From: wolf <wolf@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Thu, 30 May 2002 11:34:25 +0000 (+0000)
Subject: New members of GeometryInfo.
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c2ce895282d21c30a91ca726ac65d3762f6e59a;p=dealii-svn.git

New members of GeometryInfo.


git-svn-id: https://svn.dealii.org/trunk@5930 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/deal.II/include/grid/geometry_info.h b/deal.II/deal.II/include/grid/geometry_info.h
index 37bc3a79d9..87a10778b8 100644
--- a/deal.II/deal.II/include/grid/geometry_info.h
+++ b/deal.II/deal.II/include/grid/geometry_info.h
@@ -16,7 +16,7 @@
 
 #include <base/config.h>
 #include <base/exceptions.h>
-
+#include <base/point.h>
 
 
 
@@ -35,6 +35,96 @@ struct GeometryInfo
 
 
 
+/**
+ * Topological description of zero dimensional cells,
+ * i.e. points. This class might not look too useful but often is if
+ * in a certain dimension we would like to enquire information about
+ * objects with dimension one lower than the present, e.g. about
+ * faces.
+ *
+ * This class contains as static members information on vertices and
+ * faces of a @p{dim}-dimensional grid cell. The interface is the same
+ * for all dimensions. If a value is of no use in a low dimensional
+ * cell, it is (correctly) set to zero, e.g. @p{subfaces_per_cell} in
+ * 1d.
+ *
+ * This information should always replace hard-coded numbers of
+ * vertices, neighbors and so on, since it can be used dimension
+ * independently.
+ *
+ * @author Wolfgang Bangerth, 1998
+ */
+template <>
+struct GeometryInfo<0> 
+{
+				     /**
+				      * Present dimension. Does not
+				      * look useful, but might be.
+				      */
+    static const unsigned int dim               = 0;
+
+				     /**
+				      * Number of children a cell has.
+				      */
+    static const unsigned int children_per_cell = 1;
+
+				     /**
+				      * Number of faces a cell has.
+				      */
+    static const unsigned int faces_per_cell    = 0;
+
+				     /**
+				      * Number of children each face has
+				      * when the adjacent cell is refined.
+				      */
+    static const unsigned int subfaces_per_face = 0;
+
+				     /**
+				      * Number of vertices a cell has.
+				      */
+    static const unsigned int vertices_per_cell = 1;
+
+				     /**
+				      * Number of vertices each face has.
+				      * Since this is not useful in one
+				      * dimension, we provide a useless
+				      * number (in the hope that a compiler
+				      * may warn when it sees constructs like
+				      * @p{for (i=0; i<vertices_per_face; ++i)},
+				      * at least if @p{i} is an @p{unsigned int}.
+				      */
+    static const unsigned int vertices_per_face = 0;
+
+				     /**
+				      * Number of lines each face has.
+				      */
+    static const unsigned int lines_per_face    = 0;
+    
+				     /**
+				      * Number of quads on each face.
+				      */
+    static const unsigned int quads_per_face    = 0;
+
+				     /**
+				      * Number of lines of a cell.
+				      */
+    static const unsigned int lines_per_cell    = 0;
+
+				     /**
+				      * Number of quadrilaterals of a
+				      * cell.
+				      */
+    static const unsigned int quads_per_cell    = 0;
+
+				     /**
+				      * Number of hexahedra of a
+				      * cell.
+				      */
+    static const unsigned int hexes_per_cell    = 0;
+};
+
+
+
 /**
  * Topological description of one dimensional cells.
  *
@@ -119,8 +209,8 @@ struct GeometryInfo<1>
     static const unsigned int hexes_per_cell    = 0;
 
 				     /**
-				      * List of numbers which is
-				      * denote which face is opposite
+				      * List of numbers which
+				      * denotes which face is opposite
 				      * to a given face. In 1d, this
 				      * list is @p{{1,0}}, in 2d @p{{2, 3, 0, 1}},
 				      * in 3d @p{{1, 0, 4, 5, 2, 3}}.
@@ -191,96 +281,45 @@ struct GeometryInfo<1>
 				      */
     static unsigned int child_cell_on_face (const unsigned int face,
 					    const unsigned int subface);
-};
-
-
-
-/**
- * Topological description of zero dimensional cells,
- * i.e. points. This class might not look too useful but often is if
- * in a certain dimension we would like to enquire information about
- * objects with dimension one lower than the present, e.g. about
- * faces.
- *
- * This class contains as static members information on vertices and
- * faces of a @p{dim}-dimensional grid cell. The interface is the same
- * for all dimensions. If a value is of no use in a low dimensional
- * cell, it is (correctly) set to zero, e.g. @p{subfaces_per_cell} in
- * 1d.
- *
- * This information should always replace hard-coded numbers of
- * vertices, neighbors and so on, since it can be used dimension
- * independently.
- *
- * @author Wolfgang Bangerth, 1998
- */
-template <>
-struct GeometryInfo<0> 
-{
-				     /**
-				      * Present dimension. Does not
-				      * look useful, but might be.
-				      */
-    static const unsigned int dim               = 0;
 
 				     /**
-				      * Number of children a cell has.
+				      * Return the position of the
+				      * @p{i}th vertex on the unit
+				      * cell. The order of vertices is
+				      * the canonical one in deal.II,
+				      * as described in the
+				      * documentation of the
+				      * @ref{Triangulation} class.
 				      */
-    static const unsigned int children_per_cell = 1;
+    static Point<1> unit_cell_vertex (const unsigned int vertex);
 
 				     /**
-				      * Number of faces a cell has.
-				      */
-    static const unsigned int faces_per_cell    = 0;
-
-				     /**
-				      * Number of children each face has
-				      * when the adjacent cell is refined.
-				      */
-    static const unsigned int subfaces_per_face = 0;
-
-				     /**
-				      * Number of vertices a cell has.
-				      */
-    static const unsigned int vertices_per_cell = 1;
-
-				     /**
-				      * Number of vertices each face has.
-				      * Since this is not useful in one
-				      * dimension, we provide a useless
-				      * number (in the hope that a compiler
-				      * may warn when it sees constructs like
-				      * @p{for (i=0; i<vertices_per_face; ++i)},
-				      * at least if @p{i} is an @p{unsigned int}.
-				      */
-    static const unsigned int vertices_per_face = 0;
-
-				     /**
-				      * Number of lines each face has.
-				      */
-    static const unsigned int lines_per_face    = 0;
-    
-				     /**
-				      * Number of quads on each face.
-				      */
-    static const unsigned int quads_per_face    = 0;
-
-				     /**
-				      * Number of lines of a cell.
-				      */
-    static const unsigned int lines_per_cell    = 0;
-
-				     /**
-				      * Number of quadrilaterals of a
-				      * cell.
-				      */
-    static const unsigned int quads_per_cell    = 0;
-
-				     /**
-				      * Number of hexahedra of a
-				      * cell.
-				      */
-    static const unsigned int hexes_per_cell    = 0;
+				      * Report, for @p{vertex=0,1} the
+				      * indices of the two vertices
+				      * adjacent to the line with
+				      * index @p{line} among the lines
+				      * forming this cell. In 1d, the
+				      * only line is the cell itself,
+				      * while in 2d and 3d there are 4
+				      * and 12 lines, respectively.
+				      *
+				      * The positions of these
+				      * vertices in the unit cell can
+				      * be obtained using the
+				      * @p{unit_cell_vertex} function.
+				      *
+				      * The order of the lines, as
+				      * well as their direction (which
+				      * in turn determines which is
+				      * the first and which the second
+				      * vertex on a line) is the
+				      * canonical one in deal.II, as
+				      * described in the documentation
+				      * of the @ref{Triangulation}
+				      * class.
+				      */
+    static unsigned int vertices_adjacent_to_line (const unsigned int line,
+						   const unsigned int vertex);
 };
 
 
@@ -369,8 +408,8 @@ struct GeometryInfo<2>
     static const unsigned int hexes_per_cell    = 0;
 
 				     /**
-				      * List of numbers which is
-				      * denote which face is opposite
+				      * List of numbers which
+				      * denotes which face is opposite
 				      * to a given face. In 1d, this
 				      * list is @p{{1,0}}, in 2d @p{{2, 3, 0, 1}},
 				      * in 3d @p{{1, 0, 4, 5, 2, 3}}.
@@ -440,6 +479,46 @@ struct GeometryInfo<2>
 				      */
     static unsigned int child_cell_on_face (const unsigned int face,
 					    const unsigned int subface);
+
+
+				     /**
+				      * Return the position of the
+				      * @p{i}th vertex on the unit
+				      * cell. The order of vertices is
+				      * the canonical one in deal.II,
+				      * as described in the
+				      * documentation of the
+				      * @ref{Triangulation} class.
+				      */
+    static Point<2> unit_cell_vertex (const unsigned int i);
+
+				     /**
+				      * Report, for @p{vertex=0,1} the
+				      * indices of the two vertices
+				      * adjacent to the line with
+				      * index @p{line} among the lines
+				      * forming this cell. In 1d, the
+				      * only line is the cell itself,
+				      * while in 2d and 3d there are 4
+				      * and 12 lines, respectively.
+				      *
+				      * The positions of these
+				      * vertices in the unit cell can
+				      * be obtained using the
+				      * @p{unit_cell_vertex} function.
+				      *
+				      * The order of the lines, as
+				      * well as their direction (which
+				      * in turn determines which is
+				      * the first and which the second
+				      * vertex on a line) is the
+				      * canonical one in deal.II, as
+				      * described in the documentation
+				      * of the @ref{Triangulation}
+				      * class.
+				      */
+    static unsigned int vertices_adjacent_to_line (const unsigned int line,
+						   const unsigned int vertex);
 };
 
 
@@ -528,8 +607,8 @@ struct GeometryInfo<3>
     static const unsigned int hexes_per_cell    = 1;
 
 				     /**
-				      * List of numbers which is
-				      * denote which face is opposite
+				      * List of numbers which
+				      * denotes which face is opposite
 				      * to a given face. In 1d, this
 				      * list is @p{{1,0}}, in 2d @p{{2, 3, 0, 1}},
 				      * in 3d @p{{1, 0, 4, 5, 2, 3}}.
@@ -599,6 +678,44 @@ struct GeometryInfo<3>
 				      */
     static unsigned int child_cell_on_face (const unsigned int face,
 					    const unsigned int subface);
+				     /**
+				      * Return the position of the
+				      * @p{i}th vertex on the unit
+				      * cell. The order of vertices is
+				      * the canonical one in deal.II,
+				      * as described in the
+				      * documentation of the
+				      * @ref{Triangulation} class.
+				      */
+    static Point<3> unit_cell_vertex (const unsigned int i);
+
+				     /**
+				      * Report, for @p{vertex=0,1} the
+				      * indices of the two vertices
+				      * adjacent to the line with
+				      * index @p{line} among the lines
+				      * forming this cell. In 1d, the
+				      * only line is the cell itself,
+				      * while in 2d and 3d there are 4
+				      * and 12 lines, respectively.
+				      *
+				      * The positions of these
+				      * vertices in the unit cell can
+				      * be obtained using the
+				      * @p{unit_cell_vertex} function.
+				      *
+				      * The order of the lines, as
+				      * well as their direction (which
+				      * in turn determines which is
+				      * the first and which the second
+				      * vertex on a line) is the
+				      * canonical one in deal.II, as
+				      * described in the documentation
+				      * of the @ref{Triangulation}
+				      * class.
+				      */
+    static unsigned int vertices_adjacent_to_line (const unsigned int line,
+						   const unsigned int vertex);
 };
 
 
@@ -692,6 +809,106 @@ struct GeometryInfo<4>
 };
 
 
+/* ---------------- inline functions --------------- */
+
+inline
+Point<1>
+GeometryInfo<1>::unit_cell_vertex (const unsigned int vertex)
+{
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, vertices_per_cell));
+
+  static const Point<dim> vertices[vertices_per_cell] =
+    { Point<dim>(0.), Point<dim>(1.) };
+  return vertices[vertex];
+};
+
+
+
+inline
+Point<2>
+GeometryInfo<2>::unit_cell_vertex (const unsigned int vertex)
+{
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, vertices_per_cell));
+
+  static const Point<dim> vertices[vertices_per_cell] =
+    { Point<dim>(0., 0.), Point<dim>(1., 0.),
+      Point<dim>(1.,1.), Point<dim>(0.,1.) };
+  return vertices[vertex];
+};
+
+
+
+inline
+Point<3>
+GeometryInfo<3>::unit_cell_vertex (const unsigned int vertex)
+{
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, vertices_per_cell));
+
+  static const Point<dim> vertices[vertices_per_cell] =
+    { Point<dim>(0., 0., 0.), Point<dim>(1., 0., 0.),
+      Point<dim>(1., 0., 1.), Point<dim>(0., 0., 1.),
+      Point<dim>(0., 1., 0.), Point<dim>(1., 1., 0.),
+      Point<dim>(1., 1., 1.), Point<dim>(0., 1., 1.) };
+  return vertices[vertex];
+};
+
+
+
+inline
+unsigned int
+GeometryInfo<1>::vertices_adjacent_to_line (const unsigned int line,
+					    const unsigned int vertex)
+{
+  Assert (line < lines_per_cell,
+	  ExcIndexRange (line, 0, lines_per_cell));
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, 2));
+
+  return vertex;
+};
+
+
+
+inline
+unsigned int
+GeometryInfo<2>::vertices_adjacent_to_line (const unsigned int line,
+					    const unsigned int vertex)
+{
+  Assert (line < lines_per_cell,
+	  ExcIndexRange (line, 0, lines_per_cell));
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, 2));
+
+  static const unsigned int vertex_indices[lines_per_cell][2] =
+    { {0, 1}, {1, 2}, {3, 2}, {0, 3} };
+
+  return vertex_indices[line][vertex];
+};
+
+
+
+inline
+unsigned int
+GeometryInfo<3>::vertices_adjacent_to_line (const unsigned int line,
+					    const unsigned int vertex)
+{
+  Assert (line < lines_per_cell,
+	  ExcIndexRange (line, 0, lines_per_cell));
+  Assert (vertex < vertices_per_cell,
+	  ExcIndexRange (vertex, 0, 2));
+
+  static const unsigned int vertex_indices[lines_per_cell][2] =
+    { {0, 1}, {1, 2}, {3, 2}, {0, 3},
+      {4, 5}, {5, 6}, {7, 6}, {4, 7},
+      {0, 4}, {1, 5}, {2, 6}, {3, 7}  };
+
+  return vertex_indices[line][vertex];
+};
+
+
 
 
 #endif
diff --git a/deal.II/doc/news/2002/c-3-3.html b/deal.II/doc/news/2002/c-3-3.html
index 102e1016b8..b6bb149a3f 100644
--- a/deal.II/doc/news/2002/c-3-3.html
+++ b/deal.II/doc/news/2002/c-3-3.html
@@ -296,6 +296,17 @@ contributor's names are abbreviated by WB (Wolfgang Bangerth), GK
 <h3>deal.II</h3>
 
 <ol>
+  <li> <p> 
+       New: The <code class="class">GeometryInfo</code> class now
+       provides two methods,
+       <code class="member">unit_cell_vertex</code> and <code
+       class="member">vertices_adjacent_to_line</code>, that reveal
+       something about the placement and numbering of vertices on the
+       uni cell.
+       <br>
+       (GK 2002/05/29)
+       </p>
+
   <li> <p> 
        New: The <code class="class">GridOut::</code>
        <code class="member">write_dx</code> function is now implemented.