any_image.hpp

//
// Copyright 2005-2007 Adobe Systems Incorporated
// Copyright 2020 Samuel Debionne
//
// 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_EXTENSION_DYNAMIC_IMAGE_ANY_IMAGE_HPP
#define BOOST_GIL_EXTENSION_DYNAMIC_IMAGE_ANY_IMAGE_HPP
 
#include <boost/gil/extension/dynamic_image/any_image_view.hpp>
 
#include <boost/gil/image.hpp>
#include <boost/gil/detail/mp11.hpp>
 
#include <boost/config.hpp>
#include <boost/variant2/variant.hpp>
 
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(push)
#pragma warning(disable:4512) //assignment operator could not be generated
#endif
 
namespace boost { namespace gil {
 
namespace detail {
 
template <typename T>
using get_view_t = typename T::view_t;
 
template <typename Images>
using images_get_views_t = mp11::mp_transform<get_view_t, Images>;
 
template <typename T>
using get_const_view_t = typename T::const_view_t;
 
template <typename Images>
using images_get_const_views_t = mp11::mp_transform<get_const_view_t, Images>;
 
struct recreate_image_fnobj
{
    using result_type = void;
    point<std::ptrdiff_t> const& _dimensions;
    unsigned _alignment;
 
    recreate_image_fnobj(point<std::ptrdiff_t> const& dims, unsigned alignment)
        : _dimensions(dims), _alignment(alignment)
    {}
 
    template <typename Image>
    result_type operator()(Image& img) const { img.recreate(_dimensions,_alignment); }
};
 
template <typename AnyView>  // Models AnyViewConcept
struct any_image_get_view
{
    using result_type = AnyView;
    template <typename Image>
    result_type operator()(Image& img) const
    {
        return result_type(view(img));
    }
};
 
template <typename AnyConstView>  // Models AnyConstViewConcept
struct any_image_get_const_view
{
    using result_type = AnyConstView;
    template <typename Image>
    result_type operator()(Image const& img) const { return result_type{const_view(img)}; }
};
 
} // namespce detail
 
 
template <typename ...Images>
class any_image : public variant2::variant<Images...>
{
    using parent_t = variant2::variant<Images...>;
 
public:
    using view_t = mp11::mp_rename<detail::images_get_views_t<any_image>, any_image_view>;
    using const_view_t = mp11::mp_rename<detail::images_get_const_views_t<any_image>, any_image_view>;
    using x_coord_t = std::ptrdiff_t;
    using y_coord_t = std::ptrdiff_t;
    using point_t = point<std::ptrdiff_t>;
 
    using parent_t::parent_t;
 
    any_image& operator=(any_image const& img)
    {
        parent_t::operator=((parent_t const&)img);
        return *this;
    }
 
    template <typename Image>
    any_image& operator=(Image const& img)
    {
        parent_t::operator=(img);
        return *this;
    }
 
    template <typename ...OtherImages>
    any_image& operator=(any_image<OtherImages...> const& img)
    {
            parent_t::operator=((typename variant2::variant<OtherImages...> const&)img);
            return *this;
    }
 
    void recreate(point_t const& dims, unsigned alignment=1)
    {
        variant2::visit(detail::recreate_image_fnobj(dims, alignment), *this);
    }
 
    void recreate(x_coord_t width, y_coord_t height, unsigned alignment=1)
    {
        recreate({ width, height }, alignment);
    }
 
    std::size_t num_channels() const
    {
        return variant2::visit(detail::any_type_get_num_channels(), *this);
    }
 
    point_t dimensions() const
    {
        return variant2::visit(detail::any_type_get_dimensions(), *this);
    }
 
    x_coord_t width()  const { return dimensions().x; }
    y_coord_t height() const { return dimensions().y; }
};
 
 
 
template <typename ...Images>
BOOST_FORCEINLINE
auto view(any_image<Images...>& img) -> typename any_image<Images...>::view_t
{
    using view_t = typename any_image<Images...>::view_t;
    return variant2::visit(detail::any_image_get_view<view_t>(), img);
}
 
template <typename ...Images>
BOOST_FORCEINLINE
auto const_view(any_image<Images...> const& img) -> typename any_image<Images...>::const_view_t
{
    using view_t = typename any_image<Images...>::const_view_t;
    return variant2::visit(detail::any_image_get_const_view<view_t>(), img);
}
 
}}  // namespace boost::gil
 
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(pop)
#endif
 
#endif