###

#

pixel.hpp
//
// Copyright 2005-2007 Adobe Systems Incorporated
// Copyright 2019 Mateusz Loskot <mateusz at loskot dot net>
//
// 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_PIXEL_HPP
#define BOOST_GIL_PIXEL_HPP
#include <boost/gil/channel.hpp>
#include <boost/gil/color_base.hpp>
#include <boost/gil/color_base_algorithm.hpp>
#include <boost/gil/concepts.hpp>
#include <boost/gil/metafunctions.hpp>
#include <boost/gil/utilities.hpp>
#include <boost/gil/detail/mp11.hpp>
#include <functional>
#include <type_traits>
namespace boost { namespace gil {
// Forward-declare gray_t
struct gray_color_t;
using gray_t = mp11::mp_list<gray_color_t>;
template <typename PixelBased> struct color_space_type;
template <typename PixelBased> struct channel_mapping_type;
template <typename PixelBased> struct channel_type;
template <typename PixelBased> struct is_planar;
template <typename PixelBased>
struct color_space_type<PixelBased const> : color_space_type<PixelBased> {};
template <typename PixelBased>
struct channel_mapping_type<PixelBased const> : channel_mapping_type<PixelBased> {};
template <typename PixelBased>
struct channel_type<PixelBased const> : channel_type<PixelBased> {};
template <typename PixelBased>
struct is_planar : std::false_type {};
template <typename PixelBased>
struct is_planar<PixelBased const> : is_planar<PixelBased> {};
template <typename T> struct is_pixel : std::false_type {};
template <typename T> struct is_pixel<T const> : is_pixel<T> {};
template <typename PixelBased>
struct num_channels : mp11::mp_size<typename color_space_type<PixelBased>::type>::type {};
template <typename ChannelValue, typename Layout>
struct pixel :
detail::homogeneous_color_base
<
ChannelValue,
Layout,
mp11::mp_size<typename Layout::color_space_t>::value
>
{
private:
using channel_t = ChannelValue;
using parent_t = detail::homogeneous_color_base
<
ChannelValue,
Layout,
mp11::mp_size<typename Layout::color_space_t>::value
>;
public:
using value_type = pixel<ChannelValue, Layout>;
using reference = value_type&;
using const_reference = value_type const&;
static constexpr bool is_mutable = channel_traits<channel_t>::is_mutable;
pixel() = default;
explicit pixel(channel_t v) : parent_t(v) {} // sets all channels to v
pixel(channel_t v0, channel_t v1) : parent_t(v0, v1) {}
pixel(channel_t v0, channel_t v1, channel_t v2) : parent_t(v0, v1, v2) {}
pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3)
: parent_t(v0, v1, v2, v3)
{}
pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3, channel_t v4)
: parent_t(v0, v1, v2, v3, v4)
{}
pixel(channel_t v0, channel_t v1, channel_t v2, channel_t v3, channel_t v4, channel_t v5)
: parent_t(v0, v1, v2, v3, v4, v5)
{}
pixel(const pixel& p) : parent_t(p) {}
pixel& operator=(pixel const& p)
{
static_copy(p,*this);
return *this;
}
// Construct from another compatible pixel type
template <typename Pixel>
pixel(Pixel const& p,
typename std::enable_if<is_pixel<Pixel>::value>::type* /*dummy*/ = nullptr)
: parent_t(p)
{
check_compatible<Pixel>();
}
template <typename Pixel>
pixel& operator=(Pixel const& p)
{
assign(p, is_pixel<Pixel>());
return *this;
}
template <typename Pixel>
bool operator==(Pixel const& p) const { return equal(p, is_pixel<Pixel>()); }
template <typename Pixel>
bool operator!=(Pixel const& p) const { return !(*this == p); }
// homogeneous pixels have operator[]
auto operator[](std::size_t index)
-> typename channel_traits<channel_t>::reference
{
return dynamic_at_c(*this, index);
}
auto operator[](std::size_t index) const
-> typename channel_traits<channel_t>::const_reference
{
return dynamic_at_c(*this, index);
}
private:
template <typename Pixel>
void assign(Pixel const& p, std::true_type)
{
check_compatible<Pixel>();
static_copy(p, *this);
}
template <typename Pixel>
bool equal(Pixel const& p, std::true_type) const
{
check_compatible<Pixel>();
return static_equal(*this, p);
}
template <typename Pixel>
void check_compatible() const
{
gil_function_requires<PixelsCompatibleConcept<Pixel, pixel>>();
}
// Support for assignment/equality comparison of a channel with a grayscale pixel
private:
static void check_gray()
{
static_assert(std::is_same<typename Layout::color_space_t, gray_t>::value, "");
}
template <typename Channel>
void assign(Channel const& channel, std::false_type)
{
check_gray();
gil::at_c<0>(*this) = channel;
}
template <typename Channel>
bool equal (Channel const& channel, std::false_type) const
{
check_gray();
return gil::at_c<0>(*this) == channel;
}
public:
pixel& operator= (channel_t channel)
{
check_gray();
gil::at_c<0>(*this) = channel;
return *this;
}
bool operator==(channel_t channel) const
{
check_gray();
return gil::at_c<0>(*this) == channel;
}
};
// ColorBasedConcept
template <typename ChannelValue, typename Layout, int K>
struct kth_element_type<pixel<ChannelValue,Layout>, K>
{
using type = ChannelValue;
};
template <typename ChannelValue, typename Layout, int K>
struct kth_element_reference_type<pixel<ChannelValue,Layout>, K>
{
using type = typename channel_traits<ChannelValue>::reference;
};
template <typename ChannelValue, typename Layout, int K>
struct kth_element_reference_type<const pixel<ChannelValue,Layout>, K>
{
using type = typename channel_traits<ChannelValue>::const_reference;
};
template <typename ChannelValue, typename Layout, int K>
struct kth_element_const_reference_type<pixel<ChannelValue,Layout>, K>
{
using type = typename channel_traits<ChannelValue>::const_reference;
};
// PixelConcept
template <typename ChannelValue, typename Layout>
struct is_pixel<pixel<ChannelValue,Layout>> : std::true_type {};
// HomogeneousPixelBasedConcept
template <typename ChannelValue, typename Layout>
struct color_space_type<pixel<ChannelValue, Layout>>
{
using type = typename Layout::color_space_t;
};
template <typename ChannelValue, typename Layout>
struct channel_mapping_type<pixel<ChannelValue, Layout>>
{
using type = typename Layout::channel_mapping_t;
};
template <typename ChannelValue, typename Layout>
struct is_planar<pixel<ChannelValue, Layout>> : std::false_type {};
template <typename ChannelValue, typename Layout>
struct channel_type<pixel<ChannelValue, Layout>>
{
using type = ChannelValue;
};
}} // namespace boost::gil
#endif
boost
defined(BOOST_NO_CXX17_HDR_MEMORY_RESOURCE)
Definition: algorithm.hpp:36