Struct Spring 

pub struct Spring { /* private fields */ }

A damped spring of unit mass, set by (duration, bounce). The fields are private so the invariants hold: the duration is 0 (no spring, see Spring::NONE) or within Spring::MIN_DURATION..=Spring::MAX_DURATION, and the bounce is within -MAX_BOUNCE..=MAX_BOUNCE.

Implementations

impl Spring

pub const MIN_DURATION: f32 = 0.01

The shortest duration of a spring that moves, in seconds.

pub const MAX_DURATION: f32 = 60.0

The longest duration, in seconds.

pub const MAX_BOUNCE: f32 = 0.95

The largest bounce either way.

pub const DEFAULT: Spring

0.3 s without bounce: the default for most interface motion.

pub const NONE: Spring

No spring: values jump to their target (treated like Curve::Instant).

pub const fn new(duration: f32, bounce: f32) -> Spring

A spring of duration seconds and bounce (−0.95..=0.95). Never panics: a NaN duration gives the default 0.3 s, zero or negative gives Spring::NONE, other values are clamped to MIN_DURATION..=MAX_DURATION; a NaN bounce is 0 and others are clamped.

pub const fn from_response(response: f32, damping_ratio: f32) -> Spring

A spring from a response (the duration) and a damping ratio ζ (1 = critical, below 1 bounces). Clamped like Spring::new; a NaN ratio is 1.

pub const fn duration(self) -> f32

The duration in seconds (0 for Spring::NONE).

pub const fn bounce(self) -> f32

The bounce, −0.95..=0.95.

pub const fn is_none(self) -> bool

Whether this is no spring at all (duration 0): values jump.

pub fn damping_ratio(self) -> f32

The damping ratio ζ.

pub fn stiffness(self) -> f32

The stiffness k = ω² for unit mass (0 for Spring::NONE).

pub fn damping(self) -> f32

The damping coefficient c = 2ζω for unit mass (0 for Spring::NONE).

pub fn sample(self, x0: f32, v0: f32, target: f32, t: f32) -> (f32, f32)

Position and velocity t seconds after starting at x0 with velocity v0, pulled to target. Closed form for all three damping regimes. Non-finite inputs are replaced (position by the target, velocity by 0, a bad target by the start), t ≤ 0 returns the start, and the result is always finite.

pub fn settle_time(self, from: f32, v0: f32, target: f32, eps: Eps) -> f32

The time in seconds after which a motion from (from, v0) to target stays within eps (position and velocity) for good. Never earlier than the true settle (it is the last crossing of a bound of the motion), at most MAX_SETTLE, and 0 when already settled.

pub fn settle_time_lanes( self, lanes: impl IntoIterator<Item = (f32, f32, f32)>, eps: Eps, ) -> f32

The settle time of several lanes (from, v0, target) moving together: one bound over all of them (each coefficient of the bound is the largest of any lane’s), so it is never earlier than any lane’s settle and costs one root solve.

Trait Implementations

impl Clone for Spring

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Spring

impl Debug for Spring

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

Formats the value using the given formatter.

impl Default for Spring

fn default() -> Self

Returns the “default value” for a type.

impl From<Spring> for Curve

fn from(s: Spring) -> Self

Converts to this type from the input type.

impl PartialEq for Spring

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Spring