Delta MA

//+------------------------------------------------------------------+
//|                                                     Delta MA.mq4 |
//|                                                               Me |
//|                                                                  |
//+------------------------------------------------------------------+
#property copyright "Me"

#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Red
#property indicator_color2 Blue
#property indicator_color3 Yellow
#property indicator_color4 Violet
//---- input parameters

extern int       period=18;

//---- buffers
double UPPER[];
double LOWER[];
double MID[];
double MA[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,UPPER);
   SetIndexStyle(1,DRAW_LINE);
   SetIndexBuffer(1,LOWER);
   SetIndexStyle(2,DRAW_LINE);
   SetIndexBuffer(2,MID);
   SetIndexStyle(3,DRAW_LINE);
   SetIndexBuffer(3,MA);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   int    counted_bars=IndicatorCounted();
//----
   
   int i,limit;
   
   
   
   if (counted_bars<1)
      limit = Bars - period;
   else
      limit = Bars - counted_bars + 1;
   
   for (i=limit;i>=0;i--)
      {
         MA[i] = iMA(0,0,period,0,MODE_SMA,PRICE_CLOSE,i);
         
         
         // if MA is sloping up, we'll need a trigger below
         if (MA[i]>=MA[i+1])
            {
               LOWER[i] = Close[i+period];
            }
         if (MA[i]<=MA[i+1])
            {
               UPPER[i] = Close[i+period];
            }
         
         // put some yellow paint to fill the gaps, and make a smooth line
         if ((MA[i]>=MA[i+1] && MA[i+1]<=MA[i+2]) ||
             (MA[i]<=MA[i+1] && MA[i+1]>=MA[i+2]))
             {
               MID[i]=Close[i+period];
               MID[i+1] = Close[i+1+period];
             }
         
      }
   
   
//----
   return(0);
  }
//+------------------------------------------------------------------+