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 #include <string.h>
  33
  34 using namespace boost;
  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<simple_point<double> > PositionVec;
  41 typedef iterator_property_map<PositionVec::iterator, property_map<Graph, vertex_index_t>::type> PositionMap;
  42 #endif // HAVE_BOOST_GRAPH_LIB
  43
  44 bool isConnector(SPItem *i) {
  45         SPPath *path = NULL;
  46         if(SP_IS_PATH(i)) {
  47                 path = SP_PATH(i);
  48         }
  49         return path && path->connEndPair.isAutoRoutingConn();
  50 }
  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         int n=selected.size();
  68
  69         //Check 2 or more selected objects
  70         if (n < 2) 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         for (std::list<SPItem *>::iterator it(selected.begin());
  78                 it != selected.end();
  79                 ++it)
  80         {
  81                 SPItem *u=*it;
  82                 if(!isConnector(u)) {
  83                         std::cout<<"Creating node for id: "<<u->id<<std::endl;
  84                         nodelookup[u->id]=add_vertex(g);
  85                 }
  86         }
  87
  88         WeightMap weightmap=get(edge_weight, g);
  89         int i=0;
  90         for (std::list<SPItem *>::iterator it(selected.begin());
  91                 it != selected.end();
  92                 ++it)
  93         {
  94                 using NR::X; using NR::Y;
  95                 SPItem *itu=*it;
  96                 Vertex u=nodelookup[itu->id];
  97                 GSList *nlist=itu->avoidRef->getAttachedConnectors(Avoid::ConnRef::runningFrom);
  98                 std::list<SPItem *> neighbours;
  99                 neighbours.insert<GSListConstIterator<SPItem *> >(neighbours.end(),nlist,NULL);
 100                 for (std::list<SPItem *>::iterator ne(neighbours.begin());
 101                                 ne != neighbours.end();
 102                                 ++ne) {
 103
 104                         SPItem *itv=*ne;
 105                         Vertex v=nodelookup[itv->id];
 106                         Graph::edge_descriptor e; bool inserted;
 107                         tie(e, inserted)=add_edge(u,v,g);
 108                         weightmap[e]=1.0;
 109                 }
 110                 if(nlist) {
 111                         g_slist_free(nlist);
 112                 }
 113                 NR::Rect const item_box(sp_item_bbox_desktop(*it));
 114
 115                 NR::Point ll(item_box.min());
 116                 minX=std::min(ll[0],minX);
 117                 minY=std::min(ll[1],minY);
 118                 NR::Point ur(item_box.max());
 119                 maxX=std::max(ur[0],maxX);
 120                 maxY=std::max(ur[1],maxY);
 121         }
 122         double width=maxX-minX;
 123         double height=maxY-minY;
 124         std::cout<<"Graph has |V|="<<num_vertices(g)<<" Width="<<width<<" Height="<<height<<std::endl;
 125         PositionVec position_vec(num_vertices(g));
 126         PositionMap position(position_vec.begin(), get(vertex_index, g));
 127         write_graphviz(std::cout, g);
 128         circle_graph_layout(g, position, width/2.0);
 129         kamada_kawai_spring_layout(g, position, weightmap, side_length(width));
 130
 131         graph_traits<Graph>::vertex_iterator vi, vi_end;
 132         i=0;
 133         for (std::list<SPItem *>::iterator it(selected.begin());
 134                 it != selected.end();
 135                 ++it)
 136         {
 137                 SPItem *u=*it;
 138                 if(!isConnector(u)) {
 139                         NR::Rect const item_box(sp_item_bbox_desktop(u));
 140                         NR::Point const curr(item_box.midpoint());
 141                         NR::Point const dest(minX+width/2.0+position[nodelookup[u->id]].x,
 142                                         minY+height/2.0+position[nodelookup[u->id]].y);
 143                         sp_item_move_rel(u, NR::translate(dest - curr));
 144                 }
 145         }
 146 #else
 147         std::cout<<"Connector network layout not available!  Install boost graph library and recompile to enable."<<std::endl;
 148 #endif // HAVE_BOOST_GRAPH_LIB
 149 }