Rack/plugins/community/repos/LindenbergResearch/src/dsp/Lockhart.hpp

#pragma once

#include "WaveShaper.hpp"
#include "HQTrig.hpp"

// constants for Lockhart waveshaper model
#define LOCKHART_RL 7.5e3
#define LOCKHART_R 15e3
#define LOCKHART_VT 25.864e-3
#define LOCKHART_Is 10e-16
#define LOCKHART_THRESHOLD 10e-10


namespace dsp {

   /**
    * @brief Represents one stage of the Lockhart Wavefolder
    */
   struct LockhartWFStage {
   private:

      double fn1, xn1;
      double a, b, d;

   public:

      LockhartWFStage();

      double compute(double x);
   };


   /**
    * Lockhart Wavefolder class
    */
   struct LockhartWavefolder : WaveShaper {

   private:
      LockhartWFStage lh1, lh2, lh3, lh4;

   public:
      explicit LockhartWavefolder(float sr);

      void init() override;
      void invalidate() override;
      void process() override;
      double compute(double x) override;
   };

}