ZZS

//+------------------------------------------------------------------+
//|                                                      ZigZagS.mq4 |
//+------------------------------------------------------------------+

#property indicator_chart_window
#property indicator_buffers 1
#property indicator_color1 Red
//---- indicator parameters
extern int ExtDepth=12;
extern int ExtDeviation=5;
extern int ExtBackstep=3;
extern int nBars=150;
//---- indicator buffers
double ExtMapBuffer[];
double ExtMapBuffer2[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   IndicatorBuffers(2);
//---- drawing settings
   SetIndexStyle(0,DRAW_SECTION);
//---- indicator buffers mapping
   SetIndexBuffer(0,ExtMapBuffer);
   SetIndexBuffer(1,ExtMapBuffer2);
   SetIndexEmptyValue(0,0.0);
   ArraySetAsSeries(ExtMapBuffer,true);
   ArraySetAsSeries(ExtMapBuffer2,true);
//---- indicator short name
   IndicatorShortName("ZigZag("+ExtDepth+","+ExtDeviation+","+ExtBackstep+")");
//---- initialization done
   return(0);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int start() {
  int    shift, back, lasthighpos, lastlowpos, LoopBegin,k;
  double val, res;
  double curlow, curhigh, lasthigh, lastlow;

 	if (nBars==0) LoopBegin=Bars-ExtDepth;
  else LoopBegin=nBars;
  LoopBegin=MathMin(Bars-ExtDepth, LoopBegin);

  for(shift=LoopBegin; shift>=0; shift--) {
    val=Low[Lowest(NULL,0,MODE_LOW,ExtDepth,shift)];
    if(val==lastlow) val=0.0;
    else 
        { 
         lastlow=val; 
         if((Low[shift]-val)>(ExtDeviation*Point)) val=0.0;
         else
           {
            for(back=1; back<=ExtBackstep; back++)
              {
               res=ExtMapBuffer[shift+back];
               if((res!=0)&&(res>val)) ExtMapBuffer[shift+back]=0.0; 
              }
           }
        } 
      ExtMapBuffer[shift]=val;
      //--- high
      val=High[Highest(NULL,0,MODE_HIGH,ExtDepth,shift)];
      if(val==lasthigh) val=0.0;
      else 
        {
         lasthigh=val;
         if((val-High[shift])>(ExtDeviation*Point)) val=0.0;
         else
           {
            for(back=1; back<=ExtBackstep; back++)
              {
               res=ExtMapBuffer2[shift+back];
               if((res!=0)&&(res<val)) ExtMapBuffer2[shift+back]=0.0; 
              } 
           }
        }
      ExtMapBuffer2[shift]=val;
     }

   // final cutting 
   lasthigh=-1; lasthighpos=-1;
   lastlow=-1;  lastlowpos=-1;

   for(shift=Bars-ExtDepth; shift>=0; shift--)
     {
      curlow=ExtMapBuffer[shift];
      curhigh=ExtMapBuffer2[shift];
      if((curlow==0)&&(curhigh==0)) continue;
      //---
      if(curhigh!=0)
        {
         if(lasthigh>0) 
           {
            if(lasthigh<curhigh) ExtMapBuffer2[lasthighpos]=0;
            else ExtMapBuffer2[shift]=0;
           }
         //---
         if(lasthigh<curhigh || lasthigh<0)
           {
            lasthigh=curhigh;
            lasthighpos=shift;
           }
         lastlow=-1;
        }
      //----
      if(curlow!=0)
        {
         if(lastlow>0)
           {
            if(lastlow>curlow) ExtMapBuffer[lastlowpos]=0;
            else ExtMapBuffer[shift]=0;
           }
         //---
         if((curlow<lastlow)||(lastlow<0))
           {
            lastlow=curlow;
            lastlowpos=shift;
           } 
         lasthigh=-1;
        }
     }
  
   for(shift=Bars-1; shift>=0; shift--)
     {
      if(shift>=Bars-ExtDepth) {ExtMapBuffer[shift]=0.0;k=0;}
      else
        {
         res=ExtMapBuffer2[shift];
         if(res!=0.0) ExtMapBuffer[shift]=res;
        }
     }
  }