SeedFromConsecutiveHitsTripletOnlyCreator.cc

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#include "SeedFromConsecutiveHitsTripletOnlyCreator.h"

#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "MagneticField/Engine/interface/MagneticField.h"
#include "MagneticField/Records/interface/IdealMagneticFieldRecord.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "FWCore/Framework/interface/EventSetup.h"
#include "RecoTracker/TkTrackingRegions/interface/TrackingRegion.h"
#include "RecoTracker/TkSeedGenerator/interface/FastHelix.h"
#include "DataFormats/SiStripDetId/interface/SiStripDetId.h"

bool SeedFromConsecutiveHitsTripletOnlyCreator::initialKinematic(GlobalTrajectoryParameters & kine,
                                 const SeedingHitSet & hits) const {


  TransientTrackingRecHit::ConstRecHitPointer tth1 = hits[0];
  TransientTrackingRecHit::ConstRecHitPointer tth2 = hits[1];
  
  if (hits.size()==3 && !(hits[2]->transientHits().size()==1 && (hits[2]->geographicalId().subdetId()==SiStripDetId::TID || 
                                 hits[2]->geographicalId().subdetId()==SiStripDetId::TEC ) ) ) {
    //if 3rd hit is mono and endcap pT is not well defined so take initial state from pair
    TransientTrackingRecHit::ConstRecHitPointer tth3 = hits[2];
    FastHelix helix(tth3->globalPosition(), tth2->globalPosition(), tth1->globalPosition(), nomField, &*bfield, tth1->globalPosition());
    kine = helix.stateAtVertex();
    if unlikely(isBOFF && (theBOFFMomentum > 0)) {
      kine = GlobalTrajectoryParameters(kine.position(),
                    kine.momentum().unit() * theBOFFMomentum,
                    kine.charge(),
                    &*bfield);
    }
    return (filter ? filter->compatible(hits, kine, helix, *region) : true); 
  } 
  
  const GlobalPoint& vertexPos = region->origin();

  FastHelix helix(tth2->globalPosition(), tth1->globalPosition(), vertexPos, nomField,&*bfield);
  if (helix.isValid()) {
    kine = helix.stateAtVertex();
  } else {
    GlobalVector initMomentum(tth2->globalPosition() - vertexPos);
    initMomentum *= (100./initMomentum.perp()); 
    kine = GlobalTrajectoryParameters(vertexPos, initMomentum, 1, &*bfield);
  } 

  if unlikely(isBOFF && (theBOFFMomentum > 0)) {
      kine = GlobalTrajectoryParameters(kine.position(),
                    kine.momentum().unit() * theBOFFMomentum,
                    kine.charge(),
                    &*bfield);
  }
  return (filter ? filter->compatible(hits, kine, helix, *region) : true); 
}