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 <boost/graph/kamada_kawai_spring_layout.hpp>
  24 #include <boost/graph/circle_layout.hpp>
  25 #include <boost/graph/adjacency_list.hpp>
  26 //#include <boost/graph/simple_point.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 struct simple_point {
  36         double x;
  37         double y;
  38 };
  39 // create a typedef for the Graph type
  40 typedef adjacency_list<vecS, vecS, undirectedS, no_property,
  41         property<edge_weight_t, double> > Graph;
  42 typedef property_map<Graph, edge_weight_t>::type WeightMap;
  43 typedef graph_traits<Graph>::vertex_descriptor Vertex;
  44 typedef std::vector<simple_point> PositionVec;
  45 typedef iterator_property_map<PositionVec::iterator, property_map<Graph, vertex_index_t>::type> PositionMap;
  46
  47 bool isConnector(SPItem *i) {
  48         SPPath *path = NULL;
  49         if(SP_IS_PATH(i)) {
  50                 path = SP_PATH(i);
  51         }
  52         return path && path->connEndPair.isAutoRoutingConn();
  53 }
  54 #endif // HAVE_BOOST_GRAPH_LIB
  55 /**
  56 * Takes a list of inkscape items, extracts the graph defined by
  57 * connectors between them, and uses graph layout techniques to find
  58 * a nice layout
  59 */
  60 void graphlayout(GSList const *const items) {
  61         if(!items) {
  62                 return;
  63         }
  64 #ifdef HAVE_BOOST_GRAPH_LIB
  65
  66
  67         using Inkscape::Util::GSListConstIterator;
  68         std::list<SPItem *> selected;
  69         selected.insert<GSListConstIterator<SPItem *> >(selected.end(), items, NULL);
  70         if (selected.empty()) return;
  71
  72         Graph g;
  73
  74         double minX=DBL_MAX, minY=DBL_MAX, maxX=-DBL_MAX, maxY=-DBL_MAX;
  75
  76         std::map<std::string,Vertex> nodelookup;
  77         std::vector<std::string> labels;
  78         for (std::list<SPItem *>::iterator it(selected.begin());
  79                 it != selected.end();
  80                 ++it)
  81         {
  82                 SPItem *u=*it;
  83                 if(!isConnector(u)) {
  84                         std::cout<<"Creating node for id: "<<u->id<<std::endl;
  85                         nodelookup[u->id]=add_vertex(g);
  86                         labels.push_back(u->id);
  87                 }
  88         }
  89
  90         int n=labels.size();
  91         //Check 2 or more selected objects
  92         if (n < 2) return;
  93
  94         WeightMap weightmap=get(edge_weight, g);
  95         int i=0;
  96         for (std::list<SPItem *>::iterator it(selected.begin());
  97                 it != selected.end();
  98                 ++it)
  99         {
 100                 using NR::X; using NR::Y;
 101                 SPItem *itu=*it;
 102                 Vertex u=nodelookup[itu->id];
 103                 GSList *nlist=itu->avoidRef->getAttachedConnectors(Avoid::ConnRef::runningFrom);
 104                 std::list<SPItem *> neighbours;
 105                 neighbours.insert<GSListConstIterator<SPItem *> >(neighbours.end(),nlist,NULL);
 106                 for (std::list<SPItem *>::iterator ne(neighbours.begin());
 107                                 ne != neighbours.end();
 108                                 ++ne) {
 109
 110                         SPItem *itv=*ne;
 111                         Vertex v=nodelookup[itv->id];
 112                         Graph::edge_descriptor e; bool inserted;
 113                         tie(e, inserted)=add_edge(u,v,g);
 114                         weightmap[e]=1.0;
 115                 }
 116                 if(nlist) {
 117                         g_slist_free(nlist);
 118                 }
 119                 NR::Rect const item_box(sp_item_bbox_desktop(*it));
 120
 121                 NR::Point ll(item_box.min());
 122                 minX=std::min(ll[0],minX);
 123                 minY=std::min(ll[1],minY);
 124                 NR::Point ur(item_box.max());
 125                 maxX=std::max(ur[0],maxX);
 126                 maxY=std::max(ur[1],maxY);
 127         }
 128         double width=maxX-minX;
 129         double height=maxY-minY;
 130         std::cout<<"Graph has |V|="<<num_vertices(g)<<" Width="<<width<<" Height="<<height<<std::endl;
 131         PositionVec position_vec(num_vertices(g));
 132         PositionMap position(position_vec.begin(), get(vertex_index, g));
 133         //write_graphviz(std::cout, g, make_label_writer<std::vector<std::string>>(labels));
 134         circle_graph_layout(g, position, width/2.0);
 135         kamada_kawai_spring_layout(g, position, weightmap, side_length(width));
 136
 137         graph_traits<Graph>::vertex_iterator vi, vi_end;
 138         i=0;
 139         for (std::list<SPItem *>::iterator it(selected.begin());
 140                 it != selected.end();
 141                 ++it)
 142         {
 143                 SPItem *u=*it;
 144                 if(!isConnector(u)) {
 145                         NR::Rect const item_box(sp_item_bbox_desktop(u));
 146                         NR::Point const curr(item_box.midpoint());
 147                         NR::Point const dest(minX+width/2.0+position[nodelookup[u->id]].x,
 148                                         minY+height/2.0+position[nodelookup[u->id]].y);
 149                         sp_item_move_rel(u, NR::translate(dest - curr));
 150                 }
 151         }
 152 #else
 153         std::cout<<"Connector network layout not available!  Install boost graph library and recompile to enable."<<std::endl;
 154 #endif // HAVE_BOOST_GRAPH_LIB
 155 }