Add functions project_to_surface to the Boundary description.

git-svn-id: https://svn.dealii.org/trunk@19139 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/deal.II/include/grid/tria_boundary.h b/deal.II/deal.II/include/grid/tria_boundary.h
index 7fedc661a902ba8a2a873f09dc0bd8770850279f..d0b5f65eca419568eb839d0fe063bc17f5161668 100644 (file)
--- a/deal.II/deal.II/include/grid/tria_boundary.h
+++ b/deal.II/deal.II/include/grid/tria_boundary.h
@@ -2,7 +2,7 @@
 //    $Id$
 //    Version: $Name$
 //
-//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by the deal.II authors
+//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by the deal.II authors
 //
 //    This file is subject to QPL and may not be  distributed
 //    without copyright and license information. Please refer
@@ -73,7 +73,7 @@ template <int dim, int space_dim> class Triangulation;
  *   around a given center point.
  *
  * @ingroup boundary
- *   @author Wolfgang Bangerth, 1999, 2001, Ralf Hartmann, 2001, 2008
+ * @author Wolfgang Bangerth, 1999, 2001, 2009, Ralf Hartmann, 2001, 2008
  */
 template <int dim, int spacedim=dim>
 class Boundary : public Subscriptor
@@ -280,6 +280,46 @@ class Boundary : public Subscriptor
     virtual void
     get_normals_at_vertices (const typename Triangulation<dim,spacedim>::face_iterator &face,
                             FaceVertexNormals &face_vertex_normals) const;
+
+                                    /**
+                                     * Given a candidate point and a
+                                     * line segment characterized by
+                                     * the iterator, return a point
+                                     * that lies on the surface
+                                     * described by this object. This
+                                     * function is used in some mesh
+                                     * smoothing algorithms that try
+                                     * to move around points in order
+                                     * to improve the mesh quality
+                                     * but need to ensure that points
+                                     * that were on the boundary
+                                     * remain on the boundary.
+                                     *
+                                     * Derived classes do not need to
+                                     * implement this function unless
+                                     * mesh smoothing algorithms are
+                                     * used with a particular
+                                     * boundary object. The default
+                                     * implementation of this
+                                     * function throws an exception
+                                     * of type ExcPureFunctionCalled.
+                                     */
+    virtual
+    Point<spacedim>
+    project_to_surface (const typename Triangulation<dim,spacedim>::line_iterator &line,
+                       const Point<spacedim> &candidate) const;
+
+                                    /**
+                                     * Same function as above but for
+                                     * a point that is to be
+                                     * projected onto the area
+                                     * characterized by the given
+                                     * quad.
+                                     */
+    virtual
+    Point<spacedim>
+    project_to_surface (const typename Triangulation<dim,spacedim>::quad_iterator &quad,
+                       const Point<spacedim> &candidate) const;
 };
 
 
@@ -387,6 +427,50 @@ class StraightBoundary : public Boundary<dim,spacedim>
     virtual void
     get_normals_at_vertices (const typename Triangulation<dim,spacedim>::face_iterator &face,
                             typename Boundary<dim,spacedim>::FaceVertexNormals &face_vertex_normals) const;
+
+                                    /**
+                                     * Given a candidate point and a
+                                     * line segment characterized by
+                                     * the iterator, return a point
+                                     * that lies on the surface
+                                     * described by this object. This
+                                     * function is used in some mesh
+                                     * smoothing algorithms that try
+                                     * to move around points in order
+                                     * to improve the mesh quality
+                                     * but need to ensure that points
+                                     * that were on the boundary
+                                     * remain on the boundary.
+                                     *
+                                     * The point returned is the
+                                     * projection of the candidate
+                                     * point onto the line through
+                                     * the two vertices of the given
+                                     * line iterator.
+                                     */
+    virtual
+    Point<spacedim>
+    project_to_surface (const typename Triangulation<dim,spacedim>::line_iterator &line,
+                       const Point<spacedim> &candidate) const;
+
+                                    /**
+                                     * Same function as above but for
+                                     * a point that is to be
+                                     * projected onto the area
+                                     * characterized by the given
+                                     * quad.
+                                     *
+                                     * The point returned is the
+                                     * projection of the candidate
+                                     * point onto the bilinear
+                                     * surface spanned by the four
+                                     * vertices of the given quad
+                                     * iterator.
+                                     */
+    virtual
+    Point<spacedim>
+    project_to_surface (const typename Triangulation<dim,spacedim>::quad_iterator &quad,
+                       const Point<spacedim> &candidate) const;
 };
 
 

diff --git a/deal.II/deal.II/source/grid/tria_boundary.cc b/deal.II/deal.II/source/grid/tria_boundary.cc
index 0254258eff85832f5e1ee9789252626e0d8cca6a..c89556a76ed0a40eef87ac73adaa843f14cc4e80 100644 (file)
--- a/deal.II/deal.II/source/grid/tria_boundary.cc
+++ b/deal.II/deal.II/source/grid/tria_boundary.cc
@@ -2,7 +2,7 @@
 //    $Id$
 //    Version: $Name$
 //
-//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008 by the deal.II authors
+//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009 by the deal.II authors
 //
 //    This file is subject to QPL and may not be  distributed
 //    without copyright and license information. Please refer
@@ -163,6 +163,30 @@ get_normals_at_vertices (const typename Triangulation<dim, spacedim>::face_itera
 
 
 
+template <int dim, int spacedim>
+Point<spacedim>
+Boundary<dim, spacedim>::
+project_to_surface (const typename Triangulation<dim, spacedim>::line_iterator &,
+                   const Point<spacedim>                                &) const
+{
+  Assert (false, ExcPureFunctionCalled());
+  return Point<spacedim>();
+}
+
+
+
+template <int dim, int spacedim>
+Point<spacedim>
+Boundary<dim, spacedim>::
+project_to_surface (const typename Triangulation<dim, spacedim>::quad_iterator &,
+                   const Point<spacedim>                                &) const
+{
+  Assert (false, ExcPureFunctionCalled());
+  return Point<spacedim>();
+}
+
+
+
 /* -------------------------- StraightBoundary --------------------- */
 
 
@@ -461,6 +485,30 @@ get_normals_at_vertices (const Triangulation<3>::face_iterator &face,
 #endif
 
 
+template <int dim, int spacedim>
+Point<spacedim>
+StraightBoundary<dim, spacedim>::
+project_to_surface (const typename Triangulation<dim, spacedim>::line_iterator &,
+                   const Point<spacedim>                                &) const
+{
+  Assert (false, ExcPureFunctionCalled());
+  return Point<spacedim>();
+}
+
+
+
+template <int dim, int spacedim>
+Point<spacedim>
+StraightBoundary<dim, spacedim>::
+project_to_surface (const typename Triangulation<dim, spacedim>::quad_iterator &,
+                   const Point<spacedim>                                &) const
+{
+  Assert (false, ExcPureFunctionCalled());
+  return Point<spacedim>();
+}
+
+
+
 // explicit instantiations
 template class Boundary<deal_II_dimension>;
 template class StraightBoundary<deal_II_dimension>;