#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

std::pair< bool, PositionType >	position (const Plane &plane) const

PositionType	position (float s) 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

◆ DirectionType

using StraightLinePlaneCrossing::DirectionType = Basic3DVector<float>

Definition at line 22 of file StraightLinePlaneCrossing.h.

◆ PositionType

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::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.

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

◆ ~StraightLinePlaneCrossing()

StraightLinePlaneCrossing::~StraightLinePlaneCrossing ( )

inline

Definition at line 33 of file StraightLinePlaneCrossing.h.

33 {}

Member Function Documentation

◆ pathLength()

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 8 of file StraightLinePlaneCrossing.cc.

                                                                                     {
   //
   // 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);
 }

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

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

◆ position() [1/2]

std::pair< bool, StraightLinePlaneCrossing::PositionType > StraightLinePlaneCrossing::position ( const Plane & plane ) const

Simplified interface in case the path length is not needed

Definition at line 25 of file StraightLinePlaneCrossing.cc.

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