//+------------------------------------------------------------------+
//|                                           PatienceFX_Volumes.mq4 |
//|                                  Copyright 2025, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "3.00"
#property strict
#property indicator_separate_window
#property indicator_buffers 1

#property indicator_color1 clrWhite

double v[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- indicator buffers mapping
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,v);
//---
   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[])
  {
//---
   // Calculate starting index to update only necessary bars (including last bar for live updates)
   int start = (prev_calculated > 0) ? prev_calculated - 1 : 0;
   
   // Update the buffer using the provided volume array
   for (int i = start; i < rates_total; i++)
   {
      v[i] = (int)tick_volume[i];
   }
//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+