StraightLinePlaneCrossing Class Reference

#include <StraightLinePlaneCrossing.h>

Public Types
using	DirectionType = Basic3DVector< float >
using	PositionType = Basic3DVector< float >

Public Member Functions
std::pair< bool, double >	pathLength (const Plane &plane) const
PositionType	position (float s) const
std::pair< bool, PositionType >	position (const Plane &plane) const
	StraightLinePlaneCrossing (const PositionType &point, const DirectionType &momentum, const PropagationDirection propDir=alongMomentum)
	~StraightLinePlaneCrossing ()

Private Attributes
const PositionType	theP0
const PropagationDirection	thePropDir
const PositionType	theX0

Detailed Description

Calculates intersections of a line with a plane.

Definition at line 14 of file StraightLinePlaneCrossing.h.

Member Typedef Documentation

using StraightLinePlaneCrossing::DirectionType = Basic3DVector<float>

Definition at line 22 of file StraightLinePlaneCrossing.h.

using StraightLinePlaneCrossing::PositionType = Basic3DVector<float>

The types for position and direction are frame-neutral (not global, local, etc.) so this interface can be used in any frame. Of course, the helix and the plane must be defined in the same frame, which is also the frame of the result.

Definition at line 21 of file StraightLinePlaneCrossing.h.

Constructor & Destructor Documentation

StraightLinePlaneCrossing::StraightLinePlaneCrossing ( const PositionType &  point, const DirectionType &  momentum, const PropagationDirection  propDir = alongMomentum  )

inline

Constructor using point and momentum.

Definition at line 27 of file StraightLinePlaneCrossing.h.

                                                                    :
  theX0(point),
  theP0(momentum.unit()),
  thePropDir(propDir) {}

StraightLinePlaneCrossing::~StraightLinePlaneCrossing ( )

inline

Definition at line 35 of file StraightLinePlaneCrossing.h.

References pathLength().

{}

Member Function Documentation

std::pair< bool, double > StraightLinePlaneCrossing::pathLength

(

const Plane &

plane

)

const

Propagation status (true if valid) and (signed) path length along the helix from the starting point to the plane.

Definition at line 9 of file StraightLinePlaneCrossing.cc.

References alongMomentum, Basic3DVector< T >::dot(), f, Plane::normalVector(), oppositeToMomentum, GloballyPositioned< T >::position(), theP0, thePropDir, and theX0.

Referenced by HelixBarrelPlaneCrossingByCircle::pathLength(), position(), RKPropagatorInS::propagateParametersOnPlane(), AnalyticalPropagator::propagateParametersOnPlane(), and ~StraightLinePlaneCrossing().

                                                               {
  //
  // calculate path length
  //
  PositionType planePosition(plane.position());
  DirectionType planeNormal(plane.normalVector());
  auto pz = planeNormal.dot(theP0);
  auto dS = -planeNormal.dot(theX0-planePosition)/pz;
  // check direction
  auto opposite2Track =  (  (thePropDir==alongMomentum) & (dS<0.f) ) |
                         (  (thePropDir==oppositeToMomentum) & (dS>0.f) );
  //
  // Return result
  //
  return std::pair<bool,double>(!opposite2Track,dS);
}

PositionType StraightLinePlaneCrossing::position ( float  s ) const

inline

Position at pathlength s from the starting point.

Definition at line 44 of file StraightLinePlaneCrossing.h.

References theP0, and theX0.

Referenced by position(), CtfSpecialSeedGenerator::postCheck(), RKPropagatorInS::propagateParametersOnPlane(), and AnalyticalPropagator::propagateParametersOnPlane().

{return PositionType(theX0+s*theP0);}

std::pair< bool, StraightLinePlaneCrossing::PositionType > StraightLinePlaneCrossing::position

(

const Plane &

plane

)

const

Simplified interface in case the path length is not needed

Definition at line 27 of file StraightLinePlaneCrossing.cc.

References pathLength(), and position().

{
    auto crossed = pathLength(plane);
    if (crossed.first) return std::pair<bool,PositionType>(true, position(crossed.second));
    else return std::pair<bool,PositionType>(false, PositionType());
}

Member Data Documentation

const PositionType StraightLinePlaneCrossing::theP0

private

Definition at line 56 of file StraightLinePlaneCrossing.h.

Referenced by pathLength(), and position().

const PropagationDirection StraightLinePlaneCrossing::thePropDir

private

Definition at line 57 of file StraightLinePlaneCrossing.h.

Referenced by pathLength().

const PositionType StraightLinePlaneCrossing::theX0

private

Definition at line 55 of file StraightLinePlaneCrossing.h.

Referenced by pathLength(), and position().