HitInZ0TanLambdaBoxUsingZ.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 <tracking/trackFindingCDC/hough/boxes/Z0TanLambdaBox.h>
 
#include <tracking/trackingUtilities/eventdata/hits/CDCRecoHit3D.h>
 
#include <cdc/topology/CDCWire.h>
#include <cdc/topology/WireLine.h>
 
#include <tracking/trackingUtilities/numerics/Weight.h>
 
namespace Belle2 {
  namespace TrackFindingCDC {

    class HitInZ0TanLambdaBoxUsingZ {
    public:

      using HoughBox = Z0TanLambdaBox;

      TrackingUtilities::Weight operator()(const TrackingUtilities::CDCRecoHit3D& recoHit,
                                           const HoughBox* z0TanLambdaBox)
      {
        const CDC::CDCWire& wire = recoHit.getWire();
        const CDC::WireLine& wireLine = wire.getWireLine();
 
        float lowerZ0 = z0TanLambdaBox->getLowerZ0();
        float upperZ0 = z0TanLambdaBox->getUpperZ0();
        const float centerZ0 = 0.5 * (lowerZ0 + upperZ0);
 
        float lowerTanLambda = z0TanLambdaBox->getLowerTanLambda();
        float upperTanLambda = z0TanLambdaBox->getUpperTanLambda();
        const float centerTanLambda = 0.5 * (lowerTanLambda + upperTanLambda);
 
        float perpS = recoHit.getArcLength2D();
        const TrackingUtilities::Vector2D& recoPosition = recoHit.getRecoPos2D();
 
        float hitZ = centerTanLambda * perpS + centerZ0;
 
        TrackingUtilities::Vector2D pos2D = wireLine.nominalPos2DAtZ(hitZ);
 
        float distanceToRecoPosition = (pos2D - recoPosition).norm();
 
        return exp(-distanceToRecoPosition);
      }

      static bool compareDistances(const HoughBox& z0TanLambdaBox, const TrackingUtilities::CDCRecoHit3D& lhsRecoHit,
                                   const TrackingUtilities::CDCRecoHit3D& rhsRecoHit)
      {
        const double z0Mean = (z0TanLambdaBox.getLowerZ0() + z0TanLambdaBox.getUpperZ0()) / 2.0;
        const double tanLambdaMean = (z0TanLambdaBox.getLowerTanLambda() + z0TanLambdaBox.getUpperTanLambda()) / 2.0;
 
        const double lhsZ = lhsRecoHit.getRecoZ();
        const double rhsZ = rhsRecoHit.getRecoZ();
 
        const double lhsS = lhsRecoHit.getArcLength2D();
        const double rhsS = rhsRecoHit.getArcLength2D();
 
        const double lhsZDistance = lhsS * tanLambdaMean + z0Mean - lhsZ;
        const double rhsZDistance = rhsS * tanLambdaMean + z0Mean - rhsZ;
 
        return lhsZDistance < rhsZDistance;
      }

      static const char* debugLine() { return "[0] + [1] * x";}
    };
  }
}