//+------------------------------------------------------------------+
//|                                                 Level Sensor.mq4 |
//|                                          Copyright © 2005, Sfen. |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, Sfen"
#property indicator_chart_window
// input parameters
extern int MAX_HISTORY = 500;
extern int STEP = 1;
//----
string OBJECT_PREFIX = "LEVELS";
int ObjectId = 0;
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int init()
  {
   return(0);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
double CSH(int shift)
  {
   return (MathMax(Open[shift], Close[shift]));
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
double CSL(int shift)
  {
   return (MathMin(Open[shift],Close[shift]));
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
string IntToStr(int X)
  {
    return (DoubleToStr(X, 0));
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
string ObGetUniqueName(string Prefix)
  {
   ObjectId++;
   return (Prefix+" "+IntToStr(ObjectId));
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void ObDeleteObjectsByPrefix(string Prefix)
  {
   int L = StringLen(Prefix);
   int i = 0; 
   while(i < ObjectsTotal())
     {
       string ObjName = ObjectName(i);
       if(StringSubstr(ObjName, 0, L) != Prefix) 
         { 
           i++; 
           continue;
         }
       ObjectDelete(ObjName);
     }
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int deinit()
  {
   ObDeleteObjectsByPrefix(OBJECT_PREFIX);
   return(0);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int start()
  {
   string S;
   ObDeleteObjectsByPrefix(OBJECT_PREFIX);
   double HH = 0;
   double LL = 1000000;
   int History = MathMin(Bars,MAX_HISTORY);
   int i, j, k;
   for(i = 1; i < History; i++)
     {
       HH = MathMax(HH, CSH(i));
       LL = MathMin(LL, CSL(i));
     }
   int NumberOfPoints = (HH - LL) / (1.0*Point*STEP) + 1;
   int Count[];
   ArrayResize(Count, NumberOfPoints);
   for(i = 0; i < NumberOfPoints; i++) 
       Count[i] = 0;
   for(i = 1; i < History; i++)
     {
       double C = CSL(i);
       while(C < CSH(i))
         {
           int Index = (C-LL) / (1.0*Point*STEP);
           Count[Index]++;    
           C += 1.0*Point*STEP;
         }
     }
   for(i = 0; i < NumberOfPoints; i++)
     {
       double StartX = Time[5];
       double StartY = LL + 1.0*Point*STEP*i;
       double EndX   = Time[5+Count[i]];
       double EndY   = StartY;
       string ObjName = ObGetUniqueName(OBJECT_PREFIX);
       ObjectDelete(ObjName);
       ObjectCreate(ObjName, OBJ_TREND, 0, StartX, StartY, EndX, EndY);
       ObjectSet(ObjName, OBJPROP_RAY, 0);
       ObjectSet(ObjName, OBJPROP_COLOR, Red);
     }
   return(0);
  }
//+------------------------------------------------------------------+