00001 /* @HEADER@ */ 00002 // ************************************************************************ 00003 // 00004 // Sundance 00005 // Copyright (2005) Sandia Corporation 00006 // 00007 // Copyright (year first published) Sandia Corporation. Under the terms 00008 // of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government 00009 // retains certain rights in this software. 00010 // 00011 // This library is free software; you can redistribute it and/or modify 00012 // it under the terms of the GNU Lesser General Public License as 00013 // published by the Free Software Foundation; either version 2.1 of the 00014 // License, or (at your option) any later version. 00015 // 00016 // This library is distributed in the hope that it will be useful, but 00017 // WITHOUT ANY WARRANTY; without even the implied warranty of 00018 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00019 // Lesser General Public License for more details. 00020 // 00021 // You should have received a copy of the GNU Lesser General Public 00022 // License along with this library; if not, write to the Free Software 00023 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 00024 // USA 00025 // Questions? Contact Kevin Long (krlong@sandia.gov), 00026 // Sandia National Laboratories, Livermore, California, USA 00027 // 00028 // ************************************************************************ 00029 /* @HEADER@ */ 00030 00031 #ifndef SUNDANCE_CELLITERATOR_H 00032 #define SUNDANCE_CELLITERATOR_H 00033 00034 00035 #include "SundanceDefs.hpp" 00036 #include "SundanceSet.hpp" 00037 #include "SundanceMap.hpp" 00038 #include "SundanceCellType.hpp" 00039 #include "SundanceCellReordererImplemBase.hpp" 00040 #include "Teuchos_RefCountPtr.hpp" 00041 #include "SundanceMesh.hpp" 00042 00043 namespace Sundance 00044 { 00045 using namespace Teuchos; 00046 00047 /** 00048 * CellIterator is an iterator for walking through cell sets. 00049 * It satisfies the requirements for an input iterator in STL. 00050 * 00051 * This class design violates the usual rules of good OO style: 00052 * it has polymorphic behavior packed into a single class. The 00053 * justification for this decision is to avoid the expense 00054 * of the clone() operations that would be required by the 00055 * copy ctor for iterators were 00056 * a polymorphic class heirarchy used. 00057 * 00058 * Two cell set types exist: explicit, where the member cells LIDs 00059 * are enumerated in a physical Set<int> object, and implicit, 00060 * where no physical Set is made, rather, the sequence of cell LIDs 00061 * is obtained through some scheme of walking the mesh. 00062 * 00063 * The only cell sets that can represented implicitly are 00064 * the set of all cells of a given dimension. 00065 * 00066 * \see CellSet, CellFilter, CellIteratorPos 00067 */ 00068 class CellIterator : public std::iterator<std::input_iterator_tag, int> 00069 { 00070 public: 00071 00072 00073 /** 00074 * CellIteratorPos is used to specify whether a new CellIterator 00075 * is positioned at the beginning or end of a set. 00076 */ 00077 enum CellIteratorPos {Begin, End}; 00078 00079 /** Empty ctor */ 00080 CellIterator(); 00081 00082 /** Copy ctor */ 00083 CellIterator(const CellIterator& other); 00084 00085 /** Construct an implicit iterator for walking all cells of a given 00086 * dimension on the given mesh. */ 00087 CellIterator(const Mesh& mesh, int cellDim, CellIteratorPos pos); 00088 00089 /** Construct an explicit iterator for walking an explicitly 00090 * enumerated set of cells. */ 00091 CellIterator(const Set<int>* cells, CellIteratorPos pos); 00092 00093 /** */ 00094 CellIterator& operator=(const CellIterator& other); 00095 00096 /** Dereferencing operator */ 00097 const int& operator*() const 00098 { 00099 if (isImplicit_) return currentLID_; 00100 else return *iter_; 00101 } 00102 00103 /** Postfix increment: advances iterator and returns previous value */ 00104 CellIterator operator++(int) 00105 { 00106 CellIterator old = *this; 00107 advance(); 00108 return old; 00109 } 00110 00111 00112 /** Prefix increment: advances iterator, returning new value */ 00113 CellIterator& operator++() 00114 { 00115 advance(); 00116 return *this; 00117 } 00118 00119 /** */ 00120 bool operator==(const CellIterator& other) const 00121 { 00122 if (isImplicit_) 00123 { 00124 return currentLID_ == other.currentLID_; 00125 } 00126 else 00127 { 00128 return iter_ == other.iter_; 00129 } 00130 } 00131 00132 /** */ 00133 bool operator!=(const CellIterator& other) const 00134 { 00135 return !(*this == other); 00136 } 00137 00138 00139 private: 00140 00141 /** Advance the iterator */ 00142 void advance() 00143 { 00144 if (isImplicit_) 00145 { 00146 if (reorderer_ != 0) 00147 { 00148 currentLID_ = reorderer_->advance(currentLID_); 00149 } 00150 else currentLID_++; 00151 } 00152 else iter_++; 00153 } 00154 00155 /** Flag indicating whether this iterator is implicit */ 00156 bool isImplicit_; 00157 00158 /** The LID to which this iterator is currently pointing. 00159 * Used only for implicit iterators. */ 00160 int currentLID_; 00161 00162 /** Unmanaged pointer to the reorderer used for walking 00163 * implicit cell sets. Used only for implicit iterators. */ 00164 const CellReordererImplemBase* reorderer_; 00165 00166 /** iterator for enumerated cells. 00167 * Used only for explicit iterators. */ 00168 Set<int>::const_iterator iter_; 00169 00170 /** */ 00171 static Set<int> dummy() {static Set<int> rtn; return rtn;} 00172 }; 00173 } 00174 00175 00176 #endif