Geant4TrackerSD.cpp

// $Id$
//====================================================================
//  AIDA Detector description implementation for LCD
//--------------------------------------------------------------------
//
//  Author     : M.Frank
//
//====================================================================
// Framework include files
#include "DDG4/Geant4SensitiveDetector_inline.h"
#include "DDG4/Factories.h"
#include "DDG4/Geant4StepHandler.h"
#include "DDG4/Geant4Mapping.h"
#include "DD4hep/BitField64.h"

/*
 *   DD4hep::Simulation namespace declaration
 */
namespace DD4hep {  namespace Simulation {

  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  ///               Geant4GenericSD<Tracker>
  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  struct Tracker {};
  /// Method for generating hit(s) using the information of G4Step object.
    template <> bool Geant4GenericSD<Tracker>::buildHits(G4Step* step,G4TouchableHistory* /*hist*/ ) {

      StepHandler h(step);
      Position prePos    = h.prePos();
      Position postPos   = h.postPos();
      Position direction = postPos - prePos;
      Position position  = mean_direction(prePos,postPos);
      double   hit_len   = direction.R();
      if (hit_len > 0) {
	double new_len = mean_length(h.preMom(),h.postMom())/hit_len;
	direction *= new_len/hit_len;
      }
      
      //      G4cout << "----------- Geant4GenericSD<Tracker>::buildHits : position : " << prePos << G4endl ;
      
      Geant4TrackerHit* hit = 
	new Geant4TrackerHit(h.track->GetTrackID(),
			     h.track->GetDefinition()->GetPDGEncoding(),
			     step->GetTotalEnergyDeposit(),
			     h.track->GetGlobalTime());
      
      HitContribution contrib = Geant4Hit::extractContribution(step);
      
      hit->cellID  = getVolumeID( step ) ;

      hit->energyDeposit =  contrib.deposit ;

      hit->position = position;
      hit->momentum = direction;
      hit->length   = hit_len;
      collection(0)->insert(hit);
      return hit != 0;
    }
    typedef Geant4GenericSD<Tracker> Geant4Tracker;
  }}    // End namespace DD4hep::Simulation

DECLARE_GEANT4SENSITIVEDETECTOR(Geant4Tracker)