sub_locator.h

// Description: Sub locator
// Documentation: locators.txt

#ifndef PASTELSYS_SUB_LOCATOR_H
#define PASTELSYS_SUB_LOCATOR_H

#include "pastel/sys/locator/locator_concept.h"
#include "pastel/sys/point/point_concept.h"

namespace Pastel
{

    template <
        typename Locator>
    class Sub_Locator
    {
    public:
        static constexpr integer N = Dynamic;
        using Real = typename Locator::Real;
        using Point = typename Locator::Point;

        Sub_Locator()
        : locator_()
        , iBegin_(0)
        , iEnd_(0)
        {
        }

        Sub_Locator(
            const Locator& locator,
            integer iBegin,
            integer iEnd)
            : locator_(locator)
            , iBegin_(iBegin)
            , iEnd_(iEnd)
        {
            PENSURE_OP(iBegin, >= , 0);
            PENSURE_OP(iBegin, <= , iEnd);
            PENSURE_OP(iEnd, <= , locator.n());
        }

        integer n() const
        {
            return iEnd_ - iBegin_;
        }

        integer n(const Point& point) const
        {
            return n();
        }

        const Real& operator()(
            const Point& point, integer i) const
        {
            return locator_(point, i + iBegin_);
        }

    private:
        Locator locator_;
        integer iBegin_;
        integer iEnd_;
    };

    template <typename Locator>
    decltype(auto) subLocator(
        const Locator& locator,
        integer iBegin,
        integer iEnd)
    {
        return Sub_Locator<Locator>(locator, iBegin, iEnd);
    }

}

#endif