Struct SpringDamper 

pub struct SpringDamper {
    pub position: f32,
    pub velocity: f32,
    pub target: f32,
    pub stiffness: f32,
    pub damping: f32,
    pub mass: f32,
}

A spring-damper system that tracks a scalar value toward a target.

The spring has mass m, stiffness k, and damping d. ζ (damping ratio) = d / (2 * √k). ζ < 1: underdamped (oscillates, overshoots) ζ = 1: critically damped (fastest convergence, no overshoot) ζ > 1: overdamped (slow, no overshoot)

Fields

position: f32

velocity: f32

target: f32

stiffness: f32

damping: f32

mass: f32

Inertia. Heavy things lag behind their target and keep going once moved; light things snap. Must stay above zero or the integrator divides by it.

Implementations

impl SpringDamper

pub fn new(position: f32, stiffness: f32, damping: f32) -> Self

pub fn with_mass(self, mass: f32) -> Self

Same spring, with inertia. Values at or below zero are clamped to a small positive mass rather than blowing the simulation up.

pub fn set_mass(&mut self, mass: f32)

Set the inertia, keeping the spring stable.

pub fn critical(position: f32, speed: f32) -> Self

Create a critically damped spring (no overshoot, fastest convergence).

pub fn bouncy(position: f32, frequency: f32, damping_ratio: f32) -> Self

Create an underdamped spring (bouncy, overshoots slightly).

pub fn tick(&mut self, dt: f32)

Step the spring by dt seconds.

Explicit integration goes unstable once the step is long relative to the spring’s own period, which a very light glyph on a stiff spring will hit on an ordinary frame. Rather than clamp the physics into something wrong, the step is subdivided until it is inside the stable range.

pub fn tick_get(&mut self, dt: f32) -> f32

Step and return the new position.

pub fn set_target(&mut self, target: f32)

pub fn teleport(&mut self, position: f32)

pub fn is_settled(&self, threshold: f32) -> bool

Trait Implementations

impl Clone for SpringDamper

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SpringDamper

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

Formats the value using the given formatter.