From 3940eadb8125f10e35c75e063cec4d48fbf4514d Mon Sep 17 00:00:00 2001
From: Toh4iem9 <Toh4iem9@forge.mql5.io>
Date: Thu, 1 Jan 2026 13:41:59 +0100
Subject: [PATCH] refactor(indicators): Restored Trend/Level outputs

---
 Include/MyIncludes/Holt_Engine.mqh | 220 +++++++++++++++++------------
 1 file changed, 133 insertions(+), 87 deletions(-)

diff --git a/Include/MyIncludes/Holt_Engine.mqh b/Include/MyIncludes/Holt_Engine.mqh
index 5c4e2ec..ab94cea 100644
--- a/Include/MyIncludes/Holt_Engine.mqh
+++ b/Include/MyIncludes/Holt_Engine.mqh
@@ -1,6 +1,7 @@
 //+------------------------------------------------------------------+
 //|                                                 Holt_Engine.mqh  |
 //|        Core calculation engine for all Holt-based indicators.    |
+//|      VERSION 2.10: Restored Trend/Level outputs.                 |
 //|                                        Copyright 2025, xxxxxxxx  |
 //+------------------------------------------------------------------+
 #property copyright "Copyright 2025, xxxxxxxx"
@@ -8,9 +9,7 @@
 #include <MyIncludes\HeikinAshi_Tools.mqh>
 
 //+==================================================================+
-//|                                                                  |
 //|             CLASS 1: CHoltEngine (Base Class)                    |
-//|                                                                  |
 //+==================================================================+
 class CHoltEngine
   {
@@ -20,16 +19,21 @@ protected:
    double            m_beta;
    int               m_forecast_period;
 
+   //--- Persistent Buffers
    double            m_price[];
+   double            m_level[];
+   double            m_trend[];
 
-   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
+   virtual bool      PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
 
 public:
                      CHoltEngine(void);
    virtual          ~CHoltEngine(void) {};
 
    bool              Init(int period, double alpha, double beta, int forecast_p);
-   void              Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+
+   //--- Updated: Added trend_out and level_out back to signature
+   void              Calculate(int rates_total, int prev_calculated, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
                                double &forecast_out[], double &trend_out[], double &level_out[], double &upper_band_out[], double &lower_band_out[]);
   };
 
@@ -45,9 +49,9 @@ CHoltEngine::CHoltEngine(void) : m_period(0), m_alpha(0.1), m_beta(0.05), m_fore
 //+------------------------------------------------------------------+
 bool CHoltEngine::Init(int period, double alpha, double beta, int forecast_p)
   {
-   m_period          = (period < 2) ? 2 : period;
-   m_alpha           = (alpha <= 0) ? 0.0001 : (alpha >= 1) ? 0.9999 : alpha;
-   m_beta            = (beta <= 0) ? 0.0001 : (beta >= 1) ? 0.9999 : beta;
+   m_period          = 10; // Safe minimum
+   m_alpha           = (alpha <= 0) ? 0.1 : (alpha > 1) ? 1.0 : alpha;
+   m_beta            = (beta <= 0) ? 0.05 : (beta > 1) ? 1.0 : beta;
    m_forecast_period = (forecast_p < 1) ? 1 : forecast_p;
    return true;
   }
@@ -55,121 +59,163 @@ bool CHoltEngine::Init(int period, double alpha, double beta, int forecast_p)
 //+------------------------------------------------------------------+
 //| CHoltEngine: Main Calculation Method                             |
 //+------------------------------------------------------------------+
-void CHoltEngine::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+void CHoltEngine::Calculate(int rates_total, int prev_calculated, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
                             double &forecast_out[], double &trend_out[], double &level_out[], double &upper_band_out[], double &lower_band_out[])
   {
-   if(rates_total < m_period)
+   if(rates_total < 2)
       return;
 
-   ArrayResize(m_price, rates_total);
-   if(!PreparePriceSeries(rates_total, price_type, open, high, low, close))
-      return;
+   int start_index;
+   if(prev_calculated == 0)
+      start_index = 0;
+   else
+      start_index = prev_calculated - 1;
 
-   level_out[0] = m_price[0];
-   trend_out[0] = m_price[1] - m_price[0];
-   forecast_out[0] = level_out[0] + trend_out[0];
-   level_out[1] = m_price[1];
-   trend_out[1] = m_beta * (level_out[1] - level_out[0]) + (1 - m_beta) * trend_out[0];
-   forecast_out[1] = level_out[1] + trend_out[1];
-
-   for(int i = 2; i < rates_total; i++)
+   if(ArraySize(m_price) != rates_total)
      {
-      level_out[i] = m_alpha * m_price[i] + (1 - m_alpha) * (level_out[i-1] + trend_out[i-1]);
-      trend_out[i] = m_beta * (level_out[i] - level_out[i-1]) + (1 - m_beta) * trend_out[i-1];
-      forecast_out[i] = level_out[i] + trend_out[i];
-      upper_band_out[i] = level_out[i] + m_forecast_period * trend_out[i];
-      lower_band_out[i] = level_out[i] - m_forecast_period * trend_out[i];
+      ArrayResize(m_price, rates_total);
+      ArrayResize(m_level, rates_total);
+      ArrayResize(m_trend, rates_total);
+     }
+
+   if(!PreparePriceSeries(rates_total, start_index, price_type, open, high, low, close))
+      return;
+
+   int loop_start = MathMax(2, start_index);
+
+   if(loop_start == 2)
+     {
+      m_level[0] = m_price[0];
+      m_trend[0] = m_price[1] - m_price[0];
+      forecast_out[0] = m_level[0] + m_trend[0];
+
+      m_level[1] = m_price[1];
+      m_trend[1] = m_beta * (m_level[1] - m_level[0]) + (1 - m_beta) * m_trend[0];
+      forecast_out[1] = m_level[1] + m_trend[1];
+
+      // Fill outputs for first bars
+      trend_out[0] = m_trend[0];
+      level_out[0] = m_level[0];
+      upper_band_out[0] = forecast_out[0];
+      lower_band_out[0] = forecast_out[0];
+
+      trend_out[1] = m_trend[1];
+      level_out[1] = m_level[1];
+      upper_band_out[1] = forecast_out[1];
+      lower_band_out[1] = forecast_out[1];
+     }
+
+   for(int i = loop_start; i < rates_total; i++)
+     {
+      m_level[i] = m_alpha * m_price[i] + (1.0 - m_alpha) * (m_level[i-1] + m_trend[i-1]);
+      m_trend[i] = m_beta * (m_level[i] - m_level[i-1]) + (1.0 - m_beta) * m_trend[i-1];
+
+      forecast_out[i] = m_level[i] + m_trend[i];
+
+      // Copy internal state to output buffers
+      trend_out[i] = m_trend[i];
+      level_out[i] = m_level[i];
+
+      double width = m_forecast_period * MathAbs(m_trend[i]);
+      upper_band_out[i] = forecast_out[i] + width;
+      lower_band_out[i] = forecast_out[i] - width;
      }
   }
 
 //+------------------------------------------------------------------+
-//| CHoltEngine: Prepares the standard source price series.          |
+//| Prepare Price (Standard - Optimized)                             |
 //+------------------------------------------------------------------+
-bool CHoltEngine::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+bool CHoltEngine::PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
   {
-   switch(price_type)
+   for(int i = start_index; i < rates_total; i++)
      {
-      case PRICE_OPEN:
-         ArrayCopy(m_price, open, 0, 0, rates_total);
-         break;
-      case PRICE_HIGH:
-         ArrayCopy(m_price, high, 0, 0, rates_total);
-         break;
-      case PRICE_LOW:
-         ArrayCopy(m_price, low, 0, 0, rates_total);
-         break;
-      case PRICE_MEDIAN:
-         for(int i=0; i<rates_total; i++)
+      switch(price_type)
+        {
+         case PRICE_CLOSE:
+            m_price[i] = close[i];
+            break;
+         case PRICE_OPEN:
+            m_price[i] = open[i];
+            break;
+         case PRICE_HIGH:
+            m_price[i] = high[i];
+            break;
+         case PRICE_LOW:
+            m_price[i] = low[i];
+            break;
+         case PRICE_MEDIAN:
             m_price[i] = (high[i]+low[i])/2.0;
-         break;
-      case PRICE_TYPICAL:
-         for(int i=0; i<rates_total; i++)
+            break;
+         case PRICE_TYPICAL:
             m_price[i] = (high[i]+low[i]+close[i])/3.0;
-         break;
-      case PRICE_WEIGHTED:
-         for(int i=0; i<rates_total; i++)
+            break;
+         case PRICE_WEIGHTED:
             m_price[i] = (high[i]+low[i]+2*close[i])/4.0;
-         break;
-      default:
-         ArrayCopy(m_price, close, 0, 0, rates_total);
-         break;
+            break;
+         default:
+            m_price[i] = close[i];
+            break;
+        }
      }
    return true;
   }
 
 //+==================================================================+
-//|                                                                  |
 //|             CLASS 2: CHoltEngine_HA (Heikin Ashi)                |
-//|                                                                  |
 //+==================================================================+
 class CHoltEngine_HA : public CHoltEngine
   {
 private:
    CHeikinAshi_Calculator m_ha_calculator;
+   double            m_ha_open[], m_ha_high[], m_ha_low[], m_ha_close[];
 protected:
-   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]) override;
+   virtual bool      PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]) override;
   };
 
 //+------------------------------------------------------------------+
-//| CHoltEngine_HA: Prepares the Heikin Ashi source price.           |
+//|                                                                  |
 //+------------------------------------------------------------------+
-bool CHoltEngine_HA::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+bool CHoltEngine_HA::PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
   {
-   double ha_open[], ha_high[], ha_low[], ha_close[];
-   ArrayResize(ha_open, rates_total);
-   ArrayResize(ha_high, rates_total);
-   ArrayResize(ha_low, rates_total);
-   ArrayResize(ha_close, rates_total);
-   m_ha_calculator.Calculate(rates_total, open, high, low, close, ha_open, ha_high, ha_low, ha_close);
-
-   switch(price_type)
+   if(ArraySize(m_ha_open) != rates_total)
      {
-      case PRICE_OPEN:
-         ArrayCopy(m_price, ha_open, 0, 0, rates_total);
-         break;
-      case PRICE_HIGH:
-         ArrayCopy(m_price, ha_high, 0, 0, rates_total);
-         break;
-      case PRICE_LOW:
-         ArrayCopy(m_price, ha_low, 0, 0, rates_total);
-         break;
-      case PRICE_MEDIAN:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i])/2.0;
-         break;
-      case PRICE_TYPICAL:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i]+ha_close[i])/3.0;
-         break;
-      case PRICE_WEIGHTED:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i]+2*ha_close[i])/4.0;
-         break;
-      default:
-         ArrayCopy(m_price, ha_close, 0, 0, rates_total);
-         break;
+      ArrayResize(m_ha_open, rates_total);
+      ArrayResize(m_ha_high, rates_total);
+      ArrayResize(m_ha_low, rates_total);
+      ArrayResize(m_ha_close, rates_total);
+     }
+   m_ha_calculator.Calculate(rates_total, start_index, open, high, low, close, m_ha_open, m_ha_high, m_ha_low, m_ha_close);
+
+   for(int i = start_index; i < rates_total; i++)
+     {
+      switch(price_type)
+        {
+         case PRICE_CLOSE:
+            m_price[i] = m_ha_close[i];
+            break;
+         case PRICE_OPEN:
+            m_price[i] = m_ha_open[i];
+            break;
+         case PRICE_HIGH:
+            m_price[i] = m_ha_high[i];
+            break;
+         case PRICE_LOW:
+            m_price[i] = m_ha_low[i];
+            break;
+         case PRICE_MEDIAN:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i])/2.0;
+            break;
+         case PRICE_TYPICAL:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i]+m_ha_close[i])/3.0;
+            break;
+         case PRICE_WEIGHTED:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i]+2*m_ha_close[i])/4.0;
+            break;
+         default:
+            m_price[i] = m_ha_close[i];
+            break;
+        }
      }
    return true;
   }
 //+------------------------------------------------------------------+
-//+------------------------------------------------------------------+