Struct ludomath::vec2d::Rotation

#[repr(C)]
pub struct Rotation {
    pub cos: f32,
    pub sin: f32,
}

Represents a 2D rotation or direction.

Stores the sine and cosine of the angle of rotation, which makes the rotation faster if the same angle is used multiple times. The drawbacks are memory usage, and that combining multiple rotations is more expensive.

Fields

cos: f32

The cosine of the angle.

sin: f32

The sine of the angle.

Methods

impl Rotation

pub fn new_in_direction(dir: Vector) -> Rotation

Constructs a rotation from the direction of a vector.

The angle of the rotation is the angle from the positive x-axis to the vector.

pub fn new_rad(angle: f32) -> Rotation

Constructs a rotation of a specified angle, in radians.

pub fn new_deg(angle: f32) -> Rotation

Constructs a rotation of a specified angle, in degrees.

pub fn between(from: Vector, to: Vector) -> Rotation

Gets the rotation from one vector to another.

Rotating the first vector by the returned rotation yields a vector with the same direction as the second vector.

pub fn negate(self) -> Rotation

Negates the angle of a rotation.

pub fn add(self, other: Rotation) -> Rotation

Adds the angles of two rotations together.

pub fn sub(self, other: Rotation) -> Rotation

Subtracts the angle of one rotation from another.

Equivalent to self.add(other.negate()).

pub fn angle_rad(self) -> f32

Returns the angle of rotation, in radians.

Return values are contained in (-τ/2, τ/2], aka. (-π, π].

pub fn angle_deg(self) -> f32

Returns the angle of rotation, in degrees.

Return values are approximately contained in (-180, 180].

pub fn to_vector(self) -> Vector

Converts the rotation to a unit vector.

pub fn slerp(self, other: Rotation, t: f32) -> Rotation

Linearly interpolates the angle between two rotations.

The angle moves between the endpoints at contant speed. Like the other lerp functions, works even for t outside [0, 1]. Fairly slow, like the analogous common quaternion slerp function.

pub fn nlerp(self, other: Rotation, t: f32) -> Rotation

Quickly interpolates between two rotations.

Significantly faster than slerp, but doesn't have constant angle speed. This gets jerkier the further the two rotations are from eachother.

Treats the rotations as direction vectors, linearly interpolates between them, and normalizes the result to a new direction vector, which is used as the new rotation.

Trait Implementations

impl Clone for Rotation

fn clone(&self) -> Rotation

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Rotation

impl PartialEq for Rotation

fn eq(&self, __arg_0: &Rotation) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &Rotation) -> bool

This method tests for !=.

impl Debug for Rotation

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

Formats the value using the given formatter.