Struct MaterialSpringSpec 

pub struct MaterialSpringSpec { /* private fields */ }

Parameters of a unit-mass damped spring: x'' + 2 ζ √k x' + k (x-target) = 0.

Implementations

impl MaterialSpringSpec

pub const fn new(damping_ratio: f64, stiffness: f64) -> Self

Creates a spring. Stiffness must be positive and finite; damping must be finite and nonnegative. A zero-damping spring oscillates forever and has no settling duration.

pub const fn damping_ratio(self) -> f64

pub const fn stiffness(self) -> f64

pub fn sample( self, elapsed: f64, from: f64, target: f64, initial_velocity: f64, ) -> MaterialSpringSample

Evaluates both position and velocity analytically, independent of display refresh rate.

All three damping regimes are supported. The overdamped case uses a stable slow root and expm1 to avoid subtracting nearly equal exponentials near critical damping. The underdamped case uses sinc, so its limit at critical damping is also well behaved. A negative/NaN elapsed time leaves the initial state unchanged; positive infinity is treated as the settled state. Initial and target values must be finite.

pub fn settling_duration(self) -> f64

A conservative finite tail for the unit step, with position tolerance 0.001 and velocity tolerance 0.001 * sqrt(stiffness). Returns infinity for an undamped spring.

pub fn settling_duration_from( self, displacement: f64, velocity: f64, position_threshold: f64, velocity_threshold: f64, ) -> f64

A conservative settling time for an arbitrary interrupted spring, in seconds.

Both the position and velocity stay below their respective tolerances after this time. Unlike the unit-step adapter, this accounts for momentum when the new target is very close to the current position. Bounds are analytical exponential envelopes; this does not advance a simulation or mistake an oscillation’s zero crossing for rest.

Trait Implementations

impl Clone for MaterialSpringSpec

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 MaterialSpringSpec

impl Debug for MaterialSpringSpec

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

Formats the value using the given formatter.

impl PartialEq for MaterialSpringSpec

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MaterialSpringSpec