Bar Difference

ÿþ//+------------------------------------------------------------------+

//|                                               Bar Difference.mq5 |

//|                              Copyright © 2021, Vladimir Karputov |

//|                     https://www.mql5.com/ru/market/product/43161 |

//+------------------------------------------------------------------+

#property copyright "Copyright © 2021, Vladimir Karputov"

#property link      "https://www.mql5.com/ru/market/product/43161"

#property version   "1.00"

#property indicator_separate_window

#property indicator_buffers 1

#property indicator_plots   1

//--- plot Difference

#property indicator_label1  "Difference"

#property indicator_type1   DRAW_HISTOGRAM

#property indicator_color1  clrLightGreen

#property indicator_style1  STYLE_SOLID

#property indicator_width1  3

//--- indicator buffers

double   DifferenceBuffer[];

//+------------------------------------------------------------------+

//| Custom indicator initialization function                         |

//+------------------------------------------------------------------+

int OnInit()

  {

//--- indicator buffers mapping

   SetIndexBuffer(0,DifferenceBuffer,INDICATOR_DATA);

//---

   IndicatorSetInteger(INDICATOR_DIGITS,Digits());

//---

   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[])

  {

   if(rates_total<3)

      return(0);

//---

   int limit=prev_calculated-1;

   if(prev_calculated==0)

     {

      DifferenceBuffer[0]=0.0;

      limit=1;

     }

   for(int i=limit; i<rates_total; i++)

     {

      double diff_prev=(open[i-1]<close[i-1])?close[i-1]-open[i-1]:open[i-1]-close[i-1];

      double diff_curr=(open[i  ]<close[i  ])?close[i  ]-open[i  ]:open[i  ]-close[i  ];

      DifferenceBuffer[i]=MathAbs(diff_curr-diff_prev);

     }

//--- return value of prev_calculated for next call

   return(rates_total);

  }

//+------------------------------------------------------------------+