a helper class encapsulating the renumbering of subentities that has to take...

a helper class encapsulating the renumbering of subentities that has to take place when hiding UG behind the DUNE interface

[[Imported from SVN: r3971]]

grid/uggrid/uggridrenumberer.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+#ifndef DUNE_UGGRID_RENUMBERER_HH
+#define DUNE_UGGRID_RENUMBERER_HH
+
+/** \file
+    \brief Contains a helper class that encapsulates the vertex numbering conversions
+    between UG and DUNE
+ */
+
+namespace Dune {
+
+  /** \brief Empty generic class.  All we need is in the specializations for dim=2 and dim=3
+   */
+  template <int dim>
+  class UGGridRenumberer {};
+
+  /** \brief DUNE and UG use different local numberings for the subentities of elements.
+      This class does the conversions for 2d-grids.
+   */
+  template <>
+  class UGGridRenumberer<2> {
+
+  public:
+
+    /** \brief Turn a local vertex number from DUNE numbering to UG numbering *
+       static int verticesDUNEtoUG(int i, NewGeometryType type) {
+
+        if (type.isCube()) {
+            const int renumbering[4] = {0, 1, 3, 2};
+            return renumbering[i];
+        }
+
+        return i;
+       }
+
+       /** \brief Turn a local face number from DUNE numbering to UG numbering *
+       static int facesDUNEtoUG(int i, NewGeometryType type) {
+
+        if (type.isCube()) {
+
+            // Dune numbers the vertices of a hexahedron and quadrilaterals differently than UG.
+            // The following two lines do the transformation
+            // The renumbering scheme is {0,1,3,2} for quadrilaterals, therefore, the
+            // following code works for 2d and 3d.
+            const int renumbering[6] = {4, 2, 1, 3, 0, 5};
+            return renumbering[i];
+
+        }
+        if (type.isSimplex()) {
+
+            /** \todo Check this */
+    // Dune numbers the vertices of a hexahedron and quadrilaterals differently than UG.
+    // The following two lines do the transformation
+    // The renumbering scheme is {0,1,3,2} for quadrilaterals, therefore, the
+    // following code works for 2d and 3d.
+    const int renumbering[4] = {1, 2, 0, 3};
+    return renumbering[i];
+  }
+  return i;
+}
+
+};
+
+/** \brief DUNE and UG use different local numberings for the subentities of elements.
+    This class does the conversions for 3d-grids.
+ */
+template <>
+class UGGridRenumberer<3> {
+
+public:
+
+  /** \brief Turn a local vertex number from DUNE numbering to UG numbering *
+     static int verticesDUNEtoUG(int i, NewGeometryType type) {
+
+      if (type.isCube()) {
+          const int renumbering[8] = {0, 1, 3, 2, 4, 5, 7, 6};
+          return renumbering[i];
+      }
+
+      return i;
+     }
+
+     /** \brief Turn a local face number from DUNE numbering to UG numbering *
+     static int facesDUNEtoUG(int i, NewGeometryType type) {
+
+      if (type.isCube()) {
+
+          // Dune numbers the vertices of a hexahedron and quadrilaterals differently than UG.
+          // The following two lines do the transformation
+          // The renumbering scheme is {0,1,3,2} for quadrilaterals, therefore, the
+          // following code works for 2d and 3d.
+          const int renumbering[6] = {4, 2, 1, 3, 0, 5};
+          return renumbering[i];
+
+      }
+      if (type.isSimplex()) {
+
+          /** \todo Check this */
+  // Dune numbers the vertices of a hexahedron and quadrilaterals differently than UG.
+  // The following two lines do the transformation
+  // The renumbering scheme is {0,1,3,2} for quadrilaterals, therefore, the
+  // following code works for 2d and 3d.
+  const int renumbering[4] = {1, 2, 0, 3};
+  return renumbering[i];
+}
+return i;
+}
+
+};
+}
+
+#endif