extension/dynamic_image/image_view_factory.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_EXTENSION_DYNAMIC_IMAGE_IMAGE_VIEW_FACTORY_HPP
#define BOOST_GIL_EXTENSION_DYNAMIC_IMAGE_IMAGE_VIEW_FACTORY_HPP
 
#include <boost/gil/extension/dynamic_image/any_image_view.hpp>
 
#include <boost/gil/dynamic_step.hpp>
#include <boost/gil/image_view_factory.hpp>
#include <boost/gil/point.hpp>
#include <boost/gil/detail/mp11.hpp>
 
#include <cstdint>
 
namespace boost { namespace gil {
 
// Methods for constructing any image views from other any image views
// Extends image view factory to runtime type-specified views (any_image_view)
 
namespace detail {
 
template <typename ResultView>
struct flipped_up_down_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{flipped_up_down_view(src)};
    }
};
 
template <typename ResultView>
struct flipped_left_right_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{flipped_left_right_view(src)};
    }
};
 
template <typename ResultView>
struct rotated90cw_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{rotated90cw_view(src)};
    }
};
 
template <typename ResultView>
struct rotated90ccw_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{rotated90ccw_view(src)};
    }
};
 
template <typename ResultView>
struct transposed_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{transposed_view(src)};
    }
};
 
template <typename ResultView>
struct rotated180_view_fn
{
    using result_type = ResultView;
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{rotated180_view(src)};
    }
};
 
template <typename ResultView>
struct subimage_view_fn
{
    using result_type = ResultView;
 
    subimage_view_fn(point_t const& topleft, point_t const& dimensions)
        : _topleft(topleft), _size2(dimensions)
    {}
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{subimage_view(src,_topleft,_size2)};
    }
 
    point_t _topleft;
    point_t _size2;
};
 
template <typename ResultView>
struct subsampled_view_fn
{
    using result_type = ResultView;
 
    subsampled_view_fn(point_t const& step) : _step(step) {}
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{subsampled_view(src,_step)};
    }
 
    point_t _step;
};
 
template <typename ResultView>
struct nth_channel_view_fn
{
    using result_type = ResultView;
 
    nth_channel_view_fn(int n) : _n(n) {}
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type(nth_channel_view(src,_n));
    }
 
    int _n;
};
 
template <typename DstP, typename ResultView, typename CC = default_color_converter>
struct color_converted_view_fn
{
    using result_type = ResultView;
 
    color_converted_view_fn(CC cc = CC()): _cc(cc) {}
 
    template <typename View>
    auto operator()(View const& src) const -> result_type
    {
        return result_type{color_converted_view<DstP>(src, _cc)};
    }
 
private:
    CC _cc;
};
 
} // namespace detail
 
template <typename ...Views>
inline
auto flipped_up_down_view(any_image_view<Views...> const& src)
    -> typename dynamic_y_step_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_y_step_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::flipped_up_down_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto flipped_left_right_view(any_image_view<Views...> const& src)
    -> typename dynamic_x_step_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_x_step_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::flipped_left_right_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto transposed_view(any_image_view<Views...> const& src)
    -> typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::transposed_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto rotated90cw_view(any_image_view<Views...> const& src)
    -> typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::rotated90cw_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto rotated90ccw_view(any_image_view<Views...> const& src)
    -> typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_xy_step_transposed_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::rotated90ccw_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto rotated180_view(any_image_view<Views...> const& src)
    -> typename dynamic_xy_step_type<any_image_view<Views...>>::type
{
    using result_view_t = typename dynamic_xy_step_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::rotated180_view_fn<result_view_t>(), src);
}
 
template <typename ...Views>
inline
auto subimage_view(
    any_image_view<Views...> const& src,
    point_t const& topleft,
    point_t const& dimensions)
    -> any_image_view<Views...>
{
    using subimage_view_fn = detail::subimage_view_fn<any_image_view<Views...>>;
    return variant2::visit(subimage_view_fn(topleft, dimensions), src);
}
 
template <typename ...Views>
inline
auto subimage_view(
    any_image_view<Views...> const& src,
    std::ptrdiff_t x_min, std::ptrdiff_t y_min, std::ptrdiff_t width, std::ptrdiff_t height)
    -> any_image_view<Views...>
{
    using subimage_view_fn = detail::subimage_view_fn<any_image_view<Views...>>;
    return variant2::visit(subimage_view_fn(point_t(x_min, y_min),point_t(width, height)), src);
}
 
template <typename ...Views>
inline
auto subsampled_view(any_image_view<Views...> const& src, point_t const& step)
    -> typename dynamic_xy_step_type<any_image_view<Views...>>::type
{
    using step_type = typename dynamic_xy_step_type<any_image_view<Views...>>::type;
    using subsampled_view = detail::subsampled_view_fn<step_type>;
    return variant2::visit(subsampled_view(step), src);
}
 
template <typename ...Views>
inline
auto subsampled_view(any_image_view<Views...> const& src, std::ptrdiff_t x_step, std::ptrdiff_t y_step)
    -> typename dynamic_xy_step_type<any_image_view<Views...>>::type
{
    using step_type = typename dynamic_xy_step_type<any_image_view<Views...>>::type;
    using subsampled_view_fn = detail::subsampled_view_fn<step_type>;
    return variant2::visit(subsampled_view_fn(point_t(x_step, y_step)), src);
}
 
namespace detail {
 
template <typename View>
struct get_nthchannel_type { using type = typename nth_channel_view_type<View>::type; };
 
template <typename Views>
struct views_get_nthchannel_type : mp11::mp_transform<get_nthchannel_type, Views> {};
 
} // namespace detail
 
template <typename ...Views>
struct nth_channel_view_type<any_image_view<Views...>>
{
    using type = typename detail::views_get_nthchannel_type<any_image_view<Views...>>;
};
 
template <typename ...Views>
inline
auto nth_channel_view(any_image_view<Views...> const& src, int n)
    -> typename nth_channel_view_type<any_image_view<Views...>>::type
{
    using result_view_t = typename nth_channel_view_type<any_image_view<Views...>>::type;
    return variant2::visit(detail::nth_channel_view_fn<result_view_t>(n), src);
}
 
namespace detail {
 
template <typename Views, typename DstP, typename CC>
struct views_get_ccv_type
{
private:
   template <typename T>
    using ccvt = typename color_converted_view_type<T, DstP, CC>::type;
public:
    using type = mp11::mp_transform<ccvt, Views>;
};
 
} // namespace detail
 
template <typename ...Views, typename DstP, typename CC>
struct color_converted_view_type<any_image_view<Views...>,DstP,CC>
{
    //using type = any_image_view<typename detail::views_get_ccv_type<Views, DstP, CC>::type>;
    using type = typename detail::views_get_ccv_type<any_image_view<Views...>, DstP, CC>::type;
};
 
template <typename DstP, typename ...Views, typename CC>
inline
auto color_converted_view(any_image_view<Views...> const& src, CC cc)
    -> typename color_converted_view_type<any_image_view<Views...>, DstP, CC>::type
{
    using cc_view_t = typename color_converted_view_type<any_image_view<Views...>, DstP, CC>::type;
    return variant2::visit(detail::color_converted_view_fn<DstP, cc_view_t, CC>(cc), src);
}
 
template <typename ...Views, typename DstP>
struct color_converted_view_type<any_image_view<Views...>,DstP>
{
    using type = typename detail::views_get_ccv_type<any_image_view<Views...>, DstP, default_color_converter>::type;
};
 
template <typename DstP, typename ...Views>
inline
auto color_converted_view(any_image_view<Views...> const& src)
    -> typename color_converted_view_type<any_image_view<Views...>, DstP>::type
{
    using cc_view_t = typename color_converted_view_type<any_image_view<Views...>, DstP>::type;
    return variant2::visit(detail::color_converted_view_fn<DstP, cc_view_t>(), src);
}
 
template <typename DstP, typename ...Views, typename CC>
[[deprecated("Use color_converted_view(const any_image_view<Views...>& src, CC) instead.")]]
inline
auto any_color_converted_view(const any_image_view<Views...>& src, CC cc)
    -> typename color_converted_view_type<any_image_view<Views...>, DstP, CC>::type
{
    return color_converted_view(src, cc);
}
 
template <typename DstP, typename ...Views>
[[deprecated("Use color_converted_view(any_image_view<Views...> const& src) instead.")]]
inline
auto any_color_converted_view(const any_image_view<Views...>& src)
    -> typename color_converted_view_type<any_image_view<Views...>, DstP>::type
{
    return color_converted_view(src);
}
 
 
}}  // namespace boost::gil
 
#endif