src/graphlayout/graphlayout.cpp

   1 /** \file
   2  * Interface between Inkscape code (SPItem) and graphlayout functions.
   3  */
   4 /*
   5 * Authors:
   6 *   Tim Dwyer <tgdwyer@gmail.com>
   7 *
   8 * Copyright (C) 2005 Authors
   9 *
  10 * Released under GNU GPL.  Read the file 'COPYING' for more information.
  11 */
  12 #include "graphlayout/graphlayout.h"
  13 #include <iostream>
  14 #include <config.h>
  15
  16 #ifdef HAVE_BOOST_GRAPH_LIB
  17 #include "sp-path.h"
  18 #include "sp-item.h"
  19 #include "sp-item-transform.h"
  20 #include "sp-conn-end-pair.h"
  21 #include "conn-avoid-ref.h"
  22 #include "libavoid/connector.h"
  23 #include "libavoid/geomtypes.h"
  24 #include <boost/graph/kamada_kawai_spring_layout.hpp>
  25 #include <boost/graph/circle_layout.hpp>
  26 #include <boost/graph/adjacency_list.hpp>
  27 #include <boost/graph/graphviz.hpp>
  28 #include <map>
  29 #include <vector>
  30 #include <algorithm>
  31 #include <float.h>
  32
  33 using namespace boost;
  34
  35 // create a typedef for the Graph type
  36 typedef adjacency_list<vecS, vecS, undirectedS, no_property,
  37         property<edge_weight_t, double> > Graph;
  38 typedef property_map<Graph, edge_weight_t>::type WeightMap;
  39 typedef graph_traits<Graph>::vertex_descriptor Vertex;
  40 typedef std::vector<Avoid::Point> PositionVec;
  41 typedef iterator_property_map<PositionVec::iterator, property_map<Graph, vertex_index_t>::type> PositionMap;
  42
  43 bool isConnector(SPItem *i) {
  44         SPPath *path = NULL;
  45         if(SP_IS_PATH(i)) {
  46                 path = SP_PATH(i);
  47         }
  48         return path && path->connEndPair.isAutoRoutingConn();
  49 }
  50 #endif // HAVE_BOOST_GRAPH_LIB
  51 /**
  52 * Takes a list of inkscape items, extracts the graph defined by
  53 * connectors between them, and uses graph layout techniques to find
  54 * a nice layout
  55 */
  56 void graphlayout(GSList const *const items) {
  57         if(!items) {
  58                 return;
  59         }
  60 #ifdef HAVE_BOOST_GRAPH_LIB
  61
  62
  63         using Inkscape::Util::GSListConstIterator;
  64         std::list<SPItem *> selected;
  65         selected.insert<GSListConstIterator<SPItem *> >(selected.end(), items, NULL);
  66         if (selected.empty()) return;
  67
  68         Graph g;
  69
  70         double minX=DBL_MAX, minY=DBL_MAX, maxX=-DBL_MAX, maxY=-DBL_MAX;
  71
  72         std::map<std::string,Vertex> nodelookup;
  73         std::vector<std::string> labels;
  74         for (std::list<SPItem *>::iterator it(selected.begin());
  75                 it != selected.end();
  76                 ++it)
  77         {
  78                 SPItem *u=*it;
  79                 if(!isConnector(u)) {
  80                         std::cout<<"Creating node for id: "<<u->id<<std::endl;
  81                         nodelookup[u->id]=add_vertex(g);
  82                         labels.push_back(u->id);
  83                 }
  84         }
  85
  86         int n=labels.size();
  87         //Check 2 or more selected objects
  88         if (n < 2) return;
  89
  90         WeightMap weightmap=get(edge_weight, g);
  91         int i=0;
  92         for (std::list<SPItem *>::iterator it(selected.begin());
  93                 it != selected.end();
  94                 ++it)
  95         {
  96                 using NR::X; using NR::Y;
  97                 SPItem *itu=*it;
  98                 Vertex u=nodelookup[itu->id];
  99                 GSList *nlist=itu->avoidRef->getAttachedShapes(Avoid::ConnRef::runningFrom);
 100                 std::list<SPItem *> neighbours;
 101                 neighbours.insert<GSListConstIterator<SPItem *> >(neighbours.end(),nlist,NULL);
 102                 for (std::list<SPItem *>::iterator ne(neighbours.begin());
 103                                 ne != neighbours.end();
 104                                 ++ne) {
 105
 106                         SPItem *itv=*ne;
 107                         Vertex v=nodelookup[itv->id];
 108                         Graph::edge_descriptor e; bool inserted;
 109                         tie(e, inserted)=add_edge(u,v,g);
 110                         weightmap[e]=1.0;
 111                 }
 112                 if(nlist) {
 113                         g_slist_free(nlist);
 114                 }
 115                 NR::Rect const item_box(sp_item_bbox_desktop(*it));
 116
 117                 NR::Point ll(item_box.min());
 118                 minX=std::min(ll[0],minX);
 119                 minY=std::min(ll[1],minY);
 120                 NR::Point ur(item_box.max());
 121                 maxX=std::max(ur[0],maxX);
 122                 maxY=std::max(ur[1],maxY);
 123         }
 124         double width=maxX-minX;
 125         double height=maxY-minY;
 126         std::cout<<"Graph has |V|="<<num_vertices(g)<<" Width="<<width<<" Height="<<height<<std::endl;
 127         PositionVec position_vec(num_vertices(g));
 128         PositionMap position(position_vec.begin(), get(vertex_index, g));
 129         //write_graphviz(std::cout, g, make_label_writer<std::vector<std::string>>(labels));
 130         circle_graph_layout(g, position, width/2.0);
 131         kamada_kawai_spring_layout(g, position, weightmap, side_length(width));
 132
 133         graph_traits<Graph>::vertex_iterator vi, vi_end;
 134         i=0;
 135         for (std::list<SPItem *>::iterator it(selected.begin());
 136                 it != selected.end();
 137                 ++it)
 138         {
 139                 SPItem *u=*it;
 140                 if(!isConnector(u)) {
 141                         NR::Rect const item_box(sp_item_bbox_desktop(u));
 142                         NR::Point const curr(item_box.midpoint());
 143                         NR::Point const dest(minX+width/2.0+position[nodelookup[u->id]].x,
 144                                         minY+height/2.0+position[nodelookup[u->id]].y);
 145                         sp_item_move_rel(u, NR::translate(dest - curr));
 146                 }
 147         }
 148 #else
 149         std::cout<<"Connector network layout not available!  Install boost graph library and recompile to enable."<<std::endl;
 150 #endif // HAVE_BOOST_GRAPH_LIB
 151 }