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#ifndef PROPORTIONAL_HPP_
#define PROPORTIONAL_HPP_

#include <labust/math/NumberManipulation.hpp>
#include <labust/control/LimitPolicies.hpp>

namespace labust
{
  namespace control
  {
    /**
     * This class implements a proportional behaviour. We use this object to support
     * input/output limitations.
     */
    template <class LimitPolicy = NoLimits>
    class Proportional : public LimitPolicy
    {
    public:
      /**
       * Generic constructor.
       *
       * \param Kp Gain of the proportional action.
       */
      Proportional(double Kp = 1): Kp(Kp){};

      /**
       * This method sets the proportional gain.
       *
       * \param Kp Proportional gain
       */
      inline void setKp(double Kp){this->Kp = Kp;};
      /**
       * This method performs one proportional calculation.
       *
       * \param input Input into the proportional  action.
       * \return Processed input of the proportional action.
       */
      inline double step(double input = 0) {return Kp*input;};

    private:
      /**
       * Proportional gain.
       */
      double Kp;
    };

    /**
     * Specialization when we use limits.
     */
    template<>
    inline double Proportional<UseLimits>::step(double input)
    {
      return labust::math::coerce(Kp*input,limits);
    };
  }
}
/* PROPORTIONAL_HPP_ */
#endif
