[staggered] Add local intersectionIndexMapper

dumux/discretization/facecentered/staggered/localintersectionindexmapper.hh

+// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// vi: set et ts=4 sw=4 sts=4:
+/*****************************************************************************
+ *   See the file COPYING for full copying permissions.                      *
+ *                                                                           *
+ *   This program is free software: you can redistribute it and/or modify    *
+ *   it under the terms of the GNU General Public License as published by    *
+ *   the Free Software Foundation, either version 3 of the License, or       *
+ *   (at your option) any later version.                                     *
+ *                                                                           *
+ *   This program is distributed in the hope that it will be useful,         *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the            *
+ *   GNU General Public License for more details.                            *
+ *                                                                           *
+ *   You should have received a copy of the GNU General Public License       *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ *****************************************************************************/
+/*!
+ * \file
+ * \ingroup FaceCenteredStaggeredDiscretization
+ * \copydoc Dumux::FaceCenteredStaggeredLocalIntersectionIndexMapper
+ */
+#ifndef DUMUX_DISCRETIZATION_LOCAL_INTERSECTION_INDEX_MAPPER_HH
+#define DUMUX_DISCRETIZATION_LOCAL_INTERSECTION_INDEX_MAPPER_HH
+
+#include <array>
+#include <numeric>
+#include <dune/common/float_cmp.hh>
+#include <dumux/common/indextraits.hh>
+#include <dumux/common/math.hh>
+#include <dumux/discretization/facecentered/staggered/normalaxis.hh>
+#include <dumux/discretization/facecentered/staggered/consistentlyorientedgrid.hh>
+
+namespace Dumux {
+
+namespace Detail {
+
+template<class GridView, bool consistentlyOrientedGrid>
+class FaceCenteredStaggeredLocalIntersectionIndexMapper;
+
+/*!
+ * \ingroup FaceCenteredStaggeredDiscretization
+ * \brief Provides a mapping of local intersecton indices (indexInInside)
+ *        such that the local indices always follow the order of a reference element,
+ *        regardless of how the element is oriented.
+ */
+template<class GridView>
+class FaceCenteredStaggeredLocalIntersectionIndexMapper<GridView, false>
+{
+    using SmallLocalIndexType = typename IndexTraits<GridView>::SmallLocalIndex;
+    using Element = typename GridView::template Codim<0>::Entity;
+    static constexpr auto numElementFaces = GridView::Grid::dimension * 2;
+public:
+
+    void update(const GridView& gv, const Element& element)
+    {
+        static const bool makeConsistentlyOriented = getParam<bool>("Grid.MakeConsistentlyOriented", true);
+        if (!makeConsistentlyOriented)
+        {
+            std::iota(realToRefMap_.begin(), realToRefMap_.end(), 0);
+            refToRealMap_ = realToRefMap_;
+            return;
+        }
+
+        for (const auto& is : intersections(gv, element))
+        {
+            const auto& otherOuterNormal = is.centerUnitOuterNormal();
+            const auto idx = normalAxis(otherOuterNormal);
+            const int positveOrientation = !std::signbit(otherOuterNormal[idx]);
+            const auto refIdx = idx * 2 + positveOrientation;
+            const auto realIdx = is.indexInInside();
+            realToRefMap_[realIdx] = refIdx;
+            refToRealMap_[refIdx] = realIdx;
+        }
+    }
+
+    //! Return the intersection's actual local indexInElement given a local reference index.
+    SmallLocalIndexType realToRefIdx(const SmallLocalIndexType localIsIdx) const
+    { return realToRefMap_[localIsIdx]; }
+
+    //! Return the intersection's local reference indexInElement given an actual local index.
+    SmallLocalIndexType refToRealIdx(const SmallLocalIndexType localIsIdx) const
+    { return refToRealMap_[localIsIdx]; }
+
+private:
+    std::array<SmallLocalIndexType, numElementFaces> realToRefMap_;
+    std::array<SmallLocalIndexType, numElementFaces> refToRealMap_;
+};
+
+/*!
+ * \ingroup FaceCenteredStaggeredDiscretization
+ * \brief Provides a mapping of local intersecton indices (indexInInside)
+ *        such that the local indices always follow the order of a reference element,
+ *        regardless of how the element in oriented.
+ * \note This specialization is used for grids not supporting rotated elements.
+ *       No mapping needs to be done here.
+ */
+template<class GridView>
+class FaceCenteredStaggeredLocalIntersectionIndexMapper<GridView, true>
+{
+    using SmallLocalIndexType = typename IndexTraits<GridView>::SmallLocalIndex;
+    using Element = typename GridView::template Codim<0>::Entity;
+public:
+
+    //! Update the map for getting the corresponding local face indices in another element.
+    void update(const GridView&, const Element&) {}
+
+    //! Return the intersection's actual local indexInElement given a local reference index.
+    SmallLocalIndexType realToRefIdx(const SmallLocalIndexType localIsIdx) const
+    { return localIsIdx; }
+
+    //! Return the intersection's local reference indexInElement given an actual local index.
+    SmallLocalIndexType refToRealIdx(const SmallLocalIndexType localIsIdx) const
+    { return localIsIdx; }
+};
+
+} // end namespace Detail
+
+/*!
+ * \ingroup FaceCenteredStaggeredDiscretization
+ * \brief Provides a mapping of local intersecton indices (indexInInside)
+ *        such that the local indices always follow the order of a reference element,
+ *        regardless of how the element is oriented. Does not do anything for grids
+ *        not supporting rotated elements (such as Dune::YaspGrid).
+ */
+template<class GridView>
+using FaceCenteredStaggeredLocalIntersectionIndexMapper =
+      Detail::FaceCenteredStaggeredLocalIntersectionIndexMapper<GridView, ConsistentlyOrientedGrid<typename GridView::Grid>{}>;
+
+} // end namespace Dumux
+
+#endif