text: #pragma once
  
  #include "Filter.h"
  
  namespace filter {
  
  class Billow: public Filter
  {
  public:
    Billow(double f = 1.0, double l = 2.0, double p = 0.5, int o = 6, int s = 0);
  
    virtual double GetValue(double x, double y, double z) const;
  
  protected:
    double _Frequency;
    double _Lacunarity;
    double _Persistence;
    int _cOctaves;
    int _Seed;
  };
  
  }
  