【MQL4】ピンバーと包み足を自動検出して矢印表示するインジケーターの作り方(数値での見分け方つき)

//+------------------------------------------------------------------+
//|                                        PinbarEngulfingArrow.mq4   |
//|                     Copyright 2026, FX-EA System Project Creator |
//|                        https://creator.fx-ea-system-project.com/ |
//+------------------------------------------------------------------+
#property copyright "Copyright 2026, FX-EA System Project Creator"
#property link      "https://creator.fx-ea-system-project.com/"
#property version   "1.00"
#property strict
#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Lime
#property indicator_width1 2
#property indicator_color2 Red
#property indicator_width2 2
#property indicator_color3 DodgerBlue
#property indicator_width3 2
#property indicator_color4 Orange
#property indicator_width4 2

input double BodyRatioMax = 0.35; //実体が値幅の何%以下ならピンバー候補とするか
input double WickRatioMin = 2.0;  //長いヒゲが短いヒゲの何倍以上ならピンバーとするか

double PinBullArrow[];
double PinBearArrow[];
double EngulfBullArrow[];
double EngulfBearArrow[];

int OnInit()
  {
   SetIndexBuffer(0, PinBullArrow);
   SetIndexStyle(0, DRAW_ARROW);
   SetIndexArrow(0, 233);

   SetIndexBuffer(1, PinBearArrow);
   SetIndexStyle(1, DRAW_ARROW);
   SetIndexArrow(1, 234);

   SetIndexBuffer(2, EngulfBullArrow);
   SetIndexStyle(2, DRAW_ARROW);
   SetIndexArrow(2, 159);

   SetIndexBuffer(3, EngulfBearArrow);
   SetIndexStyle(3, DRAW_ARROW);
   SetIndexArrow(3, 159);

   IndicatorShortName("Pinbar/Engulfing Arrow");
   return(INIT_SUCCEEDED);
  }

bool IsPinBar(int i, bool &bullish)
  {
   double range = High[i] - Low[i];
   if(range <= 0)
      return(false);

   double body = MathAbs(Close[i] - Open[i]);
   if(body / range > BodyRatioMax)
      return(false);

   double upperWick = High[i] - MathMax(Open[i], Close[i]);
   double lowerWick = MathMin(Open[i], Close[i]) - Low[i];

   if(lowerWick >= upperWick * WickRatioMin && lowerWick > 0)
     {
      bullish = true; // 下ヒゲが長い=反転上昇の目安
      return(true);
     }
   if(upperWick >= lowerWick * WickRatioMin && upperWick > 0)
     {
      bullish = false; // 上ヒゲが長い=反転下落の目安
      return(true);
     }
   return(false);
  }

bool IsEngulfing(int i, bool &bullish)
  {
   bool prevBear = Close[i + 1] < Open[i + 1];
   bool prevBull = Close[i + 1] > Open[i + 1];

   bool nowBull = Close[i] > Open[i];
   bool nowBear = Close[i] < Open[i];

   if(prevBear && nowBull && Open[i] <= Close[i + 1] && Close[i] >= Open[i + 1])
     {
      bullish = true;
      return(true);
     }
   if(prevBull && nowBear && Open[i] >= Close[i + 1] && Close[i] <= Open[i + 1])
     {
      bullish = false;
      return(true);
     }
   return(false);
  }

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[])
  {
   int needed = 3;
   if(rates_total < needed)
      return(0);

   int limit = (prev_calculated == 0) ? rates_total - needed : rates_total - prev_calculated + 1;

   for(int i = limit; i >= 0; i--)
     {
      PinBullArrow[i]    = EMPTY_VALUE;
      PinBearArrow[i]    = EMPTY_VALUE;
      EngulfBullArrow[i] = EMPTY_VALUE;
      EngulfBearArrow[i] = EMPTY_VALUE;

      bool pinBullish;
      if(IsPinBar(i, pinBullish))
        {
         if(pinBullish)
            PinBullArrow[i] = Low[i] - 10 * Point;
         else
            PinBearArrow[i] = High[i] + 10 * Point;
        }

      bool engulfBullish;
      if(i + 1 < rates_total && IsEngulfing(i, engulfBullish))
        {
         if(engulfBullish)
            EngulfBullArrow[i] = Low[i] - 20 * Point;
         else
            EngulfBearArrow[i] = High[i] + 20 * Point;
        }
     }

   return(rates_total);
  }