patatap_tracker-we-will-rock-you.js

// Remix of Queen's "We will rock you" for the patatap tracker
// see: https://gist.github.com/eudes/d30365efa5e712cded7377945a690350

// - Go to http://patatap.com/
// - open the developer console (note: F12 is disabled!, open with inspect)
// - execute this snippet
// - change 'seq' to change the note sequence. Keys must be uppercase
// - you can send 1 function instead of a note to control other stuff in the page

function keypress(char) {
    $.event.trigger({type: 'keydown', which: char.charCodeAt(0)})
}

function bpmToMillis() {
    return ((60 / bpm) * 1000) / subdivisions
}

async function tracker() {
    while (seq.length > 0) { // avoid freeze if emptying seq
        for (let notes of seq) {
            if (notes.length > 0 && typeof notes[0] === 'function') {
                notes[0]()
            } else {
                if (play) notes.forEach(keypress)
                await new Promise((resolve) =>
                    setTimeout(resolve, bpmToMillis())
                )
            }
        }
    }
}
var seq = [['a']]
var bpm = 120
var subdivisions = 2
var play = true

// create a textarea for pasting sequences
$('body').append('<textarea id="seq" style="position:absolute; width:14em; height: 10em; color: black">// paste your sequence and press enter\nseq = [\n["A"]\n]</textarea>')
$('#seq').on('keyup', (e) => {
    if(e.which == 13 && !e.shiftKey && !e.altKey && !e.ctrlKey && !e.metaKey) {
        eval(e.target.value)
        e.target.style.width = '20px'
        e.target.style.height = '20px'
    }
    return e
})

tracker()


seq = [
    ['C'],
    [],
    ['C'],
    [],
    ['A'],
    [],
    [],
    [],

    ['C'],
    [],
    ['C'],
    [],
    ['A'],
    [],
    [],
    [],

    ['C'],
    [],
    ['C'],
    [],
    ['A'],
    [],
    [],
    [],

    ['C'],
    [],
    ['C'],
    [],
    ['A'],
    [],
    [],
    [],


    ['Z','C'],
    ['Z',],
    ['Z','C'],
    ['Z',],
    ['Z','K','A'],
    [],
    ['Z',],
    ['Z',],

    ['Z','D','C'],
    [],
    ['Z','D','C'],
    [],
    ['Z','A'],
    ['Z',],
    ['Z',],
    ['Z',],

    ['Z','K','C'],
    [],
    ['Z','C'],
    ['Z',],
    ['Z','A'],
    ['Z',],
    ['Z','N',],
    [],

    ['Z','H','C'],
    [],
    ['Z','H','C'],
    [],
    ['Z','A'],
    ['Z',],
    ['Z',],
    [],

    ['Z','K','C'],
    [],
    ['Z','C'],
    ['Z',],
    ['Z','J','A'],
    ['E'],
    ['Z',],
    ['E'],

    ['Z','W','C'],
    [],
    ['Z','W','C'],
    [],
    ['Z','T','A'],
    [],
    [],
    [],

    ['Z','C'],
    ['Z',],
    ['Z','C'],
    [],
    ['Z','A'],
    [],
    ['Z',],
    [],

    ['Z','C'],
    ['Z',],
    ['Z','C'],
    [],
    ['Z','A'],
    [],
    ['Z',],
    ['Z',],

    ['Z','D','C'],
    [],
    ['C'],
    [],
    ['Z','D','A'],
    [],
    [],
    [],

    ['Z','E','C'],
    [],
    ['C'],
    [],
    ['Z','E','A'],
    [],
    [],
    [],

    ['Z','D','C'],
    [],
    ['Z','D','C'],
    [],
    ['A'],
    [],
    [],
    [],

    ['Z','D','C'],
    [],
    ['Z','D','C'],
    [],
    ['A'],
    [],
    [],
    [],

]

// try changing the bpm like this:
// bpm = 164