+
/**
- * Topological description of cells.
+ * Topological description of cells. This general template is not
+ * used, rather explicit specializations are provided for all
+ * dimensions for which this class might be of use. The fields
+ * provided by each of these specializations are identical, so that
+ * access to them in a dimension independent way is possible.
+ *
+ * @author Wolfgang Bangerth, 1998
+ */
+template <int dim>
+struct GeometryInfo
+{};
+
+
+
+/**
+ * Topological description of one dimensional cells.
*
* This class contains as static members information on vertices and
* faces of a @p{dim}-dimensional grid cell. The interface is the same
*
* This information should always replace hard-coded numbers of
* vertices, neighbors and so on, since it can be used dimension
- * independent.
+ * independently.
*
- * @author Wolfgang Bangerth, Guido Kanschat, 1998, 1999
+ * @author Wolfgang Bangerth, 1998
*/
-template <int dim_>
-struct GeometryInfo
+template <>
+struct GeometryInfo<1>
{
/**
* Present dimension. Does not
* look useful, but might be.
*/
- static const unsigned int dim = dim_;
+ static const unsigned int dim = 1;
/**
* Number of children a cell has.
*/
- static const unsigned int children_per_cell = (1<<dim_);
+ static const unsigned int children_per_cell = 2;
/**
* Number of faces a cell has.
*/
- static const unsigned int faces_per_cell = 2*dim_;
+ static const unsigned int faces_per_cell = 2;
/**
* Number of children each face has
* when the adjacent cell is refined.
*/
- static const unsigned int subfaces_per_face = GeometryInfo<dim_-1>::children_per_cell;
+ static const unsigned int subfaces_per_face = 0;
/**
* Number of vertices a cell has.
*/
- static const unsigned int vertices_per_cell = (1<<dim_);
+ static const unsigned int vertices_per_cell = 2;
/**
* Number of vertices each face has.
* @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 = GeometryInfo<dim_-1>::vertices_per_cell;
+ static const unsigned int vertices_per_face = 1;
/**
* Number of lines each face has.
*/
- static const unsigned int lines_per_face = GeometryInfo<dim_-1>::lines_per_cell;
+ static const unsigned int lines_per_face = 0;
/**
* Number of quads on each face.
*/
- static const unsigned int quads_per_face = GeometryInfo<dim_-1>::quads_per_cell;
+ static const unsigned int quads_per_face = 0;
/**
* Number of lines of a cell.
- *
- * Computation of this value
- * follows the idea, that
- * building a hypercube of
- * dimension @p{dim} from one of
- * dimension @p{dim}-1 can be done
- * in the following two steps:
- *
- * 1. Duplicated it in the new coordinate direction.
- *
- * 2. Connect all corresponding
- * vertices of the original
- * hypercube and the copy by
- * lines.
*/
- static const unsigned int lines_per_cell = (2*GeometryInfo<dim_-1>::lines_per_cell
- + GeometryInfo<dim_-1>::vertices_per_cell);
-
+ static const unsigned int lines_per_cell = 1;
+
/**
- * Number of quadrilaterals of a cell.
- *
- * Computation is analogous to @p{lines_per_cell}.
+ * Number of quadrilaterals of a
+ * cell.
*/
- static const unsigned int quads_per_cell = (2*GeometryInfo<dim_-1>::quads_per_cell
- + GeometryInfo<dim_-1>::lines_per_cell);
+ static const unsigned int quads_per_cell = 0;
/**
- * Number of hexahedra of a cell.
- *
- * Computation is analogous to
- * @p{lines_per_cell}. Very
- * important for more than three
- * dimensions!
+ * Number of hexahedra of a
+ * cell.
*/
- static const unsigned int hexes_per_cell = (2*GeometryInfo<dim_-1>::hexes_per_cell
- + GeometryInfo<dim_-1>::quads_per_cell);
+ static const unsigned int hexes_per_cell = 0;
/**
* List of numbers which is
/**
- * Pseudo-class for recursive functions in
- * @ref{GeometryInfo<1>}. Actually this class is a starting point for
- * the induction ladder by which the higher @p{GeometryInfo} classes
- * are built.
+ * 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, Guido Kanschat, 1998, 1999
+ * @author Wolfgang Bangerth, 1998
*/
template <>
-struct GeometryInfo<0>
+struct GeometryInfo<0>
{
- static const unsigned int vertices_per_cell = 1;
- static const unsigned int lines_per_cell = 0;
- static const unsigned int quads_per_cell = 0;
- static const unsigned int hexes_per_cell = 0;
- static const unsigned int children_per_cell = 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;
-//TODO:[WB] Document new classes, and reference in old one.
-template <>
-struct GeometryInfo<1>
-{
- static const unsigned int dim = 1;
- static const unsigned int children_per_cell = 2;
- static const unsigned int faces_per_cell = 2;
+ /**
+ * Number of children each face has
+ * when the adjacent cell is refined.
+ */
static const unsigned int subfaces_per_face = 0;
- static const unsigned int vertices_per_cell = 2;
- static const unsigned int vertices_per_face = 1;
+
+ /**
+ * 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;
- static const unsigned int lines_per_cell = 1;
+
+ /**
+ * 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;
- static const unsigned int opposite_face[faces_per_cell];
- static unsigned int child_cell_on_face (const unsigned int face,
- const unsigned int subface);
};
+/**
+ * Topological description of two dimensional cells.
+ *
+ * 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<2>
{
+ /**
+ * Present dimension. Does not
+ * look useful, but might be.
+ */
static const unsigned int dim = 2;
+
+ /**
+ * Number of children a cell has.
+ */
static const unsigned int children_per_cell = 4;
+
+ /**
+ * Number of faces a cell has.
+ */
static const unsigned int faces_per_cell = 4;
+
+ /**
+ * Number of children each face has
+ * when the adjacent cell is refined.
+ */
static const unsigned int subfaces_per_face = 2;
+
+ /**
+ * Number of vertices a cell has.
+ */
static const unsigned int vertices_per_cell = 4;
+
+ /**
+ * 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 = 2;
+
+ /**
+ * Number of lines each face has.
+ */
static const unsigned int lines_per_face = 1;
+
+ /**
+ * 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 = 4;
+
+ /**
+ * Number of quadrilaterals of a
+ * cell.
+ */
static const unsigned int quads_per_cell = 1;
+
+ /**
+ * Number of hexahedra of a
+ * cell.
+ */
static const unsigned int hexes_per_cell = 0;
+
+ /**
+ * List of numbers which is
+ * denote 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}}.
+ */
static const unsigned int opposite_face[faces_per_cell];
+
+ /**
+ * This field store which child cells
+ * are adjacent to a certain face of
+ * the mother cell.
+ *
+ * For example, in 2D the layout of
+ * a cell is as follows:
+ * @begin{verbatim}
+ * . 2
+ * . 3-->--2
+ * . | |
+ * . 3 ^ ^ 1
+ * . | |
+ * . 0-->--1
+ * . 0
+ * @end{verbatim}
+ * Vertices and faces are indicated
+ * with their numbers, faces also with
+ * their directions.
+ *
+ * Now, when refined, the layout is
+ * like this:
+ * @begin{verbatim}
+ * *--*--*
+ * | 3|2 |
+ * *--*--*
+ * | 0|1 |
+ * *--*--*
+ * @end{verbatim}
+ *
+ * Thus, the child cells on face zero
+ * are (ordered in the direction of the
+ * face) 0 and 1, on face 2 they are
+ * 3 and 2, etc.
+ *
+ * For three spatial dimensions,
+ * the exact order of the children is
+ * laid down in the documentation of
+ * the @ref{Triangulation} class.
+ */
static unsigned int child_cell_on_face (const unsigned int face,
const unsigned int subface);
};
+/**
+ * Topological description of three dimensional cells.
+ *
+ * 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<3>
{
+ /**
+ * Present dimension. Does not
+ * look useful, but might be.
+ */
static const unsigned int dim = 3;
+
+ /**
+ * Number of children a cell has.
+ */
static const unsigned int children_per_cell = 8;
+
+ /**
+ * Number of faces a cell has.
+ */
static const unsigned int faces_per_cell = 6;
+
+ /**
+ * Number of children each face has
+ * when the adjacent cell is refined.
+ */
static const unsigned int subfaces_per_face = 4;
+
+ /**
+ * Number of vertices a cell has.
+ */
static const unsigned int vertices_per_cell = 8;
+
+ /**
+ * 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 = 4;
+
+ /**
+ * Number of lines each face has.
+ */
static const unsigned int lines_per_face = 4;
+
+ /**
+ * Number of quads on each face.
+ */
static const unsigned int quads_per_face = 1;
+
+ /**
+ * Number of lines of a cell.
+ */
static const unsigned int lines_per_cell = 12;
+
+ /**
+ * Number of quadrilaterals of a
+ * cell.
+ */
static const unsigned int quads_per_cell = 6;
+
+ /**
+ * Number of hexahedra of a
+ * cell.
+ */
static const unsigned int hexes_per_cell = 1;
+
+ /**
+ * List of numbers which is
+ * denote 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}}.
+ */
static const unsigned int opposite_face[faces_per_cell];
+
+ /**
+ * This field store which child cells
+ * are adjacent to a certain face of
+ * the mother cell.
+ *
+ * For example, in 2D the layout of
+ * a cell is as follows:
+ * @begin{verbatim}
+ * . 2
+ * . 3-->--2
+ * . | |
+ * . 3 ^ ^ 1
+ * . | |
+ * . 0-->--1
+ * . 0
+ * @end{verbatim}
+ * Vertices and faces are indicated
+ * with their numbers, faces also with
+ * their directions.
+ *
+ * Now, when refined, the layout is
+ * like this:
+ * @begin{verbatim}
+ * *--*--*
+ * | 3|2 |
+ * *--*--*
+ * | 0|1 |
+ * *--*--*
+ * @end{verbatim}
+ *
+ * Thus, the child cells on face zero
+ * are (ordered in the direction of the
+ * face) 0 and 1, on face 2 they are
+ * 3 and 2, etc.
+ *
+ * For three spatial dimensions,
+ * the exact order of the children is
+ * laid down in the documentation of
+ * the @ref{Triangulation} class.
+ */
static unsigned int child_cell_on_face (const unsigned int face,
const unsigned int subface);
};
+/**
+ * Topological description of four dimensional cells. This class is
+ * required in some exotic cases where we compute information in a
+ * one-larger dimension than the present, and do so also in 3d (for
+ * example, stacking the solutions of a d-dimensional time dependent
+ * equation timestep after timestep in a (d+1)-dimensional space).
+ *
+ * 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<4>
+{
+ /**
+ * Present dimension. Does not
+ * look useful, but might be.
+ */
+ static const unsigned int dim = 4;
+
+ /**
+ * Number of children a cell has.
+ */
+ static const unsigned int children_per_cell = 16;
+
+ /**
+ * Number of faces a cell has.
+ */
+ static const unsigned int faces_per_cell = 8;
+
+ /**
+ * Number of children each face has
+ * when the adjacent cell is refined.
+ */
+ static const unsigned int subfaces_per_face = 8;
+
+ /**
+ * Number of vertices a cell has.
+ */
+ static const unsigned int vertices_per_cell = 16;
+
+ /**
+ * 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 = 8;
+
+ /**
+ * Number of lines each face has.
+ */
+ static const unsigned int lines_per_face = 12;
+
+ /**
+ * Number of quads on each face.
+ */
+ static const unsigned int quads_per_face = 6;
+
+ /**
+ * Number of lines of a cell.
+ */
+ static const unsigned int lines_per_cell = 32;
+
+ /**
+ * Number of quadrilaterals of a
+ * cell.
+ */
+ static const unsigned int quads_per_cell = 24;
+
+ /**
+ * Number of hexahedra of a
+ * cell.
+ */
+ static const unsigned int hexes_per_cell = 8;
+};
+
+
+
#endif
projects / dealii.git / commitdiff