Struct gravitas::Spring

pub struct Spring { /* fields omitted */ }

a position controlled by a spring as defined by Hooke's law, F = -kx * cv.

Depending on the values specified for the spring's mass, constant and damping, the spring may be underdamped, critically damped or overdamped. This textbook provides a good overview of the spring model used by Gravitas.

A critically damped spring satisfies: damping * damping - 4 * mass * spring_constant == 0.

Methods

impl Spring

pub fn new(mass: f32, spring_constant: f32, damping: f32) -> Spring

Create a new spring with the given mass, spring constant and damping values.

The spring starts out "snapped" to 0.0.

pub fn set(&mut self, x: f32, velocity: f32, time: f32)

Set the spring's endpoint to the given position and velocity. If time is non-zero then the velocity of the spring at that time (before these new values are applied) is also included.

pub fn snap(&mut self, x: f32)

"Snap" the spring and set the value. The spring simulation will return this value with no velocity for all time (or until set is called again) once snapped.

Trait Implementations

impl Clone for Spring

fn clone(&self) -> Spring

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Spring

impl Simulation for Spring

fn x(&self, time: f32) -> f32

Return the position for the given time (in seconds).

fn dx(&self, time: f32) -> f32

Return the velocity for the given time (in seconds).

fn is_done(&self, time: f32) -> bool

Return true if the simulation has reached a final position at the given time (in seconds).