Bounds for a trapezoidal, planar Surface. More...

#include <Acts/Surfaces/TrapezoidBounds.hpp>

Inheritance diagram for Acts::TrapezoidBounds:

Collaboration diagram for Acts::TrapezoidBounds:

Public Types
enum	BoundValues { eHalfLengthXnegY = 0 , eHalfLengthXposY = 1 , eHalfLengthY = 2 , eRotationAngle = 3 , eSize = 4 }
	Enumeration for the bound values. More...
Public Types inherited from Acts::SurfaceBounds
enum	BoundsType : int { eCone = 0 , eCylinder = 1 , eDiamond = 2 , eDisc = 3 , eEllipse = 4 , eLine = 5 , eRectangle = 6 , eTrapezoid = 7 , eTriangle = 8 , eDiscTrapezoid = 9 , eConvexPolygon = 10 , eAnnulus = 11 , eBoundless = 12 , eOther = 13 }
	This is nested to the SurfaceBounds, as also VolumeBounds will have Bounds Type. More...

Public Member Functions
	TrapezoidBounds (const std::array< double, eSize > &values) noexcept(false)
	Constructor for symmetric Trapezoid - from fixed size array.
	TrapezoidBounds (double halfXnegY, double halfXposY, double halfY, double rotAngle=0.) noexcept(false)
	Constructor for symmetric Trapezoid.
const RectangleBounds &	boundingBox () const final
	Bounding box parameters.
Vector2	center () const final
	Calculate the center of the surface bounds in local coordinates.
Vector2	closestPoint (const Vector2 &lposition, const SquareMatrix2 &metric) const final
	Calculates the closest point on the bounds to a given local position.
double	get (BoundValues bValue) const
	Access to the bound values.
bool	inside (const Vector2 &lposition) const final
	Inside check for the bounds object.
virtual bool	inside (const Vector2 &lposition, const BoundaryTolerance &boundaryTolerance) const
	Inside check for the bounds object given a boundary tolerance.
std::ostream &	toStream (std::ostream &sl) const final
	Output Method for std::ostream.
BoundsType	type () const final
	Return the bounds type - for persistency optimization.
std::vector< double >	values () const final
	Access method for bound values, this is a dynamically sized vector containing the parameters needed to describe these bounds.
std::vector< Vector2 >	vertices (unsigned int ignoredSegments=0u) const final
	Return the vertices.
Public Member Functions inherited from Acts::PlanarBounds
SquareMatrix2	boundToCartesianJacobian (const Vector2 &lposition) const final
	Computes the bound to cartesian jacobian at a given local position.
SquareMatrix2	boundToCartesianMetric (const Vector2 &lposition) const final
	Computes the bound to cartesian metric at a given local position.
bool	isCartesian () const final
	Check if the bound coordinates are cartesian.
Public Member Functions inherited from Acts::SurfaceBounds
virtual	~SurfaceBounds ()=default
virtual double	distance (const Vector2 &lposition) const
	Calculates the distance to the bounds from a given local position.

Detailed Description

Bounds for a trapezoidal, planar Surface.

Todo: can be speed optimized by calculating kappa/delta and caching it

Member Enumeration Documentation

◆ BoundValues

enum Acts::TrapezoidBounds::BoundValues

Enumeration for the bound values.

Enumerator
eHalfLengthXnegY
eHalfLengthXposY
eHalfLengthY
eRotationAngle
eSize

Constructor & Destructor Documentation

◆ TrapezoidBounds() [1/2]

Acts::TrapezoidBounds::TrapezoidBounds	(	double	halfXnegY,
		double	halfXposY,
		double	halfY,
		double	rotAngle = 0. )

explicit

Constructor for symmetric Trapezoid.

Parameters

halfXnegY	minimal half length X, definition at negative Y
halfXposY	maximal half length X, definition at positive Y
halfY	half length Y - defined at x=0
rotAngle	rotation angle of the bounds w.r.t coordinate axes

◆ TrapezoidBounds() [2/2]

Acts::TrapezoidBounds::TrapezoidBounds ( const std::array< double, eSize > & values )

explicitnoexcept

Constructor for symmetric Trapezoid - from fixed size array.

Parameters

values the values to be stream in

Member Function Documentation

◆ boundingBox()

const RectangleBounds & Acts::TrapezoidBounds::boundingBox ( ) const

finalvirtual

Bounding box parameters.

Returns: rectangle bounds for a bounding box

Implements Acts::PlanarBounds.

◆ center()

Vector2 Acts::TrapezoidBounds::center ( ) const

finalvirtual

Calculate the center of the surface bounds in local coordinates.

This method returns a representative center point of the bounds region. The exact definition varies by bounds type and coordinate system:

Cartesian bounds (Rectangle, Diamond, Trapezoid):

Returns the geometric center or center of symmetry
For symmetric shapes: center of bounding box or origin (0,0)

Polar/Cylindrical bounds (Radial, Cylinder, Cone):

Returns (r, phi) where r is average radius, phi is average angle
Coordinates are in the bounds' natural coordinate system

Complex bounds (Annulus, ConvexPolygon):

Annulus: Pre-calculated from corner vertices (accounts for coordinate transforms)
Polygon: Average of all vertices (vertex centroid, not area centroid)

Infinite bounds: Returns conceptual center at (0,0)

Note: The returned point is guaranteed to be a reasonable representative center, but may not be the true geometric centroid for all shapes.

Returns: Vector2 representing the center position in local coordinates

Note: For TrapezoidBounds: returns center of symmetry (0,0), accounting for rotation

Implements Acts::SurfaceBounds.

◆ closestPoint()

Vector2 Acts::TrapezoidBounds::closestPoint	(	const Vector2 &	lposition,
		const SquareMatrix2 &	metric ) const

finalvirtual

Calculates the closest point on the bounds to a given local position.

Parameters

lposition	is the local position
metric	to be used for the distance calculation

Returns: the closest point on the bounds

Implements Acts::SurfaceBounds.

◆ get()

double Acts::TrapezoidBounds::get ( BoundValues bValue ) const

Access to the bound values.

Parameters

bValue the class nested enum for the array access

Returns: The bound value at the specified index

◆ inside() [1/2]

bool Acts::TrapezoidBounds::inside ( const Vector2 & lposition ) const

finalvirtual

Inside check for the bounds object.

Parameters

lposition is the local position

Returns: true if the local position is inside the bounds

The orientation of the Trapezoid is according to the figure above, in words: the shorter of the two parallel sides of the trapezoid intersects with the negative \( y \) - axis of the local frame.

The cases are:
(0) \( y \) or \( x \) bounds are 0 || 0
(1) the local position is outside \( y \) bounds
(2) the local position is inside \( y \) bounds, but outside maximum \(x \) bounds
(3) the local position is inside \( y \) bounds AND inside minimum \( x \) bounds
(4) the local position is inside \( y \) bounds AND inside maximum \( x \) bounds, so that it depends on the \( eta \) coordinate (5) the local position fails test of (4)

The inside check is done using single equations of straight lines and one has to take care if a point lies on the positive \( x \) half area(I) or the negative one(II). Denoting \( |x_{min}| \) and \( | x_{max} | \) as minHalfX respectively maxHalfX, such as \( | y_{H} | \) as halfY, the equations for the straing lines in (I) and (II) can be written as:

(I): \( y = \kappa_{I} x + \delta_{I} \)
(II): \( y = \kappa_{II} x + \delta_{II} \) ,

where \( \kappa_{I} = - \kappa_{II} = 2 \frac{y_{H}}{x_{max} - x_{min}} \)
and \( \delta_{I} = \delta_{II} = - \frac{1}{2}\kappa_{I}(x_{max} + x_{min}) \)

Implements Acts::SurfaceBounds.

◆ inside() [2/2]

virtual bool Acts::SurfaceBounds::inside	(	const Vector2 &	lposition,
		const BoundaryTolerance &	boundaryTolerance ) const

virtual

Inside check for the bounds object given a boundary tolerance.

Parameters

lposition	is the local position
boundaryTolerance	is the boundary tolerance object

Returns: true if the local position is inside the bounds and tolerance

Reimplemented from Acts::SurfaceBounds.

◆ toStream()

std::ostream & Acts::TrapezoidBounds::toStream ( std::ostream & sl ) const

finalvirtual

Output Method for std::ostream.

Parameters

sl	is the ostream to be dumped into

Returns: Modified ostream for chaining

Implements Acts::SurfaceBounds.

◆ type()

BoundsType Acts::TrapezoidBounds::type ( ) const

finalvirtual

Return the bounds type - for persistency optimization.

Returns: the bounds type

Implements Acts::SurfaceBounds.

◆ values()

std::vector< double > Acts::TrapezoidBounds::values ( ) const

finalvirtual

Access method for bound values, this is a dynamically sized vector containing the parameters needed to describe these bounds.

Returns: of the stored values for this SurfaceBounds object

Implements Acts::SurfaceBounds.

◆ vertices()

std::vector< Vector2 > Acts::TrapezoidBounds::vertices ( unsigned int ignoredSegments = 0u ) const

finalvirtual

Return the vertices.

Parameters

ignoredSegments is and ignored parameter used to describe the number of segments to approximate curved sectors.

Note: the number of segments is ignored in this representation

Returns: vector for vertices in 2D

Implements Acts::PlanarBounds.

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ BoundValues

Constructor & Destructor Documentation

◆ TrapezoidBounds() [1/2]

◆ TrapezoidBounds() [2/2]

Member Function Documentation

◆ boundingBox()

◆ center()

◆ closestPoint()

◆ get()

◆ inside() [1/2]

◆ inside() [2/2]

◆ toStream()

◆ type()

◆ values()

◆ vertices()