Struct HudElementBasis

The scale, per-axis stretch and rotation an element carries at one instant, in its own displayed (pre-mirror) space.

Inherited Members

ValueType.Equals(object)

ValueType.GetHashCode()

ValueType.ToString()

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetType()

Namespace: Serenity.GameUi.Application.Placement

Assembly: Serenity.GameUi.Application.dll

Syntax

public readonly struct HudElementBasis

Remarks

The affine map a gesture applies to a local point is R(θ)·S(Scale·StretchX, Scale·StretchY)·p: the element is stretched along its own axes first, then the whole result is rotated. Scale and stretch only ever appear multiplied together — Transform(float, float) is the one place that product is taken — which is what keeps a uniform Resize and a per-axis Deform sharing the same compensation maths without either one needing to know about the other.

Constructors

HudElementBasis(float, float, float, float)

Creates a basis.

Declaration

public HudElementBasis(float scale, float stretchX, float stretchY, float rotationDegrees)

Parameters

Type	Name	Description
float	scale	The uniform scale.
float	stretchX	The stretch along the local X axis.
float	stretchY	The stretch along the local Y axis.
float	rotationDegrees	The rotation, in displayed-space degrees.

Fields

RotationDegrees

The rotation, in displayed-space degrees.

Declaration

public readonly float RotationDegrees

Field Value

Type	Description
float

Scale

The uniform scale.

Declaration

public readonly float Scale

Field Value

Type	Description
float

StretchX

The stretch along the element's own local X axis, applied before rotation.

Declaration

public readonly float StretchX

Field Value

Type	Description
float

StretchY

The stretch along the element's own local Y axis, applied before rotation.

Declaration

public readonly float StretchY

Field Value

Type	Description
float

Methods

Transform(float, float)

Maps a local point through this basis: stretched along its own axes, then rotated.

Declaration

public (float X, float Y) Transform(float x, float y)

Parameters

Type	Name	Description
float	x	The local X coordinate.
float	y	The local Y coordinate.

Returns

Type	Description
(float X, float Y)	The transformed point.

Remarks

The stretch is folded into x/y before the rotation, and the uniform Scale is applied to the rotated result afterwards — mathematically the same thing (Scale is common to both axes, so it commutes across the rotation), but this ordering is what makes the case StretchX = StretchY = 1 reproduce the exact arithmetic — the same double-precision subtraction, the same single cast, the same one float multiply — that this solver used before stretch existed at all.