GenfitWireMeasurement.h

/*
 * Copyright (c) 2020-2024 Key4hep-Project.
 *
 * This file is part of Key4hep.
 * See https://key4hep.github.io/key4hep-doc/ for further info.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef WIRE_MEASUREMENT_H
#define WIRE_MEASUREMENT_H

#include <iostream>

#include <TDecompSVD.h>
#include <TMatrixD.h>
#include <TMatrixDSym.h>
#include <TVectorD.h>

#include <TrackPoint.h>
#include <WirePointMeasurement.h>

#include "DDSegmentation/BitFieldCoder.h"

#include "detectorCommon/WireTracker_info.h"

#include "edm4hep/SenseWireHitCollection.h"

/** @class WireMeasurement
 *
 *  Interface class that wraps a SenseWireHit object into a GENFIT-compatible WirePointMeasurement.
 *
 *  This class converts a hit in a drift chamber wire (represented by `edm4hep::SenseWireHit`) into a
 *  `genfit::WirePointMeasurement`, which can be used in GENFIT's track fitting. The conversion requires
 *  additional detector information such as geometry and segmentation, provided through DD4hep.
 *
 *  The constructor initializes the GENFIT measurement using drift radius and wire geometry, and assigns
 *  detector and hit indices for identification and debugging purposes.
 *
 *
 *  Author: Andrea De Vita
 *  Date  : 2025-06
 *
 */

namespace GenfitInterface {

class WireMeasurement {
public:
  WireMeasurement(const edm4hep::SenseWireHit& hit, const dd4hep::rec::WireTracker_info_struct* wire_info,
                  const dd4hep::DDSegmentation::BitFieldCoder* decoder, const bool has_sectors, const int det_idx,
                  const int hit_idx, const int debug_lvl);

  genfit::WirePointMeasurement* getGenFit() const { return m_genfitHit; };

private:
  // This pointer is used to create a genfit::TrackPoint, which is then stored
  // inside a genfit::Track. The Track aggregates a collection of TrackPoints
  // representing the hits used for the track fit.
  //
  // GENFIT manages ownership of the full chain:
  // - A genfit::Track owns its TrackPoints
  // - When a Track is deleted, all associated TrackPoints are automatically deleted
  // - When a TrackPoint is deleted, the associated measurement object used to
  //   construct it is also released
  //
  // Therefore, this pointer is NOT owned by this class and must not be deleted here.
  genfit::WirePointMeasurement* m_genfitHit;
};

} // namespace GenfitInterface

#endif