//+------------------------------------------------------------------+
//|                                                    TrendLine.mq5 |
//|                                             Copyright 2024, AM2. |
//|                                      http://www.forexsystems.biz |
//+------------------------------------------------------------------+
#property copyright "Copyright 2024, AM2."
#property link      "http://www.forexsystems.biz"
#property version   "1.00"
#property indicator_chart_window

#property indicator_buffers 2
#property indicator_plots   2
#property indicator_color1 clrLime
#property indicator_color2 clrRed
#property indicator_width1 4
#property indicator_width2 4
#property indicator_type1 DRAW_LINE
#property indicator_type2 DRAW_LINE

#property strict

double up[];
double dn[];

input int Count = 10;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- indicator buffers mapping
   SetIndexBuffer(0,up,INDICATOR_DATA);
   SetIndexBuffer(1,dn,INDICATOR_DATA);
//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//---
   for(int i=0; i<rates_total; i++)
     {
      double hi=iHighest(NULL,0,MODE_HIGH,Count,i);
      double lo=iLowest(NULL,0,MODE_LOW,Count,i);

      if(close[i]>(hi+lo)/2)
        {
         up[i]=(hi+lo)/2;
        }

      if(close[i]<(hi+lo)/2)
        {
         dn[i]=(hi+lo)/2;
        }
     }

//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+