transformedview.h

// Description: TransformedView class
// Detail: An adapter view to change the apparent type of the data.
// Documentation: concrete_views.txt

#ifndef PASTELSYS_TRANSFORMEDVIEW_H
#define PASTELSYS_TRANSFORMEDVIEW_H

#include "pastel/sys/view/view.h"
#include "pastel/sys/view/transformedviewcursor.h"

namespace Pastel
{

    //! An adapter view to change the apparent type of the data.
    /*!
   This view is only given as a non-mutable version. This is because
   the transformed data is constructed on the fly as it is accessed.
   The transformation is given by a user-supplied functor TransformFunctor.

   class TransformFunctor
   {
   public:
       using Input_ = unspecified_type;
       using Output_ = unspecified_type;

       Output_ operator()(const Input_& input) const;
   };
   */

    template <integer N, typename TransformFunctor, typename Contained_ConstView>
    class ConstTransformedView
    {
    public:
        static constexpr int Dimension = N;

        using Element = typename Contained_ConstView::Element;
        using ConstReference = typename Contained_ConstView::ConstReference;

        typedef TransformedView_::ConstTransformedViewCursor<N, TransformFunctor,
            typename Contained_ConstView::ConstCursor> ConstCursor;

        explicit ConstTransformedView(
            const Contained_ConstView& view,
            const TransformFunctor& transform)
            : view_(view)
            , transform_(transform)
        {
        }

        const Vector<integer, N>& extent() const
        {
            return view_.extent();
        }

        ConstCursor constCursor(
            const Vector<integer, N>& position) const
        {
            return ConstCursor(view_.constCursor(position), transform_);
        }

    protected:
        Contained_ConstView view_;
        TransformFunctor transform_;
    };

    template <typename TransformFunctor, integer N, typename Input_Element, typename Input_ConstView>
    ConstView<N, Input_Element, ConstTransformedView<N, TransformFunctor, Input_ConstView> >
        constTransformedView(
        const ConstView<N, Input_Element, Input_ConstView>& view,
        const TransformFunctor& transform)
    {
        return wrapConstView(
            ConstTransformedView<N, TransformFunctor, Input_ConstView>(
            view.contained(), transform));
    }

}

#endif