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