LayerCrossingSide Class Reference

#include <LayerCrossingSide.h>

Static Public Member Functions
static int	barrelSide (const TrajectoryStateOnSurface &startingState, const Propagator &prop)
	returns 0 if barrel layer crossed from inside, 1 if from outside More...
static int	endcapSide (const TrajectoryStateOnSurface &startingState, const Propagator &prop)

Detailed Description

Helper class to determine if a TrajectoryStateOnSurface would cross a layer from the inside, or from the outside, if propagated with a propagator with a defined direction. No propagations performed, the result is very fast but not correct in case of a looping track that first goes outwards, then inwards, before crossing a layer.

Definition at line 15 of file LayerCrossingSide.h.

Member Function Documentation

static int LayerCrossingSide::barrelSide ( const TrajectoryStateOnSurface &  startingState, const Propagator &  prop  )

inlinestatic

returns 0 if barrel layer crossed from inside, 1 if from outside

Definition at line 19 of file LayerCrossingSide.h.

References alongMomentum, dir, TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::globalPosition(), oppositeToMomentum, and Propagator::propagationDirection().

Referenced by TBLayer::groupedCompatibleDetsV().

                                                                                               {
    auto pos = startingState.globalPosition();
    auto dir = startingState.globalMomentum();
    bool outwards = (pos.x()*dir.x() + pos.y()*dir.y()) > 0;

    auto inout = outwards ? alongMomentum :  oppositeToMomentum;

    return (prop.propagationDirection() == inout ? 0 : 1);
    
  }

static int LayerCrossingSide::endcapSide ( const TrajectoryStateOnSurface &  startingState, const Propagator &  prop  )

inlinestatic

returns 0 if endcap layer crossed from inside, ie from the side of the interation region, 1 if from outside

Definition at line 33 of file LayerCrossingSide.h.

References alongMomentum, TrajectoryStateOnSurface::globalMomentum(), TrajectoryStateOnSurface::globalPosition(), oppositeToMomentum, Propagator::propagationDirection(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by TECLayer::groupedCompatibleDetsV().

                                                                                               {
    auto zpos = startingState.globalPosition().z();
    bool outwards = (startingState.globalMomentum().z() * zpos) > 0; 

    auto inout = outwards ? alongMomentum :  oppositeToMomentum;

    return (prop.propagationDirection() == inout ? 0 : 1);

  }