CbmRichRingSelectImpl.h

Go to the documentation of this file.

/* Copyright (C) 2010-2012 UGiessen/JINR-LIT, Giessen/Dubna
   SPDX-License-Identifier: GPL-3.0-only
   Authors: Semen Lebedev [committer] */
 
#ifndef CBM_RICH_RING_SELECT_IMPL
#define CBM_RICH_RING_SELECT_IMPL
 
#include "CbmRichRingLight.h"
 
#include <algorithm>
#include <cmath>
#include <iostream>
#include <vector>
 
class CbmRichRingSelectImpl {
 private:
  static const int kMAX_NOF_HITS = 100;  // Maximum number of hits in ring
 
 public:
  CbmRichRingSelectImpl() : fAlpha(), fPhi()
  {
    fAlpha.resize(kMAX_NOF_HITS);
    fPhi.resize(kMAX_NOF_HITS);
  };
 
  ~CbmRichRingSelectImpl(){};
 
  int GetNofHitsOnRingCircle(CbmRichRingLight* ring)
  {
    int count = 0;
    int nHits = ring->GetNofHits();
    for (int iH = 0; iH < nHits; iH++) {
      CbmRichHitLight hitRing = ring->GetHit(iH);
      float rx                = hitRing.fX - ring->GetCenterX();
      float ry                = hitRing.fY - ring->GetCenterY();
      float r                 = sqrt(rx * rx + ry * ry) - ring->GetRadius();
      if (r < 0.35f) count++;
    }
    return count;
  }
 
  float GetAngle(CbmRichRingLight* ring)
  {
    int nHits = ring->GetNofHits();
    if (nHits > kMAX_NOF_HITS) return 0.2f;
    if (nHits < 4) return 999.f;
 
    float Pi    = 3.14159265;
    float TwoPi = 2. * 3.14159265;
    float xRing = ring->GetCenterX();
    float yRing = ring->GetCenterY();
    float xHit, yHit;
 
    for (int iH = 0; iH < nHits; iH++) {
      CbmRichHitLight hit = ring->GetHit(iH);
      xHit                = hit.fX;
      yHit                = hit.fY;
 
      if (yHit - yRing == 0 || xHit - xRing == 0) continue;
 
      if (xHit > xRing) {
        if (yHit > yRing) {
          fAlpha[iH] = atan(fabs((yHit - yRing) / (xHit - xRing)));
        }
        else {
          fAlpha[iH] = TwoPi - atan(fabs((yHit - yRing) / (xHit - xRing)));
        }
      }
      else {
        if (yHit > yRing) {
          fAlpha[iH] = Pi - atan(fabs((yHit - yRing) / (xHit - xRing)));
        }
        else {
          fAlpha[iH] = Pi + atan(fabs((yHit - yRing) / (xHit - xRing)));
        }
      }
    }
 
    sort(fAlpha.begin(), fAlpha.begin() + nHits);
 
    for (int i = 0; i < nHits - 1; i++)
      fPhi[i] = fAlpha[i + 1] - fAlpha[i];
    fPhi[nHits - 1] = TwoPi - fAlpha[nHits - 1] + fAlpha[0];
    sort(fPhi.begin(), fPhi.begin() + nHits);
 
    float angle = fPhi[nHits - 1] + fPhi[nHits - 2] + fPhi[nHits - 3];
 
    return angle;
  }
 
 protected:
  std::vector<float> fAlpha;
  std::vector<float> fPhi;
};
 
 
#endif