SiStripRecHitMatcher.h

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#ifndef RECOLOCALTRACKER_SISTRIPCLUSTERIZER_SISTRIPRECHITMATCH_H
#define RECOLOCALTRACKER_SISTRIPCLUSTERIZER_SISTRIPRECHITMATCH_H

#include "DataFormats/TrackerRecHit2D/interface/SiStripRecHit2D.h"
#include "DataFormats/TrackerRecHit2D/interface/SiStripRecHit2DCollection.h"
#include "DataFormats/TrackerRecHit2D/interface/SiStripMatchedRecHit2D.h"
#include "DataFormats/TrackerRecHit2D/interface/SiStripMatchedRecHit2DCollection.h"
#include "DataFormats/DetId/interface/DetId.h"
#include "Geometry/CommonDetUnit/interface/GeomDetUnit.h"
#include "Geometry/CommonTopologies/interface/StripTopology.h"

#include "DataFormats/CLHEP/interface/AlgebraicObjects.h"

#include "FWCore/ParameterSet/interface/ParameterSet.h"

#include "TrackingTools/TransientTrackingRecHit/interface/HelpertRecHit2DLocalPos.h"


class GluedGeomDet;

#include <cfloat>
#include <memory>

#include <boost/function.hpp>

class SiStripRecHitMatcher {
public:
  
  // may become a template argument
  typedef SiStripMatchedRecHit2DCollectionNew::FastFiller CollectorMatched;

  typedef SiStripRecHit2DCollectionNew::DetSet::const_iterator RecHitIterator;
  typedef std::vector<const SiStripRecHit2D *>              SimpleHitCollection;
  typedef SimpleHitCollection::const_iterator               SimpleHitIterator;

  typedef boost::function<void(SiStripMatchedRecHit2D const&)>    Collector;


  typedef std::pair<LocalPoint,LocalPoint>                  StripPosition; 

  SiStripRecHitMatcher(const edm::ParameterSet& conf);
  SiStripRecHitMatcher(const double theScale);

  bool preFilter() const { return preFilter_;}  


  inline   
  static float sigmaPitch(LocalPoint const& pos, LocalError const & err, 
           const StripTopology& topol) {
    MeasurementError error = topol.measurementError(pos,err);
    auto pitch=topol.localPitch(pos);
    return error.uu()*pitch*pitch;
  }


  // optimized matching iteration (the algo is the same, just recoded)
  template<typename MonoIterator, typename StereoIterator,  typename CollectorHelper>
  void doubleMatch(MonoIterator monoRHiter, MonoIterator monoRHend,
           StereoIterator seconditer, StereoIterator seconditerend,
           const GluedGeomDet* gluedDet,  LocalVector trdir, 
           CollectorHelper & collectorHelper) const;
  
  
 //match a single hit
  std::unique_ptr<SiStripMatchedRecHit2D> match(const SiStripRecHit2D *monoRH,
                 const SiStripRecHit2D *stereoRH,
                 const GluedGeomDet* gluedDet,
                 LocalVector trackdirection, bool force=false) const;

  
// this is the one used by the RecHitConverter
  void
  match( const SiStripRecHit2D *monoRH,
     RecHitIterator begin, RecHitIterator end,
     CollectorMatched & collector,
     const GluedGeomDet* gluedDet,
     LocalVector trackdirection) const;

  
  void
  match( const SiStripRecHit2D *monoRH,
     SimpleHitIterator begin, SimpleHitIterator end,
     CollectorMatched & collector,
     const GluedGeomDet* gluedDet,
     LocalVector trackdirection) const;
  
  
  
  
  // project strip coordinates on Glueddet
  
  StripPosition project(const GeomDetUnit *det,const GluedGeomDet* glueddet,StripPosition strip,LocalVector trackdirection) const;
  
  
  // needed by the obsolete version still in use on some architectures
  void
  match( const SiStripRecHit2D *monoRH,
     SimpleHitIterator begin, SimpleHitIterator end,
     edm::OwnVector<SiStripMatchedRecHit2D> & collector, 
     const GluedGeomDet* gluedDet,
     LocalVector trackdirection) const;



  void
  match( const SiStripRecHit2D *monoRH,
     SimpleHitIterator begin, SimpleHitIterator end,
     std::vector<SiStripMatchedRecHit2D*> & collector, 
     const GluedGeomDet* gluedDet,
     LocalVector trackdirection) const;
   
 
  
  void
  match( const SiStripRecHit2D *monoRH,
     SimpleHitIterator begin, SimpleHitIterator end,
     Collector & collector, 
     const GluedGeomDet* gluedDet,
     LocalVector trackdirection) const;
  
  
  float scale_;
  bool  preFilter_=false;
};




#include "DataFormats/GeometryVector/interface/Basic3DVector.h"
#if defined(USE_SSEVECT) || defined(USE_EXTVECT)
#define DOUBLE_MATCH
#endif

#ifdef DOUBLE_MATCH

#if defined(USE_SSEVECT)
  using  mathSSE::Vec3F;
  using  mathSSE::Vec2D;
  using  mathSSE::Vec3D;
  using  mathSSE::Rot3F;
#endif 
 
#include "Geometry/TrackerGeometryBuilder/interface/GluedGeomDet.h"
#include "TrackingTools/TransientTrackingRecHit/interface/HelpertRecHit2DLocalPos.h"

namespace matcherDetails {  
  
  struct StereoInfo {
    Vec2D c1vec;
    const SiStripRecHit2D * secondHit;
    float sigmap22;
    double m10, m11;
  };
  
}

template<typename MonoIterator, typename StereoIterator,  typename CollectorHelper>
void SiStripRecHitMatcher::doubleMatch(MonoIterator monoRHiter, MonoIterator monoRHend,
                       StereoIterator seconditer, StereoIterator seconditerend,
                       const GluedGeomDet* gluedDet,    LocalVector trdir, 
                       CollectorHelper & collectorHelper) const{
  
  using  matcherDetails::StereoInfo;

  typedef  GloballyPositioned<float> ToGlobal;
  typedef  typename GloballyPositioned<float>::ToLocal ToLocal;
  
  // hits in both mono and stero
  // match
  bool notk = trdir.mag2()<float(FLT_MIN);
  // FIXME we shall find a faster approximation for trdir: not useful to compute it each time for each strip
  
  // stripdet = mono
  // partnerstripdet = stereo
  const GeomDetUnit* stripdet = gluedDet->monoDet();
  const GeomDetUnit* partnerstripdet = gluedDet->stereoDet();
  const StripTopology& topol=(const StripTopology&)stripdet->topology();
  const StripTopology& partnertopol=(const StripTopology&)partnerstripdet->topology();
  
  // toGlobal is fast,  toLocal is slow
  ToGlobal const & stripDetTrans =  stripdet->surface();
  ToGlobal const & partnerStripDetTrans = partnerstripdet->surface();
  ToLocal          gluedDetInvTrans(gluedDet->surface());
  
  
  
  StereoInfo cache[std::distance(seconditer,seconditerend)];
  //iterate on stereo rechits
  // fill cache with relevant info
  int  cacheSize=0;
  for (;seconditer!=seconditerend; ++seconditer){
    
    const SiStripRecHit2D & secondHit = CollectorHelper::stereoHit(seconditer);
    
    float sigmap22 = sigmaPitch(secondHit.localPosition(),secondHit.localPositionError(),partnertopol);
    // assert (sigmap22>=0);
    
    auto STEREOpointX=partnertopol.measurementPosition( secondHit.localPositionFast()).x();
    MeasurementPoint STEREOpointini(STEREOpointX,-0.5f);
    MeasurementPoint STEREOpointend(STEREOpointX,0.5f);
    
    LocalPoint locp1 = partnertopol.localPosition(STEREOpointini);
    LocalPoint locp2 = partnertopol.localPosition(STEREOpointend);
    
    GlobalPoint globalpointini=partnerStripDetTrans.toGlobal(locp1);
    GlobalPoint globalpointend=partnerStripDetTrans.toGlobal(locp2);
    
    // position of the initial and final point of the strip in glued local coordinates
    LocalPoint positiononGluedini=gluedDetInvTrans.toLocal(globalpointini);
    LocalPoint positiononGluedend=gluedDetInvTrans.toLocal(globalpointend); 
    
   // in case of no track hypothesis assume a track from the origin through the center of the strip
    if(notk){
      LocalPoint lcenterofstrip=secondHit.localPositionFast();
      GlobalPoint gcenterofstrip= partnerStripDetTrans.toGlobal(lcenterofstrip);
      GlobalVector gtrackdirection=gcenterofstrip-GlobalPoint(0,0,0);
      trdir=gluedDetInvTrans.toLocal(gtrackdirection);
    }
  

    Vec3F offset = trdir.basicVector().v * positiononGluedini.z()/trdir.z();
    
    
    Vec3F ret1 = positiononGluedini.basicVector().v - offset;
    Vec3F ret2 = positiononGluedend.basicVector().v - offset;
    
    double m10=-(ret2[1] - ret1[1]); 
    double m11=  ret2[0] - ret1[0];
    double dd = m11*ret1[1] + m10 * ret1[0];    

    Vec2D c1vec{dd,dd};
    
    // store
    StereoInfo info = {c1vec,&secondHit,sigmap22,m10,m11};
    cache[cacheSize++] = info;
  }
  
  
  
  for (;monoRHiter != monoRHend; ++monoRHiter) {
    
    SiStripRecHit2D const & monoRH = CollectorHelper::monoHit(monoRHiter);
    
    // position of the initial and final point of the strip (RPHI cluster) in local strip coordinates
    auto RPHIpointX = topol.measurementPosition(monoRH.localPositionFast()).x();
    MeasurementPoint RPHIpointini(RPHIpointX,-0.5f);
    MeasurementPoint RPHIpointend(RPHIpointX,0.5f);
    
    // position of the initial and final point of the strip in local coordinates (mono det)
    //StripPosition stripmono=StripPosition(topol.localPosition(RPHIpointini),topol.localPosition(RPHIpointend));
    LocalPoint locp1o = topol.localPosition(RPHIpointini);
    LocalPoint locp2o = topol.localPosition(RPHIpointend);
    
    
    // in case of no track hypothesis assume a track from the origin through the center of the strip
    if(notk){
      LocalPoint lcenterofstrip=monoRH.localPositionFast();
      GlobalPoint gcenterofstrip= stripDetTrans.toGlobal(lcenterofstrip);
      GlobalVector gtrackdirection=gcenterofstrip-GlobalPoint(0,0,0);
      trdir=gluedDetInvTrans.toLocal(gtrackdirection);
    }
    
    
    //project mono hit on glued det
    //StripPosition projectedstripmono=project(stripdet,gluedDet,stripmono,trackdirection);
    
    
    GlobalPoint globalpointini=stripDetTrans.toGlobal(locp1o);
    GlobalPoint globalpointend=stripDetTrans.toGlobal(locp2o);
    
    // position of the initial and final point of the strip in glued local coordinates
    LocalPoint positiononGluedini=gluedDetInvTrans.toLocal(globalpointini);
    LocalPoint positiononGluedend=gluedDetInvTrans.toLocal(globalpointend); 
    
    Vec3F offset = trdir.basicVector().v * positiononGluedini.z()/trdir.z();
    
    
    Vec3F projini= positiononGluedini.basicVector().v - offset;
    Vec3F projend = positiononGluedend.basicVector().v -offset;
    
    // ret1o = ret1o + (trdir * (ret1o.getSimd(2) / trdirz));
    // ret2o = ret2o + (trdir * (ret2o.getSimd(2) / trdirz));
    
    double m00 = -(projend[1] - projini[1]);         //-(projectedstripmono.second.y()-projectedstripmono.first.y()); 
    double m01 =  (projend[0] - projini[0]);        // (projectedstripmono.second.x()-projectedstripmono.first.x());
    double c0  =  m01*projini[1] + m00*projini[0];  //m01*projectedstripmono.first.y()   + m00*projectedstripmono.first.x();
    
    Vec2D c0vec{c0,c0};
    Vec2D minv00{-m01, m00};
    
    //error calculation (the part that depends on mono RH only)
    double c1 = -m00;
    double s1 = -m01;
    double l1 = 1./(c1*c1+s1*s1);
    
    float sigmap12 = sigmaPitch(monoRH.localPosition(), monoRH.localPositionError(),topol);
    // float sigmap12 = monoRH.sigmaPitch();
    // assert(sigmap12>=0); 

    //float code
    float fc1(c1), fs1(s1);
    Vec3F scc1{fs1, fc1, fc1, 0.f};
    Vec3F ssc1{fs1, fs1, fc1, 0.f};
    const Vec3F cslsimd = scc1 * ssc1 * float(l1);
    
    for (int i=0; i!=cacheSize; ++i) {
      StereoInfo const si = cache[i];
      
      // match 
      Vec2D minv10{si.m11, -si.m10};
      double mult = 1./(m00*si.m11 - m01*si.m10);
      Vec2D resultmatmul = mult * (minv10 * c0vec + minv00 * si.c1vec);
      
      Local2DPoint position(resultmatmul[0], resultmatmul[1]);
      
      // LocalError tempError (100,0,100);
      if (!((gluedDet->surface()).bounds().inside(position,10.f*scale_))) continue;                                                       
      
      double c2 = -si.m10;
      double s2 = -si.m11;
      double l2 = 1./(c2*c2+s2*s2);
      
      double diff=(c1*s2-c2*s1);
      double invdet2 = 1./(diff*diff*l1*l2);
      
      float fc2(c2), fs2(s2), fid2(invdet2);    
      Vec3F invdet2simd{fid2, -fid2, fid2, 0.f};
      Vec3F ccssimd{fs2, fc2, fc2, 0.f};
      Vec3F csssimd{fs2, fs2, fc2, 0.f};
      Vec3F result = invdet2simd * (si.sigmap22 * cslsimd + sigmap12 * ccssimd * csssimd * float(l2));
      
      
      LocalError error(result[0], result[1], result[2]);
      
      
      if((gluedDet->surface()).bounds().inside(position,error,scale_)){ //if it is inside the gluedet bonds
    
    //Change NSigmaInside in the configuration file to accept more hits
    //...and add it to the Rechit collection 
    
    collectorHelper.collector()(SiStripMatchedRecHit2D(LocalPoint(position), error,
                               *gluedDet,&monoRH,si.secondHit));
      }
      
    } // loop on cache info
    
    collectorHelper.closure(monoRHiter);
  } // loop on mono hit
  
}

#endif //DOUBLE_MATCH



#endif  //  RECOLOCALTRACKER_SISTRIPCLUSTERIZER_SISTRIPRECHITMATCH_H