SiStripCluster.h

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#ifndef DATAFORMATS_SISTRIPCLUSTER_H
#define DATAFORMATS_SISTRIPCLUSTER_H

#include "DataFormats/SiStripDigi/interface/SiStripDigi.h"
#include <vector>
#include <numeric>

class SiStripCluster {
public:
  typedef std::vector<SiStripDigi>::const_iterator SiStripDigiIter;
  typedef std::pair<SiStripDigiIter, SiStripDigiIter> SiStripDigiRange;

  static const uint16_t stripIndexMask = 0x7FFF;   // The first strip index is in the low 15 bits of firstStrip_
  static const uint16_t mergedValueMask = 0x8000;  // The merged state is given by the high bit of firstStrip_

  SiStripCluster() {}

  explicit SiStripCluster(const SiStripDigiRange& range);

  SiStripCluster(uint16_t firstStrip, std::vector<uint8_t>&& data)
      : amplitudes_(std::move(data)), firstStrip_(firstStrip) {}

  template <typename Iter>
  SiStripCluster(const uint16_t& firstStrip, Iter begin, Iter end) : amplitudes_(begin, end), firstStrip_(firstStrip) {}

  template <typename Iter>
  SiStripCluster(const uint16_t& firstStrip, Iter begin, Iter end, bool merged)
      : amplitudes_(begin, end), firstStrip_(firstStrip) {
    if (merged)
      firstStrip_ |= mergedValueMask;  // if this is a candidate merged cluster
  }

  // extend the cluster
  template <typename Iter>
  void extend(Iter begin, Iter end) {
    amplitudes_.insert(amplitudes_.end(), begin, end);
  }

  uint16_t firstStrip() const { return firstStrip_ & stripIndexMask; }

  uint16_t endStrip() const { return firstStrip() + size(); }

  uint8_t const* begin() const { return amplitudes_.data(); }
  uint8_t const* end() const { return begin() + size(); }
  uint8_t size() const { return amplitudes_.size(); }
  uint8_t operator[](int i) const { return *(begin() + i); }
  bool empty() const { return 0 == size(); }
  bool full() const { return false; }

  SiStripCluster const& amplitudes() const { return *this; }

  float barycenter() const;

  int charge() const { return std::accumulate(begin(), end(), int(0)); }

  bool isMerged() const { return (firstStrip_ & mergedValueMask) != 0; }
  void setMerged(bool mergedState) { mergedState ? firstStrip_ |= mergedValueMask : firstStrip_ &= stripIndexMask; }

  float getSplitClusterError() const { return error_x; }
  void setSplitClusterError(float errx) { error_x = errx; }

private:
  std::vector<uint8_t> amplitudes_;

  uint16_t firstStrip_ = 0;

  // ggiurgiu@fnal.gov, 01/05/12
  // Add cluster errors to be used by rechits from split clusters.
  // A rechit from a split cluster has larger errors than rechits from normal clusters.
  // However, when presented with a cluster, the CPE does not know if the cluster comes
  // from a splitting procedure or not. That's why we have to instruct the CPE to use
  // appropriate errors for split clusters.
  // To avoid increase of data size on disk,these new data members are set as transient in:
  // DataFormats/SiStripCluster/src/classes_def.xml
  float error_x = -99999.9;

  // ggiurgiu@fnal.gov, 01/05/12
  // Initialize the split cluster errors to un-physical values.
  // The CPE will check these errors and if they are not un-physical,
  // it will recognize the clusters as split and assign these (increased)
  // errors to the corresponding rechit.
};

// Comparison operators
inline bool operator<(const SiStripCluster& one, const SiStripCluster& other) {
  return one.firstStrip() < other.firstStrip();
}

inline bool operator<(const SiStripCluster& cluster, const uint16_t& firstStrip) {
  return cluster.firstStrip() < firstStrip;
}

inline bool operator<(const uint16_t& firstStrip, const SiStripCluster& cluster) {
  return firstStrip < cluster.firstStrip();
}
#endif  // DATAFORMATS_SISTRIPCLUSTER_H