Smooth

Library for creating animations that depend on user interaction using the lerp technique.

About LERP technique

• David Khourshid. Lerp Technique.
• Paul Lewis. Leaner, Meaner, Faster Animations with requestAnimationFrame. 2012

Installation

npm install @web-alchemy/smooth

Import

// with bundlers
import { Smooth } from '@web-alchemy/smooth'

// import from `node_modules`
import { Smooth } from 'node_modules/@web-alchemy/smooth/dist/smooth.module.js'

// import from CDN
import { Smooth } from 'https://unpkg.com/@web-alchemy/smooth/dist/smooth.module.js'

Using example - animated custom cursor

<div class="cursor"></div>

import { Smooth } from '@web-alchemy/smooth'

const cursor = document.querySelector('.cursor')

const initialValue = [window.innerWidth / 2, window.innerHeight / 2]

const smooth = new Smooth({
  value: initialValue, // array of numbers
  step: 0.075, // should be between 0 and 1
  accuracy: 0.001 // should be less than 1
})

function render(x, y) {
  cursor.style.setProperty('--x', x.toFixed(2))
  cursor.style.setProperty('--y', y.toFixed(2))
}

document.addEventListener('pointermove', (event) => {
  // store user values
  smooth.update([event.clientX, event.clientY])
})

// render interpolated values
smooth.addEventListener('update', (event) => {
  const [x, y] = event.detail
  render(x, y)
})

smooth.start()
// or
// render(initialValue[0], initialValue[1])

.cursor {
  --_x: var(--x, 0);
  --_y: var(--y, 0);
  --_size: var(--size, 2rem);
  position: fixed;
  top: 0;
  left: 0;
  transform:
    translate3d(
      calc(var(--x) * 1px - 50%),
      calc(var(--y) * 1px - 50%),
      0
    );
  box-sizing: border-box;
  border: 2px solid;
  width: var(--_size);
  aspect-ratio: 1;
  border-radius: 50%;
}

Examples

Clone git repo and run web server with examples for local testing

npm start

or check https://web-alchemy.github.io/smooth