ext/OGDF/src/labeling/ELabelPosSimple.cpp

   1 /*
   2  * $Revision: 2552 $
   3  *
   4  * last checkin:
   5  *   $Author: gutwenger $
   6  *   $Date: 2012-07-05 16:45:20 +0200 (Do, 05. Jul 2012) $
   7  ***************************************************************/
   8
   9 /** \file
  10  * \brief Implements simple labeling algorithm
  11  *
  12  * \author Joachim Kupke
  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
  44 #include <ogdf/labeling/ELabelPosSimple.h>
  45
  46 namespace ogdf {
  47
  48
  49         ELabelPosSimple::ELabelPosSimple() :
  50 m_absolut(true),
  51         m_marginDistance(0.2),
  52         m_edgeDistance(0.2),
  53         m_midOnEdge(true)
  54 { }
  55
  56
  57 ELabelPosSimple::~ELabelPosSimple()
  58 { }
  59
  60
  61 // returns the segment of the polyline containing the point
  62 // that is fraction*bends.length() away from the start
  63 static DLine segment(DPolyline &bends, double fraction)
  64 {
  65         double targetpos = bends.length()*fraction;
  66         double pos = 0.0;
  67
  68         ListConstIterator<DPoint> iter, next;
  69         for (iter = next = bends.begin(), next++; next.valid(); iter++, next++) {
  70                 pos += (*iter).distance(*next);
  71                 if (pos >= targetpos)
  72                         return DLine(*iter, *next);
  73         }
  74
  75         return DLine(*--iter, bends.back());
  76 }
  77
  78
  79 // liefert den Punkt neben dem Segment (links oder rechts, siehe 'left'), der orthogonal von
  80 // 'p' die Entfernung 'newLen' von diesem Segment hat.
  81 static DPoint leftOfSegment(const DLine &segment, const DPoint &p, double newLen, bool left = true)
  82 {
  83         DVector v;
  84         if (p == segment.start())
  85                 v = segment.end() - p;
  86         else
  87                 v = p - segment.start();
  88
  89         DVector newPos;
  90         if (left) newPos = ++v;
  91         else      newPos = --v;
  92
  93         // newPos hat immer L?nge != 0
  94         newPos = (newPos * newLen) / newPos.length();
  95
  96         return p + newPos;
  97 }
  98
  99
 100 void ELabelPosSimple::call(GraphAttributes &ug, ELabelInterface<double> &eli)
 101 {
 102         //ug.addNodeCenter2Bends();
 103         edge e;
 104         forall_edges(e, ug.constGraph()) {
 105                 EdgeLabel<double> &el = eli.getLabel(e);
 106                 DPolyline       bends = ug.bends(e);
 107
 108                 bends.normalize();
 109
 110                 if (bends.size() < 2)
 111                         OGDF_THROW_PARAM(AlgorithmFailureException, afcLabel);
 112
 113                 double frac;
 114
 115                 if (m_absolut) {
 116                         double len = bends.length();
 117                         if (len == 0.0)
 118                                 frac = 0.0;
 119                         else
 120                                 frac = m_marginDistance / len;
 121
 122                 }
 123                 else {
 124                         frac = m_marginDistance;
 125                 }
 126
 127                 if (frac < 0.0) frac = 0.0;
 128                 if (frac > 0.4) frac = 0.4;
 129
 130                 double midFrac   = 0.5;
 131                 double startFrac = frac;
 132                 double endFrac   = 1.0 -frac;
 133
 134                 // hole Positionen auf der Kante
 135                 DPoint midPoint   = bends.position(midFrac);
 136                 DPoint startPoint = bends.position(startFrac);
 137                 DPoint endPoint   = bends.position(endFrac);
 138
 139                 // hole die beteiligten Segmente
 140                 DLine midLine   = segment(bends, midFrac);
 141                 DLine startLine = segment(bends, startFrac);
 142                 DLine endLine   = segment(bends, endFrac);
 143
 144                 // berechne die Labelpositionen
 145                 if (el.usedLabel(elEnd1)) {
 146                         DPoint np = leftOfSegment(startLine, startPoint, m_edgeDistance, true);
 147                         el.setX(elEnd1, np.m_x);
 148                         el.setY(elEnd1, np.m_y);
 149                 }
 150
 151                 if (el.usedLabel(elMult1)) {
 152                         DPoint np = leftOfSegment(startLine, startPoint, m_edgeDistance, false);
 153                         el.setX(elMult1, np.m_x);
 154                         el.setY(elMult1, np.m_y);
 155                 }
 156
 157                 if (el.usedLabel(elName)) {
 158                         DPoint np = m_midOnEdge ? midPoint : leftOfSegment(midLine, midPoint, m_edgeDistance, true);
 159                         el.setX(elName, np.m_x);
 160                         el.setY(elName, np.m_y);
 161                 }
 162
 163                 if (el.usedLabel(elEnd2)) {
 164                         DPoint np = leftOfSegment(endLine, endPoint, m_edgeDistance, true);
 165                         el.setX(elEnd2, np.m_x);
 166                         el.setY(elEnd2, np.m_y);
 167                 }
 168
 169                 if (el.usedLabel(elMult2)) {
 170                         DPoint np = leftOfSegment(endLine, endPoint, m_edgeDistance, false);
 171                         el.setX(elMult2, np.m_x);
 172                         el.setY(elMult2, np.m_y);
 173                 }
 174         }
 175 }
 176
 177 }