ext/OGDF/ogdf/planarity/EmbedderMinDepthMaxFace.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 minimum depth and
  11  * maximum external face.
  12  *
  13  * \author Thorsten Kerkhof
  14  *
  15  * \par License:
  16  * This file is part of the Open Graph Drawing Framework (OGDF).
  17  *
  18  * \par
  19  * Copyright (C)<br>
  20  * See README.txt in the root directory of the OGDF installation for details.
  21  *
  22  * \par
  23  * This program is free software; you can redistribute it and/or
  24  * modify it under the terms of the GNU General Public License
  25  * Version 2 or 3 as published by the Free Software Foundation;
  26  * see the file LICENSE.txt included in the packaging of this file
  27  * for details.
  28  *
  29  * \par
  30  * This program is distributed in the hope that it will be useful,
  31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33  * GNU General Public License for more details.
  34  *
  35  * \par
  36  * You should have received a copy of the GNU General Public
  37  * License along with this program; if not, write to the Free
  38  * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  39  * Boston, MA 02110-1301, USA.
  40  *
  41  * \see  http://www.gnu.org/copyleft/gpl.html
  42  ***************************************************************/
  43
  44 #ifdef _MSC_VER
  45 #pragma once
  46 #endif
  47
  48 #ifndef OGDF_EMBEDDER_MIN_DEPTH_MAX_FACE_H
  49 #define OGDF_EMBEDDER_MIN_DEPTH_MAX_FACE_H
  50
  51 #include <ogdf/module/EmbedderModule.h>
  52 #include <ogdf/decomposition/BCTree.h>
  53 #include <ogdf/internal/planarity/MDMFLengthAttribute.h>
  54
  55 namespace ogdf {
  56
  57 //! Planar graph embedding with minimum block-nesting depth and maximum external face.
  58 /**
  59  * See the paper "Graph Embedding with Minimum Depth and Maximum External Face"
  60  * by C. Gutwenger and P. Mutzel (2004) for details.
  61  */
  62 class OGDF_EXPORT EmbedderMinDepthMaxFace : public EmbedderModule
  63 {
  64 public:
  65         //constructor:
  66         EmbedderMinDepthMaxFace() { }
  67
  68         /**
  69          * \brief Call embedder algorithm.
  70          * \param G is the original graph. Its adjacency list has to be  changed by the embedder.
  71          * \param adjExternal is 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 Bottom-up-traversal of bcTree computing the values \a m_{cT, bT}
  78          * for all edges \a (cT, bT) in the BC-tree. The length of each vertex
  79          * \f$v \neq c in \a bT\f$ is set to 1 if \f$v \in M_{bT}\f$ and to 0 otherwise.
  80          *
  81          * \param bT is a block vertex in the BC-tree.
  82          * \param cH is a vertex in the original graph \a G.
  83          * \return Minimum depth of an embedding of \a bT with \a cH on the external
  84          *    face.
  85          */
  86         int md_bottomUpTraversal(const node& bT, const node& cH);
  87
  88         /**
  89          * \brief Top-down-traversal of BC-tree. The minimum depth of the BC-tree-node
  90          * bT is calculated and before calling the function recursively for all
  91          * children of bT in the BC-tree, the nodeLength of the cut-vertex which bT
  92          * and the child have in common is computed. The length of each node is set to
  93          * 1 if it is in M_B and 0 otherwise, except for |M_B| = 1, than it is set to
  94          * 1 if it is in M2 with m2 = \f$\max_{v \in V_B, v != c} m_B(v)\f$ and
  95          * M2 = \f${c \in V_B \ {v} | m_B(c) = m2}\f$.
  96          *
  97          * \param bT is a block vertex in the BC-tree.
  98          */
  99         void md_topDownTraversal(const node& bT);
 100
 101         /**
 102          * \brief Bottom up traversal of BC-tree.
 103          *
 104          * \param bT is the BC-tree node treated in this function call.
 105          * \param cH is the block node which is related to the cut vertex which is
 106          *   parent of bT in BC-tree.
 107          */
 108         int mf_constraintMaxFace(const node& bT, const node& cH);
 109
 110         /**
 111          * \brief Top down traversal of BC-tree.
 112          *
 113          * \param bT is the tree node treated in this function call.
 114          * \param bT_opt is assigned a block node in BC-tree which contains a face which
 115          *   cann be expanded to a maximum face.
 116          * \param ell_opt is the size of a maximum face.
 117          */
 118         void mf_maximumFaceRec(const node& bT, node& bT_opt, int& ell_opt);
 119
 120         /**
 121          * \brief Computes the adjacency list for all nodes in a block and calls
 122          * recursively the function for all blocks incident to nodes in bT.
 123          *
 124          * \param bT is the tree node treated in this function call.
 125          */
 126         void embedBlock(const node& bT);
 127
 128         /**
 129          * \brief Computes the adjacency list for all nodes in a block and calls
 130          * recursively the function for all blocks incident to nodes in bT.
 131          *
 132          * \param bT is the tree node treated in this function call.
 133          * \param cT is the parent cut vertex node of bT in the BC-tree. cT is 0 if bT
 134          *   is the root block.
 135          * \param after is the adjacency entry of the cut vertex, after which bT has to
 136          *   be inserted.
 137          */
 138         void embedBlock(const node& bT, const node& cT, ListIterator<adjEntry>& after);
 139
 140 private:
 141         /** the BC-tree of G */
 142         BCTree* pBCTree;
 143
 144         /** an adjacency entry on the external face */
 145         adjEntry* pAdjExternal;
 146
 147         /** saving for each node in the block graph its length */
 148         NodeArray<int> md_nodeLength;
 149
 150         /** an array containing the minimum depth of each block */
 151         NodeArray<int> md_minDepth;
 152
 153         /** an array saving the length for each edge in the BC-tree */
 154         EdgeArray<int> md_m_cB;
 155
 156         /** M_B = \f${cH \in B | m_B(cH) = m_B}\f$ with m_B = \f$\max_{c \in B} m_B(c)\f$
 157          *  and m_B(c) = \f$\max {0} \cup {m_{c, B'} | c \in B', B' \neq B}\f$. */
 158         NodeArray< List<node> > md_M_B;
 159
 160         /** M2 is empty, if |M_B| != 1, otherwise M_B = {cH}
 161          *  M2 = \f${cH' \in V_B \ {v} | m_B(cH') = m2}\f$ with
 162          *  m2 = \f$\max_{vH \in V_B, vH != cH} m_B(vH)\f$. */
 163         NodeArray< List<node> > md_M2;
 164
 165         /** is saving for each node of the block graph its length */
 166         NodeArray<int> mf_nodeLength;
 167
 168         /** is saving for each node of the block graph its cstrLength */
 169         NodeArray<int> mf_cstrLength;
 170
 171         /** an array containing the maximum face size of each block */
 172         NodeArray<int> mf_maxFaceSize;
 173
 174         /** is saving for each node of the block graph its length */
 175         NodeArray<MDMFLengthAttribute> mdmf_nodeLength;
 176
 177         /** is saving for each edge of the block graph its length */
 178         EdgeArray<MDMFLengthAttribute> mdmf_edgeLength;
 179
 180         /** saves for every node of G the new adjacency list */
 181         NodeArray< List<adjEntry> > newOrder;
 182
 183         /** treeNodeTreated saves for all block nodes in the
 184          *  BC-tree if it has already been treated or not. */
 185         NodeArray<bool> treeNodeTreated;
 186 };
 187
 188 } // end namespace ogdf
 189
 190 #endif