Acts::Direction Class Reference

The direction is always with respect to a given momentum, surface normal or other general axes. More...

#include <Acts/Definitions/Direction.hpp>

Public Member Functions
constexpr std::size_t	index () const
	Convert dir to index [0,1] which allows to store direction dependent objects in std::array<T, 2u>.
constexpr Direction	invert () const
	Reverse the direction.
constexpr int	sign () const
	Turns the direction into a signed value.
std::string	toString () const
	Convert direction to string representation.

Static Public Member Functions
static constexpr Direction	AlongNormal ()
	Create direction along normal (positive).
static constexpr Direction	Backward ()
	Create backward direction (equivalent to negative).
static constexpr Direction	Forward ()
	Create forward direction (equivalent to positive).
static constexpr Direction	fromIndex (std::size_t index)
	Convert and index [0,1] to a direction e.g.
static constexpr Direction	fromScalar (double scalar)
	This turns a signed value into a direction.
static constexpr Direction	fromScalarZeroAsPositive (double scalar)
	This turns a signed value into a direction and 0 will be handled as a positive direction.
static constexpr Direction	Negative ()
	Create negative direction (-1).
static constexpr Direction	OppositeNormal ()
	Create direction opposite to normal (negative).
static constexpr Direction	Positive ()
	Create positive direction (+1).

Detailed Description

The direction is always with respect to a given momentum, surface normal or other general axes.

Member Function Documentation

AlongNormal()

constexpr Direction Acts::Direction::AlongNormal ( )

staticconstexpr

Create direction along normal (positive).

Returns

Direction with positive value, along surface normal

Backward()

constexpr Direction Acts::Direction::Backward ( )

staticconstexpr

Create backward direction (equivalent to negative).

Returns

Direction with negative value for backward propagation

Forward()

constexpr Direction Acts::Direction::Forward ( )

staticconstexpr

Create forward direction (equivalent to positive).

Returns

Direction with positive value for forward propagation

fromIndex()

constexpr Direction Acts::Direction::fromIndex ( std::size_t index )

staticconstexpr

Convert and index [0,1] to a direction e.g.

for sorting in std::array<T, 2u>

Parameters

index

is the direction at input

Returns

Direction corresponding to the index (0->Negative, 1->Positive)

fromScalar()

constexpr Direction Acts::Direction::fromScalar ( double scalar )

staticconstexpr

This turns a signed value into a direction.

Will assert on zero.

Parameters

scalar

is the signed value

Returns

a direction enum

fromScalarZeroAsPositive()

constexpr Direction Acts::Direction::fromScalarZeroAsPositive ( double scalar )

staticconstexpr

This turns a signed value into a direction and 0 will be handled as a positive direction.

Only use this when you are convinced that the 0 case is properly handled downstream.

Parameters

scalar

is the signed value

Returns

a direction enum

index()

std::size_t Acts::Direction::index ( ) const

constexpr

Convert dir to index [0,1] which allows to store direction dependent objects in std::array<T, 2u>.

Returns

either 0 or 1

invert()

Direction Acts::Direction::invert ( ) const

constexpr

Reverse the direction.

Returns

an opposite direction

Negative()

constexpr Direction Acts::Direction::Negative ( )

staticconstexpr

Create negative direction (-1).

Returns

Direction with negative value

OppositeNormal()

constexpr Direction Acts::Direction::OppositeNormal ( )

staticconstexpr

Create direction opposite to normal (negative).

Returns

Direction with negative value, opposite to surface normal

Positive()

constexpr Direction Acts::Direction::Positive ( )

staticconstexpr

Create positive direction (+1).

Returns

Direction with positive value

sign()

int Acts::Direction::sign ( ) const

constexpr

Turns the direction into a signed value.

Returns

a signed value

toString()

std::string Acts::Direction::toString

(

)

const

Convert direction to string representation.

Returns

String representation of the direction ("positive" or "negative")