source: lemon-0.x/src/lemon/graph_to_eps.h @ 1085:5b7ca75297b5

/* -*- C++ -*-
 * src/lemon/graph_to_eps.h - Part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Combinatorial Optimization Research Group, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef LEMON_GRAPH_TO_EPS_H
#define LEMON_GRAPH_TO_EPS_H

#include<iostream>
#include<fstream>
#include<sstream>
#include<algorithm>
#include<vector>

#include<lemon/xy.h>
#include<lemon/maps.h>
#include<lemon/bezier.h>

///\ingroup misc
///\file
///\brief Simple graph drawer
///
///\author Alpar Juttner

namespace lemon {

///Data structure representing RGB colors.

///Data structure representing RGB colors.
///\ingroup misc
class Color
{
  double _r,_g,_b;
public:
  ///Default constructor
  Color() {}
  ///Constructor
  Color(double r,double g,double b) :_r(r),_g(g),_b(b) {};
  ///Returns the red component
  double getR() {return _r;}
  ///Returns the green component
  double getG() {return _g;}
  ///Returns the blue component
  double getB() {return _b;}
  ///Set the color components
  void set(double r,double g,double b) { _r=r;_g=g;_b=b; };
};
  
///Default traits class of \ref GraphToEps

///Default traits class of \ref GraphToEps
///
///\c G is the type of the underlying graph.
template<class G>
struct DefaultGraphToEpsTraits
{
  typedef G Graph;
  typedef typename Graph::Node Node;
  typedef typename Graph::NodeIt NodeIt;
  typedef typename Graph::Edge Edge;
  typedef typename Graph::EdgeIt EdgeIt;
  typedef typename Graph::InEdgeIt InEdgeIt;
  typedef typename Graph::OutEdgeIt OutEdgeIt;
  

  const Graph &g;

  std::ostream& os;
  
  ConstMap<typename Graph::Node,xy<double> > _coords;
  ConstMap<typename Graph::Node,double > _nodeSizes;

  ConstMap<typename Graph::Node,Color > _nodeColors;
  ConstMap<typename Graph::Edge,Color > _edgeColors;

  ConstMap<typename Graph::Edge,double > _edgeWidths;
  
  double _edgeWidthScale;
  
  double _nodeScale;
  double _xBorder, _yBorder;
  double _scale;
  double _nodeBorderQuotient;
  
  bool _drawArrows;
  double _arrowLength, _arrowWidth;
  
  bool _showNodes, _showEdges;

  bool _enableParallel;
  double _parEdgeDist;

  bool _showNodeText;
  ConstMap<typename Graph::Node,bool > _nodeTexts;  
  double _nodeTextSize;

  bool _showNodePsText;
  ConstMap<typename Graph::Node,bool > _nodePsTexts;  
  char *_nodePsTextsPreamble;
  
  bool _undir;
  bool _pleaseRemoveOsStream;
  ///Constructor

  ///Constructor
  ///\param _g is a reference to the graph to be printed
  ///\param _os is a reference to the output stream.
  ///\param _os is a reference to the output stream.
  ///\param _pros If it is \c true, then the \c ostream referenced by \c _os
  ///will be explicitly deallocated by the destructor.
  ///By default it is <tt>std::cout</tt>
  DefaultGraphToEpsTraits(const G &_g,std::ostream& _os=std::cout,
                          bool _pros=false) :
    g(_g), os(_os),
    _coords(xy<double>(1,1)), _nodeSizes(1.0),
    _nodeColors(Color(1,1,1)), _edgeColors(Color(0,0,0)),
    _edgeWidths(1), _edgeWidthScale(0.3),
    _nodeScale(1.0), _xBorder(10), _yBorder(10), _scale(1.0),
    _nodeBorderQuotient(.1),
    _drawArrows(false), _arrowLength(1), _arrowWidth(0.3),
    _showNodes(true), _showEdges(true),
    _enableParallel(false), _parEdgeDist(1),
    _showNodeText(false), _nodeTexts(false), _nodeTextSize(1),
    _showNodePsText(false), _nodePsTexts(false), _nodePsTextsPreamble(0),
    _undir(false),
    _pleaseRemoveOsStream(_pros) {}
};

///Helper class to implement the named parameters of \ref graphToEps()

///Helper class to implement the named parameters of \ref graphToEps()
///\todo Is 'helper class' a good name for this?
///
template<class T> class GraphToEps : public T 
{
  typedef typename T::Graph Graph;
  typedef typename Graph::Node Node;
  typedef typename Graph::NodeIt NodeIt;
  typedef typename Graph::Edge Edge;
  typedef typename Graph::EdgeIt EdgeIt;
  typedef typename Graph::InEdgeIt InEdgeIt;
  typedef typename Graph::OutEdgeIt OutEdgeIt;

  bool dontPrint;

  class edgeLess {
    const Graph &g;
  public:
    edgeLess(const Graph &_g) : g(_g) {}
    bool operator()(Edge a,Edge b) const 
    {
      Node ai=min(g.source(a),g.target(a));
      Node aa=max(g.source(a),g.target(a));
      Node bi=min(g.source(b),g.target(b));
      Node ba=max(g.source(b),g.target(b));
      return ai<bi ||
        (ai==bi && (aa < ba || 
                    (aa==ba && ai==g.source(a) && bi==g.target(b))));
    }
  };
  bool isParallel(Edge e,Edge f) const
  {
    return (g.source(e)==g.source(f)&&g.target(e)==g.target(f))||
      (g.source(e)==g.target(f)&&g.target(e)==g.source(f));
  }
  static xy<double> rot(xy<double> v) 
  {
    return xy<double>(v.y,-v.x);
  }
  template<class xy>
  static std::string psOut(const xy &p) 
    {
      std::ostringstream os;    
      os << p.x << ' ' << p.y;
      return os.str();
    }
  
public:
  GraphToEps(const T &t) : T(t), dontPrint(false) {};
  
  template<class X> struct CoordsTraits : public T {
    const X &_coords;
    CoordsTraits(const T &t,const X &x) : T(t), _coords(x) {}
  };
  ///Sets the map of the node coordinates

  ///Sets the map of the node coordinates.
  ///\param x must be a node map with xy<double> or xy<int> values. 
  template<class X> GraphToEps<CoordsTraits<X> > coords(const X &x) {
    dontPrint=true;
    return GraphToEps<CoordsTraits<X> >(CoordsTraits<X>(*this,x));
  }
  template<class X> struct NodeSizesTraits : public T {
    const X &_nodeSizes;
    NodeSizesTraits(const T &t,const X &x) : T(t), _nodeSizes(x) {}
  };
  ///Sets the map of the node sizes

  ///Sets the map of the node sizes
  ///\param x must be a node map with \c double (or convertible) values. 
  template<class X> GraphToEps<NodeSizesTraits<X> > nodeSizes(const X &x)
  {
    dontPrint=true;
    return GraphToEps<NodeSizesTraits<X> >(NodeSizesTraits<X>(*this,x));
  }
  template<class X> struct NodeTextsTraits : public T {
    const X &_nodeTexts;
    NodeTextsTraits(const T &t,const X &x) : T(t), _nodeTexts(x) {}
  };
  ///Sets the text printed on the nodes

  ///Sets the text printed on the nodes
  ///\param x must be a node map with type that can be pushed to a standard
  ///ostream. 
  template<class X> GraphToEps<NodeTextsTraits<X> > nodeTexts(const X &x)
  {
    dontPrint=true;
    _showNodeText=true;
    return GraphToEps<NodeTextsTraits<X> >(NodeTextsTraits<X>(*this,x));
  }
  template<class X> struct NodePsTextsTraits : public T {
    const X &_nodePsTexts;
    NodePsTextsTraits(const T &t,const X &x) : T(t), _nodePsTexts(x) {}
  };
  ///Inserts a PostScript block to the nodes

  ///With this command it is possible to insert a verbatim PostScript
  ///block to the nodes.
  ///The PS current point will be moved to the centre of the node before
  ///the PostScript block inserted.
  ///
  ///Before and after the block a newline character is inserted to you
  ///don't have to bother with the separators.
  ///
  ///\param x must be a node map with type that can be pushed to a standard
  ///ostream.
  ///
  ///\sa nodePsTextsPreamble()
  ///\todo Offer the choise not to move to the centre but pass the coordinates
  ///to the Postscript block inserted.
  template<class X> GraphToEps<NodePsTextsTraits<X> > nodePsTexts(const X &x)
  {
    dontPrint=true;
    _showNodePsText=true;
    return GraphToEps<NodePsTextsTraits<X> >(NodePsTextsTraits<X>(*this,x));
  }
  template<class X> struct EdgeWidthsTraits : public T {
    const X &_edgeWidths;
    EdgeWidthsTraits(const T &t,const X &x) : T(t), _edgeWidths(x) {}
  };
  ///Sets the map of the edge widths

  ///Sets the map of the edge widths
  ///\param x must be a edge map with \c double (or convertible) values. 
  template<class X> GraphToEps<EdgeWidthsTraits<X> > edgeWidths(const X &x)
  {
    dontPrint=true;
    return GraphToEps<EdgeWidthsTraits<X> >(EdgeWidthsTraits<X>(*this,x));
  }

  template<class X> struct NodeColorsTraits : public T {
    const X &_nodeColors;
    NodeColorsTraits(const T &t,const X &x) : T(t), _nodeColors(x) {}
  };
  ///Sets the map of the node colors

  ///Sets the map of the node colors
  ///\param x must be a node map with \ref Color values. 
  template<class X> GraphToEps<NodeColorsTraits<X> >
  nodeColors(const X &x)
  {
    dontPrint=true;
    return GraphToEps<NodeColorsTraits<X> >(NodeColorsTraits<X>(*this,x));
  }
  template<class X> struct EdgeColorsTraits : public T {
    const X &_edgeColors;
    EdgeColorsTraits(const T &t,const X &x) : T(t), _edgeColors(x) {}
  };
  ///Sets the map of the edge colors

  ///Sets the map of the edge colors
  ///\param x must be a edge map with \ref Color values. 
  template<class X> GraphToEps<EdgeColorsTraits<X> >
  edgeColors(const X &x)
  {
    dontPrint=true;
    return GraphToEps<EdgeColorsTraits<X> >(EdgeColorsTraits<X>(*this,x));
  }
  ///Sets a global scale factor for node sizes

  ///Sets a global scale factor for node sizes
  ///
  GraphToEps<T> &nodeScale(double d) {_nodeScale=d;return *this;}
  ///Sets a global scale factor for edge widths

  ///Sets a global scale factor for edge widths
  ///
  GraphToEps<T> &edgeWidthScale(double d) {_edgeWidthScale=d;return *this;}
  ///Sets a global scale factor for the whole picture

  ///Sets a global scale factor for the whole picture
  ///
  GraphToEps<T> &scale(double d) {_scale=d;return *this;}
  ///Sets the width of the border around the picture

  ///Sets the width of the border around the picture
  ///
  GraphToEps<T> &border(double b) {_xBorder=_yBorder=b;return *this;}
  ///Sets the width of the border around the picture

  ///Sets the width of the border around the picture
  ///
  GraphToEps<T> &border(double x, double y) {
    _xBorder=x;_yBorder=y;return *this;
  }
  ///Sets whether to draw arrows

  ///Sets whether to draw arrows
  ///
  GraphToEps<T> &drawArrows(bool b=true) {_drawArrows=b;return *this;}
  ///Sets the length of the arrowheads

  ///Sets the length of the arrowheads
  ///
  GraphToEps<T> &arrowLength(double d) {_arrowLength*=d;return *this;}
  ///Sets the width of the arrowheads

  ///Sets the width of the arrowheads
  ///
  GraphToEps<T> &arrowWidth(double d) {_arrowWidth*=d;return *this;}
  
  ///Enables parallel edges

  ///Enables parallel edges
  ///\todo Partially implemented
  GraphToEps<T> &enableParallel(bool b=true) {_enableParallel=b;return *this;}
  
  ///Sets the distance 
  
  ///Sets the distance 
  ///
  GraphToEps<T> &parEdgeDist(double d) {_parEdgeDist*=d;return *this;}
  
  ///Hides the edges
  
  ///Hides the edges
  ///
  GraphToEps<T> &hideEdges(bool b=true) {_showEdges=!b;return *this;}
  ///Hides the nodes
  
  ///Hides the nodes
  ///
  GraphToEps<T> &hideNodes(bool b=true) {_showNodes=!b;return *this;}
  
  ///Sets the size of the node texts
  
  ///Sets the size of the node texts
  ///
  GraphToEps<T> &nodeTextSize(double d) {_nodeTextSize=d;return *this;}
  ///Gives a preamble block for node Postscript block.
  
  ///Gives a preamble block for node Postscript block.
  ///
  ///\sa nodePsTexts()
  GraphToEps<T> & nodePsTextsPreamble(const char *str) {
    _nodePsTextsPreamble=s ;return *this;
  }
  ///Sets whether the the graph is undirected

  ///Sets whether the the graph is undirected
  ///
  GraphToEps<T> &undir(bool b=true) {_undir=b;return *this;}
  ///Sets whether the the graph is directed

  ///Sets whether the the graph is directed.
  ///Use it to show the undirected edges as a pair of directed ones.
  GraphToEps<T> &bidir(bool b=true) {_undir=!b;return *this;}
  
  ~GraphToEps() 
  {
    if(dontPrint) return;
    
    os << "%!PS-Adobe-2.0 EPSF-2.0\n";
    //\todo: Chech whether the graph is empty.
    BoundingBox<double> bb;
    for(NodeIt n(g);n!=INVALID;++n) {
      double ns=_nodeSizes[n]*_nodeScale;
      xy<double> p(ns,ns);
      bb+=p+_coords[n];
      bb+=-p+_coords[n];
      }
    os << "%%BoundingBox: "
         << bb.left()*  _scale-_xBorder << ' '
         << bb.bottom()*_scale-_yBorder << ' '
         << bb.right()* _scale+_xBorder << ' '
         << bb.top()*   _scale+_yBorder << '\n';
    //x1 y1 x2 y2 x3 y3 cr cg cb w
    os << "/lb { setlinewidth setrgbcolor newpath moveto\n"
       << "      4 2 roll 1 index 1 index curveto stroke } bind def\n";
    os << "/l { setlinewidth setrgbcolor newpath moveto lineto stroke } bind def\n";
    os << "/c { newpath dup 3 index add 2 index moveto 0 360 arc closepath } bind def\n";
    // x y r cr cg cb
    os << "/n { setrgbcolor 2 index 2 index 2 index c fill\n"
       << "     0 0 0 setrgbcolor dup "
       << _nodeBorderQuotient << " mul setlinewidth "
       << 1+_nodeBorderQuotient/2 << " div c stroke\n"
       << "   } bind def\n";
    os << "/arrl " << _arrowLength << " def\n";
    os << "/arrw " << _arrowWidth << " def\n";
    // l dx_norm dy_norm
    os << "/lrl { 2 index mul exch 2 index mul exch rlineto pop} bind def\n";
    //len w dx_norm dy_norm x1 y1 cr cg cb
    os << "/arr { setrgbcolor /y1 exch def /x1 exch def /dy exch def /dx exch def\n"
       << "       /w exch def /len exch def\n"
      //         << "       0.1 setlinewidth x1 y1 moveto dx len mul dy len mul rlineto stroke"
       << "       newpath x1 dy w 2 div mul add y1 dx w 2 div mul sub moveto\n"
       << "       len w sub arrl sub dx dy lrl\n"
       << "       arrw dy dx neg lrl\n"
       << "       dx arrl w add mul dy w 2 div arrw add mul sub\n"
       << "       dy arrl w add mul dx w 2 div arrw add mul add rlineto\n"
       << "       dx arrl w add mul neg dy w 2 div arrw add mul sub\n"
       << "       dy arrl w add mul neg dx w 2 div arrw add mul add rlineto\n"
       << "       arrw dy dx neg lrl\n"
       << "       len w sub arrl sub neg dx dy lrl\n"
       << "       closepath fill } bind def\n";
    os << "/cshow { 2 index 2 index moveto dup stringwidth pop\n"
       << "         neg 2 div fosi .35 mul neg rmoveto show pop pop} def\n";

    os << "\ngsave\n";
    if(_scale!=1.0) os << _scale << " dup scale\n";
    
    if(_showEdges) {
      os << "%Edges:\ngsave\n";      
      if(_enableParallel) {
        std::vector<Edge> el;
        for(EdgeIt e(g);e!=INVALID;++e)
          if(!_undir||g.source(e)<g.target(e)) el.push_back(e);
        sort(el.begin(),el.end(),edgeLess(g));
        
        typename std::vector<Edge>::iterator j;
        for(typename std::vector<Edge>::iterator i=el.begin();i!=el.end();i=j) {
          for(j=i+1;j!=el.end()&&isParallel(*i,*j);++j) ;

          double sw=0;
          for(typename std::vector<Edge>::iterator e=i;e!=j;++e)
            sw+=_edgeWidths[*e]*_edgeWidthScale+_parEdgeDist;
          sw-=_parEdgeDist;
          sw/=-2.0;
          xy<double> dvec(_coords[g.target(*i)]-_coords[g.source(*i)]);
          double l=sqrt(dvec.normSquare());
          xy<double> d(dvec/l);
          xy<double> m;
//        m=xy<double>(_coords[g.target(*i)]+_coords[g.source(*i)])/2.0;

//        m=xy<double>(_coords[g.source(*i)])+
//          dvec*(double(_nodeSizes[g.source(*i)])/
//             (_nodeSizes[g.source(*i)]+_nodeSizes[g.target(*i)]));

          m=xy<double>(_coords[g.source(*i)])+
            d*(l+_nodeSizes[g.source(*i)]-_nodeSizes[g.target(*i)])/2.0;

          for(typename std::vector<Edge>::iterator e=i;e!=j;++e) {
            sw+=_edgeWidths[*e]*_edgeWidthScale/2.0;
            xy<double> mm=m+rot(d)*sw/.75;
            if(_drawArrows) {
              const int INERPOL_PREC=20;
              xy<double> s=_coords[g.source(*e)];
              xy<double> t=_coords[g.target(*e)];
              double rn=_nodeSizes[g.target(*e)]*_nodeScale;
              rn*=rn;
              Bezier3 bez(s,mm,mm,t);
              double t1=0,t2=1;
              for(int i=0;i<INERPOL_PREC;++i)
                if((bez((t1+t2)/2)-t).normSquare()>rn) t1=(t1+t2)/2;
                else t2=(t1+t2)/2;
              xy<double> apoint=bez((t1+t2)/2);
              rn = _nodeSizes[g.target(*e)]*_nodeScale+_arrowLength+
                _edgeWidths[*e]*_edgeWidthScale;
              rn*=rn;
              t1=0;t2=1;
              for(int i=0;i<INERPOL_PREC;++i)
                if((bez((t1+t2)/2)-t).normSquare()>rn) t1=(t1+t2)/2;
                else t2=(t1+t2)/2;
              xy<double> linend=bez((t1+t2)/2);       
              bez=bez.before((t1+t2)/2);
              rn=_nodeSizes[g.source(*e)]*_nodeScale; rn*=rn;
              t1=0;t2=1;
              for(int i=0;i<INERPOL_PREC;++i)
                if((bez((t1+t2)/2)-s).normSquare()>rn) t2=(t1+t2)/2;
                else t1=(t1+t2)/2;
              bez=bez.after((t1+t2)/2);
              os << _edgeWidths[*e]*_edgeWidthScale << " setlinewidth "
                 << _edgeColors[*e].getR() << ' '
                 << _edgeColors[*e].getG() << ' '
                 << _edgeColors[*e].getB() << " setrgbcolor newpath\n"
                 << bez.p1.x << ' ' <<  bez.p1.y << " moveto\n"
                 << bez.p2.x << ' ' << bez.p2.y << ' '
                 << bez.p3.x << ' ' << bez.p3.y << ' '
                 << bez.p4.x << ' ' << bez.p4.y << " curveto stroke\n";
              xy<double> dd(rot(linend-apoint));
              dd*=(_edgeWidths[*e]*_edgeWidthScale+_arrowWidth)/
                sqrt(dd.normSquare());
              os << "newpath " << psOut(apoint) << " moveto "
                 << psOut(linend+dd) << " lineto "
                 << psOut(linend-dd) << " lineto closepath fill\n";
            }
            else {
              os << _coords[g.source(*e)].x << ' '
                 << _coords[g.source(*e)].y << ' '
                 << mm.x << ' ' << mm.y << ' '
                 << _coords[g.target(*e)].x << ' '
                 << _coords[g.target(*e)].y << ' '
                 << _edgeColors[*e].getR() << ' '
                 << _edgeColors[*e].getG() << ' '
                 << _edgeColors[*e].getB() << ' '
                 << _edgeWidths[*e]*_edgeWidthScale << " lb\n";
            }
            sw+=_edgeWidths[*e]*_edgeWidthScale/2.0+_parEdgeDist;
          }
        }
      }
      else for(EdgeIt e(g);e!=INVALID;++e)
        if(!_undir||g.source(e)<g.target(e))
          if(_drawArrows) {
            xy<double> d(_coords[g.target(e)]-_coords[g.source(e)]);
            double l=sqrt(d.normSquare());
            d/=l;
            xy<double> x1(d*_nodeScale*_nodeSizes[g.source(e)]+
                          _coords[g.source(e)]);
            os << l-(_nodeSizes[g.source(e)]+
                     _nodeSizes[g.target(e)])*_nodeScale << ' '
               << _edgeWidths[e]*_edgeWidthScale << ' '
               << d.x << ' ' << d.y << ' '
               << x1.x << ' ' << x1.y << ' '
               << _edgeColors[e].getR() << ' '
               << _edgeColors[e].getG() << ' '
               << _edgeColors[e].getB() << " arr\n";
          }
          else os << _coords[g.source(e)].x << ' '
                  << _coords[g.source(e)].y << ' '
                  << _coords[g.target(e)].x << ' '
                  << _coords[g.target(e)].y << ' '
                  << _edgeColors[e].getR() << ' '
                  << _edgeColors[e].getG() << ' '
                  << _edgeColors[e].getB() << ' '
                  << _edgeWidths[e]*_edgeWidthScale << " l\n";
      os << "grestore\n";
    }
    if(_showNodes) {
      os << "%Nodes:\ngsave\n";
      for(NodeIt n(g);n!=INVALID;++n)
        os << _coords[n].x << ' ' << _coords[n].y << ' '
           << _nodeSizes[n]*_nodeScale << ' '
           << _nodeColors[n].getR() << ' '
           << _nodeColors[n].getG() << ' '
           << _nodeColors[n].getB() << " n\n";
      os << "grestore\n";
    }
    if(_showNodeText) {
      os << "%Node texts:\ngsave\n";
      os << "/fosi " << _nodeTextSize << " def\n";
      os << "(Helvetica) findfont fosi scalefont setfont\n";
      os << "0 0 0 setrgbcolor\n";
      for(NodeIt n(g);n!=INVALID;++n)
        os << _coords[n].x << ' ' << _coords[n].y
           << " (" << _nodeTexts[n] << ") cshow\n";
      os << "grestore\n";
    }
    if(_showNodePsText) {
      os << "%Node PS blocks:\ngsave\n";
      for(NodeIt n(g);n!=INVALID;++n)
        os << _coords[n].x << ' ' << _coords[n].y
           << " moveto\n" << _nodePsTexts[n] << "\n";
      os << "grestore\n";
    }
    
    os << "grestore\n";

    //CleanUp:
    if(_pleaseRemoveOsStream) {delete &os;}
  } 
};


///Generates an EPS file from a graph

///\ingroup misc
///Generates an EPS file from a graph.
///\param g is a reference to the graph to be printed
///\param os is a reference to the output stream.
///By default it is <tt>std::cout</tt>
///
///This function also has a lot of \ref named-templ-param "named parameters",
///they are declared as the members of class \ref GraphToEps. The following
///example shows how to use these parameters.
///\code
/// graphToEps(g).scale(10).coords(coords)
///              .nodeScale(2).nodeSizes(sizes)
///              .edgeWidthScale(.4);
///\endcode
///\sa GraphToEps
///\sa graphToEps(G &g, char *file_name)
template<class G>
GraphToEps<DefaultGraphToEpsTraits<G> > 
graphToEps(G &g, std::ostream& os=std::cout)
{
  return 
    GraphToEps<DefaultGraphToEpsTraits<G> >(DefaultGraphToEpsTraits<G>(g,os));
}
 
///Generates an EPS file from a graph

//\ingroup misc
///This function does the same as
///\ref graphToEps(G &g,std::ostream& os)
///but it writes its output into the file \c file_name
///instead of a stream.
///\sa graphToEps(G &g, std::ostream& os)
template<class G>
GraphToEps<DefaultGraphToEpsTraits<G> > 
graphToEps(G &g,char *file_name)
{
  return GraphToEps<DefaultGraphToEpsTraits<G> >
    (DefaultGraphToEpsTraits<G>(g,*new std::ofstream(file_name),true));
}

} //END OF NAMESPACE LEMON

#endif // LEMON_GRAPH_TO_EPS_H