TkDetUtil.cc

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#include "TkDetUtil.h"

#include "TrackingTools/DetLayers/interface/MeasurementEstimator.h"
#include "DataFormats/GeometrySurface/interface/Plane.h"
#include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"


namespace tkDetUtil {

  float computeWindowSize( const GeomDet* det, 
               const TrajectoryStateOnSurface& tsos, 
               const MeasurementEstimator& est)
  {
    const Plane& startPlane = det->surface();  
    MeasurementEstimator::Local2DVector maxDistance = 
      est.maximalLocalDisplacement( tsos, startPlane);
    return calculatePhiWindow( maxDistance, tsos, startPlane);
  }


  float 
  calculatePhiWindow( const MeasurementEstimator::Local2DVector& maxDistance, 
              const TrajectoryStateOnSurface& ts, 
              const Plane& plane)
  {
    
    LocalPoint start = ts.localPosition();
    float corners[]  =  { plane.toGlobal(LocalPoint( start.x()+maxDistance.x(), start.y()+maxDistance.y() )).barePhi(),
              plane.toGlobal(LocalPoint( start.x()-maxDistance.x(), start.y()+maxDistance.y() )).barePhi(),
              plane.toGlobal(LocalPoint( start.x()-maxDistance.x(), start.y()-maxDistance.y() )).barePhi(),
              plane.toGlobal(LocalPoint( start.x()+maxDistance.x(), start.y()-maxDistance.y() )).barePhi() 
    };
    
    float phimin = corners[0];
    float phimax = phimin;
    for ( int i = 1; i<4; i++) {
      float cPhi = corners[i];
      if ( Geom::phiLess(cPhi, phimin) ) { phimin = cPhi; }
      if ( Geom::phiLess( phimax, cPhi) ) { phimax = cPhi; }
    }
    float phiWindow = phimax - phimin;
    if ( phiWindow < 0.) { phiWindow +=  2.*Geom::pi();}
    
    return phiWindow;
  }




}