kite3d/io.github.yuroyami.kite3d.math/Quaternion

Quaternion

class Quaternion(x: Double = 0.0, y: Double = 0.0, z: Double = 0.0, w: Double = 1.0) : Iterable<Double>

A quaternion, used to represent rotations.

Iterating through an instance yields its components (x, y, z, w) in order.

Rotation methods expect a normalized (unit length) quaternion.

Instances are mutable and not thread-safe. Use each instance from one thread only.

Reading x/y/z/w has no side effect. Writing any of them, or calling a mutating method, fires the registered onChange callback (see that method).

Constructors

Quaternion

constructor(x: Double = 0.0, y: Double = 0.0, z: Double = 0.0, w: Double = 1.0)

Types

Companion

object Companion

Properties

var w: Double

The w value of this quaternion. Assigning fires the onChange callback.

var x: Double

The x value of this quaternion. Assigning fires the onChange callback.

var y: Double

The y value of this quaternion. Assigning fires the onChange callback.

var z: Double

The z value of this quaternion. Assigning fires the onChange callback.

Functions

angleTo

fun angleTo(q: Quaternion): Double

Returns the angle between this quaternion and q in radians.

clone

fun clone(): Quaternion

Returns a new quaternion with copied values from this instance.

conjugate

fun conjugate(): Quaternion

Sets this quaternion to its conjugate: the same rotation in the opposite direction about the same axis.

copy

fun copy(quaternion: Quaternion): Quaternion

Copies the values of quaternion into this instance.

dot

fun dot(v: Quaternion): Double

Returns the dot product of this quaternion and v.

equals

open operator override fun equals(other: Any?): Boolean

Structural equality: true when other is a Quaternion with equal components (component-wise ==, so NaN != NaN).

fromArray

fun fromArray(array: DoubleArray, offset: Int = 0): Quaternion

Sets this quaternion's components from array starting at offset.

fromBufferAttribute

fun fromBufferAttribute(attribute: AttributeLike, index: Int): Quaternion

Sets the components of this quaternion from attribute at index.

hashCode

open override fun hashCode(): Int

identity

fun identity(): Quaternion

Sets this quaternion to the identity quaternion (no rotation).

invert

fun invert(): Quaternion

Inverts this quaternion via conjugate. The quaternion is assumed to have unit length.

iterator

open operator override fun iterator(): Iterator<Double>

length

fun length(): Double

Returns the Euclidean length of this quaternion (as a 4D vector).

lengthSq

fun lengthSq(): Double

Returns the squared Euclidean length of this quaternion (as a 4D vector).

multiply

fun multiply(q: Quaternion): Quaternion

Multiplies this quaternion by q.

multiplyQuaternions

fun multiplyQuaternions(a: Quaternion, b: Quaternion): Quaternion

Multiplies a and b and stores the result in this instance.

normalize

fun normalize(): Quaternion

Normalizes this quaternion. It computes the quaternion that performs the same rotation but has length 1. A zero-length quaternion becomes the identity.

onChange

fun onChange(callback: () -> Unit): Quaternion

Registers callback to run whenever this quaternion's state changes (via a component setter or a mutating method). Reads never fire it.

premultiply

fun premultiply(q: Quaternion): Quaternion

Pre-multiplies this quaternion by q.

random

fun random(): Quaternion

Sets this quaternion to a uniformly random, normalized quaternion.

rotateTowards

fun rotateTowards(q: Quaternion, step: Double): Quaternion

Rotates this quaternion by an angular step (in radians) toward q, without overshooting it.

set

fun set(x: Double, y: Double, z: Double, w: Double): Quaternion

Sets the quaternion components.

setFromAxisAngle

fun setFromAxisAngle(axis: Vector3, angle: Double): Quaternion

Sets this quaternion from the given axis and angle.

setFromEuler

fun setFromEuler(euler: Euler, update: Boolean = true): Quaternion

Sets this quaternion from the rotation specified by the given Euler angles.

setFromRotationMatrix

fun setFromRotationMatrix(m: Matrix4): Quaternion

Sets this quaternion from the given rotation matrix m (the upper 3x3 of which must be an unscaled rotation).

setFromUnitVectors

fun setFromUnitVectors(vFrom: Vector3, vTo: Vector3): Quaternion

Sets this quaternion to the rotation required to rotate the direction vector vFrom to the direction vector vTo. Both are assumed normalized.

slerp

fun slerp(qb: Quaternion, t: Double): Quaternion

Performs a spherical linear interpolation between this quaternion and qb by factor t. Values in [0, 1] interpolate; values outside extrapolate.

slerpQuaternions

fun slerpQuaternions(qa: Quaternion, qb: Quaternion, t: Double): Quaternion

Performs a spherical linear interpolation between qa and qb and stores the result in this quaternion.

toArray

fun toArray(array: MutableList<Double> = mutableListOf(), offset: Int = 0): MutableList<Double>

Writes the components of this quaternion into array at offset, growing the list as needed, and returns it.

toJSON

fun toJSON(): MutableList<Double>

Serialization result: the components of this quaternion as [x, y, z, w].

toString

open override fun toString(): String