PidWithExternalState.h

#pragma once
 
#include <limits>
 
struct PidSettings
{
   double P = 0.0; 
   double I = 0.0; 
   double D = 0.0; 
 
   double minOut = -std::numeric_limits<double>::infinity(); 
   double maxOut = std::numeric_limits<double>::infinity();  
 
   double initOutput        = 0.0;                                     
   double maxIntegratorPart = std::numeric_limits<double>::infinity(); 
   double maxDerivativePart = std::numeric_limits<double>::infinity(); 
};
 
class PidWithExternalState
{
public:
   void Initialize(const PidSettings& settings);
 
   double Output(double error, double integratedError, double time) const;
 
   double IntegralRate(double error, double integratedError) const;
 
   void Accept(double error, double time);
 
private:
   double IntegralPart(double integratedError) const;
 
   PidSettings m_settings;
   bool        m_hasLast       = false;
   double      m_lastError     = 0.0;
   double      m_lastTime      = 0.0;
   double      m_heldErrorRate = 0.0; 
};