DigitizationProcessor.h

#pragma once
 
#include "Framework/RandomNumberSeedService.h"
#include "Tracking/Reco/TrackingGeometryUser.h"
 
//--- ACTS ---//
#include "Acts/Definitions/Units.hpp"
#include "Acts/Surfaces/RectangleBounds.hpp"
#include "Acts/Surfaces/Surface.hpp"
 
//--- LDMX ---//
#include "Tracking/Digitization/PulseShape.h"
#include "Tracking/Digitization/SiStripConstants.h"
#include "Tracking/Digitization/SiStripDigitizer.h"
#include "Tracking/Event/Measurement.h"
#include "Tracking/Event/RawSiStripHit.h"
#include "Tracking/Sim/TrackingUtils.h"
#include "Tracking/geo/DetectorElement.h"
 
//--- C++ ---//
#include <chrono>
#include <memory>
#include <random>
#include <unordered_map>
#include <utility>
 
namespace ldmx {
class Measurement;
}
 
namespace tracking::reco {
 
class DigitizationProcessor : public TrackingGeometryUser {
 public:
  DigitizationProcessor(const std::string& name, framework::Process& process);
  virtual ~DigitizationProcessor() = default;
 
  void onProcessStart() override;
 
  void configure(framework::config::Parameters& parameters) override;
 
  void onNewRun(const ldmx::RunHeader& header) override;
 
  void produce(framework::Event& event) override;
 
  std::vector<ldmx::Measurement> digitizeHits(
      const std::vector<ldmx::SimTrackerHit>& sim_hits,
      std::vector<ldmx::RawSiStripHit>* raw_hits = nullptr);
 
  // TODO avoid copies and use references
  bool mergeSimHits(const std::vector<ldmx::SimTrackerHit>& sim_hits,
                    std::vector<ldmx::SimTrackerHit>& merged_hits);
  bool mergeHits(const std::vector<ldmx::SimTrackerHit>& sihits,
                 std::vector<ldmx::SimTrackerHit>& mergedHits);
 
 private:
  std::string hit_collection_;
  std::string out_collection_;
 
  double min_e_dep_;
  int track_id_;
  bool merge_hits_{false};
 
  // -------------------------------------------------------------------------
  // Mode 0: Gaussian smearing
  // -------------------------------------------------------------------------
  bool do_smearing_{true};
  double sigma_u_{0};
  double sigma_v_{0};
 
  // -------------------------------------------------------------------------
  // Mode 1: Realistic charge digitization
  // -------------------------------------------------------------------------
  bool use_charge_digitization_{false};
  tracking::digitization::SiStripDigitizer::SensorParams sensor_params_;
  std::unique_ptr<tracking::digitization::SiStripDigitizer> strip_digitizer_;
 
  // ADC conversion and pulse shaping (Mode 1 only)
  std::string out_raw_collection_{""};
  std::unique_ptr<tracking::digitization::PulseShape> pulse_shape_;
 
  // -------------------------------------------------------------------------
  // Lorentz angle computation (Mode 1, optional)
  // -------------------------------------------------------------------------
  bool use_lorentz_{true};
  std::string field_map_{""};
  std::unordered_map<unsigned int, std::pair<double, double>>
      lorentz_tan_cache_;
 
  void buildLorentzCache();
 
  // -------------------------------------------------------------------------
  // Common
  // -------------------------------------------------------------------------
  std::string tracker_hit_passname_;
 
  std::string dump_geo_csv_{""};
 
  std::default_random_engine generator_;
  std::shared_ptr<std::normal_distribution<float>> normal_;
};  // DigitizationProcessor
 
}  // namespace tracking::reco