/* -*- 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,int > _nodeShapes;

   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), _nodeShapes(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;

   static const int INTERPOL_PREC=20;

   bool dontPrint;

   enum NodeShapes { CIRCLE=0, SQUARE=1, DIAMOND=2 };

   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 NodeShapesTraits : public T {

     const X &_nodeShapes;

     NodeShapesTraits(const T &t,const X &x) : T(t), _nodeShapes(x) {}

   };

   ///Sets the map of the node shapes

   ///Sets the map of the node shapes

   ///\param x must be a node map with \c int (or convertible) values. 

   ///\todo Incomplete doc.

   template<class X> GraphToEps<NodeShapesTraits<X> > nodeShapes(const X &x)

   {

     dontPrint=true;

     return GraphToEps<NodeShapesTraits<X> >(NodeShapesTraits<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;}

 protected:

   bool isInsideNode(xy<double> p, double r,int t) 

   {

     switch(t) {

     case CIRCLE:

       return p.normSquare()<=r*r;

     case SQUARE:

       return p.x<=r&&p.x>=-r&&p.y<=r&&p.y>=-r;

     case DIAMOND:

       return p.x+p.y<=r && p.x-p.y<=r && -p.x+p.y<=r && -p.x-p.y<=r;

     }

     return false;

   }

 public:

   ~GraphToEps() { }

   ///Draws the graph.

   ///Like other functions using

   ///\ref named-templ-func-param "named template parameters",

   ///this function calles the algorithm itself, i.e. in this case

   ///it draws the graph.

   void run() {

     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";

     //x y r

     os << "/c { newpath dup 3 index add 2 index moveto 0 360 arc closepath } bind def\n";

     //x y r

     os << "/sq { newpath 2 index 1 index add 2 index 2 index add moveto\n"

        << "      2 index 1 index sub 2 index 2 index add lineto\n"

        << "      2 index 1 index sub 2 index 2 index sub lineto\n"

        << "      2 index 1 index add 2 index 2 index sub lineto\n"

        << "      closepath pop pop pop} bind def\n";

     //x y r

     os << "/di { newpath 2 index 1 index add 2 index moveto\n"

        << "      2 index             2 index 2 index add lineto\n"

        << "      2 index 1 index sub 2 index             lineto\n"

        << "      2 index             2 index 2 index sub lineto\n"

        << "      closepath pop pop pop} bind def\n";

     // x y r cr cg cb

     os << "/nc { 0 0 0 setrgbcolor 5 index 5 index 5 index c fill\n"

        << "     setrgbcolor " << 1+_nodeBorderQuotient << " div c fill\n"

        << "   } bind def\n";

     os << "/nsq { 0 0 0 setrgbcolor 5 index 5 index 5 index sq fill\n"

        << "     setrgbcolor " << 1+_nodeBorderQuotient << " div sq fill\n"

        << "   } bind def\n";

     os << "/ndi { 0 0 0 setrgbcolor 5 index 5 index 5 index di fill\n"

        << "     setrgbcolor " << 1+_nodeBorderQuotient << " div di fill\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) {

 	      int node_shape;

 	      xy<double> s=_coords[g.source(*e)];

 	      xy<double> t=_coords[g.target(*e)];

 	      double rn=_nodeSizes[g.target(*e)]*_nodeScale;

 	      node_shape=_nodeShapes[g.target(*e)];

 	      Bezier3 bez(s,mm,mm,t);

 	      double t1=0,t2=1;

 	      for(int i=0;i<INTERPOL_PREC;++i)

 		if(isInsideNode(bez((t1+t2)/2)-t,rn,node_shape)) t2=(t1+t2)/2;

 		else t1=(t1+t2)/2;

 	      xy<double> apoint=bez((t1+t2)/2);

 	      rn = _arrowLength+_edgeWidths[*e]*_edgeWidthScale;

 	      rn*=rn;

 	      t2=(t1+t2)/2;t1=0;

 	      for(int i=0;i<INTERPOL_PREC;++i)

 		if((bez((t1+t2)/2)-apoint).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;

 // 	      node_shape=_nodeShapes[g.source(*e)];

 // 	      t1=0;t2=1;

 // 	      for(int i=0;i<INTERPOL_PREC;++i)

 // 		if(isInsideNode(bez((t1+t2)/2)-t,rn,node_shape)) t1=(t1+t2)/2;

 // 		else t2=(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*=(.5*_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 rn=_nodeSizes[g.target(e)]*_nodeScale;

 	    int node_shape=_nodeShapes[g.target(e)];

 	    double t1=0,t2=1;

 	    for(int i=0;i<INTERPOL_PREC;++i)

 	      if(isInsideNode((-(t1+t2)/2)*d,rn,node_shape)) t1=(t1+t2)/2;

 	      else t2=(t1+t2)/2;

 	    double l=sqrt(d.normSquare());

 	    d/=l;

 	    os << l*(1-(t1+t2)/2) << ' '

 	       << _edgeWidths[e]*_edgeWidthScale << ' '

 	       << d.x << ' ' << d.y << ' '

 	       << _coords[g.source(e)].x << ' '

 	       << _coords[g.source(e)].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() << ' ';

 	switch(_nodeShapes[n]) {

 	case CIRCLE:

 	  os<< "nc";break;

 	case SQUARE:

 	  os<< "nsq";break;

 	case DIAMOND:

 	  os<< "ndi";break;

 	}

 	os<<'\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-func-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).run();

 ///\endcode

 ///\warning Don't forget to put the \ref GraphToEps::run() "run()"

 ///to the end of the parameter list.

 ///\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