ext/OGDF/ogdf/planarity/EmbedderMaxFace.h

   1 /*
   2  * $Revision: 2589 $
   3  *
   4  * last checkin:
   5  *   $Author: gutwenger $
   6  *   $Date: 2012-07-12 23:31:45 +0200 (Do, 12. Jul 2012) $
   7  ***************************************************************/
   8
   9 /** \file
  10  * \brief Computes an embedding of a graph with maximum external face.
  11  *
  12  * \author Thorsten Kerkhof
  13  *
  14  * \par License:
  15  * This file is part of the Open Graph Drawing Framework (OGDF).
  16  *
  17  * \par
  18  * Copyright (C)<br>
  19  * See README.txt in the root directory of the OGDF installation for details.
  20  *
  21  * \par
  22  * This program is free software; you can redistribute it and/or
  23  * modify it under the terms of the GNU General Public License
  24  * Version 2 or 3 as published by the Free Software Foundation;
  25  * see the file LICENSE.txt included in the packaging of this file
  26  * for details.
  27  *
  28  * \par
  29  * This program is distributed in the hope that it will be useful,
  30  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  31  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  32  * GNU General Public License for more details.
  33  *
  34  * \par
  35  * You should have received a copy of the GNU General Public
  36  * License along with this program; if not, write to the Free
  37  * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  38  * Boston, MA 02110-1301, USA.
  39  *
  40  * \see  http://www.gnu.org/copyleft/gpl.html
  41  ***************************************************************/
  42
  43 #ifdef _MSC_VER
  44 #pragma once
  45 #endif
  46
  47 #ifndef OGDF_EMBEDDER_MAX_FACE_H
  48 #define OGDF_EMBEDDER_MAX_FACE_H
  49
  50 #include <ogdf/module/EmbedderModule.h>
  51 #include <ogdf/decomposition/BCTree.h>
  52 #include <ogdf/decomposition/StaticSPQRTree.h>
  53
  54 namespace ogdf {
  55
  56 //! Planar graph embedding with maximum external face.
  57 /**
  58  * See the paper "Graph Embedding with Minimum Depth and Maximum External
  59  * Face" by C. Gutwenger and P. Mutzel (2004) for details.
  60  */
  61 class OGDF_EXPORT EmbedderMaxFace : public EmbedderModule
  62 {
  63 public:
  64         //constructor and destructor
  65         EmbedderMaxFace() { }
  66         ~EmbedderMaxFace() { }
  67
  68         /**
  69          * \brief Computes an embedding of \a G with maximum external face.
  70          * \param G is the original graph. Its adjacency list has to be  changed by the embedder.
  71          * \param adjExternal is assigned an adjacency entry on the external face and has to be set by the embedder.
  72          */
  73         void call(Graph& G, adjEntry& adjExternal);
  74
  75 private:
  76         /**
  77          * \brief Computes recursively the block graph for every block.
  78          *
  79          * \param bT is a block node in the BC-tree.
  80          * \param cH is a node of bT in the block graph.
  81          */
  82         void computeBlockGraphs(const node& bT, const node& cH);
  83
  84         /**
  85          * \brief Bottom up traversal of BC-tree.
  86          *
  87          * \param bT is the BC-tree node treated in this function call.
  88          * \param cH is the block node which is related to the cut vertex which is
  89          *   parent of bT in BC-tree.
  90          */
  91         int constraintMaxFace(const node& bT, const node& cH);
  92
  93         /**
  94          * \brief Top down traversal of BC-tree.
  95          *
  96          * \param bT is the tree node treated in this function call.
  97          * \param bT_opt is assigned a block node in BC-tree which contains a face which
  98          *   cann be expanded to a maximum face.
  99          * \param ell_opt is the size of a maximum face.
 100          */
 101         void maximumFaceRec(const node& bT, node& bT_opt, int& ell_opt);
 102
 103         /**
 104          * \brief Computes the adjacency list for all nodes in a block and calls
 105          * recursively the function for all blocks incident to nodes in bT.
 106          *
 107          * \param bT is the tree node treated in this function call.
 108          */
 109         void embedBlock(const node& bT);
 110
 111         /**
 112          * \brief Computes the adjacency list for all nodes in a block and calls
 113          * recursively the function for all blocks incident to nodes in bT.
 114          *
 115          * \param bT is the tree node treated in this function call.
 116          * \param cT is the parent cut vertex node of bT in the BC-tree. cT is 0 if bT
 117          *   is the root block.
 118          * \param after is the adjacency entry of the cut vertex, after which bT has to
 119          *   be inserted.
 120          */
 121         void embedBlock(const node& bT, const node& cT, ListIterator<adjEntry>& after);
 122
 123 private:
 124         /** BC-tree of the original graph */
 125         BCTree* pBCTree;
 126
 127         /** an adjacency entry on the external face */
 128         adjEntry* pAdjExternal;
 129
 130         /** all blocks */
 131         NodeArray<Graph> blockG;
 132
 133         /** a mapping of nodes in the auxiliaryGraph of the BC-tree to blockG */
 134         NodeArray< NodeArray<node> > nH_to_nBlockEmbedding;
 135
 136         /** a mapping of edges in the auxiliaryGraph of the BC-tree to blockG */
 137         NodeArray< EdgeArray<edge> > eH_to_eBlockEmbedding;
 138
 139         /** a mapping of nodes in blockG to the auxiliaryGraph of the BC-tree */
 140         NodeArray< NodeArray<node> > nBlockEmbedding_to_nH;
 141
 142         /** a mapping of edges in blockG to the auxiliaryGraph of the BC-tree */
 143         NodeArray< EdgeArray<edge> > eBlockEmbedding_to_eH;
 144
 145         /** saving for each node in the block graphs its length */
 146         NodeArray< NodeArray<int> > nodeLength;
 147
 148         /** is saving for each node in the block graphs its cstrLength */
 149         NodeArray< NodeArray<int> > cstrLength;
 150
 151         /** saves for every node of PG the new adjacency list */
 152         NodeArray< List<adjEntry> > newOrder;
 153
 154         /** treeNodeTreated saves for all block nodes in the
 155          *  BC-tree if it has already been treated or not. */
 156         NodeArray<bool> treeNodeTreated;
 157
 158         /** The SPQR-trees of the blocks */
 159         NodeArray<StaticSPQRTree*> spqrTrees;
 160 };
 161
 162 } // end namespace ogdf
 163
 164 #endif