Struct SpringCurve 

#[repr(C)]
pub struct SpringCurve {
    pub stiffness: f32,
    pub damping: f32,
    pub mass: f32,
}

Mass-spring-damper parameters for AnimationInterpolationFunction::Spring.

Lives here rather than in azul-core because it is part of a #[repr(C)] CSS enum that crosses the C ABI; azul-core re-exports it so the animation engine can keep talking about Spring without reaching across layers.

Fields

stiffness: f32

Pull toward the target. Higher = faster, more eager.

damping: f32

Resistance. Higher = less overshoot; at critical damping, none.

mass: f32

Inertia. Higher = more sluggish, more overshoot for a given stiffness.

Implementations

impl SpringCurve

pub const SMOOTH: Self

No overshoot, quick settle. The safe default for UI motion.

pub const GENTLE: Self

Soft and slow; for large surfaces where snappiness reads as jarring.

pub const SNAPPY: Self

Fast with a slight overshoot; for small controls that should feel crisp.

pub const MAX_STEP_SECS: f32 = 0.05

Longest step handed to the integrator, in seconds (~3 frames at 60 Hz).

pub const EPSILON_VALUE: f32 = 0.06

Distance below which a spring counts as arrived (~a sixteenth of a device px).

pub const EPSILON_VELOCITY: f32 = 0.06

Speed below which a spring counts as stopped, in units/second.

pub fn damping_ratio(&self) -> f32

The damping ratio: < 1 under-damped (overshoots), 1 critical, > 1 over-damped.

pub fn step( &self, value: f32, target: f32, velocity: f32, dt: f32, ) -> (f32, f32)

One integration step. Returns the new (value, velocity).

dt is clamped: a stalled frame (tab restored, breakpoint hit) must not hand the integrator a huge step and fling the value off to infinity.

pub fn is_settled(&self, value: f32, target: f32, velocity: f32) -> bool

Whether the spring has effectively arrived.

Both conditions are required: near the target AND barely moving. Position alone would settle at the peak of an overshoot, mid-flight.

Trait Implementations

impl Clone for SpringCurve

fn clone(&self) -> SpringCurve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SpringCurve

impl Debug for SpringCurve

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

Formats the value using the given formatter.

impl Default for SpringCurve

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for SpringCurve

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SpringCurve