boost/gil/color_base.hpp
// // Copyright 2005-2007 Adobe Systems Incorporated // // Distributed under 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 // #ifndef BOOST_GIL_COLOR_BASE_HPP #define BOOST_GIL_COLOR_BASE_HPP #include <boost/gil/utilities.hpp> #include <boost/gil/concepts.hpp> #include <boost/assert.hpp> #include <boost/config.hpp> #include <boost/mpl/range_c.hpp> #include <boost/mpl/size.hpp> #include <boost/mpl/vector_c.hpp> #include <boost/type_traits.hpp> namespace boost { namespace gil { // Forward-declare template <typename P> P* memunit_advanced(const P* p, std::ptrdiff_t diff); // Forward-declare semantic_at_c template <int K, typename ColorBase> auto semantic_at_c(ColorBase& p) -> typename std::enable_if < !std::is_const<ColorBase>::value, typename kth_semantic_element_reference_type<ColorBase, K>::type >::type; template <int K, typename ColorBase> typename kth_semantic_element_const_reference_type<ColorBase,K>::type semantic_at_c(const ColorBase& p); // Forward declare element_reference_type template <typename ColorBase> struct element_reference_type; template <typename ColorBase> struct element_const_reference_type; template <typename ColorBase, int K> struct kth_element_type; template <typename ColorBase, int K> struct kth_element_type<const ColorBase,K> : public kth_element_type<ColorBase,K> {}; template <typename ColorBase, int K> struct kth_element_reference_type; template <typename ColorBase, int K> struct kth_element_reference_type<const ColorBase,K> : public kth_element_reference_type<ColorBase,K> {}; template <typename ColorBase, int K> struct kth_element_const_reference_type; template <typename ColorBase, int K> struct kth_element_const_reference_type<const ColorBase,K> : public kth_element_const_reference_type<ColorBase,K> {}; namespace detail { template <typename DstLayout, typename SrcLayout, int K> struct mapping_transform : public mpl::at<typename SrcLayout::channel_mapping_t, typename detail::type_to_index<typename DstLayout::channel_mapping_t,mpl::integral_c<int,K> >::type >::type {}; /// \defgroup ColorBaseModelHomogeneous detail::homogeneous_color_base /// \ingroup ColorBaseModel /// \brief A homogeneous color base holding one color element. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// If the element type models Regular, this class models HomogeneousColorBaseValueConcept. #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) #pragma warning(push) #pragma warning(disable:4512) //assignment operator could not be generated #endif /// \brief A homogeneous color base holding one color element. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// \ingroup ColorBaseModelHomogeneous template <typename Element, typename Layout> struct homogeneous_color_base<Element,Layout,1> { private: Element _v0; public: using layout_t = Layout; typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) { return _v0; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) const { return _v0; } homogeneous_color_base() {} homogeneous_color_base(Element v) : _v0(v) {} // grayscale pixel values are convertible to channel type operator Element () const { return _v0; } template <typename E2, typename L2> homogeneous_color_base(const homogeneous_color_base<E2,L2,1>& c) : _v0(gil::at_c<0>(c)) {} }; /// \brief A homogeneous color base holding two color elements. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// \ingroup ColorBaseModelHomogeneous template <typename Element, typename Layout> struct homogeneous_color_base<Element,Layout,2> { private: Element _v0, _v1; public: using layout_t = Layout; typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) { return _v0; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) const { return _v0; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) { return _v1; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) const { return _v1; } homogeneous_color_base() {} explicit homogeneous_color_base(Element v) : _v0(v), _v1(v) {} homogeneous_color_base(Element v0, Element v1) : _v0(v0), _v1(v1) {} template <typename E2, typename L2> homogeneous_color_base(const homogeneous_color_base<E2,L2,2>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)) {} // Support for l-value reference proxy copy construction template <typename E2, typename L2> homogeneous_color_base( homogeneous_color_base<E2,L2,2>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)) {} // Support for planar_pixel_iterator construction and dereferencing template <typename P> homogeneous_color_base(P* p,bool) : _v0(&semantic_at_c<0>(*p)), _v1(&semantic_at_c<1>(*p)) {} template <typename Ref> Ref deref() const { return Ref(*semantic_at_c<0>(*this), *semantic_at_c<1>(*this)); } // Support for planar_pixel_reference offset constructor template <typename Ptr> homogeneous_color_base(const Ptr& ptr, std::ptrdiff_t diff) : _v0(*memunit_advanced(semantic_at_c<0>(ptr),diff)), _v1(*memunit_advanced(semantic_at_c<1>(ptr),diff)) {} // Support for planar_pixel_reference operator[] Element at_c_dynamic(std::size_t i) const { if (i==0) return _v0; return _v1; } }; /// \brief A homogeneous color base holding three color elements. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// \ingroup ColorBaseModelHomogeneous template <typename Element, typename Layout> struct homogeneous_color_base<Element,Layout,3> { private: Element _v0, _v1, _v2; public: using layout_t = Layout; typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) { return _v0; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) const { return _v0; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) { return _v1; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) const { return _v1; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) { return _v2; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) const { return _v2; } homogeneous_color_base() {} explicit homogeneous_color_base(Element v) : _v0(v), _v1(v), _v2(v) {} homogeneous_color_base(Element v0, Element v1, Element v2) : _v0(v0), _v1(v1), _v2(v2) {} template <typename E2, typename L2> homogeneous_color_base(const homogeneous_color_base<E2,L2,3>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)) {} // Support for l-value reference proxy copy construction template <typename E2, typename L2> homogeneous_color_base( homogeneous_color_base<E2,L2,3>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)) {} // Support for planar_pixel_iterator construction and dereferencing template <typename P> homogeneous_color_base(P* p,bool) : _v0(&semantic_at_c<0>(*p)), _v1(&semantic_at_c<1>(*p)), _v2(&semantic_at_c<2>(*p)) {} template <typename Ref> Ref deref() const { return Ref(*semantic_at_c<0>(*this), *semantic_at_c<1>(*this), *semantic_at_c<2>(*this)); } // Support for planar_pixel_reference offset constructor template <typename Ptr> homogeneous_color_base(const Ptr& ptr, std::ptrdiff_t diff) : _v0(*memunit_advanced(semantic_at_c<0>(ptr),diff)), _v1(*memunit_advanced(semantic_at_c<1>(ptr),diff)), _v2(*memunit_advanced(semantic_at_c<2>(ptr),diff)) {} // Support for planar_pixel_reference operator[] Element at_c_dynamic(std::size_t i) const { switch (i) { case 0: return _v0; case 1: return _v1; } return _v2; } }; /// \brief A homogeneous color base holding four color elements. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// \ingroup ColorBaseModelHomogeneous template <typename Element, typename Layout> struct homogeneous_color_base<Element,Layout,4> { private: Element _v0, _v1, _v2, _v3; public: using layout_t = Layout; typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) { return _v0; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) const { return _v0; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) { return _v1; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) const { return _v1; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) { return _v2; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) const { return _v2; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<3>) { return _v3; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<3>) const { return _v3; } homogeneous_color_base() {} explicit homogeneous_color_base(Element v) : _v0(v), _v1(v), _v2(v), _v3(v) {} homogeneous_color_base(Element v0, Element v1, Element v2, Element v3) : _v0(v0), _v1(v1), _v2(v2), _v3(v3) {} template <typename E2, typename L2> homogeneous_color_base(const homogeneous_color_base<E2,L2,4>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)), _v3(gil::at_c<mapping_transform<Layout,L2,3>::value>(c)) {} // Support for l-value reference proxy copy construction template <typename E2, typename L2> homogeneous_color_base( homogeneous_color_base<E2,L2,4>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)), _v3(gil::at_c<mapping_transform<Layout,L2,3>::value>(c)) {} // Support for planar_pixel_iterator construction and dereferencing template <typename P> homogeneous_color_base(P* p,bool) : _v0(&semantic_at_c<0>(*p)), _v1(&semantic_at_c<1>(*p)), _v2(&semantic_at_c<2>(*p)), _v3(&semantic_at_c<3>(*p)) {} template <typename Ref> Ref deref() const { return Ref(*semantic_at_c<0>(*this), *semantic_at_c<1>(*this), *semantic_at_c<2>(*this), *semantic_at_c<3>(*this)); } // Support for planar_pixel_reference offset constructor template <typename Ptr> homogeneous_color_base(const Ptr& ptr, std::ptrdiff_t diff) : _v0(*memunit_advanced(semantic_at_c<0>(ptr),diff)), _v1(*memunit_advanced(semantic_at_c<1>(ptr),diff)), _v2(*memunit_advanced(semantic_at_c<2>(ptr),diff)), _v3(*memunit_advanced(semantic_at_c<3>(ptr),diff)) {} // Support for planar_pixel_reference operator[] Element at_c_dynamic(std::size_t i) const { switch (i) { case 0: return _v0; case 1: return _v1; case 2: return _v2; } return _v3; } }; /// \brief A homogeneous color base holding five color elements. Models HomogeneousColorBaseConcept or HomogeneousColorBaseValueConcept /// \ingroup ColorBaseModelHomogeneous template <typename Element, typename Layout> struct homogeneous_color_base<Element,Layout,5> { private: Element _v0, _v1, _v2, _v3, _v4; public: using layout_t = Layout; typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) { return _v0; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<0>) const { return _v0; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) { return _v1; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<1>) const { return _v1; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) { return _v2; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<2>) const { return _v2; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<3>) { return _v3; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<3>) const { return _v3; } typename element_reference_type<homogeneous_color_base>::type at(mpl::int_<4>) { return _v4; } typename element_const_reference_type<homogeneous_color_base>::type at(mpl::int_<4>) const { return _v4; } homogeneous_color_base() {} explicit homogeneous_color_base(Element v) : _v0(v), _v1(v), _v2(v), _v3(v), _v4(v) {} homogeneous_color_base(Element v0, Element v1, Element v2, Element v3, Element v4) : _v0(v0), _v1(v1), _v2(v2), _v3(v3), _v4(v4) {} template <typename E2, typename L2> homogeneous_color_base(const homogeneous_color_base<E2,L2,5>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)), _v3(gil::at_c<mapping_transform<Layout,L2,3>::value>(c)), _v4(gil::at_c<mapping_transform<Layout,L2,4>::value>(c)) {} // Support for l-value reference proxy copy construction template <typename E2, typename L2> homogeneous_color_base( homogeneous_color_base<E2,L2,5>& c) : _v0(gil::at_c<mapping_transform<Layout,L2,0>::value>(c)), _v1(gil::at_c<mapping_transform<Layout,L2,1>::value>(c)), _v2(gil::at_c<mapping_transform<Layout,L2,2>::value>(c)), _v3(gil::at_c<mapping_transform<Layout,L2,3>::value>(c)), _v4(gil::at_c<mapping_transform<Layout,L2,4>::value>(c)) {} // Support for planar_pixel_iterator construction and dereferencing template <typename P> homogeneous_color_base(P* p,bool) : _v0(&semantic_at_c<0>(*p)), _v1(&semantic_at_c<1>(*p)), _v2(&semantic_at_c<2>(*p)), _v3(&semantic_at_c<3>(*p)), _v4(&semantic_at_c<4>(*p)) {} template <typename Ref> Ref deref() const { return Ref(*semantic_at_c<0>(*this), *semantic_at_c<1>(*this), *semantic_at_c<2>(*this), *semantic_at_c<3>(*this), *semantic_at_c<4>(*this)); } // Support for planar_pixel_reference offset constructor template <typename Ptr> homogeneous_color_base(const Ptr& ptr, std::ptrdiff_t diff) : _v0(*memunit_advanced(semantic_at_c<0>(ptr),diff)), _v1(*memunit_advanced(semantic_at_c<1>(ptr),diff)), _v2(*memunit_advanced(semantic_at_c<2>(ptr),diff)), _v3(*memunit_advanced(semantic_at_c<3>(ptr),diff)), _v4(*memunit_advanced(semantic_at_c<4>(ptr),diff)) {} // Support for planar_pixel_reference operator[] Element at_c_dynamic(std::size_t i) const { switch (i) { case 0: return _v0; case 1: return _v1; case 2: return _v2; case 3: return _v3; } return _v4; } }; #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) #pragma warning(pop) #endif // The following way of casting adjacent channels (the contents of color_base) into an array appears to be unsafe // -- there is no guarantee that the compiler won't add any padding between adjacent channels. // Note, however, that GIL _must_ be compiled with compiler settings ensuring there is no padding in the color base structs. // This is because the color base structs must model the interleaved organization in memory. In other words, the client may // have existing RGB image in the form "RGBRGBRGB..." and we must be able to represent it with an array of RGB color bases (i.e. RGB pixels) // with no padding. We have tested with char/int/float/double channels on gcc and VC and have so far discovered no problem. // We have even tried using strange channels consisting of short + char (3 bytes). With the default 4-byte alignment on VC, the size // of this channel is padded to 4 bytes, so an RGB pixel of it will be 4x3=12 bytes. The code below will still work properly. // However, the client must nevertheless ensure that proper compiler settings are used for their compiler and their channel types. template <typename Element, typename Layout, int K> typename element_reference_type<homogeneous_color_base<Element,Layout,K> >::type dynamic_at_c(homogeneous_color_base<Element,Layout,K>& cb, std::size_t i) { BOOST_ASSERT(i < K); return (gil_reinterpret_cast<Element*>(&cb))[i]; } template <typename Element, typename Layout, int K> typename element_const_reference_type<homogeneous_color_base<Element,Layout,K> >::type dynamic_at_c(const homogeneous_color_base<Element,Layout,K>& cb, std::size_t i) { BOOST_ASSERT(i < K); return (gil_reinterpret_cast_c<const Element*>(&cb))[i]; } template <typename Element, typename Layout, int K> typename element_reference_type<homogeneous_color_base<Element&,Layout,K> >::type dynamic_at_c(const homogeneous_color_base<Element&,Layout,K>& cb, std::size_t i) { BOOST_ASSERT(i < K); return cb.at_c_dynamic(i); } template <typename Element, typename Layout, int K> typename element_const_reference_type<homogeneous_color_base<const Element&,Layout,K> >::type dynamic_at_c(const homogeneous_color_base<const Element&,Layout,K>& cb, std::size_t i) { BOOST_ASSERT(i < K); return cb.at_c_dynamic(i); } } // namespace detail template <typename Element, typename Layout, int K1, int K> struct kth_element_type<detail::homogeneous_color_base<Element,Layout,K1>, K> { using type = Element; }; template <typename Element, typename Layout, int K1, int K> struct kth_element_reference_type<detail::homogeneous_color_base<Element,Layout,K1>, K> : public add_reference<Element> {}; template <typename Element, typename Layout, int K1, int K> struct kth_element_const_reference_type<detail::homogeneous_color_base<Element,Layout,K1>, K> : public add_reference<typename add_const<Element>::type> {}; /// \brief Provides mutable access to the K-th element, in physical order /// \ingroup ColorBaseModelHomogeneous template <int K, typename E, typename L, int N> inline typename add_reference<E>::type at_c( detail::homogeneous_color_base<E,L,N>& p) { return p.at(mpl::int_<K>()); } /// \brief Provides constant access to the K-th element, in physical order /// \ingroup ColorBaseModelHomogeneous template <int K, typename E, typename L, int N> inline typename add_reference<typename add_const<E>::type>::type at_c(const detail::homogeneous_color_base<E,L,N>& p) { return p.at(mpl::int_<K>()); } namespace detail { struct swap_fn { template <typename T> void operator()(T& x, T& y) const { using std::swap; swap(x,y); } }; } template <typename E, typename L, int N> inline void swap(detail::homogeneous_color_base<E,L,N>& x, detail::homogeneous_color_base<E,L,N>& y) { static_for_each(x,y,detail::swap_fn()); } } } // namespace boost::gil #endif