A C++ class to smooth out DSP parameters

Smoother.h

#ifndef SMOOTHER_H
#define SMOOTHER_H

#include <math.h>

class Smoother {
private:
  double mSampleRate;
  double mLastOutput{};
  double mA{};
  double mB{};

public:
  Smoother(double pInitialSmoothingTimeInMs, double pSampleRate) : mSampleRate(pSampleRate) {
    setSmoothingTime(pInitialSmoothingTimeInMs);
  }

  double process(double pInput) {
    mLastOutput = (pInput * mB) + (mLastOutput * mA);
    return mLastOutput;
  }

  void setSmoothingTime(double pSmoothingTimeInMs) {
    mA = exp(-(M_PI * 2) / (pSmoothingTimeInMs * 0.001 * mSampleRate));
    mB = 1.0 - mA;
  }
};

#endif // SMOOTHER_H