//------------------------------------------------------------------
#property copyright "www.forex-tsd.com"
#property link      "www.forex-tsd.com"
//------------------------------------------------------------------
#property indicator_separate_window
#property indicator_buffers 4
#property indicator_plots   2
#property indicator_label1  "T3 velocity histo"
#property indicator_type1   DRAW_COLOR_HISTOGRAM
#property indicator_color1  clrLimeGreen,clrPaleVioletRed
#property indicator_style1  STYLE_SOLID
#property indicator_width1  1
#property indicator_label2  "T3 velocity"
#property indicator_type2   DRAW_COLOR_LINE
#property indicator_color2  clrLimeGreen,clrPaleVioletRed
#property indicator_style2  STYLE_SOLID
#property indicator_width2  3

//
//
//
//
//

enum enPrices
{
   pr_close,      // Close
   pr_open,       // Open
   pr_high,       // High
   pr_low,        // Low
   pr_median,     // Median
   pr_typical,    // Typical
   pr_weighted,   // Weighted
   pr_average     // Average (high+low+oprn+close)/4
};

input double   T3Period    = 14;       // T3 velocity calculation period
input double   T3Hot       = 1.0;      // T3 hot value
input bool     T3Original  = false;    // T3 original Tillson calculation?
input enPrices Price       = pr_close; // Price to use

//
//
//
//
//
//

double vel[];
double velh[];
double colorBuffer[];
double colorBufferh[];

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

int OnInit()
{
   SetIndexBuffer(0,velh,INDICATOR_DATA); 
   SetIndexBuffer(1,colorBufferh,INDICATOR_COLOR_INDEX); 
   SetIndexBuffer(2,vel,INDICATOR_DATA); 
   SetIndexBuffer(3,colorBuffer,INDICATOR_COLOR_INDEX); 
   return(0);
}

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

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[])
{

   //
   //
   //
   //
   //

   for (int i=(int)MathMax(prev_calculated-1,0); i<rates_total; i++)
   {
      double price = getPrice(Price,open,close,high,low,i,rates_total);
             vel[i]  = iT3(price,T3Period,T3Hot,T3Original,i,rates_total,0)-iT3(price,T3Period,T3Hot/2.0,T3Original,i,rates_total,1);      
             velh[i] = vel[i];
             if (i>0)
             {
                colorBuffer[i]  = colorBuffer[i-1];
                colorBufferh[i] = colorBufferh[i-1];
                    if (vel[i] > vel[i-1]) colorBuffer[i] = 0;
                    if (vel[i] < vel[i-1]) colorBuffer[i] = 1;
                    if (vel[i] > 0)        colorBufferh[i]= 0;
                    if (vel[i] < 0)        colorBufferh[i]= 1;
             }                    
   }
   return(rates_total);
}


//------------------------------------------------------------------
//
//------------------------------------------------------------------
//
//
//
//
//

double workT3[][12];
double workT3Coeffs[][12];
#define _period 0
#define _c1     1
#define _c2     2
#define _c3     3
#define _c4     4
#define _alpha  5

//
//
//
//
//

double iT3(double price, double period, double hot, bool original, int r, int bars, int instanceNo=0)
{
   if (ArrayRange(workT3,0) != bars)                ArrayResize(workT3,bars);
   if (ArrayRange(workT3Coeffs,0) < (instanceNo+1)) ArrayResize(workT3Coeffs,instanceNo+1);

   if (workT3Coeffs[instanceNo][_period] != period)
   {
     workT3Coeffs[instanceNo][_period] = period;
        double a = hot;
            workT3Coeffs[instanceNo][_c1] = -a*a*a;
            workT3Coeffs[instanceNo][_c2] = 3*a*a+3*a*a*a;
            workT3Coeffs[instanceNo][_c3] = -6*a*a-3*a-3*a*a*a;
            workT3Coeffs[instanceNo][_c4] = 1+3*a+a*a*a+3*a*a;
            if (original)
                 workT3Coeffs[instanceNo][_alpha] = 2.0/(1.0 + period);
            else workT3Coeffs[instanceNo][_alpha] = 2.0/(2.0 + (period-1.0)/2.0);
   }
   
   //
   //
   //
   //
   //
   
   int buffer = instanceNo*6;
   if (r == 0)
      {
         workT3[r][0+buffer] = price;
         workT3[r][1+buffer] = price;
         workT3[r][2+buffer] = price;
         workT3[r][3+buffer] = price;
         workT3[r][4+buffer] = price;
         workT3[r][5+buffer] = price;
      }
   else
      {
         workT3[r][0+buffer] = workT3[r-1][0+buffer]+workT3Coeffs[instanceNo][_alpha]*(price              -workT3[r-1][0+buffer]);
         workT3[r][1+buffer] = workT3[r-1][1+buffer]+workT3Coeffs[instanceNo][_alpha]*(workT3[r][0+buffer]-workT3[r-1][1+buffer]);
         workT3[r][2+buffer] = workT3[r-1][2+buffer]+workT3Coeffs[instanceNo][_alpha]*(workT3[r][1+buffer]-workT3[r-1][2+buffer]);
         workT3[r][3+buffer] = workT3[r-1][3+buffer]+workT3Coeffs[instanceNo][_alpha]*(workT3[r][2+buffer]-workT3[r-1][3+buffer]);
         workT3[r][4+buffer] = workT3[r-1][4+buffer]+workT3Coeffs[instanceNo][_alpha]*(workT3[r][3+buffer]-workT3[r-1][4+buffer]);
         workT3[r][5+buffer] = workT3[r-1][5+buffer]+workT3Coeffs[instanceNo][_alpha]*(workT3[r][4+buffer]-workT3[r-1][5+buffer]);
      }

   //
   //
   //
   //
   //
   
   return(workT3Coeffs[instanceNo][_c1]*workT3[r][5+buffer] + 
          workT3Coeffs[instanceNo][_c2]*workT3[r][4+buffer] + 
          workT3Coeffs[instanceNo][_c3]*workT3[r][3+buffer] + 
          workT3Coeffs[instanceNo][_c4]*workT3[r][2+buffer]);
}

//------------------------------------------------------------------
//                                                                  
//------------------------------------------------------------------
//
//
//
//
//

double getPrice(enPrices price, const double& open[], const double& close[], const double& high[], const double& low[], int i, int bars)
{
   switch (price)
   {
      case pr_close:     return(close[i]);
      case pr_open:      return(open[i]);
      case pr_high:      return(high[i]);
      case pr_low:       return(low[i]);
      case pr_median:    return((high[i]+low[i])/2.0);
      case pr_typical:   return((high[i]+low[i]+close[i])/3.0);
      case pr_weighted:  return((high[i]+low[i]+close[i]+close[i])/4.0);
      case pr_average:   return((high[i]+low[i]+close[i]+open[i])/4.0);
   }
   return(0);
}