<?php
 /*
     pSpring - class to draw spring graphs

     Version     : 2.1.4
     Made by     : Jean-Damien POGOLOTTI
     Last Update : 19/01/2014

     This file can be distributed under the license you can find at :

                       http://www.pchart.net/license

     You can find the whole class documentation on the pChart web site.
 */

 define("NODE_TYPE_FREE"	, 690001);
 define("NODE_TYPE_CENTRAL"	, 690002);

 define("NODE_SHAPE_CIRCLE"	, 690011);
 define("NODE_SHAPE_TRIANGLE"	, 690012);
 define("NODE_SHAPE_SQUARE"	, 690013);

 define("ALGORITHM_RANDOM"	, 690021);
 define("ALGORITHM_WEIGHTED"	, 690022);
 define("ALGORITHM_CIRCULAR"	, 690023);
 define("ALGORITHM_CENTRAL"	, 690024);

 define("LABEL_CLASSIC"		, 690031);
 define("LABEL_LIGHT"		, 690032);

 /* pSpring class definition */
 class pSpring
  {
   var $History;
   var $pChartObject;
   var $Data;
   var $Links;
   var $X1;
   var $Y1;
   var $X2;
   var $Y2;
   var $AutoComputeFreeZone;
   var $Labels;

   /* Class creator */
   function pSpring()
    {
     /* Initialise data arrays */
     $this->Data = "";
     $this->Links = "";

     /* Set nodes defaults */
     $this->Default["R"]		= 255;
     $this->Default["G"]		= 255;
     $this->Default["B"]		= 255;
     $this->Default["Alpha"]		= 100;
     $this->Default["BorderR"]		= 0;
     $this->Default["BorderG"]		= 0;
     $this->Default["BorderB"]		= 0;
     $this->Default["BorderAlpha"]	= 100;
     $this->Default["Surrounding"]	= NULL;
     $this->Default["BackgroundR"]	= 255;
     $this->Default["BackgroundG"]	= 255;
     $this->Default["BackgroundB"]	= 255;
     $this->Default["BackgroundAlpha"]	= 0;
     $this->Default["Force"]		= 1;
     $this->Default["NodeType"]		= NODE_TYPE_FREE;
     $this->Default["Size"]		= 5;
     $this->Default["Shape"]		= NODE_SHAPE_CIRCLE;
     $this->Default["FreeZone"]		= 40;
     $this->Default["LinkR"]		= 0;
     $this->Default["LinkG"]		= 0;
     $this->Default["LinkB"]		= 0;
     $this->Default["LinkAlpha"]	= 0;

     $this->Labels["Type"]		= LABEL_CLASSIC;
     $this->Labels["R"]			= 0;
     $this->Labels["G"]			= 0;
     $this->Labels["B"]			= 0;
     $this->Labels["Alpha"]		= 100;

     $this->AutoComputeFreeZone         = FALSE;
    }

   /* Set default links options */
   function setLinkDefaults($Settings="")
    {
     if ( isset($Settings["R"]) )     { $this->Default["LinkR"] = $Settings["R"]; }
     if ( isset($Settings["G"]) )     { $this->Default["LinkG"] = $Settings["G"]; }
     if ( isset($Settings["B"]) )     { $this->Default["LinkB"] = $Settings["B"]; }
     if ( isset($Settings["Alpha"]) ) { $this->Default["LinkAlpha"] = $Settings["Alpha"]; }
    }

   /* Set default links options */
   function setLabelsSettings($Settings="")
    {
     if ( isset($Settings["Type"]) )  { $this->Labels["Type"] = $Settings["Type"]; }
     if ( isset($Settings["R"]) )     { $this->Labels["R"] = $Settings["R"]; }
     if ( isset($Settings["G"]) )     { $this->Labels["G"] = $Settings["G"]; }
     if ( isset($Settings["B"]) )     { $this->Labels["B"] = $Settings["B"]; }
     if ( isset($Settings["Alpha"]) ) { $this->Labels["Alpha"] = $Settings["Alpha"]; }
    }

   /* Auto compute the FreeZone size based on the number of connections */
   function autoFreeZone()
    {
     /* Check connections reciprocity */
     foreach($this->Data as $Key => $Settings)
      {
       if ( isset($Settings["Connections"]) )
        { $this->Data[$Key]["FreeZone"] = count($Settings["Connections"])*10 + 20; }
       else
        { $this->Data[$Key]["FreeZone"] = 20; }
      }

    }

   /* Set link properties */
   function linkProperties($FromNode,$ToNode,$Settings)
    {
     if ( !isset($this->Data[$FromNode]) ) { return(0); }
     if ( !isset($this->Data[$ToNode]) )   { return(0); }

     $R			= isset($Settings["R"]) ? $Settings["R"] : 0;
     $G			= isset($Settings["G"]) ? $Settings["G"] : 0;
     $B			= isset($Settings["B"]) ? $Settings["B"] : 0;
     $Alpha		= isset($Settings["Alpha"]) ? $Settings["Alpha"] : 100;
     $Name		= isset($Settings["Name"]) ? $Settings["Name"] : NULL;
     $Ticks		= isset($Settings["Ticks"]) ? $Settings["Ticks"] : NULL;

     $this->Links[$FromNode][$ToNode]["R"] = $R;         $this->Links[$ToNode][$FromNode]["R"] = $R;
     $this->Links[$FromNode][$ToNode]["G"] = $G;         $this->Links[$ToNode][$FromNode]["G"] = $G;
     $this->Links[$FromNode][$ToNode]["B"] = $B;         $this->Links[$ToNode][$FromNode]["B"] = $B;
     $this->Links[$FromNode][$ToNode]["Alpha"] = $Alpha; $this->Links[$ToNode][$FromNode]["Alpha"] = $Alpha;
     $this->Links[$FromNode][$ToNode]["Name"] = $Name;   $this->Links[$ToNode][$FromNode]["Name"] = $Name;
     $this->Links[$FromNode][$ToNode]["Ticks"] = $Ticks; $this->Links[$ToNode][$FromNode]["Ticks"] = $Ticks;
    }

   function setNodeDefaults($Settings="")
    {
     if ( isset($Settings["R"]) ) { $this->Default["R"]					= $Settings["R"]; }
     if ( isset($Settings["G"]) ) { $this->Default["G"]					= $Settings["G"]; }
     if ( isset($Settings["B"]) ) { $this->Default["B"]					= $Settings["B"]; }
     if ( isset($Settings["Alpha"]) ) { $this->Default["Alpha"]				= $Settings["Alpha"]; }
     if ( isset($Settings["BorderR"]) ) { $this->Default["BorderR"]			= $Settings["BorderR"]; }
     if ( isset($Settings["BorderG"]) ) { $this->Default["BorderG"]			= $Settings["BorderG"]; }
     if ( isset($Settings["BorderB"]) ) { $this->Default["BorderB"]			= $Settings["BorderB"]; }
     if ( isset($Settings["BorderAlpha"]) ) { $this->Default["BorderAlpha"]		= $Settings["BorderAlpha"]; }
     if ( isset($Settings["Surrounding"]) ) { $this->Default["Surrounding"]		= $Settings["Surrounding"]; }
     if ( isset($Settings["BackgroundR"]) ) { $this->Default["BackgroundR"]		= $Settings["BackgroundR"]; }
     if ( isset($Settings["BackgroundG"]) ) { $this->Default["BackgroundG"]		= $Settings["BackgroundG"]; }
     if ( isset($Settings["BackgroundB"]) ) { $this->Default["BackgroundB"]		= $Settings["BackgroundB"]; }
     if ( isset($Settings["BackgroundAlpha"]) ) { $this->Default["BackgroundAlpha"]	= $Settings["BackgroundAlpha"]; }
     if ( isset($Settings["NodeType"]) ) { $this->Default["NodeType"]			= $Settings["NodeType"]; }
     if ( isset($Settings["Size"]) ) { $this->Default["Size"]				= $Settings["Size"]; }
     if ( isset($Settings["Shape"]) ) { $this->Default["Shape"]				= $Settings["Shape"]; }
     if ( isset($Settings["FreeZone"]) ) { $this->Default["FreeZone"]			= $Settings["FreeZone"]; }
    }

   /* Add a node */
   function addNode($NodeID,$Settings="")
    {
     /* if the node already exists, ignore */
     if (isset($this->Data[$NodeID])) { return(0); }

     $Name		= isset($Settings["Name"]) ? $Settings["Name"] : "Node ".$NodeID;
     $Connections	= isset($Settings["Connections"]) ? $Settings["Connections"] : NULL;

     $R			= isset($Settings["R"]) ? $Settings["R"] : $this->Default["R"];
     $G			= isset($Settings["G"]) ? $Settings["G"] : $this->Default["G"];
     $B			= isset($Settings["B"]) ? $Settings["B"] : $this->Default["B"];
     $Alpha		= isset($Settings["Alpha"]) ? $Settings["Alpha"] : $this->Default["Alpha"];
     $BorderR		= isset($Settings["BorderR"]) ? $Settings["BorderR"] : $this->Default["BorderR"];
     $BorderG		= isset($Settings["BorderG"]) ? $Settings["BorderG"] : $this->Default["BorderG"];
     $BorderB		= isset($Settings["BorderB"]) ? $Settings["BorderB"] : $this->Default["BorderB"];
     $BorderAlpha	= isset($Settings["BorderAlpha"]) ? $Settings["BorderAlpha"] : $this->Default["BorderAlpha"];
     $Surrounding	= isset($Settings["Surrounding"]) ? $Settings["Surrounding"] : $this->Default["Surrounding"];
     $BackgroundR	= isset($Settings["BackgroundR"]) ? $Settings["BackgroundR"] : $this->Default["BackgroundR"];
     $BackgroundG	= isset($Settings["BackgroundG"]) ? $Settings["BackgroundG"] : $this->Default["BackgroundG"];
     $BackgroundB	= isset($Settings["BackgroundB"]) ? $Settings["BackgroundB"] : $this->Default["BackgroundB"];
     $BackgroundAlpha	= isset($Settings["BackgroundAlpha"]) ? $Settings["BackgroundAlpha"] : $this->Default["BackgroundAlpha"];
     $Force		= isset($Settings["Force"]) ? $Settings["Force"] :  $this->Default["Force"];
     $NodeType		= isset($Settings["NodeType"]) ? $Settings["NodeType"] : $this->Default["NodeType"];
     $Size		= isset($Settings["Size"]) ? $Settings["Size"] : $this->Default["Size"];
     $Shape		= isset($Settings["Shape"]) ? $Settings["Shape"] : $this->Default["Shape"];
     $FreeZone		= isset($Settings["FreeZone"]) ? $Settings["FreeZone"] : $this->Default["FreeZone"];

     if ( $Surrounding != NULL ) { $BorderR = $R + $Surrounding; $BorderG = $G + $Surrounding; $BorderB = $B + $Surrounding; }

     $this->Data[$NodeID]["R"] = $R; $this->Data[$NodeID]["G"] = $G; $this->Data[$NodeID]["B"] = $B; $this->Data[$NodeID]["Alpha"] = $Alpha;
     $this->Data[$NodeID]["BorderR"] = $BorderR; $this->Data[$NodeID]["BorderG"] = $BorderG; $this->Data[$NodeID]["BorderB"] = $BorderB; $this->Data[$NodeID]["BorderAlpha"] = $BorderAlpha;
     $this->Data[$NodeID]["BackgroundR"]	= $BackgroundR; $this->Data[$NodeID]["BackgroundG"] = $BackgroundG; $this->Data[$NodeID]["BackgroundB"] = $BackgroundB; $this->Data[$NodeID]["BackgroundAlpha"] = $BackgroundAlpha;
     $this->Data[$NodeID]["Name"]		= $Name;
     $this->Data[$NodeID]["Force"]		= $Force;
     $this->Data[$NodeID]["Type"]		= $NodeType;
     $this->Data[$NodeID]["Size"]		= $Size;
     $this->Data[$NodeID]["Shape"]		= $Shape;
     $this->Data[$NodeID]["FreeZone"]		= $FreeZone;
     if ( $Connections != NULL )
      {
       if ( is_array($Connections ) )
        {
         foreach($Connections as $Key => $Value)
          $this->Data[$NodeID]["Connections"][] = $Value;
        }
       else
        $this->Data[$NodeID]["Connections"][] = $Connections;
      }
    }

   /* Set color attribute for a list of nodes */
   function setNodesColor($Nodes,$Settings="")
    {
     if ( is_array($Nodes) )
      {
       foreach ($Nodes as $Key => $NodeID)
        {
         if (isset($this->Data[$NodeID]) )
          {
           if ( isset($Settings["R"]) ) { $this->Data[$NodeID]["R"] = $Settings["R"]; }
           if ( isset($Settings["G"]) ) { $this->Data[$NodeID]["G"] = $Settings["G"]; }
           if ( isset($Settings["B"]) ) { $this->Data[$NodeID]["B"] = $Settings["B"]; }
           if ( isset($Settings["Alpha"]) ) { $this->Data[$NodeID]["Alpha"] = $Settings["Alpha"]; }
           if ( isset($Settings["BorderR"]) ) { $this->Data[$NodeID]["BorderR"] = $Settings["BorderR"]; }
           if ( isset($Settings["BorderG"]) ) { $this->Data[$NodeID]["BorderG"] = $Settings["BorderG"]; }
           if ( isset($Settings["BorderB"]) ) { $this->Data[$NodeID]["BorderB"] = $Settings["BorderB"]; }
           if ( isset($Settings["BorderAlpha"]) ) { $this->Data[$NodeID]["BorderAlpha"] = $Settings["BorderAlpha"]; }
           if ( isset($Settings["Surrounding"]) ) { $this->Data[$NodeID]["BorderR"] = $this->Data[$NodeID]["R"] + $Settings["Surrounding"]; $this->Data[$NodeID]["BorderG"] = $this->Data[$NodeID]["G"] + $Settings["Surrounding"]; $this->Data[$NodeID]["BorderB"] = $this->Data[$NodeID]["B"] + $Settings["Surrounding"]; }
          }
        }
      }
     else
      {
       if ( isset($Settings["R"]) ) { $this->Data[$Nodes]["R"] = $Settings["R"]; }
       if ( isset($Settings["G"]) ) { $this->Data[$Nodes]["G"] = $Settings["G"]; }
       if ( isset($Settings["B"]) ) { $this->Data[$Nodes]["B"] = $Settings["B"]; }
       if ( isset($Settings["Alpha"]) ) { $this->Data[$Nodes]["Alpha"] = $Settings["Alpha"]; }
       if ( isset($Settings["BorderR"]) ) { $this->Data[$Nodes]["BorderR"] = $Settings["BorderR"]; }
       if ( isset($Settings["BorderG"]) ) { $this->Data[$Nodes]["BorderG"] = $Settings["BorderG"]; }
       if ( isset($Settings["BorderB"]) ) { $this->Data[$Nodes]["BorderB"] = $Settings["BorderB"]; }
       if ( isset($Settings["BorderAlpha"]) ) { $this->Data[$Nodes]["BorderAlpha"] = $Settings["BorderAlpha"]; }
       if ( isset($Settings["Surrounding"]) ) { $this->Data[$Nodes]["BorderR"] = $this->Data[$NodeID]["R"] + $Settings["Surrounding"]; $this->Data[$NodeID]["BorderG"] = $this->Data[$NodeID]["G"] + $Settings["Surrounding"]; $this->Data[$NodeID]["BorderB"] = $this->Data[$NodeID]["B"] + $Settings["Surrounding"]; }
      }
    }

   /* Returns all the nodes details */
   function dumpNodes()
    { return($this->Data); }

   /* Check if a connection exists and create it if required */
   function checkConnection($SourceID, $TargetID)
    {
     if ( isset($this->Data[$SourceID]["Connections"]) )
      {
       foreach ($this->Data[$SourceID]["Connections"] as $Key => $ConnectionID)
        { if ( $TargetID == $ConnectionID ) { return(TRUE); } }
      }
     $this->Data[$SourceID]["Connections"][] = $TargetID;
    }
   /* Get the median linked nodes position */
   function getMedianOffset($Key,$X,$Y)
    {
     $Cpt = 1;
     if ( isset($this->Data[$Key]["Connections"]) )
      {
       foreach($this->Data[$Key]["Connections"] as $ID => $NodeID)
        {
         if ( isset($this->Data[$NodeID]["X"]) && isset($this->Data[$NodeID]["Y"]) )
          {
           $X = $X + $this->Data[$NodeID]["X"];
           $Y = $Y + $this->Data[$NodeID]["Y"];
           $Cpt++;
          }
        }
      }
     return(array("X"=>$X/$Cpt,"Y"=>$Y/$Cpt));
    }

   /* Return the ID of the attached partner with the biggest weight */
   function getBiggestPartner($Key)
    {
     if ( !isset($this->Data[$Key]["Connections"]) ) { return(""); }

     $MaxWeight = 0; $Result = "";
     foreach($this->Data[$Key]["Connections"] as $Key => $PeerID)
      {
       if ( $this->Data[$PeerID]["Weight"] > $MaxWeight )
        { $MaxWeight = $this->Data[$PeerID]["Weight"]; $Result = $PeerID; }
      }
     return($Result);
    }

   /* Do the initial node positions computing pass */
   function firstPass($Algorithm)
    {
     $CenterX = ($this->X2 - $this->X1) / 2 + $this->X1;
     $CenterY = ($this->Y2 - $this->Y1) / 2 + $this->Y1;

     /* Check connections reciprocity */
     foreach($this->Data as $Key => $Settings)
      {
       if ( isset($Settings["Connections"]) )
        {
         foreach($Settings["Connections"] as $ID => $ConnectionID)
          $this->checkConnection($ConnectionID,$Key);
        }
      }

     if ( $this->AutoComputeFreeZone ) { $this->autoFreeZone(); }

     /* Get the max number of connections */
     $MaxConnections = 0;
     foreach($this->Data as $Key => $Settings)
      { if ( isset($Settings["Connections"]) ) { if ( $MaxConnections < count($Settings["Connections"] ) ) { $MaxConnections = count($Settings["Connections"]); } } }

     if ( $Algorithm == ALGORITHM_WEIGHTED )
      {
       foreach($this->Data as $Key => $Settings)
        {
         if ( $Settings["Type"] == NODE_TYPE_CENTRAL ) { $this->Data[$Key]["X"] = $CenterX; $this->Data[$Key]["Y"] = $CenterY; }
         if ( $Settings["Type"] == NODE_TYPE_FREE )
          {
           if ( isset($Settings["Connections"]) )
            { $Connections = count($Settings["Connections"]); }
           else
            { $Connections = 0; }

           $Ring  = $MaxConnections - $Connections;
           $Angle = rand(0,360);
           
           $this->Data[$Key]["X"] = cos(deg2rad($Angle)) * ($Ring*$this->RingSize) + $CenterX;
           $this->Data[$Key]["Y"] = sin(deg2rad($Angle)) * ($Ring*$this->RingSize) + $CenterY;
          }
        }
      }
     elseif ( $Algorithm == ALGORITHM_CENTRAL )
      {
       /* Put a weight on each nodes */
       foreach($this->Data as $Key => $Settings)
        {
         if ( isset($Settings["Connections"]) )
          $this->Data[$Key]["Weight"] = count($Settings["Connections"]);
         else
          $this->Data[$Key]["Weight"] = 0;
        }

       $MaxConnections = $MaxConnections + 1;
       for($i=$MaxConnections;$i>=0;$i--)
        {
         foreach($this->Data as $Key => $Settings)
          {
           if ( $Settings["Type"] == NODE_TYPE_CENTRAL ) { $this->Data[$Key]["X"] = $CenterX; $this->Data[$Key]["Y"] = $CenterY; }
           if ( $Settings["Type"] == NODE_TYPE_FREE )
            {
             if ( isset($Settings["Connections"]) )
              { $Connections = count($Settings["Connections"]); }
             else
              { $Connections = 0; }

             if ( $Connections == $i )
              {
               $BiggestPartner = $this->getBiggestPartner($Key);
               if ( $BiggestPartner != "" )
                {
                 $Ring          = $this->Data[$BiggestPartner]["FreeZone"];
                 $Weight        = $this->Data[$BiggestPartner]["Weight"];
                 $AngleDivision = 360 / $this->Data[$BiggestPartner]["Weight"];
                 $Done          = FALSE; $Tries = 0;
                 while (!$Done && $Tries <= $Weight*2)
                  {
                   $Tries++;
                   $Angle = floor(rand(0,$Weight)*$AngleDivision);
                   if ( !isset($this->Data[$BiggestPartner]["Angular"][$Angle]) || !isset($this->Data[$BiggestPartner]["Angular"]) )
                    {
                     $this->Data[$BiggestPartner]["Angular"][$Angle] = $Angle;
                     $Done = TRUE; 
                    }
                  }
                 if ( !$Done )
                  { $Angle = rand(0,360); $this->Data[$BiggestPartner]["Angular"][$Angle] = $Angle; }

                 $X = cos(deg2rad($Angle)) * ($Ring) + $this->Data[$BiggestPartner]["X"];
                 $Y = sin(deg2rad($Angle)) * ($Ring) + $this->Data[$BiggestPartner]["Y"];

                 $this->Data[$Key]["X"] = $X;
                 $this->Data[$Key]["Y"] = $Y;
                }
              }
            }
          }
        }
      }
     elseif ( $Algorithm == ALGORITHM_CIRCULAR )
      {
       $MaxConnections = $MaxConnections + 1;
       for($i=$MaxConnections;$i>=0;$i--)
        {
         foreach($this->Data as $Key => $Settings)
          {
           if ( $Settings["Type"] == NODE_TYPE_CENTRAL ) { $this->Data[$Key]["X"] = $CenterX; $this->Data[$Key]["Y"] = $CenterY; }
           if ( $Settings["Type"] == NODE_TYPE_FREE )
            {
             if ( isset($Settings["Connections"]) )
              { $Connections = count($Settings["Connections"]); }
             else
              { $Connections = 0; }

             if ( $Connections == $i )
              {
               $Ring  = $MaxConnections - $Connections;
               $Angle = rand(0,360);

               $X = cos(deg2rad($Angle)) * ($Ring*$this->RingSize) + $CenterX;
               $Y = sin(deg2rad($Angle)) * ($Ring*$this->RingSize) + $CenterY;

               $MedianOffset = $this->getMedianOffset($Key,$X,$Y);

               $this->Data[$Key]["X"] = $MedianOffset["X"];
               $this->Data[$Key]["Y"] = $MedianOffset["Y"];
              }
            }
          }
        }
      }
     elseif ( $Algorithm == ALGORITHM_RANDOM )
      {
       foreach($this->Data as $Key => $Settings)
        {
         if ( $Settings["Type"] == NODE_TYPE_FREE )
          {
           $this->Data[$Key]["X"] = $CenterX + rand(-20,20);
           $this->Data[$Key]["Y"] = $CenterY + rand(-20,20);
          }
         if ( $Settings["Type"] == NODE_TYPE_CENTRAL ) { $this->Data[$Key]["X"] = $CenterX; $this->Data[$Key]["Y"] = $CenterY; }
        }
      }
    }

   /* Compute one pass */
   function doPass()
    {
     /* Compute vectors */
     foreach($this->Data as $Key => $Settings)
      {
       if ( $Settings["Type"] != NODE_TYPE_CENTRAL )
        {
         unset($this->Data[$Key]["Vectors"]);

         $X1 = $Settings["X"];
         $Y1 = $Settings["Y"];

         /* Repulsion vectors */
         foreach($this->Data as $Key2 => $Settings2)
          {
           if ( $Key != $Key2 )
            {
             $X2 = $this->Data[$Key2]["X"];
             $Y2 = $this->Data[$Key2]["Y"];
             $FreeZone = $this->Data[$Key2]["FreeZone"];

             $Distance = $this->getDistance($X1,$Y1,$X2,$Y2);
             $Angle    = $this->getAngle($X1,$Y1,$X2,$Y2) + 180;

             /* Nodes too close, repulsion occurs */
             if ( $Distance < $FreeZone )
              {
               $Force = log(pow(2,$FreeZone-$Distance));
               if ( $Force > 1 )
                { $this->Data[$Key]["Vectors"][] = array("Type"=>"R","Angle"=>$Angle % 360,"Force"=>$Force); }
              }
            }
          }

         /* Attraction vectors */
         if ( isset($Settings["Connections"]) )
          {
           foreach($Settings["Connections"] as $ID => $NodeID)
            {
             if ( isset($this->Data[$NodeID]) )
              {
               $X2 = $this->Data[$NodeID]["X"];
               $Y2 = $this->Data[$NodeID]["Y"];
               $FreeZone = $this->Data[$Key2]["FreeZone"];

               $Distance = $this->getDistance($X1,$Y1,$X2,$Y2);
               $Angle    = $this->getAngle($X1,$Y1,$X2,$Y2);

               if ( $Distance > $FreeZone )
                $Force = log(($Distance-$FreeZone)+1);
               else
                { $Force = log(($FreeZone-$Distance)+1); ($Angle = $Angle + 180); }

               if ( $Force > 1 )
                $this->Data[$Key]["Vectors"][] = array("Type"=>"A","Angle"=>$Angle % 360,"Force"=>$Force);
              }
            }
          }
        }
      }

     /* Move the nodes accoding to the vectors */
     foreach($this->Data as $Key => $Settings)
      {
       $X = $Settings["X"];
       $Y = $Settings["Y"];

       if ( isset($Settings["Vectors"]) && $Settings["Type"] != NODE_TYPE_CENTRAL )
        {
         foreach($Settings["Vectors"] as $ID => $Vector)
          {
           $Type  = $Vector["Type"];
           $Force = $Vector["Force"];
           $Angle = $Vector["Angle"];
           $Factor = $Type == "A" ? $this->MagneticForceA : $this->MagneticForceR;

           $X = cos(deg2rad($Angle)) * $Force * $Factor + $X;
           $Y = sin(deg2rad($Angle)) * $Force * $Factor + $Y;
          }
        }

       $this->Data[$Key]["X"] = $X;
       $this->Data[$Key]["Y"] = $Y;
      }
    }

   function lastPass()
    {
     /* Put everything inside the graph area */
     foreach($this->Data as $Key => $Settings)
      {
       $X = $Settings["X"];
       $Y = $Settings["Y"];

       if ( $X < $this->X1 ) { $X = $this->X1; }
       if ( $X > $this->X2 ) { $X = $this->X2; }
       if ( $Y < $this->Y1 ) { $Y = $this->Y1; }
       if ( $Y > $this->Y2 ) { $Y = $this->Y2; }

       $this->Data[$Key]["X"] = $X;
       $this->Data[$Key]["Y"] = $Y;
      }

     /* Dump all links */
     $Links = "";
     foreach($this->Data as $Key => $Settings)
      {
       $X1 = $Settings["X"];
       $Y1 = $Settings["Y"];

       if ( isset($Settings["Connections"]) )
        {
         foreach ($Settings["Connections"] as $ID => $NodeID)
          {
           if ( isset($this->Data[$NodeID]) )
            {
             $X2 = $this->Data[$NodeID]["X"];
             $Y2 = $this->Data[$NodeID]["Y"];

             $Links[] = array("X1"=>$X1,"Y1"=>$Y1,"X2"=>$X2,"Y2"=>$Y2,"Source"=>$Settings["Name"],"Destination"=>$this->Data[$NodeID]["Name"]);
            }
          }
        }
      }

     /* Check collisions */
     $Conflicts = 0;
     foreach($this->Data as $Key => $Settings)
      {
       $X1 = $Settings["X"];
       $Y1 = $Settings["Y"];

       if ( isset($Settings["Connections"]) )
        {
         foreach ($Settings["Connections"] as $ID => $NodeID)
          {
           if ( isset($this->Data[$NodeID]) )
            {
             $X2 = $this->Data[$NodeID]["X"];
             $Y2 = $this->Data[$NodeID]["Y"];

             foreach($Links as $IDLinks => $Link)
              {
               $X3 = $Link["X1"]; $Y3 = $Link["Y1"]; $X4 = $Link["X2"]; $Y4 = $Link["Y2"];

               if ( !($X1 == $X3 && $X2 == $X4 && $Y1 == $Y3 && $Y2 == $Y4 ) )
                {
                 if ( $this->intersect($X1,$Y1,$X2,$Y2,$X3,$Y3,$X4,$Y4) )
                  {
                   if ( $Link["Source"] != $Settings["Name"] && $Link["Source"] != $this->Data[$NodeID]["Name"] && $Link["Destination"] != $Settings["Name"] && $Link["Destination"] != $this->Data[$NodeID]["Name"] )
                    { $Conflicts++; }
                  }
                }
              }
            }
          }
        }
      }
     return($Conflicts/2);
    }

   /* Center the graph */
   function center()
    {
     /* Determine the real center */
     $TargetCenterX = ($this->X2 - $this->X1) / 2 + $this->X1;
     $TargetCenterY = ($this->Y2 - $this->Y1) / 2 + $this->Y1;

     /* Get current boundaries */
     $XMin = $this->X2; $XMax = $this->X1;
     $YMin = $this->Y2; $YMax = $this->Y1;
     foreach($this->Data as $Key => $Settings)
      {
       $X = $Settings["X"];
       $Y = $Settings["Y"];

       if ( $X < $XMin) { $XMin = $X; }
       if ( $X > $XMax) { $XMax = $X; }
       if ( $Y < $YMin) { $YMin = $Y; }
       if ( $Y > $YMax) { $YMax = $Y; }
      }
     $CurrentCenterX = ($XMax - $XMin) / 2 + $XMin;
     $CurrentCenterY = ($YMax - $YMin) / 2 + $YMin;

     /* Compute the offset to apply */
     $XOffset = $TargetCenterX - $CurrentCenterX;
     $YOffset = $TargetCenterY - $CurrentCenterY;

     /* Correct the points position */
     foreach($this->Data as $Key => $Settings)
      {
       $this->Data[$Key]["X"] = $Settings["X"] + $XOffset;
       $this->Data[$Key]["Y"] = $Settings["Y"] + $YOffset;
      }
    }

   /* Create the encoded string */
   function drawSpring($Object,$Settings="")
    {
     $this->pChartObject = $Object;

     $Pass			= isset($Settings["Pass"]) ? $Settings["Pass"] : 50;
     $Retries			= isset($Settings["Retry"]) ? $Settings["Retry"] : 10;
     $this->MagneticForceA	= isset($Settings["MagneticForceA"]) ? $Settings["MagneticForceA"] : 1.5;
     $this->MagneticForceR	= isset($Settings["MagneticForceR"]) ? $Settings["MagneticForceR"] : 2;
     $this->RingSize		= isset($Settings["RingSize"]) ? $Settings["RingSize"] : 40;
     $DrawVectors		= isset($Settings["DrawVectors"]) ? $Settings["DrawVectors"] : FALSE;
     $DrawQuietZone		= isset($Settings["DrawQuietZone"]) ? $Settings["DrawQuietZone"] : FALSE;
     $CenterGraph		= isset($Settings["CenterGraph"]) ? $Settings["CenterGraph"] : TRUE;
     $TextPadding		= isset($Settings["TextPadding"]) ? $Settings["TextPadding"] : 4;
     $Algorithm			= isset($Settings["Algorithm"]) ? $Settings["Algorithm"] : ALGORITHM_WEIGHTED;

     $FontSize		= $Object->FontSize;
     $this->X1		= $Object->GraphAreaX1;
     $this->Y1		= $Object->GraphAreaY1;
     $this->X2		= $Object->GraphAreaX2;
     $this->Y2		= $Object->GraphAreaY2;

     $Conflicts = 1; $Jobs = 0; $this->History["MinimumConflicts"] = -1;
     while ($Conflicts != 0 && $Jobs < $Retries )
      {
       $Jobs++;

       /* Compute the initial settings */
       $this->firstPass($Algorithm);

       /* Apply the vectors */
       if ( $Pass > 0 ) 
        {
         for ($i=0; $i<=$Pass; $i++) { $this->doPass(); }
        }

       $Conflicts = $this->lastPass();
       if ( $this->History["MinimumConflicts"] == -1 || $Conflicts < $this->History["MinimumConflicts"] )
        { $this->History["MinimumConflicts"] = $Conflicts; $this->History["Result"] = $this->Data; }
      }

     $Conflicts  = $this->History["MinimumConflicts"];
     $this->Data = $this->History["Result"];

     if ( $CenterGraph ) { $this->center(); }

     /* Draw the connections */
     $Drawn = "";
     foreach($this->Data as $Key => $Settings)
      {
       $X	= $Settings["X"];
       $Y	= $Settings["Y"];

       if ( isset($Settings["Connections"]) )
        {
         foreach ($Settings["Connections"] as $ID => $NodeID)
          {
           if ( !isset($Drawn[$Key]) )    { $Drawn[$Key] = ""; }
           if ( !isset($Drawn[$NodeID]) ) { $Drawn[$NodeID] = ""; }

           if ( isset($this->Data[$NodeID]) && !isset($Drawn[$Key][$NodeID]) && !isset($Drawn[$NodeID][$Key]) )
            {
             $Color = array("R"=>$this->Default["LinkR"],"G"=>$this->Default["LinkG"],"B"=>$this->Default["LinkB"],"Alpha"=>$this->Default["Alpha"]);

             if ( $this->Links != "" )
              {
               if ( isset($this->Links[$Key][$NodeID]["R"]) )
                { $Color = array("R"=>$this->Links[$Key][$NodeID]["R"],"G"=>$this->Links[$Key][$NodeID]["G"],"B"=>$this->Links[$Key][$NodeID]["B"],"Alpha"=>$this->Links[$Key][$NodeID]["Alpha"]); }

               if ( isset($this->Links[$Key][$NodeID]["Ticks"]) )
                 { $Color["Ticks"] = $this->Links[$Key][$NodeID]["Ticks"]; }
              }

             $X2 = $this->Data[$NodeID]["X"];
             $Y2 = $this->Data[$NodeID]["Y"];
             $this->pChartObject->drawLine($X,$Y,$X2,$Y2,$Color);
             $Drawn[$Key][$NodeID] = TRUE;

             if ( isset($this->Links) && $this->Links != "" )
              {
               if ( isset($this->Links[$Key][$NodeID]["Name"]) || isset($this->Links[$NodeID][$Key]["Name"]) )
                {
                 $Name  = isset($this->Links[$Key][$NodeID]["Name"]) ? $this->Links[$Key][$NodeID]["Name"] : $this->Links[$NodeID][$Key]["Name"];
                 $TxtX  = ($X2 - $X)/2 + $X;
                 $TxtY  = ($Y2 - $Y)/2 + $Y;

                 if ( $X <= $X2 )
                  $Angle = (360-$this->getAngle($X,$Y,$X2,$Y2)) % 360;
                 else
                  $Angle = (360-$this->getAngle($X2,$Y2,$X,$Y)) % 360;

                 $Settings          = $Color;
                 $Settings["Angle"] = $Angle;
                 $Settings["Align"] = TEXT_ALIGN_BOTTOMMIDDLE;
                 $this->pChartObject->drawText($TxtX,$TxtY,$Name,$Settings);
                }
              }
            }
          }
        }
      }

     /* Draw the quiet zones */
     if ( $DrawQuietZone )
      {
       foreach($this->Data as $Key => $Settings)
        {
         $X	 = $Settings["X"];
         $Y	 = $Settings["Y"];
         $FreeZone = $Settings["FreeZone"];

         $this->pChartObject->drawFilledCircle($X,$Y,$FreeZone,array("R"=>0,"G"=>0,"B"=>0,"Alpha"=>2));
        }
      }


     /* Draw the nodes */
     foreach($this->Data as $Key => $Settings)
      {
       $X	 = $Settings["X"];
       $Y	 = $Settings["Y"];
       $Name	 = $Settings["Name"];
       $FreeZone = $Settings["FreeZone"];
       $Shape    = $Settings["Shape"];
       $Size     = $Settings["Size"];

       $Color	 = array("R"=>$Settings["R"],"G"=>$Settings["G"],"B"=>$Settings["B"],"Alpha"=>$Settings["Alpha"],"BorderR"=>$Settings["BorderR"],"BorderG"=>$Settings["BorderG"],"BorderB"=>$Settings["BorderB"],"BorderApha"=>$Settings["BorderAlpha"]);

       if ( $Shape == NODE_SHAPE_CIRCLE )
        {
         $this->pChartObject->drawFilledCircle($X,$Y,$Size,$Color);
        }
       elseif ( $Shape == NODE_SHAPE_TRIANGLE )
        {
         $Points = "";
         $Points[] = cos(deg2rad(270)) * $Size + $X; $Points[] = sin(deg2rad(270)) * $Size + $Y;
         $Points[] = cos(deg2rad(45)) * $Size + $X;  $Points[] = sin(deg2rad(45)) * $Size + $Y;
         $Points[] = cos(deg2rad(135)) * $Size + $X; $Points[] = sin(deg2rad(135)) * $Size + $Y;
         $this->pChartObject->drawPolygon($Points,$Color);
        }
       elseif ( $Shape == NODE_SHAPE_SQUARE )
        {
         $Offset = $Size/2; $Size = $Size / 2;
         $this->pChartObject->drawFilledRectangle($X-$Offset,$Y-$Offset,$X+$Offset,$Y+$Offset,$Color);
        }

       if ( $Name != "" )
        {
         $LabelOptions = array("R"=>$this->Labels["R"],"G"=>$this->Labels["G"],"B"=>$this->Labels["B"],"Alpha"=>$this->Labels["Alpha"]);

         if ( $this->Labels["Type"] == LABEL_LIGHT )
          {
           $LabelOptions["Align"] = TEXT_ALIGN_BOTTOMLEFT;
           $this->pChartObject->drawText($X,$Y,$Name,$LabelOptions);
          }
         elseif ( $this->Labels["Type"] == LABEL_CLASSIC )
          {
           $LabelOptions["Align"]         = TEXT_ALIGN_TOPMIDDLE;
           $LabelOptions["DrawBox"]       = TRUE;
           $LabelOptions["BoxAlpha"]      = 50;
           $LabelOptions["BorderOffset"]  = 4;
           $LabelOptions["RoundedRadius"] = 3;
           $LabelOptions["BoxRounded"]    = TRUE;
           $LabelOptions["NoShadow"]      = TRUE;

           $this->pChartObject->drawText($X,$Y+$Size+$TextPadding,$Name,$LabelOptions);
          }
        }
      }

     /* Draw the vectors */
     if ( $DrawVectors )
      {
       foreach($this->Data as $Key => $Settings)
        {
         $X1 = $Settings["X"];
         $Y1 = $Settings["Y"];

         if ( isset($Settings["Vectors"]) && $Settings["Type"] != NODE_TYPE_CENTRAL )
          {
           foreach($Settings["Vectors"] as $ID => $Vector)
            {
             $Type  = $Vector["Type"];
             $Force = $Vector["Force"];
             $Angle = $Vector["Angle"];
             $Factor = $Type == "A" ? $this->MagneticForceA : $this->MagneticForceR;
             $Color  = $Type == "A" ? array("FillR"=>255,"FillG"=>0,"FillB"=>0) : array("FillR"=>0,"FillG"=>255,"FillB"=>0);

             $X2 = cos(deg2rad($Angle)) * $Force * $Factor + $X1;
             $Y2 = sin(deg2rad($Angle)) * $Force * $Factor + $Y1;

             $this->pChartObject->drawArrow($X1,$Y1,$X2,$Y2,$Color);
            }
          }
        }
      }

     return(array("Pass"=>$Jobs,"Conflicts"=>$Conflicts));
    }

   /* Return the distance between two points */
   function getDistance($X1,$Y1,$X2,$Y2)
    { return (sqrt(($X2-$X1)*($X2-$X1)+($Y2-$Y1)*($Y2-$Y1))); }

   /* Return the angle made by a line and the X axis */
   function getAngle($X1,$Y1,$X2,$Y2)
    {
     $Opposite = $Y2 - $Y1; $Adjacent = $X2 - $X1;$Angle = rad2deg(atan2($Opposite,$Adjacent));
     if ($Angle > 0) { return($Angle); } else { return(360-abs($Angle)); }
    }

   function intersect($X1,$Y1,$X2,$Y2,$X3,$Y3,$X4,$Y4)
    {
     $A = (($X3 * $Y4 - $X4 * $Y3) * ($X1 - $X2) - ($X1 * $Y2 - $X2 * $Y1) * ($X3 - $X4));
     $B = (($Y1 - $Y2) * ($X3 - $X4) - ($Y3 - $Y4) * ($X1 - $X2));

     if ( $B == 0 ) { return(FALSE); }
     $Xi = $A / $B;

     $C = ($X1 - $X2);
     if ( $C == 0 ) { return(FALSE); }
     $Yi = $Xi * (($Y1 - $Y2)/$C) + (($X1 * $Y2 - $X2 * $Y1)/$C);

     if ( $Xi >= min($X1,$X2) && $Xi >= min($X3,$X4) && $Xi <= max($X1,$X2) && $Xi <= max($X3,$X4))
      {
       if ( $Yi >= min($Y1,$Y2) && $Yi >= min($Y3,$Y4) && $Yi <= max($Y1,$Y2) && $Yi <= max($Y3,$Y4))
        { return(TRUE); }
      }

      return(FALSE);   
    }
  }
?>