Struct Spring 

pub struct Spring<Value> { /* private fields */ }

A finite physical spring between arbitrary interpolatable values.

Initial velocity is in endpoint distances per second. The default mass is one, stiffness 100, damping 10 and initial velocity zero. Duration is the conservative displacement-envelope settling time at threshold 0.001, rounded up to ticks. Values at/before zero and at/after duration are exact stored endpoints.

Builders validate the complete candidate configuration immediately. Nonfinite or nonpositive physical parameters, an unrepresentable response or settling time, and invalid thresholds panic. Zero damping is rejected because this type promises a finite settling duration. Use a signal for undamped oscillation.

use motion_core::prelude::*;
use motion_core::{
    DisplayList, RasterLimits, ResourcePool, ValidatedDisplayList, MAX_PATH_VERBS,
    MAX_STROKE_VERBS, MAX_SVG_PATH_BYTES, sample_offsets,
};
let movement = Spring::new(Point::ORIGIN, Point::new(100.0, 40.0))
    .damping(20.0)
    .settling_threshold(0.0001);
let end = movement.duration().unwrap();
assert_eq!(movement.sample(end), Point::new(100.0, 40.0));
assert_eq!(movement.sample((-1).seconds()), Point::ORIGIN);

Implementations

impl<Value> Spring<Value>

pub fn new(from: Value, to: Value) -> Self

Creates a spring with the default physical parameters and settling threshold.

pub fn mass(self, mass: f64) -> Self

Sets finite positive mass and recomputes the finite response immediately.

pub fn stiffness(self, stiffness: f64) -> Self

Sets finite positive stiffness and recomputes the response immediately.

pub fn damping(self, damping: f64) -> Self

Sets finite strictly positive damping. Zero has no finite settling time.

pub fn initial_velocity(self, velocity: f64) -> Self

Sets finite normalized velocity towards the target; negative moves away. Units are endpoint distances per second, not pixels per second.

pub fn settling_threshold(self, threshold: f64) -> Self

Sets a finite relative displacement-envelope threshold strictly between zero and one. This is not a pixel tolerance or a velocity threshold.

Trait Implementations

impl<Value: Interpolate + Send + Sync> Animation<Value> for Spring<Value>

fn sample(&self, time: Time) -> Value

Samples without advancing a clock or changing playback state.

fn duration(&self) -> Option<Duration>

Returns the finite duration, or None for an unbounded signal.

fn map<Output, Function>(self, function: Function) -> Map<Self, Function, Value>

where Self: Sized, Function: Fn(Value) -> Output + Send + Sync,

Transforms values without changing timing.

fn zip<OtherValue, Other>(self, other: Other) -> Zip<Self, Other>

where Self: Sized, Other: Animation<OtherValue>,

Samples in parallel; the duration is infinite if either input is infinite.

fn delay(self, offset: Duration) -> Delay<Self>

where Self: Sized,

Delays a finite animation, holding its initial value before the offset. Infinite signals shift their signed time instead. Negative offsets and finite duration overflow panic at construction.

fn speed(self, factor: f64) -> Speed<Self>

where Self: Sized,

Changes playback speed by a finite, strictly positive factor. Durations round to the nearest tick; a collapsed finite animation becomes instantaneous. Invalid factors and unrepresentable durations panic.

fn then<Next: Animation<Value>>(self, next: Next) -> Then<Self, Next>

where Self: Sized,

Runs two finite animations in sequence. The second owns their shared boundary. Infinite sources or duration overflow panic at construction.

fn reverse(self) -> Reverse<Self>

where Self: Sized,

Reverses a finite animation. Infinite sources panic at construction.

fn repeat(self, count: u32) -> Repeat<Self>

where Self: Sized,

Plays a finite animation count times. Intermediate boundaries restart; the final boundary holds the target. Zero repeats hold the initial value. Infinite sources or duration overflow panic at construction.

fn ping_pong(self) -> PingPong<Self>

where Self: Sized,

Plays a finite animation forward then backward, ending at its initial value. Infinite sources or duration overflow panic at construction.

fn boxed(self) -> Arc<dyn Animation<Value>>

where Self: Sized + 'static,

Shares a type-erased animation, retaining sampling and combinators.

impl<Value: Clone> Clone for Spring<Value>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Value: Debug> Debug for Spring<Value>

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

Formats the value using the given formatter.

impl Default for Spring<f64>

fn default() -> Self

Returns the “default value” for a type.