#include <grid/geometry_info.h>
+template <int dim> class Triangulation;
-/**
- * Workaround for a bug in egcs snapshot 1998/08/03.
- */
-template <int dim>
-struct BoundaryHelper;
-
-/**
- * Workaround for a bug in egcs snapshot 1998/08/03.
- */
-template <>
-struct BoundaryHelper<1> {
- /**
- * Declare a data type for the derived
- * classes.
- *
- * actually, this does not make much
- * sense, but declaring a zero-sized
- * array is forbidden nowadays.
- */
- typedef const Point<1> *PointArray[1];
-};
-
-/**
- * Workaround for a bug in egcs snapshot 1998/08/03.
- */
-template <>
-struct BoundaryHelper<2> {
- /**
- * Declare a data type for the derived
- * classes.
- */
- typedef const Point<2> *PointArray[GeometryInfo<2>::vertices_per_face];
-};
-
-/**
- * Workaround for a bug in egcs snapshot 1998/08/03.
- */
-template <>
-struct BoundaryHelper<3> {
- /**
- * Declare a data type for the derived
- * classes.
- */
- typedef const Point<3> *PointArray[GeometryInfo<3>::vertices_per_face];
-};
/**
* following code (here in two dimensions):
* \begin{verbatim}
* ...
- * const Point<2> *neighbors[2] = {&neighbor1, &neighbor2};
- * Point<2> new_vertex = boundary.in_between (neighbors);
+ * Point<2> new_vertex = boundary.get_new_point_on_line (line);
* ...
* \end{verbatim}
- * #neighbor1# and #neighbor2# are the two vertices bounding the old
- * line on the boundary, which is to be subdivided. #boundary# is an
- * object of type #Boundary<dim>#.
+ * #line# denotes the line at the boundary that shall be refined
+ * and for which we seek the common point of the two child lines.
*
* In 3D, a new vertex may be placed on the middle of a line or on
- * the middle of a side. In the both cases, an array with four points
- * has to be passed to #in_between#; in the latter case the two end
- * points of the line have to be given consecutively twice, as
- * elements 0 and 1, and 2 and 3, respectively.
+ * the middle of a side. Respectively, the library calls
+ * \begin{verbatim}
+ * ...
+ * Point<3> new_line_vertices[4]
+ * = { boundary.get_new_point_on_line (face->line(0)),
+ * boundary.get_new_point_on_line (face->line(1)),
+ * boundary.get_new_point_on_line (face->line(2)),
+ * boundary.get_new_point_on_line (face->line(3)) };
+ * ...
+ * \end{verbatim}
+ * to get the four midpoints of the lines bounding the quad at the
+ * boundary, and after that
+ * \begin{verbatim}
+ * ...
+ * Point<3> new_quad_vertex = boundary.get_new_point_on_quad (face);
+ * ...
+ * \end{verbatim}
+ * to get the midpoint of the face. It is guaranteed that this order
+ * (first lines, then faces) holds, so you can use information from
+ * the children of the four lines of a face, since these already exist
+ * at the time the midpoint of the face is to be computed.
*
+ * Since iterators are passed to the functions, you may use information
+ * about boundary indicators and the like, as well as all other information
+ * provided by these objects.
+ *
* There are specialisations, #StraightBoundary<dim>#, which places
* the new point right into the middle of the given points, and
* #HyperBallBoundary<dim># creating a hyperball with given radius
* around a given center point.
*
- * @author Wolfgang Bangerth, 1998
+ * @author Wolfgang Bangerth, 1999
*/
template <int dim>
class Boundary : public Subscriptor {
public:
- /**
- * Typedef an array of the needed number
- * of old points to compute the new
- * middle point of a face. This does not
- * make much sense in 1D, so we set the
- * array size to a dummy value.
- */
- typedef typename BoundaryHelper<dim>::PointArray PointArray;
-// this is the way it should be, but egcs throws an internal compiler error
-// on this, so we invented the above workaround
-// typedef const Point<dim>* PointArray[((dim==1) ?
-// 1 :
-// GeometryInfo<dim>::vertices_per_face)];
-
/**
* Destructor. Does nothing here, but
* needs to be declared to make it
* virtual.
*/
virtual ~Boundary ();
-
+
+ /**
+ * Return the point which shall become
+ * the new middle vertex of the two
+ * children of a regular line. In 2D,
+ * this line is a line at the boundary,
+ * while in 3d, it is bounding a face
+ * at the boundary (the lines therefore
+ * is also on the boundary).
+ */
+ virtual Point<dim>
+ get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const = 0;
+
+ /**
+ * Return the point which shall become
+ * the common point of the four children
+ * of a quad at the boundary in three
+ * or more spatial dimensions. This
+ * function therefore is only useful in
+ * at least three dimensions and should
+ * not be called for lower dimensions.
+ *
+ * This function is called after the
+ * four lines bounding the given #quad#
+ * are refined, so you may want to use
+ * the information provided by
+ * #quad->line(i)->child(j)#, #i=0...3#,
+ * #j=0,1#.
+ *
+ * Because in 2D, this function is not
+ * needed, it is not made pure virtual,
+ * to avoid the need to overload it.
+ * The default implementation throws
+ * an error in any case, however.
+ */
+ virtual Point<dim>
+ get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;
+
/**
- * This function calculates the position
- * of the new vertex.
+ * Exception.
*/
- virtual Point<dim> in_between (const PointArray &neighbors) const = 0;
+ DeclException0 (ExcPureVirtualFunctionCalled);
};
class StraightBoundary : public Boundary<dim> {
public:
/**
- * This function calculates the position
- * of the new vertex.
+ * Refer to the general documentation of
+ * this class and the documentation of the
+ * base class.
*/
- virtual Point<dim> in_between (const PointArray &neighbors) const;
+ virtual Point<dim>
+ get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const;
+
+ /**
+ * Refer to the general documentation of
+ * this class and the documentation of the
+ * base class.
+ */
+ virtual Point<dim>
+ get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;
};
center(p), radius(radius) {};
/**
- * This function calculates the position
- * of the new vertex.
+ * Refer to the general documentation of
+ * this class and the documentation of the
+ * base class.
+ */
+ virtual Point<dim>
+ get_new_point_on_line (const typename Triangulation<dim>::line_iterator &line) const;
+
+ /**
+ * Refer to the general documentation of
+ * this class and the documentation of the
+ * base class.
*/
- virtual Point<dim> in_between (const PointArray &neighbors) const;
+ virtual Point<dim>
+ get_new_point_on_quad (const typename Triangulation<dim>::quad_iterator &quad) const;
private:
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