Chris@16: /*
Chris@16:     Copyright 2005-2007 Adobe Systems Incorporated
Chris@16:    
Chris@16:     Use, modification and distribution are subject to the Boost Software License,
Chris@16:     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt).
Chris@16: 
Chris@16:     See http://opensource.adobe.com/gil for most recent version including documentation.
Chris@16: */
Chris@16: 
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: #ifndef GIL_ALGORITHM_HPP
Chris@16: #define GIL_ALGORITHM_HPP
Chris@16: 
Chris@16: #include <cassert>
Chris@16: #include <cstddef>
Chris@16: #include <cstring>
Chris@16: #include <algorithm>
Chris@16: #include <iterator>
Chris@16: #include <memory>
Chris@16: #include <typeinfo>
Chris@16: #include "gil_config.hpp"
Chris@16: #include "gil_concept.hpp"
Chris@16: #include "color_base_algorithm.hpp"
Chris@16: #include "image_view.hpp"
Chris@16: #include "image_view_factory.hpp"
Chris@16: #include "bit_aligned_pixel_iterator.hpp"
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file               
Chris@16: /// \brief Some basic STL-style algorithms when applied to image views
Chris@16: /// \author Lubomir Bourdev and Hailin Jin \n
Chris@16: ///         Adobe Systems Incorporated
Chris@16: /// \date   2005-2008 \n Last updated on March 12, 2008
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: //#ifdef _MSC_VER
Chris@16: //#pragma warning(push)
Chris@16: //#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)
Chris@16: //#endif
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: //forward declarations
Chris@16: template <typename ChannelPtr, typename ColorSpace>
Chris@16: struct planar_pixel_iterator;
Chris@16: template <typename Iterator>
Chris@16: class memory_based_step_iterator;
Chris@16: template <typename StepIterator>
Chris@16: class memory_based_2d_locator;
Chris@16: 
Chris@16: // a tag denoting incompatible arguments
Chris@16: struct error_t {};
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithms STL-like Algorithms
Chris@16: /// \ingroup ImageViewAlgorithm
Chris@16: /// \brief Image view-equivalents of STL algorithms
Chris@16: ///
Chris@16: /// Image views provide 1D iteration of their pixels via \p begin() and \p end() methods,
Chris@16: /// which makes it possible to use STL algorithms with them. However, using nested loops
Chris@16: /// over X and Y is in many cases more efficient. The algorithms in this section resemble
Chris@16: /// STL algorithms, but they abstract away the nested loops and take views (as opposed to ranges) as input.
Chris@16: ///
Chris@16: /// Most algorithms check whether the image views are 1D-traversable. A 1D-traversable image view has no gaps
Chris@16: /// 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
Chris@16: /// it will move to the first pixel of the next row. When image views are 1D-traversable, the algorithms use
Chris@16: /// a single loop and run more efficiently. If one or more of the input views are not 1D-traversable, the algorithms
Chris@16: /// fall-back to an X-loop nested inside a Y-loop.
Chris@16: ///
Chris@16: /// The algorithms typically delegate the work to their corresponding STL algorithms. For example, \p copy_pixels calls
Chris@16: /// \p std::copy either for each row, or, when the images are 1D-traversable, once for all pixels.
Chris@16: ///
Chris@16: /// In addition, overloads are sometimes provided for the STL algorithms. For example, std::copy for planar iterators
Chris@16: /// is overloaded to perform \p std::copy for each of the planes. \p std::copy over bitwise-copiable pixels results in
Chris@16: /// std::copy over unsigned char, which STL typically implements via \p memmove.
Chris@16: ///
Chris@16: /// As a result \p copy_pixels may result in a single call to \p memmove for interleaved 1D-traversable views, 
Chris@16: /// or one per each plane of planar 1D-traversable views, or one per each row of interleaved non-1D-traversable images, etc.
Chris@16: 
Chris@16: 
Chris@16: /// \defgroup STLOptimizations  Performance overloads of STL algorithms
Chris@16: /// \ingroup ImageViewAlgorithm
Chris@16: /// \brief overloads of STL algorithms allowing more efficient implementation when used with GIL constructs
Chris@16: 
Chris@16: /// \brief A generic binary operation on views
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: ///
Chris@16: /// Use this class as a convenience superclass when defining an operation for any image views.
Chris@16: /// Many operations have different behavior when the two views are compatible. This class checks
Chris@16: /// for compatibility and invokes apply_compatible(V1,V2) or apply_incompatible(V1,V2) of the subclass.
Chris@16: /// You must provide apply_compatible(V1,V2) method in your subclass, but apply_incompatible(V1,V2)
Chris@16: /// is not required and the default throws std::bad_cast.
Chris@16: template <typename Derived, typename Result=void>
Chris@16: struct binary_operation_obj {
Chris@16:     typedef Result result_type;
Chris@16: 
Chris@16:     template <typename V1, typename V2> GIL_FORCEINLINE
Chris@16:     result_type operator()(const std::pair<const V1*,const V2*>& p) const {
Chris@16:         return apply(*p.first, *p.second, typename views_are_compatible<V1,V2>::type());
Chris@16:     }
Chris@16: 
Chris@16:     template <typename V1, typename V2> GIL_FORCEINLINE
Chris@16:     result_type operator()(const V1& v1, const V2& v2) const {
Chris@16:         return apply(v1, v2, typename views_are_compatible<V1,V2>::type());
Chris@16:     }
Chris@16: 
Chris@16:     result_type operator()(const error_t&) const { throw std::bad_cast(); }
Chris@16: private:
Chris@16: 
Chris@16:     // dispatch from apply overload to a function with distinct name
Chris@16:     template <typename V1, typename V2>
Chris@16:     GIL_FORCEINLINE result_type apply(const V1& v1, const V2& v2, mpl::false_) const {
Chris@16:         return ((const Derived*)this)->apply_incompatible(v1,v2);
Chris@16:     }
Chris@16: 
Chris@16:     // dispatch from apply overload to a function with distinct name
Chris@16:     template <typename V1, typename V2>
Chris@16:     GIL_FORCEINLINE result_type apply(const V1& v1, const V2& v2, mpl::true_) const {
Chris@16:         return ((const Derived*)this)->apply_compatible(v1,v2);
Chris@16:     }
Chris@16: 
Chris@16:     // function with distinct name - it can be overloaded by subclasses
Chris@16:     template <typename V1, typename V2>
Chris@16:     GIL_FORCEINLINE result_type apply_incompatible(const V1& v1, const V2& v2) const {
Chris@16:         throw std::bad_cast();
Chris@16:     }
Chris@16: };
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// std::copy and gil::copy_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsCopyPixels copy_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::copy for image views
Chris@16: 
Chris@16: namespace std {
Chris@16: 
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief Copy when both src and dst are interleaved and of the same type can be just memmove
Chris@16: template<typename T, typename Cs> 
Chris@16: GIL_FORCEINLINE boost::gil::pixel<T,Cs>* 
Chris@16: copy(boost::gil::pixel<T,Cs>* first, boost::gil::pixel<T,Cs>* last, 
Chris@16:      boost::gil::pixel<T,Cs>* dst) { 
Chris@16:     return (boost::gil::pixel<T,Cs>*)std::copy((unsigned char*)first,(unsigned char*)last, (unsigned char*)dst);
Chris@16: }
Chris@16: 
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief Copy when both src and dst are interleaved and of the same type can be just memmove
Chris@16: template<typename T, typename Cs> 
Chris@16: GIL_FORCEINLINE boost::gil::pixel<T,Cs>* 
Chris@16: copy(const boost::gil::pixel<T,Cs>* first, const boost::gil::pixel<T,Cs>* last, 
Chris@16:      boost::gil::pixel<T,Cs>* dst) { 
Chris@16:     return (boost::gil::pixel<T,Cs>*)std::copy((unsigned char*)first,(unsigned char*)last, (unsigned char*)dst);
Chris@16: }
Chris@16: } // namespace std
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: namespace detail {
Chris@16: template <typename I, typename O> struct copy_fn { 
Chris@16:     GIL_FORCEINLINE I operator()(I first, I last, O dst) const { return std::copy(first,last,dst); } 
Chris@16: };
Chris@16: } // namespace detail
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: namespace std {
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief Copy when both src and dst are planar pointers is copy for each channel
Chris@16: template<typename Cs, typename IC1, typename IC2> GIL_FORCEINLINE
Chris@16: 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) { 
Chris@16:     boost::gil::gil_function_requires<boost::gil::ChannelsCompatibleConcept<typename std::iterator_traits<IC1>::value_type,typename std::iterator_traits<IC2>::value_type> >();
Chris@16:     static_for_each(first,last,dst,boost::gil::detail::copy_fn<IC1,IC2>());
Chris@16:     return dst+(last-first);
Chris@16: }
Chris@16: } // namespace std
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: namespace detail {
Chris@16: /// Does a copy-n. If the inputs contain image iterators, performs a copy at each row using the row iterators
Chris@16: /// \ingroup CopyPixels
Chris@16: template <typename I, typename O>
Chris@16: struct copier_n {
Chris@16:     GIL_FORCEINLINE void operator()(I src, typename std::iterator_traits<I>::difference_type n, O dst) const { std::copy(src,src+n, dst); }
Chris@16: };
Chris@16: 
Chris@16: /// Source range is delimited by image iterators
Chris@16: template <typename IL, typename O>  // IL Models ConstPixelLocatorConcept, O Models PixelIteratorConcept
Chris@16: struct copier_n<iterator_from_2d<IL>,O> {
Chris@16:     typedef typename std::iterator_traits<iterator_from_2d<IL> >::difference_type diff_t;
Chris@16:     GIL_FORCEINLINE void operator()(iterator_from_2d<IL> src, diff_t n, O dst) const {
Chris@16:         gil_function_requires<PixelLocatorConcept<IL> >();
Chris@16:         gil_function_requires<MutablePixelIteratorConcept<O> >();
Chris@16:         while (n>0) {
Chris@16:             typedef typename iterator_from_2d<IL>::difference_type diff_t;
Chris@16:             diff_t l=src.width()-src.x_pos();
Chris@16:             diff_t numToCopy=(n<l ? n:l);
Chris@16:             detail::copy_n(src.x(), numToCopy, dst);
Chris@16:             dst+=numToCopy;
Chris@16:             src+=numToCopy;
Chris@16:             n-=numToCopy;
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /// Destination range is delimited by image iterators
Chris@16: template <typename I, typename OL> // I Models ConstPixelIteratorConcept, OL Models PixelLocatorConcept
Chris@16: struct copier_n<I,iterator_from_2d<OL> > {
Chris@16:     typedef typename std::iterator_traits<I>::difference_type diff_t;
Chris@16:     GIL_FORCEINLINE void operator()(I src, diff_t n, iterator_from_2d<OL> dst) const {
Chris@16:         gil_function_requires<PixelIteratorConcept<I> >();
Chris@16:         gil_function_requires<MutablePixelLocatorConcept<OL> >();
Chris@16:         while (n>0) {
Chris@16:             diff_t l=dst.width()-dst.x_pos();
Chris@16:             diff_t numToCopy=(n<l ? n:l);
Chris@16:             detail::copy_n(src, numToCopy, dst.x());
Chris@16:             dst+=numToCopy;
Chris@16:             src+=numToCopy;
Chris@16:             n-=numToCopy;
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /// Both source and destination ranges are delimited by image iterators
Chris@16: template <typename IL, typename OL>
Chris@16: struct copier_n<iterator_from_2d<IL>,iterator_from_2d<OL> > {
Chris@16:    typedef typename iterator_from_2d<IL>::difference_type diff_t;
Chris@16:    GIL_FORCEINLINE void operator()(iterator_from_2d<IL> src, diff_t n, iterator_from_2d<OL> dst) const {
Chris@16:         gil_function_requires<PixelLocatorConcept<IL> >();
Chris@16:         gil_function_requires<MutablePixelLocatorConcept<OL> >();
Chris@16:         if (src.x_pos()!=dst.x_pos() || src.width()!=dst.width()) {
Chris@16:             while(n-->0) {
Chris@16:                 *dst++=*src++;
Chris@16:             }
Chris@16:         }
Chris@16:         while (n>0) {
Chris@16:             diff_t l=dst.width()-dst.x_pos();
Chris@16:             diff_t numToCopy=(n<l ? n : l);
Chris@16:             detail::copy_n(src.x(), numToCopy, dst.x());
Chris@16:             dst+=numToCopy;
Chris@16:             src+=numToCopy;
Chris@16:             n-=numToCopy;
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename SrcIterator, typename DstIterator>
Chris@16: GIL_FORCEINLINE DstIterator copy_with_2d_iterators(SrcIterator first, SrcIterator last, DstIterator dst) {
Chris@16:     typedef typename SrcIterator::x_iterator src_x_iterator;
Chris@16:     typedef typename DstIterator::x_iterator dst_x_iterator;
Chris@16: 
Chris@16:     typename SrcIterator::difference_type n = last - first;
Chris@16: 
Chris@16:     if (first.is_1d_traversable()) {
Chris@16:         if (dst.is_1d_traversable())
Chris@16:             copier_n<src_x_iterator,dst_x_iterator>()(first.x(),n, dst.x());
Chris@16:         else
Chris@16:             copier_n<src_x_iterator,DstIterator >()(first.x(),n, dst);
Chris@16:     } else {
Chris@16:         if (dst.is_1d_traversable())
Chris@16:             copier_n<SrcIterator,dst_x_iterator>()(first,n, dst.x());
Chris@16:         else
Chris@16:             copier_n<SrcIterator,DstIterator>()(first,n,dst);
Chris@16:     }
Chris@16:     return dst+n;
Chris@16: }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: namespace std {
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief  std::copy(I1,I1,I2) with I1 and I2 being a iterator_from_2d
Chris@16: template <typename IL, typename OL>
Chris@16: 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) {
Chris@16:     return boost::gil::detail::copy_with_2d_iterators(first,last,dst);
Chris@16: }
Chris@16: 
Chris@16: } // namespace std
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsCopyPixels
Chris@16: /// \brief std::copy for image views
Chris@16: template <typename View1, typename View2> GIL_FORCEINLINE
Chris@16: void copy_pixels(const View1& src, const View2& dst) { 
Chris@16:     assert(src.dimensions()==dst.dimensions());
Chris@16:     detail::copy_with_2d_iterators(src.begin(),src.end(),dst.begin());
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// copy_and_convert_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsCopyAndConvertPixels copy_and_convert_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief copies src view into dst view, color converting if necessary.
Chris@16: ///
Chris@16: /// Versions taking static and runtime views are provided. Versions taking user-defined color convered are provided.
Chris@16: 
Chris@16: namespace detail {
Chris@16: template <typename CC>
Chris@16: class copy_and_convert_pixels_fn : public binary_operation_obj<copy_and_convert_pixels_fn<CC> > {
Chris@16: private:
Chris@16:     CC _cc;
Chris@16: public:
Chris@16:     typedef typename binary_operation_obj<copy_and_convert_pixels_fn<CC> >::result_type result_type;
Chris@16:     copy_and_convert_pixels_fn() {}
Chris@16:     copy_and_convert_pixels_fn(CC cc_in) : _cc(cc_in) {}
Chris@16:    // when the two color spaces are incompatible, a color conversion is performed
Chris@16:     template <typename V1, typename V2> GIL_FORCEINLINE 
Chris@16:     result_type apply_incompatible(const V1& src, const V2& dst) const {
Chris@16:         copy_pixels(color_converted_view<typename V2::value_type>(src,_cc),dst);
Chris@16:     }
Chris@16: 
Chris@16:     // If the two color spaces are compatible, copy_and_convert is just copy
Chris@16:     template <typename V1, typename V2> GIL_FORCEINLINE 
Chris@16:     result_type apply_compatible(const V1& src, const V2& dst) const {
Chris@16:          copy_pixels(src,dst);
Chris@16:     }
Chris@16: };
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsCopyAndConvertPixels
Chris@16: template <typename V1, typename V2,typename CC> 
Chris@16: GIL_FORCEINLINE 
Chris@16: void copy_and_convert_pixels(const V1& src, const V2& dst,CC cc) { 
Chris@16:     detail::copy_and_convert_pixels_fn<CC> ccp(cc);
Chris@16:     ccp(src,dst);
Chris@16: }
Chris@16: 
Chris@16: struct default_color_converter;
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsCopyAndConvertPixels
Chris@16: template <typename View1, typename View2> 
Chris@16: GIL_FORCEINLINE 
Chris@16: void copy_and_convert_pixels(const View1& src, const View2& dst) { 
Chris@16:     detail::copy_and_convert_pixels_fn<default_color_converter> ccp;
Chris@16:     ccp(src,dst);
Chris@16: }
Chris@16: 
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: // std::fill and gil::fill_pixels
Chris@16: //
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsFillPixels fill_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::fill for image views
Chris@16: 
Chris@16: 
Chris@16: namespace std {
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief std::fill(I,I,V) with I being a iterator_from_2d
Chris@16: ///
Chris@16: /// Invoked when one calls std::fill(I,I,V) with I being a iterator_from_2d (which is
Chris@16: /// a 1D iterator over the pixels in an image). For contiguous images (i.e. images that have
Chris@16: /// no alignment gap at the end of each row) it is more efficient to use the underlying 
Chris@16: /// pixel iterator that does not check for the end of rows. For non-contiguous images fill
Chris@16: /// resolves to fill of each row using the underlying pixel iterator, which is still faster
Chris@16: template <typename IL, typename V>
Chris@16: void fill(boost::gil::iterator_from_2d<IL> first, boost::gil::iterator_from_2d<IL> last, const V& val) {
Chris@16:     boost::gil::gil_function_requires<boost::gil::MutablePixelLocatorConcept<IL> >();
Chris@16:     if (first.is_1d_traversable()) {
Chris@16:         std::fill(first.x(), last.x(), val);
Chris@16:     } else {
Chris@16:         // fill row by row
Chris@16:         std::ptrdiff_t n=last-first;
Chris@16:         while (n>0) {
Chris@16:             std::ptrdiff_t numToDo=std::min<const std::ptrdiff_t>(n,(std::ptrdiff_t)(first.width()-first.x_pos()));
Chris@16:             fill_n(first.x(), numToDo, val);
Chris@16:             first+=numToDo;
Chris@16:             n-=numToDo;
Chris@16:         }
Chris@16:     }
Chris@16: } 
Chris@16: } // namespace std
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: namespace detail {
Chris@16: /// struct to do std::fill
Chris@16: struct std_fill_t {
Chris@16:     template <typename It, typename P>
Chris@16:     void operator()(It first, It last, const P& p_in) {
Chris@16:         std::fill(first,last,p_in);
Chris@16:     }
Chris@16: };
Chris@16: /// std::fill for planar iterators
Chris@16: template <typename It, typename P>
Chris@16: GIL_FORCEINLINE 
Chris@16: void fill_aux(It first, It last, const P& p, mpl::true_) {
Chris@16:     static_for_each(first,last,p,std_fill_t());
Chris@16: }
Chris@16: /// std::fill for interleaved iterators
Chris@16: template <typename It, typename P>
Chris@16: GIL_FORCEINLINE 
Chris@16: void fill_aux(It first, It last, const P& p,mpl::false_) {
Chris@16:     std::fill(first,last,p);
Chris@16: }
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsFillPixels
Chris@16: /// \brief std::fill for image views
Chris@16: template <typename View, typename Value> GIL_FORCEINLINE 
Chris@16: void fill_pixels(const View& img_view, const Value& val) {
Chris@16:     if (img_view.is_1d_traversable())
Chris@16:         detail::fill_aux(img_view.begin().x(), img_view.end().x(), 
Chris@16:                  val,is_planar<View>());
Chris@16:     else
Chris@16:         for (std::ptrdiff_t y=0; y<img_view.height(); ++y)
Chris@16:             detail::fill_aux(img_view.row_begin(y),img_view.row_end(y),
Chris@16:                      val,is_planar<View>());
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// destruct_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsDestructPixels destruct_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief invokes the destructor on every pixel of an image view
Chris@16: 
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template <typename It> GIL_FORCEINLINE
Chris@16: void destruct_range_impl(It first, It last, mpl::true_) {
Chris@16:     typedef typename std::iterator_traits<It>::value_type value_t;
Chris@16:     if (boost::has_trivial_destructor<value_t>::value)
Chris@16:         return;
Chris@16:     while (first!=last) {
Chris@16:         first->~value_t();
Chris@16:         ++first;
Chris@16:     }
Chris@16: }
Chris@16: template <typename It> GIL_FORCEINLINE
Chris@16: void destruct_range_impl(It, It, mpl::false_) {}
Chris@16: 
Chris@16: template <typename It> GIL_FORCEINLINE
Chris@16: void destruct_range(It first, It last) {
Chris@16:     destruct_range_impl(first,last,typename is_pointer<It>::type());
Chris@16: }
Chris@16: 
Chris@16: struct std_destruct_t {
Chris@16:     template <typename It> void operator()(It first, It last) const { destruct_range(first,last); }
Chris@16: };
Chris@16: 
Chris@16: /// destruct for planar iterators
Chris@16: template <typename It>
Chris@16: GIL_FORCEINLINE 
Chris@16: void destruct_aux(It first, It last, mpl::true_) {
Chris@16:     static_for_each(first,last,std_destruct_t());
Chris@16: }
Chris@16: /// destruct for interleaved iterators
Chris@16: template <typename It>
Chris@16: GIL_FORCEINLINE 
Chris@16: void destruct_aux(It first, It last, mpl::false_) {
Chris@16:     destruct_range(first,last);
Chris@16: }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsDestructPixels
Chris@16: /// \brief Invokes the in-place destructor on every pixel of the view
Chris@16: template <typename View> GIL_FORCEINLINE 
Chris@16: void destruct_pixels(const View& img_view) {
Chris@16:     if (img_view.is_1d_traversable()) 
Chris@16:         detail::destruct_aux(img_view.begin().x(), img_view.end().x(), 
Chris@16:                                        is_planar<View>());
Chris@16:     else
Chris@16:         for (std::ptrdiff_t y=0; y<img_view.height(); ++y)
Chris@16:             detail::destruct_aux(img_view.row_begin(y),img_view.row_end(y),
Chris@16:                                            is_planar<View>());
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// uninitialized_fill_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsUninitializedFillPixels uninitialized_fill_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::uninitialized_fill for image views
Chris@16: 
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: /// std::uninitialized_fill for planar iterators
Chris@16: /// If an exception is thrown destructs any in-place copy-constructed objects
Chris@16: template <typename It, typename P>
Chris@16: GIL_FORCEINLINE 
Chris@16: void uninitialized_fill_aux(It first, It last,
Chris@16:                             const P& p, mpl::true_) {
Chris@16:     int channel=0;
Chris@16:     try {
Chris@16:         typedef typename std::iterator_traits<It>::value_type pixel_t;
Chris@16:         while (channel < num_channels<pixel_t>::value) {
Chris@16:             std::uninitialized_fill(dynamic_at_c(first,channel), dynamic_at_c(last,channel), 
Chris@16:                                     dynamic_at_c(p,channel));
Chris@16:             ++channel;
Chris@16:         }
Chris@16:     } catch (...) {
Chris@16:         for (int c=0; c<channel; ++c)
Chris@16:             destruct_range(dynamic_at_c(first,c), dynamic_at_c(last,c));
Chris@16:         throw;
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: /// std::uninitialized_fill for interleaved iterators
Chris@16: /// If an exception is thrown destructs any in-place copy-constructed objects
Chris@16: template <typename It, typename P>
Chris@16: GIL_FORCEINLINE 
Chris@16: void uninitialized_fill_aux(It first, It last,
Chris@16:                             const P& p,mpl::false_) {
Chris@16:     std::uninitialized_fill(first,last,p);
Chris@16: }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsUninitializedFillPixels
Chris@16: /// \brief std::uninitialized_fill for image views.
Chris@16: /// Does not support planar heterogeneous views.
Chris@16: /// If an exception is thrown destructs any in-place copy-constructed pixels
Chris@16: template <typename View, typename Value> 
Chris@16: void uninitialized_fill_pixels(const View& img_view, const Value& val) {
Chris@16:     if (img_view.is_1d_traversable()) 
Chris@16:         detail::uninitialized_fill_aux(img_view.begin().x(), img_view.end().x(), 
Chris@16:                                        val,is_planar<View>());
Chris@16:     else {
Chris@16:         typename View::y_coord_t y;
Chris@16:         try {
Chris@16:             for (y=0; y<img_view.height(); ++y)
Chris@16:                 detail::uninitialized_fill_aux(img_view.row_begin(y),img_view.row_end(y),
Chris@16:                                                val,is_planar<View>());
Chris@16:         } catch(...) {
Chris@16:             for (typename View::y_coord_t y0=0; y0<y; ++y0)
Chris@16:                 detail::destruct_aux(img_view.row_begin(y0),img_view.row_end(y0), is_planar<View>());
Chris@16:             throw;
Chris@16:         }
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// default_construct_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsDefaultConstructPixels default_construct_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief invokes the default constructor on every pixel of an image view
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template <typename It> GIL_FORCEINLINE 
Chris@16: void default_construct_range_impl(It first, It last, mpl::true_) {
Chris@16:     typedef typename std::iterator_traits<It>::value_type value_t;
Chris@16:     It first1=first;
Chris@16:     try {
Chris@16:         while (first!=last) {
Chris@16:             new (first) value_t();
Chris@16:             ++first;
Chris@16:         }
Chris@16:     } catch (...) {
Chris@16:         destruct_range(first1,first);
Chris@16:         throw;
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: template <typename It> GIL_FORCEINLINE 
Chris@16: void default_construct_range_impl(It, It, mpl::false_) {}
Chris@16: 
Chris@16: template <typename It> GIL_FORCEINLINE 
Chris@16: void default_construct_range(It first, It last) { default_construct_range_impl(first, last, typename is_pointer<It>::type()); }
Chris@16: 
Chris@16: /// uninitialized_default_construct for planar iterators
Chris@16: template <typename It>
Chris@16: GIL_FORCEINLINE 
Chris@16: void default_construct_aux(It first, It last, mpl::true_) {
Chris@16:     int channel=0;
Chris@16:     try {
Chris@16:         typedef typename std::iterator_traits<It>::value_type pixel_t;
Chris@16:         while (channel < num_channels<pixel_t>::value) {
Chris@16:             default_construct_range(dynamic_at_c(first,channel), dynamic_at_c(last,channel));
Chris@16:             ++channel;
Chris@16:         }
Chris@16:     } catch (...) {
Chris@16:         for (int c=0; c<channel; ++c)
Chris@16:             destruct_range(dynamic_at_c(first,c), dynamic_at_c(last,c));
Chris@16:         throw;
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: /// uninitialized_default_construct for interleaved iterators
Chris@16: template <typename It>
Chris@16: GIL_FORCEINLINE 
Chris@16: void default_construct_aux(It first, It last, mpl::false_) {
Chris@16:     default_construct_range(first,last);
Chris@16: }
Chris@16: 
Chris@16: template <typename View, bool IsPlanar>
Chris@16: struct has_trivial_pixel_constructor : public boost::has_trivial_constructor<typename View::value_type> {};
Chris@16: template <typename View>
Chris@16: struct has_trivial_pixel_constructor<View, true> : public boost::has_trivial_constructor<typename channel_type<View>::type> {};
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsDefaultConstructPixels
Chris@16: /// \brief Invokes the in-place default constructor on every pixel of the (uninitialized) view.
Chris@16: /// Does not support planar heterogeneous views.
Chris@16: /// If an exception is thrown destructs any in-place default-constructed pixels
Chris@16: template <typename View> 
Chris@16: void default_construct_pixels(const View& img_view) {
Chris@16:     if (detail::has_trivial_pixel_constructor<View, is_planar<View>::value>::value)
Chris@16:         return;
Chris@16: 
Chris@16:     if (img_view.is_1d_traversable()) 
Chris@16:         detail::default_construct_aux(img_view.begin().x(), img_view.end().x(), is_planar<View>());
Chris@16:     else {
Chris@16:         typename View::y_coord_t y;
Chris@16:         try {
Chris@16:             for (y=0; y<img_view.height(); ++y)
Chris@16:                 detail::default_construct_aux(img_view.row_begin(y),img_view.row_end(y), is_planar<View>());
Chris@16:         } catch(...) {
Chris@16:             for (typename View::y_coord_t y0=0; y0<y; ++y0)
Chris@16:                 detail::destruct_aux(img_view.row_begin(y0),img_view.row_end(y0), is_planar<View>());
Chris@16:             throw;
Chris@16:         }
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// uninitialized_copy_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsUninitializedCopyPixels uninitialized_copy_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::uninitialized_copy for image views
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: /// std::uninitialized_copy for pairs of planar iterators
Chris@16: template <typename It1, typename It2>
Chris@16: GIL_FORCEINLINE 
Chris@16: void uninitialized_copy_aux(It1 first1, It1 last1,
Chris@16:                             It2 first2, mpl::true_) {
Chris@16:     int channel=0;
Chris@16:     try {
Chris@16:         typedef typename std::iterator_traits<It1>::value_type pixel_t;
Chris@16:         while (channel < num_channels<pixel_t>::value) {
Chris@16:             std::uninitialized_copy(dynamic_at_c(first1,channel), dynamic_at_c(last1,channel), dynamic_at_c(first2,channel));
Chris@16:             ++channel;
Chris@16:         }
Chris@16:     } catch (...) {
Chris@16:         It2 last2=first2;
Chris@16:         std::advance(last2, std::distance(first1,last1));
Chris@16:         for (int c=0; c<channel; ++c)
Chris@16:             destruct_range(dynamic_at_c(first2,c), dynamic_at_c(last2,c));
Chris@16:         throw;
Chris@16:     }
Chris@16: }
Chris@16: /// std::uninitialized_copy for interleaved or mixed iterators
Chris@16: template <typename It1, typename It2>
Chris@16: GIL_FORCEINLINE 
Chris@16: void uninitialized_copy_aux(It1 first1, It1 last1,
Chris@16:                             It2 first2,mpl::false_) {
Chris@16:     std::uninitialized_copy(first1,last1,first2);
Chris@16: }
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsUninitializedCopyPixels
Chris@16: /// \brief std::uninitialized_copy for image views.
Chris@16: /// Does not support planar heterogeneous views.
Chris@16: /// If an exception is thrown destructs any in-place copy-constructed objects
Chris@16: template <typename View1, typename View2> 
Chris@16: void uninitialized_copy_pixels(const View1& view1, const View2& view2) {
Chris@16:     typedef mpl::bool_<is_planar<View1>::value && is_planar<View2>::value> is_planar;  
Chris@16:     assert(view1.dimensions()==view2.dimensions());
Chris@16:     if (view1.is_1d_traversable() && view2.is_1d_traversable())
Chris@16:         detail::uninitialized_copy_aux(view1.begin().x(), view1.end().x(), 
Chris@16:                                        view2.begin().x(), 
Chris@16:                                        is_planar());
Chris@16:     else {
Chris@16:         typename View1::y_coord_t y;
Chris@16:         try {
Chris@16:             for (y=0; y<view1.height(); ++y)
Chris@16:                 detail::uninitialized_copy_aux(view1.row_begin(y), view1.row_end(y),
Chris@16:                                                view2.row_begin(y),
Chris@16:                                                is_planar());
Chris@16:         } catch(...) {
Chris@16:             for (typename View1::y_coord_t y0=0; y0<y; ++y0)
Chris@16:                 detail::destruct_aux(view2.row_begin(y0),view2.row_end(y0), is_planar());
Chris@16:             throw;
Chris@16:         }
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// for_each_pixel
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsForEachPixel for_each_pixel
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::for_each for image views
Chris@16: ///
Chris@16: /// For contiguous images (i.e. images that have no alignment gap at the end of each row) it is 
Chris@16: /// more efficient to use the underlying pixel iterator that does not check for the end of rows. 
Chris@16: /// For non-contiguous images for_each_pixel resolves to for_each of each row using the underlying 
Chris@16: /// pixel iterator, which is still faster
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsForEachPixel
Chris@16: template <typename V, typename F>
Chris@16: F for_each_pixel(const V& img, F fun) {
Chris@16:     if (img.is_1d_traversable()) {
Chris@16:         return std::for_each(img.begin().x(), img.end().x(), fun);
Chris@16:     } else {
Chris@16:         for (std::ptrdiff_t y=0; y<img.height(); ++y)
Chris@16:             fun = std::for_each(img.row_begin(y),img.row_end(y),fun);
Chris@16:         return fun;
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsForEachPixelPosition for_each_pixel_position
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief adobe::for_each_position for image views (passes locators, instead of pixel references, to the function object)
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsForEachPixelPosition
Chris@16: template <typename View, typename F>
Chris@16: F for_each_pixel_position(const View& img, F fun) {
Chris@16:     typename View::xy_locator loc=img.xy_at(0,0);
Chris@16:     for (std::ptrdiff_t y=0; y<img.height(); ++y) {
Chris@16:         for (std::ptrdiff_t x=0; x<img.width(); ++x, ++loc.x())
Chris@16:             fun(loc);
Chris@16:         loc.x()-=img.width(); ++loc.y();
Chris@16:     }
Chris@16:     return fun;
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// generate_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsGeneratePixels generate_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::generate for image views
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsGeneratePixels
Chris@16: /// \brief std::generate for image views
Chris@16: template <typename View, typename F>
Chris@16: void generate_pixels(const View& v, F fun) {
Chris@16:     if (v.is_1d_traversable()) {
Chris@16:         std::generate(v.begin().x(), v.end().x(), fun);
Chris@16:     } else {
Chris@16:         for (std::ptrdiff_t y=0; y<v.height(); ++y)
Chris@16:             std::generate(v.row_begin(y),v.row_end(y),fun);
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// std::equal and gil::equal_pixels for GIL constructs
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsEqualPixels equal_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::equal for image views
Chris@16: 
Chris@16: template <typename I1, typename I2> GIL_FORCEINLINE bool equal_n(I1 i1, std::ptrdiff_t n, I2 i2);
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template <typename I1, typename I2>
Chris@16: struct equal_n_fn {
Chris@16:     GIL_FORCEINLINE bool operator()(I1 i1, std::ptrdiff_t n, I2 i2) const { return std::equal(i1,i1+n, i2); }
Chris@16: };
Chris@16: 
Chris@16: /// Equal when both ranges are interleaved and of the same type. 
Chris@16: /// GIL pixels are bitwise comparable, so memcmp is used. User-defined pixels that are not bitwise comparable need to provide an overload
Chris@16: template<typename T, typename Cs>
Chris@16: struct equal_n_fn<const pixel<T,Cs>*, const pixel<T,Cs>*> {
Chris@16:     GIL_FORCEINLINE bool operator()(const pixel<T,Cs>* i1, std::ptrdiff_t n, const pixel<T,Cs>* i2) const { 
Chris@16:         return memcmp(i1, i2, n*sizeof(pixel<T,Cs>))==0;
Chris@16:     }
Chris@16: };
Chris@16: template<typename T, typename Cs>
Chris@16: struct equal_n_fn<pixel<T,Cs>*, pixel<T,Cs>*> : equal_n_fn<const pixel<T,Cs>*, const pixel<T,Cs>*> {};
Chris@16: 
Chris@16: /// EqualPixels
Chris@16: /// Equal when both ranges are planar pointers of the same type. memcmp is invoked for each channel plane
Chris@16: ///  User-defined channels that are not bitwise comparable need to provide an overload
Chris@16: template<typename IC, typename Cs>
Chris@16: struct equal_n_fn<planar_pixel_iterator<IC,Cs>, planar_pixel_iterator<IC,Cs> > {
Chris@16:     GIL_FORCEINLINE bool operator()(const planar_pixel_iterator<IC,Cs> i1, std::ptrdiff_t n, const planar_pixel_iterator<IC,Cs> i2) const { 
Chris@16:         ptrdiff_t numBytes=n*sizeof(typename std::iterator_traits<IC>::value_type);
Chris@16: 
Chris@16:         for (std::ptrdiff_t i=0; i<mpl::size<Cs>::value; ++i)
Chris@16:             if (memcmp(dynamic_at_c(i1,i), dynamic_at_c(i2,i), numBytes)!=0)
Chris@16:                 return false;
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: /// Source range is delimited by image iterators
Chris@16: template <typename Loc, typename I2>  // IL Models ConstPixelLocatorConcept, O Models PixelIteratorConcept
Chris@16: struct equal_n_fn<boost::gil::iterator_from_2d<Loc>,I2> {
Chris@16:     GIL_FORCEINLINE bool operator()(boost::gil::iterator_from_2d<Loc> i1, std::ptrdiff_t n, I2 i2) const {
Chris@16:         gil_function_requires<boost::gil::PixelLocatorConcept<Loc> >();
Chris@16:         gil_function_requires<boost::gil::PixelIteratorConcept<I2> >();
Chris@16:         while (n>0) {
Chris@16:             std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n, i1.width()-i1.x_pos());
Chris@16:             if (!equal_n(i1.x(), num, i2))
Chris@16:                 return false;
Chris@16:             i1+=num;
Chris@16:             i2+=num;
Chris@16:             n-=num;
Chris@16:         }
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /// Destination range is delimited by image iterators
Chris@16: template <typename I1, typename Loc> // I Models PixelIteratorConcept, OL Models PixelLocatorConcept
Chris@16: struct equal_n_fn<I1,boost::gil::iterator_from_2d<Loc> > {
Chris@16:     GIL_FORCEINLINE bool operator()(I1 i1, std::ptrdiff_t n, boost::gil::iterator_from_2d<Loc> i2) const {
Chris@16:         gil_function_requires<boost::gil::PixelIteratorConcept<I1> >();
Chris@16:         gil_function_requires<boost::gil::PixelLocatorConcept<Loc> >();
Chris@16:         while (n>0) {
Chris@16:             std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n,i2.width()-i2.x_pos());
Chris@16:             if (!equal_n(i1, num, i2.x()))
Chris@16:                 return false;
Chris@16:             i1+=num;
Chris@16:             i2+=num;
Chris@16:             n-=num;
Chris@16:         }
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /// Both source and destination ranges are delimited by image iterators
Chris@16: template <typename Loc1, typename Loc2>
Chris@16: struct equal_n_fn<boost::gil::iterator_from_2d<Loc1>,boost::gil::iterator_from_2d<Loc2> > {
Chris@16:    GIL_FORCEINLINE bool operator()(boost::gil::iterator_from_2d<Loc1> i1, std::ptrdiff_t n, boost::gil::iterator_from_2d<Loc2> i2) const {
Chris@16:         gil_function_requires<boost::gil::PixelLocatorConcept<Loc1> >();
Chris@16:         gil_function_requires<boost::gil::PixelLocatorConcept<Loc2> >();
Chris@16:         if (i1.x_pos()!=i2.x_pos() || i1.width()!=i2.width()) {
Chris@16:             while(n-->0) {
Chris@16:                 if (*i1++!=*i2++) return false;
Chris@16:             }
Chris@16:         }
Chris@16:         while (n>0) {
Chris@16:             std::ptrdiff_t num=std::min<const std::ptrdiff_t>(n,i2.width()-i2.x_pos());
Chris@16:             if (!equal_n(i1.x(), num, i2.x()))
Chris@16:                 return false;
Chris@16:             i1+=num;
Chris@16:             i2+=num;
Chris@16:             n-=num;
Chris@16:         }
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: } // namespace detail
Chris@16: 
Chris@16: template <typename I1, typename I2> GIL_FORCEINLINE
Chris@16: bool equal_n(I1 i1, std::ptrdiff_t n, I2 i2) {
Chris@16:     return detail::equal_n_fn<I1,I2>()(i1,n,i2);
Chris@16: }
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: namespace std {
Chris@16: /// \ingroup STLOptimizations
Chris@16: /// \brief  std::equal(I1,I1,I2) with I1 and I2 being a iterator_from_2d
Chris@16: ///
Chris@16: /// Invoked when one calls std::equal(I1,I1,I2) with I1 and I2 being a iterator_from_2d (which is
Chris@16: /// a 1D iterator over the pixels in an image). Attempts to demote the source and destination 
Chris@16: /// iterators to simpler/faster types if the corresponding range is contiguous.
Chris@16: /// For contiguous images (i.e. images that have
Chris@16: /// no alignment gap at the end of each row) it is more efficient to use the underlying 
Chris@16: /// pixel iterator that does not check for the end of rows. If the underlying pixel iterator
Chris@16: /// happens to be a fundamental planar/interleaved pointer, the call may further resolve
Chris@16: /// to memcmp. Otherwise it resolves to copying each row using the underlying pixel iterator
Chris@16: template <typename Loc1, typename Loc2> GIL_FORCEINLINE 
Chris@16: bool equal(boost::gil::iterator_from_2d<Loc1> first, boost::gil::iterator_from_2d<Loc1> last, boost::gil::iterator_from_2d<Loc2> first2) {
Chris@16:     boost::gil::gil_function_requires<boost::gil::PixelLocatorConcept<Loc1> >();
Chris@16:     boost::gil::gil_function_requires<boost::gil::PixelLocatorConcept<Loc2> >();
Chris@16:     std::ptrdiff_t n=last-first;
Chris@16:     if (first.is_1d_traversable()) {
Chris@16:         if (first2.is_1d_traversable())
Chris@16:             return boost::gil::detail::equal_n_fn<typename Loc1::x_iterator,typename Loc2::x_iterator>()(first.x(),n, first2.x());
Chris@16:         else
Chris@16:             return boost::gil::detail::equal_n_fn<typename Loc1::x_iterator,boost::gil::iterator_from_2d<Loc2> >()(first.x(),n, first2);
Chris@16:     } else {
Chris@16:         if (first2.is_1d_traversable())
Chris@16:             return boost::gil::detail::equal_n_fn<boost::gil::iterator_from_2d<Loc1>,typename Loc2::x_iterator>()(first,n, first2.x());
Chris@16:         else
Chris@16:             return boost::gil::detail::equal_n_fn<boost::gil::iterator_from_2d<Loc1>,boost::gil::iterator_from_2d<Loc2> >()(first,n,first2);
Chris@16:     }
Chris@16: }
Chris@16: } // namespace std
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsEqualPixels
Chris@16: /// \brief std::equal for image views
Chris@16: template <typename View1, typename View2> GIL_FORCEINLINE 
Chris@16: bool equal_pixels(const View1& v1, const View2& v2) {
Chris@16:     assert(v1.dimensions()==v2.dimensions());
Chris@16:     return std::equal(v1.begin(),v1.end(),v2.begin()); // std::equal has overloads with GIL iterators for optimal performance
Chris@16: }
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: /// transform_pixels
Chris@16: ///
Chris@16: //////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsTransformPixels transform_pixels
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief std::transform for image views
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsTransformPixels
Chris@16: /// \brief std::transform for image views
Chris@16: template <typename View1, typename View2, typename F> GIL_FORCEINLINE 
Chris@16: F transform_pixels(const View1& src,const View2& dst, F fun) {
Chris@16:     assert(src.dimensions()==dst.dimensions());
Chris@16:     for (std::ptrdiff_t y=0; y<src.height(); ++y) {
Chris@16:         typename View1::x_iterator srcIt=src.row_begin(y);
Chris@16:         typename View2::x_iterator dstIt=dst.row_begin(y);
Chris@16:         for (std::ptrdiff_t x=0; x<src.width(); ++x)
Chris@16:             dstIt[x]=fun(srcIt[x]);
Chris@16:     }
Chris@16:     return fun;
Chris@16: }
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsTransformPixels
Chris@16: /// \brief transform_pixels with two sources
Chris@16: template <typename View1, typename View2, typename View3, typename F> GIL_FORCEINLINE 
Chris@16: F transform_pixels(const View1& src1, const View2& src2,const View3& dst, F fun) {
Chris@16:     for (std::ptrdiff_t y=0; y<dst.height(); ++y) {
Chris@16:         typename View1::x_iterator srcIt1=src1.row_begin(y);
Chris@16:         typename View2::x_iterator srcIt2=src2.row_begin(y);
Chris@16:         typename View3::x_iterator dstIt=dst.row_begin(y);
Chris@16:         for (std::ptrdiff_t x=0; x<dst.width(); ++x)
Chris@16:             dstIt[x]=fun(srcIt1[x],srcIt2[x]);
Chris@16:     }
Chris@16:     return fun;
Chris@16: }
Chris@16: 
Chris@16: /// \defgroup ImageViewSTLAlgorithmsTransformPixelPositions transform_pixel_positions
Chris@16: /// \ingroup ImageViewSTLAlgorithms
Chris@16: /// \brief adobe::transform_positions for image views (passes locators, instead of pixel references, to the function object) 
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsTransformPixelPositions
Chris@16: /// \brief Like transform_pixels but passes to the function object pixel locators instead of pixel references
Chris@16: template <typename View1, typename View2, typename F> GIL_FORCEINLINE 
Chris@16: F transform_pixel_positions(const View1& src,const View2& dst, F fun) {
Chris@16:     assert(src.dimensions()==dst.dimensions());
Chris@16:     typename View1::xy_locator loc=src.xy_at(0,0);
Chris@16:     for (std::ptrdiff_t y=0; y<src.height(); ++y) {
Chris@16:         typename View2::x_iterator dstIt=dst.row_begin(y);
Chris@16:         for (std::ptrdiff_t x=0; x<src.width(); ++x, ++loc.x())
Chris@16:             dstIt[x]=fun(loc);
Chris@16:         loc.x()-=src.width(); ++loc.y();
Chris@16:     }
Chris@16:     return fun;
Chris@16: }
Chris@16: 
Chris@16: /// \ingroup ImageViewSTLAlgorithmsTransformPixelPositions
Chris@16: /// \brief transform_pixel_positions with two sources
Chris@16: template <typename View1, typename View2, typename View3, typename F> GIL_FORCEINLINE 
Chris@16: F transform_pixel_positions(const View1& src1,const View2& src2,const View3& dst, F fun) {
Chris@16:     assert(src1.dimensions()==dst.dimensions());
Chris@16:     assert(src2.dimensions()==dst.dimensions());
Chris@16:     typename View1::xy_locator loc1=src1.xy_at(0,0);
Chris@16:     typename View2::xy_locator loc2=src2.xy_at(0,0);
Chris@16:     for (std::ptrdiff_t y=0; y<src1.height(); ++y) {
Chris@16:         typename View3::x_iterator dstIt=dst.row_begin(y);
Chris@16:         for (std::ptrdiff_t x=0; x<src1.width(); ++x, ++loc1.x(), ++loc2.x())
Chris@16:             dstIt[x]=fun(loc1,loc2);
Chris@16:         loc1.x()-=src1.width(); ++loc1.y();
Chris@16:         loc2.x()-=src2.width(); ++loc2.y();
Chris@16:     }
Chris@16:     return fun;
Chris@16: }
Chris@16: 
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: //#ifdef _MSC_VER
Chris@16: //#pragma warning(pop)
Chris@16: //#endif
Chris@16: 
Chris@16: #endif