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 "util/glib-list-iterators.h"
  13 #include "graphlayout/graphlayout.h"
  14 #include <iostream>
  15 #include <config.h>
  16
  17 #ifdef HAVE_BOOST_GRAPH_LIB
  18 #include "sp-path.h"
  19 #include "sp-item.h"
  20 #include "sp-item-transform.h"
  21 #include "sp-conn-end-pair.h"
  22 #include "conn-avoid-ref.h"
  23 #include "libavoid/connector.h"
  24 #include "libavoid/geomtypes.h"
  25 #include <boost/graph/kamada_kawai_spring_layout.hpp>
  26 #include <boost/graph/circle_layout.hpp>
  27 #include <boost/graph/adjacency_list.hpp>
  28 #include <boost/graph/graphviz.hpp>
  29 #include <map>
  30 #include <vector>
  31 #include <algorithm>
  32 #include <float.h>
  33
  34 using namespace boost;
  35
  36 // create a typedef for the Graph type
  37 typedef adjacency_list<vecS, vecS, undirectedS, no_property,
  38         property<edge_weight_t, double> > Graph;
  39 typedef property_map<Graph, edge_weight_t>::type WeightMap;
  40 typedef graph_traits<Graph>::vertex_descriptor Vertex;
  41 typedef std::vector<Avoid::Point> PositionVec;
  42 typedef iterator_property_map<PositionVec::iterator, property_map<Graph, vertex_index_t>::type> PositionMap;
  43
  44 /**
  45  * Returns true if item is a connector
  46  */
  47 bool isConnector(SPItem const *const 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
  55 /**
  56  * Scans the items list and places those items that are
  57  * not connectors in filtered
  58  */
  59 void filterConnectors(GSList const *const items, std::list<SPItem *> &filtered) {
  60         for(GSList *i=(GSList *)items; i!=NULL; i=i->next) {
  61                 SPItem *item=SP_ITEM(i->data);
  62                 if(!isConnector(item)) {
  63                         filtered.push_back(item);
  64                 }
  65         }
  66 }
  67 /**
  68 * Takes a list of inkscape items, extracts the graph defined by
  69 * connectors between them, and uses graph layout techniques to find
  70 * a nice layout
  71 */
  72 void graphlayout(GSList const *const items) {
  73         if(!items) {
  74                 return;
  75         }
  76
  77         using Inkscape::Util::GSListConstIterator;
  78         std::list<SPItem *> selected;
  79         filterConnectors(items,selected);
  80         if (selected.empty()) return;
  81
  82         int n=selected.size();
  83         std::cout<<"|V|="<<n<<std::endl;
  84
  85         Graph g;
  86
  87         double minX=DBL_MAX, minY=DBL_MAX, maxX=-DBL_MAX, maxY=-DBL_MAX;
  88
  89         std::map<std::string,Vertex> nodelookup;
  90         for (std::list<SPItem *>::iterator i(selected.begin());
  91                 i != selected.end();
  92                 ++i)
  93         {
  94                 SPItem *u=*i;
  95                 std::cout<<"Creating node for id: "<<u->id<<std::endl;
  96                 nodelookup[u->id]=add_vertex(g);
  97         }
  98
  99         //Check 2 or more selected objects
 100         if (n < 2) return;
 101
 102         WeightMap weightmap=get(edge_weight, g);
 103         for (std::list<SPItem *>::iterator i(selected.begin());
 104                 i != selected.end();
 105                 ++i)
 106         {
 107                 using NR::X; using NR::Y;
 108                 SPItem *iu=*i;
 109                 std::cout<<"Getting neighbours for id: "<<iu->id<<std::endl;
 110                 Vertex u=nodelookup[iu->id];
 111                 GSList *nlist=iu->avoidRef->getAttachedShapes(Avoid::ConnRef::runningFrom);
 112                 std::list<SPItem *> neighbours;
 113                 neighbours.insert<GSListConstIterator<SPItem *> >(neighbours.end(),nlist,NULL);
 114                 for (std::list<SPItem *>::iterator j(neighbours.begin());
 115                                 j != neighbours.end();
 116                                 ++j) {
 117
 118                         SPItem *iv=*j;
 119                         Vertex v=nodelookup[iv->id];
 120                         Graph::edge_descriptor e; bool inserted;
 121                         tie(e, inserted)=add_edge(u,v,g);
 122                         weightmap[e]=1.0;
 123                 }
 124                 if(nlist) {
 125                         g_slist_free(nlist);
 126                 }
 127                 NR::Rect const item_box(sp_item_bbox_desktop(*i));
 128
 129                 NR::Point ll(item_box.min());
 130                 minX=std::min(ll[0],minX);
 131                 minY=std::min(ll[1],minY);
 132                 NR::Point ur(item_box.max());
 133                 maxX=std::max(ur[0],maxX);
 134                 maxY=std::max(ur[1],maxY);
 135         }
 136         double width=maxX-minX;
 137         double height=maxY-minY;
 138         std::cout<<"Graph has |V|="<<num_vertices(g)<<" Width="<<width<<" Height="<<height<<std::endl;
 139         PositionVec position_vec(num_vertices(g));
 140         PositionMap position(position_vec.begin(), get(vertex_index, g));
 141         write_graphviz(std::cout, g);
 142         circle_graph_layout(g, position, width/2.0);
 143         kamada_kawai_spring_layout(g, position, weightmap, side_length(width));
 144
 145         graph_traits<Graph>::vertex_iterator vi, vi_end;
 146         for (std::list<SPItem *>::iterator it(selected.begin());
 147                 it != selected.end();
 148                 ++it)
 149         {
 150                 SPItem *u=*it;
 151                 if(!isConnector(u)) {
 152                         NR::Rect const item_box(sp_item_bbox_desktop(u));
 153                         NR::Point const curr(item_box.midpoint());
 154                         NR::Point const dest(minX+width/2.0+position[nodelookup[u->id]].x,
 155                                         minY+height/2.0+position[nodelookup[u->id]].y);
 156                         sp_item_move_rel(u, NR::translate(dest - curr));
 157                 }
 158         }
 159 }
 160 #else
 161 void graphlayout(GSList const *const items) {
 162         std::cout<<"Connector network layout not available!  Install boost graph library and recompile to enable."<<std::endl;
 163 }
 164 #endif // HAVE_BOOST_GRAPH_LIB