//+------------------------------------------------------------------+
//|                                             Gann_Multi_Trend.mq4 |
//|                      Copyright © 2011, Mikhail Pashnin (raxxla). |
//|                                        http://www.mql4.com       |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2011, Mikhail Pashnin."
#property link      "http://www.mql4.com"

#property indicator_chart_window
#property indicator_buffers 6
#property indicator_color1 Red
#property indicator_color2 Green
#property indicator_color3 Red
#property indicator_color4 Green
#property indicator_color5 Red
#property indicator_color6 Green

extern int Bars1 = 3;
extern int Bars2 = 5;
extern int Bars3 = 8;

//---- buffers
double Buffer1Up[];
double Buffer1Dn[];
double Buffer2Up[];
double Buffer2Dn[];
double Buffer3Up[];
double Buffer3Dn[];


//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_LINE, STYLE_SOLID, 3);
   SetIndexBuffer(0,Buffer3Up);
   SetIndexStyle(1,DRAW_LINE, STYLE_SOLID, 3);
   SetIndexBuffer(1,Buffer3Dn);

   SetIndexStyle(2,DRAW_LINE, STYLE_SOLID, 2);
   SetIndexBuffer(2,Buffer2Up);
   SetIndexStyle(3,DRAW_LINE, STYLE_SOLID, 2);
   SetIndexBuffer(3,Buffer2Dn);

   SetIndexStyle(4,DRAW_LINE, STYLE_SOLID, 1);
   SetIndexBuffer(4,Buffer1Up);
   SetIndexStyle(5,DRAW_LINE, STYLE_SOLID, 1);
   SetIndexBuffer(5,Buffer1Dn);
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   int    counted_bars=IndicatorCounted();
//----

   if(Bars<=Bars1) return(0);
   
   if (counted_bars<0) return(-1);
//---- last counted bar will be recounted
   if (counted_bars>0) counted_bars--;
   
   int pos=Bars-counted_bars-Bars3;

   if(Bars1>0)
   { 
      while(pos>=0)
      {
         SetBufferData(Buffer1Up, Buffer1Dn, Bars1, pos);
         pos--;
      }
   }

   pos=Bars-counted_bars-Bars1;

   if(Bars2>0)
   { 
      while(pos>=0)
      {
         SetBufferData(Buffer2Up, Buffer2Dn, Bars2, pos);
         pos--;
      }
   }

   pos=Bars-counted_bars-Bars1;

   if(Bars3>0)
   { 
      while(pos>=0)
      {
         SetBufferData(Buffer3Up, Buffer3Dn, Bars3, pos);
         pos--;
      }
   }

   Comment("Gunn_Multi_Trend("+Bars1+"/"+Bars2+"/"+Bars3+")");
   
//----
   return(0);
  }
//+------------------------------------------------------------------+

void SetBufferData(double& up[], double& dn[], int bars, int index)
{
   int max_i = iHighest(NULL, 0, MODE_HIGH, bars, index+1);
   int min_i = iLowest(NULL, 0, MODE_LOW, bars, index+1);

   double max = High[max_i];
   double min = Low[min_i];
   
   if(High[index]>=max && Low[index]>min)
   {
      dn[index]=EMPTY_VALUE;
      up[index]=High[index];
      
      return;
   }

   if(Low[index]<=min && High[index]<max)
   {
      up[index]=EMPTY_VALUE;
      dn[index]=Low[index];
      
      return;
   }

   if(Low[index]<=min && High[index]>=max)
   {
      up[index]=High[index];
      dn[index]=Low[index];
      
      return;
   }

   up[index]=up[index+1];
   dn[index]=dn[index+1];

}