Demo at : okazari.github.io/Rythm.js/

A javascript library that makes your page dance.

Getting started

Install with npm

npm install rythm.js

CDN :

https://unpkg.com/rythm.js/
https://cdnjs.cloudflare.com/ajax/libs/rythm.js/2.1.0/rythm.min.js

Good old way

Import rythm into your page

<script type="text/javascript" src="/path/to/rythm.min.js"></script>

Add one of the rythm css classes to indicate which element will dance.

<div class="rythm-bass"></div>

Create a Rythm object and give it your audio url then use the start function.

var rythm = new Rythm();
rythm.setMusic("path/to/sample.mp3");
rythm.start();

ES6 module

import Rythm from 'rythm.js'
const rythm = new Rythm();
rythm.setMusic("path/to/sample.mp3");
rythm.start();

API Documentation

Rythm object

var rythm = new Rythm();

/* The starting scale is the minimum scale your elements will take (Scale ratio is startingScale + (pulseRatio * currentPulse));
 * Value in percentage between 0-1
 * Default 0.75
 */
rythm.startingScale = value;

/* The pulse ratio is be the maximum additionnal scale your element will take (Scale ratio is startingScale + (pulseRatio * currentPulse))
 * Value in percentage between 0-1
 * Default 0.30
 */
rythm.pulseRatio = value;

/* The max value history represent the number of passed value that will be stored to evaluate the current pulse.
 * Int value, minimum 1
 * Default 100
 */
rythm.maxValueHistory = value;

/* Set the music the page will dance to.
 * @audioUrl : '../example/mysong.mp3'
 */
rythm.setMusic(audioUrl);

/* Used to collaborate with other players library
 * You can connect Rythm to an audioElement, and then control the audio with your other player
 */
rythm.connectExternalAudioElement(audioElement)

/* Adjust music's gain.
 * @value : Number
 */
rythm.setGain(value);

/* Add your own rythm-class
 * @elementClass: Class that you want to link your rythm to.
 * @danceType : Use any of the build in effect or give your own function;
 * @startValue: The starting frequence of your rythm.
 * @nbValue: The number of frequences of your rythm.
 * 1024 Frequences, your rythm will react to the average of your selected frequences.
 * Examples : bass 0-10 ; medium 150-40 ; high 500-100
 */
rythm.addRythm(elementClass, danceType, startValue, nbValue);

/* Plug your computer microphone to rythm.js
 * This function return a promise resolved when the microphone is up.
 * Require your website to be run in HTTPS
 */
rythm.plugMicrophone().then(function(){...})

//Let's dance
rythm.start();

//Stop the party
rythm.stop();

Build in classes with "pulse" effect

• rythm-bass
• rythm-medium
• rythm-high

Custom-classes

You can use the addRythm function to make your own classes listen to specifics frequences. Here is how the basics classes are created :

• addRythm('rythm-bass','pulse',0,10);
• addRythm('rythm-medium','pulse',150,40);
• addRythm('rythm-high','pulse',500,100);

Availables dance types

For more control of theses dance types, you can give a configuration object as last argument to addRythm

addRythm('rythm-high', 'shake', 500, 100, { direction:'left', min: 20, max: 300});

Here are the build in dances and their options

• pulse
  • min : Minimum value given to transform: scale(). Default: 0.75
  • max : Maximum value given to transform: scale(). Default: 1.25
• jump
  • min : Minimum value given to transform: translateY(). Default: 0
  • max : Maximum value given to transform: translateY(). Default: 30
• shake
  • min : Minimum value given to transform: translateX(). Default: -15
  • max : Maximum value given to transform: translateX(). Default: 15
  • direction : left for a right to left move, right for a left to right move. Default: right
• twist
  • min : Minimum value given to transform: rotate(). Default: -20
  • max : Maximum value given to transform: rotate(). Default: 20
  • direction : left for a right to left move, right for a left to right move. Default: right
• vanish
  • min : Minimum value (between 0 and 1) given to opacity. Default: 0
  • max : Maximum value (between 0 and 1) given to opacity. Default: 1
  • reverse : Boolean to reverse the effect. Default false (Higher the pulse is, the more visible it will be)
• color
  • from : Array of integer between 0 and 255 corresponding to a RGB color. Default: [0,0,0]
  • to : Array of integer between 0 and 255 corresponding to a RGB color. Default: [255,255,255]

To see each visual effect, you can go to the Demo

Custom dance type

If you want to use your own dance type, you can give a function as the 2nd argument of addRythm

/* The custom function signature is :
 * @elem: The HTML element target you want to apply your effect to
 * @value: The current pulse ratio (percentage between 0 and 1)
 * @options: The option object user can give as last argument of addRythm function
 */
const pulse = (elem, value, options = {}) => {
  const max = options.max || 1.25
  const min = options.min || 0.75
  const scale = (max - min) * value
  elem.style.transform = `scale(${min + scale})`
}

addRythm('my-css-class', pulse, 150, 40)

Features

• Your HTML can dance by using any of the available dance types
• You can use custom functions to build you own dance type (and if it looks awesome ! Feel free to make a PR ;) )

Contribute

Any pull request will be apreciated. You can start coding on this project following this steps :

• Fork the project
• Clone your repository
• run npm install
• run npm start in the main folder to launch a development webserver.
• Enjoy the rythm.

Adding new dance type

In v2.0.x adding a new dance type is pretty easy

• Create a new file in src\dances
• This file must export your custom dance type function

For example, here is the content of jump.js file

/* The function signature is :
 * @elem: The HTML element target you want to apply your effect to
 * @value: The current pulse ratio (percentage between 0 and 1)
 * @options: The option object user can give as last argument of addRythm function
 */
export default (elem, value, options = {}) => {
  const max = options.max || 30
  const min = options.min || 0
  const jump = (max - min) * value
  elem.style.transform = `translateY(${-jump}px)`
}

• Import it and register it into the constructor of Dancer.js file

import jump from './dances/jump.js'
class Dancer {
  constructor() {
    this.registerDance('jump', jump)
  }
}

• Commit it and create a PR. Then look at everyone enjoying your contribution :) !

Licence : GNU GPL

Author: @OkazariBzh