// $Id: point_locator_list.h 2501 2007-11-20 02:33:29Z benkirk $// The libMesh Finite Element Library.// Copyright (C) 2002-2007  Benjamin S. Kirk, John W. Peterson  // This library is free software; you can redistribute it and/or// modify it under the terms of the GNU Lesser General Public// License as published by the Free Software Foundation; either// version 2.1 of the License, or (at your option) any later version.  // This library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU// Lesser General Public License for more details.  // You should have received a copy of the GNU Lesser General Public// License along with this library; if not, write to the Free Software// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA#ifndef __point_locator_list_h__#define __point_locator_list_h__// C++ includes#include <utility> // pair#include <vector>// Local Includes#include "point_locator_base.h"// Forward Declarationsclass MeshBase;class Point;class Elem;/** * This is a point locator.  It locates points in space * using a list of element centroids: given a mesh this  * locator returns the element that is @e closest to the  * given point in global coordinates. * Note that this may yield @e severe difficulties in * case of extremely distorted elements, e.g.\ infinite * elements. * * This list version is not efficient, but especially * @e reliable for the case of finding the @e closest  * dim-1 element (nearest-surface-element, e.g. used * for projecting boundary conditions from a surface * mesh onto a volumetric mesh). * It should be noted that this class only works when * the element list in the associated mesh object is * @e not modified (like refinement etc).  Otherwise, * the point locator has to be cleared and re-initialized. * Use \p PointLocatorBase::build() to create objects  * of this type at run time. * * @author Daniel Dreyer, 2003 */// ------------------------------------------------------------// PointLocatorList class definitionclass PointLocatorList : public PointLocatorBase{public:  /**   * Constructor.  Needs the \p mesh which holds the    * elements that should be identified as being close.   * Optionally takes a master interpolator.  This master    * helps in saving memory by simply only setting up @e    * one list for all point locators.  Only the master    * locator holds a list, the others simply  use the    * master's list.   */  PointLocatorList (const MeshBase& mesh,		    const PointLocatorBase* master = NULL);public:  /**   * Destructor.   */  ~PointLocatorList ();  /**   * Clears the locator.  Overloaded from base class.  This method   * frees dynamic memory using "delete".   */  virtual void clear();  /**   * Initializes the locator, so that the \p operator() methods can   * be used.  Overloaded from base class.  This method allocates dynamic   * memory using "new".   */  virtual void init();  /**   * Locates the element in which the point with global coordinates   * \p p is located.  Overloaded from base class.   */  virtual const Elem* operator() (const Point& p) const;  /**   * Enables out-of-mesh mode.  In this mode, if asked to find a point   * that is contained in no mesh at all, the point locator will   * return a NULL pointer instead of crashing.  Per default, this   * mode is off.   */  virtual void enable_out_of_mesh_mode (void);  /**   * Disables out-of-mesh mode (default).  If asked to find a point   * that is contained in no mesh at all, the point locator will now   * crash.   */  virtual void disable_out_of_mesh_mode (void);protected:  /**   * Pointer to the list of element centroids.  Only the   * master @e has such a list.  For servants, this   * pointer points to the list of the master.   Note that   * it's not a std::list as the name might suggest, but a std::vector.   */  std::vector<std::pair<Point, const Elem *> >* _list;};// ------------------------------------------------------------// PointLocatorList inline methods#endif