Horizontal lines(levels) indicator lagging MT5

[timmytrade]

I have noticed that this level indicator on chart causes bad price lagging when US market opens and trading activity steps in.
How to reduce the number of lines so that lines are drawn only in the active screen?
At the moment lot of lines will be drawn.

#property indicator_chart_window
#property version "2.0"
#property strict

input string H=" --- Mode_Settings ---";
input bool Show_00_50_Levels=true;
input bool Show_20_80_Levels=true;
input color Level_00_Color=C'187,187,247';
input color Level_50_Color=C'147,221,166';
input color Level_20_Color=C'219,210,176';
input color Level_80_Color=C'219,210,176';

double dXPoint=1;
double Div=0;
double i=0;
double HighPrice= 0;
double LowPrice = 0;
int iDigits;
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int OnInit()
  {
   iDigits=_Digits;
   if(_Digits==5 || _Digits==3)
      dXPoint=10;
   if(_Digits==3)
      iDigits=2;
   if(_Digits==5)
      iDigits=4;

   Div=0.1/(_Point*dXPoint);
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
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[]
)
  {
   ArraySetAsSeries(high,true);
   ArraySetAsSeries(low,true);
   ArraySetAsSeries(time,true);
   int ih=ArrayMaximum(high, 2);
   if(ih<0)
      return rates_total;
   int il=ArrayMinimum(low, 2);
   if(il<0)
      return rates_total;
   HighPrice= MathRound((high[ih]+1)*Div);
   LowPrice = MathRound((low[il]-1)*Div);

   if(Show_00_50_Levels)
     {
      for(i=LowPrice; i<=HighPrice; i++)
        {
         if(MathMod(i,5)==0.0)
           {
            string name="RoundPrice "+DoubleToString(i,0);
            if(ObjectFind(0,name)!=0)
              {
               ObjectCreate(0,name,OBJ_HLINE,0,time[1],i/Div);
               ObjectSetInteger(0,name,OBJPROP_STYLE,STYLE_SOLID);
               ObjectSetInteger(0,name,OBJPROP_WIDTH,1);
               ObjectSetInteger(0,name,OBJPROP_BACK,true);

               if(MathMod(i,10)==0.0)
                  ObjectSetInteger(0,name,OBJPROP_COLOR,Level_00_Color);
               else
                  ObjectSetInteger(0,name,OBJPROP_COLOR,Level_50_Color);
              }
           }
        }

     }

   if(Show_20_80_Levels)
     {
      for(i=LowPrice; i<=HighPrice; i++)
        {
         if(StringSubstr(DoubleToString(i/Div,iDigits),StringLen(DoubleToString(i/Div,iDigits))-2,2)=="20")
           {
            string name="RoundPrice "+DoubleToString(i,0);
            if(ObjectFind(0,name)!=0)
              {
               ObjectCreate(0,name,OBJ_HLINE,0,time[1],i/Div);
               ObjectSetInteger(0,name,OBJPROP_STYLE,STYLE_SOLID);
               ObjectSetInteger(0,name,OBJPROP_COLOR,Level_20_Color);
               ObjectSetInteger(0,name,OBJPROP_BACK,true);
              }
           }
         if(StringSubstr(DoubleToString(i/Div,iDigits),StringLen(DoubleToString(i/Div,iDigits))-2,2)=="80")
           {
            string name="RoundPrice "+DoubleToString(i,0);
            if(ObjectFind(0,name)!=0)
              {
               ObjectCreate(0,name,OBJ_HLINE,0,time[1],i/Div);
               ObjectSetInteger(0,name,OBJPROP_STYLE,STYLE_SOLID);
               ObjectSetInteger(0,name,OBJPROP_COLOR,Level_80_Color);
               ObjectSetInteger(0,name,OBJPROP_BACK,true);
              }
           }
        }
     }
   return(rates_total);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   Comment("");
   ObjectsDeleteAll(0,"Round");
  }
//+------------------------------------------------------------------+