





namespace detail {



template <typename It> GIL_FORCEINLINE

void destruct_range_impl(It first, It last, mpl::true_) {

    typedef typename std::iterator_traits<It>::value_type value_t;

    if (boost::has_trivial_destructor<value_t>::value)

        return;

    while (first!=last) {

        first->~value_t();

        ++first;

    }

}

template <typename It> GIL_FORCEINLINE

void destruct_range_impl(It first, It last, mpl::false_) {}



template <typename It> GIL_FORCEINLINE

void destruct_range(It first, It last) {

    destruct_range_impl(first,last,typename is_pointer<It>::type());

}



struct std_destruct_t {

    template <typename It> void operator()(It first, It last) const { destruct_range(first,last); }

};



/// destruct for planar iterators

template <typename It>

GIL_FORCEINLINE 

void destruct_aux(It first, It last, mpl::true_) {

    static_for_each(first,last,std_destruct_t());

}

/// destruct for interleaved iterators

template <typename It>

GIL_FORCEINLINE 

void destruct_aux(It first, It last, mpl::false_) {

    destruct_range(first,last);

}



} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsDestructPixels

/// \brief Invokes the in-place destructor on every pixel of the view

template <typename View> GIL_FORCEINLINE 

void destruct_pixels(const View& img_view) {

    if (img_view.is_1d_traversable()) 

        detail::destruct_aux(img_view.begin().x(), img_view.end().x(), 

                                       is_planar<View>());

    else

        for (std::ptrdiff_t y=0; y<img_view.height(); ++y)

            detail::destruct_aux(img_view.row_begin(y),img_view.row_end(y),

                                           is_planar<View>());

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// uninitialized_fill_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsUninitializedFillPixels uninitialized_fill_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::uninitialized_fill for image views





namespace detail {



/// std::uninitialized_fill for planar iterators

/// If an exception is thrown destructs any in-place copy-constructed objects

template <typename It, typename P>

GIL_FORCEINLINE 

void uninitialized_fill_aux(It first, It last,

                            const P& p, mpl::true_) {

    int channel=0;

    try {

        typedef typename std::iterator_traits<It>::value_type pixel_t;

        while (channel < num_channels<pixel_t>::value) {

            std::uninitialized_fill(dynamic_at_c(first,channel), dynamic_at_c(last,channel), 

                                    dynamic_at_c(p,channel));

            ++channel;

        }

    } catch (...) {

        for (int c=0; c<channel; ++c)

            destruct_range(dynamic_at_c(first,c), dynamic_at_c(last,c));

        throw;

    }

}



/// std::uninitialized_fill for interleaved iterators

/// If an exception is thrown destructs any in-place copy-constructed objects

template <typename It, typename P>

GIL_FORCEINLINE 

void uninitialized_fill_aux(It first, It last,

                            const P& p,mpl::false_) {

    std::uninitialized_fill(first,last,p);

}



} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsUninitializedFillPixels

/// \brief std::uninitialized_fill for image views.

/// Does not support planar heterogeneous views.

/// If an exception is thrown destructs any in-place copy-constructed pixels

template <typename View, typename Value> 

void uninitialized_fill_pixels(const View& img_view, const Value& val) {

    if (img_view.is_1d_traversable()) 

        detail::uninitialized_fill_aux(img_view.begin().x(), img_view.end().x(), 

                                       val,is_planar<View>());

    else {

        typename View::y_coord_t y;

        try {

            for (y=0; y<img_view.height(); ++y)

                detail::uninitialized_fill_aux(img_view.row_begin(y),img_view.row_end(y),

                                               val,is_planar<View>());

        } catch(...) {

            for (typename View::y_coord_t y0=0; y0<y; ++y0)

                detail::destruct_aux(img_view.row_begin(y0),img_view.row_end(y0), is_planar<View>());

            throw;

        }

    }

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// default_construct_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsDefaultConstructPixels default_construct_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief invokes the default constructor on every pixel of an image view



namespace detail {



template <typename It> GIL_FORCEINLINE 

void default_construct_range_impl(It first, It last, mpl::true_) {

    typedef typename std::iterator_traits<It>::value_type value_t;

    It first1=first;

    try {

        while (first!=last) {

            new (first) value_t();

            ++first;

        }

    } catch (...) {

        destruct_range(first1,first);

        throw;

    }

}



template <typename It> GIL_FORCEINLINE 

void default_construct_range_impl(It first, It last, mpl::false_) {}



template <typename It> GIL_FORCEINLINE 

void default_construct_range(It first, It last) { default_construct_range_impl(first, last, typename is_pointer<It>::type()); }



/// uninitialized_default_construct for planar iterators

template <typename It>

GIL_FORCEINLINE 

void default_construct_aux(It first, It last, mpl::true_) {

    int channel=0;

    try {

        typedef typename std::iterator_traits<It>::value_type pixel_t;

        while (channel < num_channels<pixel_t>::value) {

            default_construct_range(dynamic_at_c(first,channel), dynamic_at_c(last,channel));

            ++channel;

        }

    } catch (...) {

        for (int c=0; c<channel; ++c)

            destruct_range(dynamic_at_c(first,c), dynamic_at_c(last,c));

        throw;

    }

}



/// uninitialized_default_construct for interleaved iterators

template <typename It>

GIL_FORCEINLINE 

void default_construct_aux(It first, It last, mpl::false_) {

    default_construct_range(first,last);

}



template <typename View, bool IsPlanar>

struct has_trivial_pixel_constructor : public boost::has_trivial_constructor<typename View::value_type> {};

template <typename View>

struct has_trivial_pixel_constructor<View, true> : public boost::has_trivial_constructor<typename channel_type<View>::type> {};



} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsDefaultConstructPixels

/// \brief Invokes the in-place default constructor on every pixel of the (uninitialized) view.

/// Does not support planar heterogeneous views.

/// If an exception is thrown destructs any in-place default-constructed pixels

template <typename View> 

void default_construct_pixels(const View& img_view) {

    if (detail::has_trivial_pixel_constructor<View, is_planar<View>::value>::value)

        return;



    if (img_view.is_1d_traversable()) 

        detail::default_construct_aux(img_view.begin().x(), img_view.end().x(), is_planar<View>());

    else {

        typename View::y_coord_t y;

        try {

            for (y=0; y<img_view.height(); ++y)

                detail::default_construct_aux(img_view.row_begin(y),img_view.row_end(y), is_planar<View>());

        } catch(...) {

            for (typename View::y_coord_t y0=0; y0<y; ++y0)

                detail::destruct_aux(img_view.row_begin(y0),img_view.row_end(y0), is_planar<View>());

            throw;

        }

    }

}





//////////////////////////////////////////////////////////////////////////////////////

///

/// uninitialized_copy_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsUninitializedCopyPixels uninitialized_copy_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::uninitialized_copy for image views



namespace detail {



/// std::uninitialized_copy for pairs of planar iterators

template <typename It1, typename It2>

GIL_FORCEINLINE 

void uninitialized_copy_aux(It1 first1, It1 last1,

                            It2 first2, mpl::true_) {

    int channel=0;

    try {

        typedef typename std::iterator_traits<It1>::value_type pixel_t;

        while (channel < num_channels<pixel_t>::value) {

            std::uninitialized_copy(dynamic_at_c(first1,channel), dynamic_at_c(last1,channel), dynamic_at_c(first2,channel));

            ++channel;

        }

    } catch (...) {

        It2 last2=first2;

        std::advance(last2, std::distance(first1,last1));

        for (int c=0; c<channel; ++c)

            destruct_range(dynamic_at_c(first2,c), dynamic_at_c(last2,c));

        throw;

    }

}

/// std::uninitialized_copy for interleaved or mixed iterators

template <typename It1, typename It2>

GIL_FORCEINLINE 

void uninitialized_copy_aux(It1 first1, It1 last1,

                            It2 first2,mpl::false_) {

    std::uninitialized_copy(first1,last1,first2);

}

} // namespace detail



/// \ingroup ImageViewSTLAlgorithmsUninitializedCopyPixels

/// \brief std::uninitialized_copy for image views.

/// Does not support planar heterogeneous views.

/// If an exception is thrown destructs any in-place copy-constructed objects

template <typename View1, typename View2> 

void uninitialized_copy_pixels(const View1& view1, const View2& view2) {

    typedef mpl::bool_<is_planar<View1>::value && is_planar<View2>::value> is_planar;  

    assert(view1.dimensions()==view2.dimensions());

    if (view1.is_1d_traversable() && view2.is_1d_traversable())

        detail::uninitialized_copy_aux(view1.begin().x(), view1.end().x(), 

                                       view2.begin().x(), 

                                       is_planar());

    else {

        typename View1::y_coord_t y;

        try {

            for (y=0; y<view1.height(); ++y)

                detail::uninitialized_copy_aux(view1.row_begin(y), view1.row_end(y),

                                               view2.row_begin(y),

                                               is_planar());

        } catch(...) {

            for (typename View1::y_coord_t y0=0; y0<y; ++y0)

                detail::destruct_aux(view2.row_begin(y0),view2.row_end(y0), is_planar());

            throw;

        }

    }

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// for_each_pixel

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsForEachPixel for_each_pixel

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::for_each for image views

///

/// For contiguous images (i.e. images that have no alignment gap at the end of each row) it is 

/// more efficient to use the underlying pixel iterator that does not check for the end of rows. 

/// For non-contiguous images for_each_pixel resolves to for_each of each row using the underlying 

/// pixel iterator, which is still faster



/// \ingroup ImageViewSTLAlgorithmsForEachPixel

template <typename V, typename F>

F for_each_pixel(const V& img, F fun) {

    if (img.is_1d_traversable()) {

        return std::for_each(img.begin().x(), img.end().x(), fun);

    } else {

        for (std::ptrdiff_t y=0; y<img.height(); ++y)

            fun = std::for_each(img.row_begin(y),img.row_end(y),fun);

        return fun;

    }

}



/// \defgroup ImageViewSTLAlgorithmsForEachPixelPosition for_each_pixel_position

/// \ingroup ImageViewSTLAlgorithms

/// \brief adobe::for_each_position for image views (passes locators, instead of pixel references, to the function object)



/// \ingroup ImageViewSTLAlgorithmsForEachPixelPosition

template <typename View, typename F>

F for_each_pixel_position(const View& img, F fun) {

    typename View::xy_locator loc=img.xy_at(0,0);

    for (std::ptrdiff_t y=0; y<img.height(); ++y) {

        for (std::ptrdiff_t x=0; x<img.width(); ++x, ++loc.x())

            fun(loc);

        loc.x()-=img.width(); ++loc.y();

    }

    return fun;

}





//////////////////////////////////////////////////////////////////////////////////////

///

/// generate_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsGeneratePixels generate_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::generate for image views



/// \ingroup ImageViewSTLAlgorithmsGeneratePixels

/// \brief std::generate for image views

template <typename View, typename F>

void generate_pixels(const View& v, F fun) {

    if (v.is_1d_traversable()) {

        std::generate(v.begin().x(), v.end().x(), fun);

    } else {

        for (std::ptrdiff_t y=0; y<v.height(); ++y)

            std::generate(v.row_begin(y),v.row_end(y),fun);

    }

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// std::equal and gil::equal_pixels for GIL constructs

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsEqualPixels equal_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::equal for image views



template <typename I1, typename I2> GIL_FORCEINLINE bool equal_n(I1 i1, std::ptrdiff_t n, I2 i2);



namespace detail {



template <typename I1, typename I2>

struct equal_n_fn {

    GIL_FORCEINLINE bool operator()(I1 i1, std::ptrdiff_t n, I2 i2) const { return std::equal(i1,i1+n, i2); }

};



/// Equal when both ranges are interleaved and of the same type. 

/// GIL pixels are bitwise comparable, so memcmp is used. User-defined pixels that are not bitwise comparable need to provide an overload

template<typename T, typename Cs>

struct equal_n_fn<const pixel<T,Cs>*, const pixel<T,Cs>*> {

    GIL_FORCEINLINE bool operator()(const pixel<T,Cs>* i1, std::ptrdiff_t n, const pixel<T,Cs>* i2) const { 

        return memcmp(i1, i2, n*sizeof(pixel<T,Cs>))==0;

    }

};

template<typename T, typename Cs>

struct equal_n_fn<pixel<T,Cs>*, pixel<T,Cs>*> : equal_n_fn<const pixel<T,Cs>*, const pixel<T,Cs>*> {};



/// EqualPixels

/// Equal when both ranges are planar pointers of the same type. memcmp is invoked for each channel plane

///  User-defined channels that are not bitwise comparable need to provide an overload

template<typename IC, typename Cs>

struct equal_n_fn<planar_pixel_iterator<IC,Cs>, planar_pixel_iterator<IC,Cs> > {

    GIL_FORCEINLINE bool operator()(const planar_pixel_iterator<IC,Cs> i1, std::ptrdiff_t n, const planar_pixel_iterator<IC,Cs> i2) const { 

        ptrdiff_t numBytes=n*sizeof(typename std::iterator_traits<IC>::value_type);



        for (std::ptrdiff_t i=0; i<mpl::size<Cs>::value; ++i)

            if (memcmp(dynamic_at_c(i1,i), dynamic_at_c(i2,i), numBytes)!=0)

                return false;

        return true;

    }

};





/// Source range is delimited by image iterators

template <typename Loc, typename I2>  // IL Models ConstPixelLocatorConcept, O Models PixelIteratorConcept

struct equal_n_fn<boost::gil::iterator_from_2d<Loc>,I2> {

    GIL_FORCEINLINE bool operator()(boost::gil::iterator_from_2d<Loc> i1, std::ptrdiff_t n, I2 i2) const {

        gil_function_requires<boost::gil::PixelLocatorConcept<Loc> >();

        gil_function_requires<boost::gil::PixelIteratorConcept<I2> >();

        while (n>0) {

            std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n, i1.width()-i1.x_pos());

            if (!equal_n(i1.x(), num, i2))

                return false;

            i1+=num;

            i2+=num;

            n-=num;

        }

        return true;

    }

};



/// Destination range is delimited by image iterators

template <typename I1, typename Loc> // I Models PixelIteratorConcept, OL Models PixelLocatorConcept

struct equal_n_fn<I1,boost::gil::iterator_from_2d<Loc> > {

    GIL_FORCEINLINE bool operator()(I1 i1, std::ptrdiff_t n, boost::gil::iterator_from_2d<Loc> i2) const {

        gil_function_requires<boost::gil::PixelIteratorConcept<I1> >();

        gil_function_requires<boost::gil::PixelLocatorConcept<Loc> >();

        while (n>0) {

            std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n,i2.width()-i2.x_pos());

            if (!equal_n(i1, num, i2.x()))

                return false;

            i1+=num;

            i2+=num;

            n-=num;

        }

        return true;

    }

};



/// Both source and destination ranges are delimited by image iterators

template <typename Loc1, typename Loc2>

struct equal_n_fn<boost::gil::iterator_from_2d<Loc1>,boost::gil::iterator_from_2d<Loc2> > {

   GIL_FORCEINLINE bool operator()(boost::gil::iterator_from_2d<Loc1> i1, std::ptrdiff_t n, boost::gil::iterator_from_2d<Loc2> i2) const {

        gil_function_requires<boost::gil::PixelLocatorConcept<Loc1> >();

        gil_function_requires<boost::gil::PixelLocatorConcept<Loc2> >();

        if (i1.x_pos()!=i2.x_pos() || i1.width()!=i2.width()) {

            while(n-->0) {

                if (*i1++!=*i2++) return false;

            }

        }

        while (n>0) {

            std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n,i2.width()-i2.x_pos());

            if (!equal_n(i1.x(), num, i2.x()))

                return false;

            i1+=num;

            i2+=num;

            n-=num;

        }

        return true;

    }

};

} // namespace detail



template <typename I1, typename I2> GIL_FORCEINLINE

bool equal_n(I1 i1, std::ptrdiff_t n, I2 i2) {

    return detail::equal_n_fn<I1,I2>()(i1,n,i2);

}

} }  // namespace boost::gil



namespace std {

/// \ingroup STLOptimizations

/// \brief  std::equal(I1,I1,I2) with I1 and I2 being a iterator_from_2d

///

/// Invoked when one calls std::equal(I1,I1,I2) with I1 and I2 being a iterator_from_2d (which is

/// a 1D iterator over the pixels in an image). Attempts to demote the source and destination 

/// iterators to simpler/faster types if the corresponding range is contiguous.

/// For contiguous images (i.e. images that have

/// no alignment gap at the end of each row) it is more efficient to use the underlying 

/// pixel iterator that does not check for the end of rows. If the underlying pixel iterator

/// happens to be a fundamental planar/interleaved pointer, the call may further resolve

/// to memcmp. Otherwise it resolves to copying each row using the underlying pixel iterator

template <typename Loc1, typename Loc2> GIL_FORCEINLINE 

bool equal(boost::gil::iterator_from_2d<Loc1> first, boost::gil::iterator_from_2d<Loc1> last, boost::gil::iterator_from_2d<Loc2> first2) {

    boost::gil::gil_function_requires<boost::gil::PixelLocatorConcept<Loc1> >();

    boost::gil::gil_function_requires<boost::gil::PixelLocatorConcept<Loc2> >();

    std::ptrdiff_t n=last-first;

    if (first.is_1d_traversable()) {

        if (first2.is_1d_traversable())

            return boost::gil::detail::equal_n_fn<typename Loc1::x_iterator,typename Loc2::x_iterator>()(first.x(),n, first2.x());

        else

            return boost::gil::detail::equal_n_fn<typename Loc1::x_iterator,boost::gil::iterator_from_2d<Loc2> >()(first.x(),n, first2);

    } else {

        if (first2.is_1d_traversable())

            return boost::gil::detail::equal_n_fn<boost::gil::iterator_from_2d<Loc1>,typename Loc2::x_iterator>()(first,n, first2.x());

        else

            return boost::gil::detail::equal_n_fn<boost::gil::iterator_from_2d<Loc1>,boost::gil::iterator_from_2d<Loc2> >()(first,n,first2);

    }

}

} // namespace std



namespace boost { namespace gil {



/// \ingroup ImageViewSTLAlgorithmsEqualPixels

/// \brief std::equal for image views

template <typename View1, typename View2> GIL_FORCEINLINE 

bool equal_pixels(const View1& v1, const View2& v2) {

    assert(v1.dimensions()==v2.dimensions());

    return std::equal(v1.begin(),v1.end(),v2.begin()); // std::equal has overloads with GIL iterators for optimal performance

}



//////////////////////////////////////////////////////////////////////////////////////

///

/// transform_pixels

///

//////////////////////////////////////////////////////////////////////////////////////



/// \defgroup ImageViewSTLAlgorithmsTransformPixels transform_pixels

/// \ingroup ImageViewSTLAlgorithms

/// \brief std::transform for image views



/// \ingroup ImageViewSTLAlgorithmsTransformPixels

/// \brief std::transform for image views

template <typename View1, typename View2, typename F> GIL_FORCEINLINE 

F transform_pixels(const View1& src,const View2& dst, F fun) {

    assert(src.dimensions()==dst.dimensions());

    for (std::ptrdiff_t y=0; y<src.height(); ++y) {

        typename View1::x_iterator srcIt=src.row_begin(y);

        typename View2::x_iterator dstIt=dst.row_begin(y);

        for (std::ptrdiff_t x=0; x<src.width(); ++x)

            dstIt[x]=fun(srcIt[x]);

    }

    return fun;

}



/// \ingroup ImageViewSTLAlgorithmsTransformPixels

/// \brief transform_pixels with two sources

template <typename View1, typename View2, typename View3, typename F> GIL_FORCEINLINE 

F transform_pixels(const View1& src1, const View2& src2,const View3& dst, F fun) {

    for (std::ptrdiff_t y=0; y<dst.height(); ++y) {

        typename View1::x_iterator srcIt1=src1.row_begin(y);

        typename View2::x_iterator srcIt2=src2.row_begin(y);

        typename View3::x_iterator dstIt=dst.row_begin(y);

        for (std::ptrdiff_t x=0; x<dst.width(); ++x)

            dstIt[x]=fun(srcIt1[x],srcIt2[x]);

    }

    return fun;

}



/// \defgroup ImageViewSTLAlgorithmsTransformPixelPositions transform_pixel_positions

/// \ingroup ImageViewSTLAlgorithms

/// \brief adobe::transform_positions for image views (passes locators, instead of pixel references, to the function object) 



/// \ingroup ImageViewSTLAlgorithmsTransformPixelPositions

/// \brief Like transform_pixels but passes to the function object pixel locators instead of pixel references

template <typename View1, typename View2, typename F> GIL_FORCEINLINE 

F transform_pixel_positions(const View1& src,const View2& dst, F fun) {

    assert(src.dimensions()==dst.dimensions());

    typename View1::xy_locator loc=src.xy_at(0,0);

    for (std::ptrdiff_t y=0; y<src.height(); ++y) {

        typename View2::x_iterator dstIt=dst.row_begin(y);

        for (std::ptrdiff_t x=0; x<src.width(); ++x, ++loc.x())

            dstIt[x]=fun(loc);

        loc.x()-=src.width(); ++loc.y();

    }

    return fun;

}



/// \ingroup ImageViewSTLAlgorithmsTransformPixelPositions

/// \brief transform_pixel_positions with two sources

template <typename View1, typename View2, typename View3, typename F> GIL_FORCEINLINE 

F transform_pixel_positions(const View1& src1,const View2& src2,const View3& dst, F fun) {

    assert(src1.dimensions()==dst.dimensions());

    assert(src2.dimensions()==dst.dimensions());

    typename View1::xy_locator loc1=src1.xy_at(0,0);

    typename View2::xy_locator loc2=src2.xy_at(0,0);

    for (std::ptrdiff_t y=0; y<src1.height(); ++y) {

        typename View3::x_iterator dstIt=dst.row_begin(y);

        for (std::ptrdiff_t x=0; x<src1.width(); ++x, ++loc1.x(), ++loc2.x())

            dstIt[x]=fun(loc1,loc2);

        loc1.x()-=src1.width(); ++loc1.y();

        loc2.x()-=src2.width(); ++loc2.y();

    }

    return fun;

}



} }  // namespace boost::gil



//#ifdef _MSC_VER

//#pragma warning(pop)

//#endif



#endif

