Angle.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#pragma once
 
#include <TMath.h>
 
#include <utility>
 
namespace Belle2 {
  class BaseAngle {
  public:
    BaseAngle(double angle, double error) : m_angle(angle), m_error(error) {};
 
    virtual ~BaseAngle() {};
 
    double getAngle() const { return m_angle; }
 
    double getError() const { return m_error; }
 
    double getAngleInDeg() const { return m_angle * TMath::RadToDeg(); }
 
    double getErrorInDeg() const { return m_error * TMath::RadToDeg(); }
 
  protected:
 
    double m_angle; 
    double m_error; 
  };
 
 
  class ThetaAngle : public BaseAngle {
  public:
    ThetaAngle(double angle, double error) : BaseAngle(angle, error)
    {
      m_angle = std::fabs(std::fmod(m_angle, TMath::Pi()));
    }
 
    bool contains(const ThetaAngle& angle) const
    {
      return containsIn(angle, 1);
    }
 
    bool containsIn(const ThetaAngle& angle, double sigma) const
    {
      double angularDistance, sigmaError;
      /* Distance in the range [0, pi]. */
      angularDistance = std::abs(m_angle - angle.getAngle());
      sigmaError = sigma * (m_error + angle.getError());
      return angularDistance < sigmaError;
    }
 
  };
 
 
  class PhiAngle : public BaseAngle {
  public:
    PhiAngle(double angle, double error) : BaseAngle(angle, error)
    {
      /* Angle in the range (-2 * pi, 2 * pi). */
      m_angle = std::fmod(m_angle, TMath::TwoPi());
      if (m_angle < 0)
        m_angle = m_angle + TMath::TwoPi();
    }
 
    bool contains(const PhiAngle& angle) const
    {
      return containsIn(angle, 1);
    }
 
    bool containsIn(const PhiAngle& angle, double sigma) const
    {
      double angularDistance, shortestAngularDistance, sigmaError;
      /* Distance in the range [0, 2 * pi). */
      angularDistance = std::abs(m_angle - angle.getAngle());
      /* Distance in the range [0, pi]. */
      if (angularDistance > TMath::Pi())
        shortestAngularDistance = TMath::TwoPi() - angularDistance;
      else
        shortestAngularDistance = angularDistance;
      sigmaError = sigma * (m_error + angle.getError());
      return shortestAngularDistance < sigmaError;
    }
 
  };
 
}