π Documentation | π Example | π Internet modules
- Framerate-independant spring physics
- Small, < 1kb gzipped
- Control the spring with tension and friction
- Adjustable timestep for the physics solver
onStart/onStopcallbacks- This lib was made to learn more about fixed timesteps and integration.
- It's a pretty basic Euler integration - not sure it will work for complex structures like spring chaining.
- If you need a rock-solid spring physics library, use ReboundJS
- Articles used :
- ES6 Modules support
- Using a module bundler like Webpack, Rollup or Parcel
- Native support from browser
- From NodeJS with esm
- Spring
- new Spring([options])
- Methods
- Properties
Create a new Spring instance.
| Param | Type | Default | Description |
|---|---|---|---|
| [options] | Object |
{} |
Spring options. |
| [options.initial] | number |
0 |
Initial value / targetValue of your spring. |
| [options.tension] | number |
0.1 |
Tension/Stifness of your spring. |
| [options.friction] | number |
0.2 |
From 0 to 1. Friction (Damping) of your spring. |
| [options.step] | number |
10 |
Timestep of the physics solver (in ms). Step > 16.67ms will give you pretty bad results. |
| [options.onStart] | function |
onStart will be called when the spring starts moving. |
|
| [options.onStop] | function |
onStop will be called when your the spring stops moving. |
|
| [options.precisionStop] | number |
0.0001 |
Minimum distance between value and target to consider the spring stopped. |
| [options.perfectStop] | boolean |
false |
Define if value is set precisely to targetValue when the spring stops moving. |
Example
import { raf } from '@internet/raf' import Spring from '@internet/spring' const move = new Spring({ initial: 0 }) move.setTarget(300) raf.add(dt => { move.update(dt) console.log(move.value) })
Change the current position of the spring. Can retrigger onStart / onStop.
Kind: instance method of Spring
Category: Methods
| Param | Type | Description |
|---|---|---|
| newCurrent | number |
New current value. |
Update target / resting position of the spring. Can retrigger onStart / onStop.
Kind: instance method of Spring
Category: Methods
| Param | Type | Description |
|---|---|---|
| newTarget | number |
New target value. |
Update tension of the spring
Kind: instance method of Spring
Category: Methods
| Param | Type | Description |
|---|---|---|
| tensionValue | number |
New tension value. |
Update friction of the spring
Kind: instance method of Spring
Category: Methods
| Param | Type | Description |
|---|---|---|
| frictionValue | number |
New friction value. |
Force re-start of the spring. Only needed if you force-stop the spring with stop()
Kind: instance method of Spring
Category: Methods
Force-stop the spring.
Kind: instance method of Spring
Category: Methods
Update the spring physic state
Kind: instance method of Spring
Category: Methods
| Param | Type | Description |
|---|---|---|
| dt | number |
Elapsed time since the last frame (in ms) |
Stop the spring and remove callbacks referenced in onStart and onStop.
Kind: instance method of Spring
Category: Methods
Initial position of the spring
Kind: instance property of Spring
Category: Properties
Current position of the spring
Kind: instance property of Spring
Category: Properties
Previous frame position of the spring
Kind: instance property of Spring
Category: Properties
Current velocity of the spring
Kind: instance property of Spring
Category: Properties
Optional function called when the spring starts
Kind: instance property of Spring
Category: Properties
Optional function called when the spring stops
Kind: instance property of Spring
Category: Properties