//+------------------------------------------------------------------+
//|                                                   带箭头信号的MACD.mq4 |
//|                                          Copyright 2023, 100w123 |
//|                                              https://100w123.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2023, 100w123"
#property link      "https://100w123.com"
#property version   "1.00"
#property strict

#property indicator_separate_window
#property indicator_buffers 4
#property indicator_color1 clrSilver
#property indicator_width1 1
#property indicator_color2 clrRed
#property indicator_width2 1
#property indicator_style2 STYLE_DOT
#property indicator_color3 clrLightBlue
#property indicator_width3 2
#property indicator_color4 clrLightPink
#property indicator_width4 2

extern int  FastEMA_Period = 12;
extern int  SlowEMA_Period = 26;
extern int  Signal_Period  = 9;

double macd[];
double macd_sig[];
double up[];
double dn[];
double fast_ema[];
double slow_ema[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit() {
    IndicatorBuffers(6);

    SetIndexBuffer(0, macd);
    SetIndexStyle(0, DRAW_HISTOGRAM);
    SetIndexBuffer(1, macd_sig);
    SetIndexStyle(1, DRAW_LINE);

    SetIndexBuffer(2, up);
    SetIndexStyle(2, DRAW_ARROW);
    SetIndexBuffer(3, dn);
    SetIndexStyle(3, DRAW_ARROW);

    SetIndexArrow(2, 233);
    SetIndexArrow(3, 234);

    SetIndexBuffer(4, fast_ema);
    SetIndexBuffer(5, slow_ema);

    SetIndexLabel(0, "MACD");
    SetIndexLabel(1, "Signal");

    string short_name = "MACD(" + (string)FastEMA_Period + ",";
    short_name += (string)SlowEMA_Period + ",";
    short_name += (string)Signal_Period + ")";
    IndicatorShortName(short_name);

    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[]) {
    int i, j;
    int limit;
    if (prev_calculated == 0)
        limit = rates_total - 1;
    else
        limit = rates_total - prev_calculated;

    for (i = limit; i >= 0; i--) {
        fast_ema[i] = iMA(NULL, 0, FastEMA_Period, 0, MODE_EMA, PRICE_CLOSE, i);
        slow_ema[i] = iMA(NULL, 0, SlowEMA_Period, 0, MODE_EMA, PRICE_CLOSE, i);

        macd[i] = fast_ema[i] - slow_ema[i];

        if (i + Signal_Period <= Bars) {
            macd_sig[i] = 0;
            for (j = 0; j < Signal_Period; j++) macd_sig[i] += macd[i + j];
            macd_sig[i] /= Signal_Period;
        }

        if (i + Signal_Period < Bars) {

            up[i] = EMPTY_VALUE;
            dn[i] = EMPTY_VALUE;

            if (macd[i + 1] <= macd_sig[i + 1] && macd[i] > macd_sig[i]) up[i] = macd_sig[i];
            if (macd[i + 1] >= macd_sig[i + 1] && macd[i] < macd_sig[i]) dn[i] = macd_sig[i];
        }
    }

    return(rates_total);
}
//+------------------------------------------------------------------+