Struct Quaternion 

pub struct Quaternion {
    pub w: f64,
    pub x: f64,
    pub y: f64,
    pub z: f64,
}

四元数（用于表示3D旋转）

四元数是表示3D旋转的数学工具，避免了欧拉角的万向节锁问题。

Fields

w: f64

实部

x: f64

虚部 i

y: f64

虚部 j

z: f64

虚部 k

Implementations

impl Quaternion

pub const IDENTITY: Self

单位四元数（无旋转）

pub fn from_euler(roll: Rad, pitch: Rad, yaw: Rad) -> Self

从欧拉角创建四元数（Roll-Pitch-Yaw, ZYX顺序）

参数

• roll: 绕X轴旋转
• pitch: 绕Y轴旋转
• yaw: 绕Z轴旋转

pub fn to_euler(self) -> (Rad, Rad, Rad)

转换为欧拉角（Roll-Pitch-Yaw）

返回 (roll, pitch, yaw)

pub fn normalize(&self) -> Self

归一化（确保单位四元数）

数值稳定性

如果四元数的模接近 0（< 1e-10），返回默认单位四元数 (1, 0, 0, 0) 以避免除零错误和 NaN 扩散。

这种情况理论上不应发生，但在初始化错误、序列化错误或数值计算 累积误差时可能出现。

pub fn multiply(&self, other: &Quaternion) -> Quaternion

四元数乘法（组合旋转）

pub fn conjugate(&self) -> Quaternion

共轭（逆旋转）

Trait Implementations

impl Clone for Quaternion

fn clone(&self) -> Quaternion

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Quaternion

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Quaternion

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Quaternion

fn eq(&self, other: &Quaternion) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Quaternion

impl StructuralPartialEq for Quaternion