MagneticFieldComponent3D.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 <framework/dbobjects/MagneticFieldComponent.h>
#include <framework/geometry/B2Vector3.h>
 
#include <vector>
 
namespace Belle2 {
  class MagneticFieldComponent3D final: public MagneticFieldComponent {
  public:
    MagneticFieldComponent3D(): MagneticFieldComponent(false) {};
    MagneticFieldComponent3D(double minR, double maxR, double minZ, double maxZ,
                             int nR, int nPhi, int nZ,
                             std::vector<ROOT::Math::XYZVector>&& fieldmap):
      MagneticFieldComponent(true), m_minR(minR), m_maxR(maxR), m_minZ(minZ), m_maxZ(maxZ), m_mapSize{nR, nPhi, nZ},
      m_gridPitch{static_cast<float>((maxR - minR) / (nR - 1)), static_cast<float>(M_PI / (nPhi - 1)), static_cast<float>((maxZ - minZ) / (nZ - 1))},
      m_invgridPitch{static_cast<float>(1. / m_gridPitch[0]), static_cast<float>(1. / m_gridPitch[1]), static_cast<float>(1. / m_gridPitch[2])},
      m_bmap(fieldmap)
    {}

    bool inside(const ROOT::Math::XYZVector& pos) const override
    {
      const float z = pos.Z();
      if (z < m_minZ || z > m_maxZ) return false;
      const float r = pos.Rho();
      return (r >= m_minR && r <= m_maxR);
    }

    ROOT::Math::XYZVector getField(const ROOT::Math::XYZVector& pos) const override;
  private:
    ROOT::Math::XYZVector interpolate(unsigned int ir, unsigned int iphi, unsigned int iz, double wr, double wphi, double wz) const;
    float m_minR{0};
    float m_maxR{0};
    float m_minZ{0};
    float m_maxZ{0};
    int m_mapSize[3] {0};
    float m_gridPitch[3] {0};
    float m_invgridPitch[3] {0};
    std::vector<ROOT::Math::XYZVector> m_bmap;
    ClassDefOverride(MagneticFieldComponent3D, 2);
  };

}; // Belle2 namespace