Cohost Bouncy Eggbug

cohost-bouncing-eggbug.user.js

// ==UserScript==
// @name         Cohost Bouncy Eggbug
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Boing
// @icon         https://www.google.com/s2/favicons?sz=64&domain=cohost.org
// @author       @sciman101
// @match        *://cohost.org/*
// @grant        none
// ==/UserScript==

const randomSign = () => Math.random() < 0.5 ? -1 : 1;
const sign = (x) => x > 0 ? 1 : -1;

const gravity = 900;
const startSpeed = 100;
const size = 200;
const eggbugPicture = 'https://cohost.org/static/f0c56e99113f1a0731b4.svg';

let x = Math.random() * (window.innerWidth - size - 40) + 20;
let y = 20;
let vx = randomSign() * startSpeed;
let vy = 0;
let angle = 0;
let spin = 10 * randomSign();
let juggle = 0;

let eggbug;
let lastTimestamp;

function setJuggle(j) {
    juggle = j;
}

function move(time) {
    if (time) {
        if (lastTimestamp === undefined) {
            lastTimestamp = time;
        }

        let dt = (time - lastTimestamp) / 1000; // Delta time in milliseconds
        if (dt > 1) dt = 0.1;

        angle += dt * spin;
        if (Math.abs(spin) > 10) {
            spin -= dt * 75 * sign(spin);
            if (Math.abs(spin) < 10) spin = sign(spin) * 10;
        }

        if (x < 0 || x > window.innerWidth - size) vx *= -1;
        if (y < 0 || y > window.innerHeight - size) {
            vy *= -0.9;
            if (y >= 0) {
                setJuggle(0);
            }
        }

        x = Math.max(Math.min(x,window.innerWidth - size),0);
        y = Math.max(Math.min(y,window.innerHeight - size),0);

        x += vx * dt;
        y += vy * dt;
        vy += gravity * dt;

        eggbug.style.left = x+'px';
        eggbug.style.top = y+'px';
        eggbug.style.transform = `rotate(${angle}deg)`;

        lastTimestamp = time;
    }
    requestAnimationFrame(move);
}

function makeEggbug() {
    eggbug = document.createElement('img');
    eggbug.src = eggbugPicture;
    document.body.appendChild(eggbug);

    eggbug.style.width = size+'px';
    eggbug.style.position = 'fixed';
    eggbug.style.left = '0px';
    eggbug.style.top = '0px';
    eggbug.style.zIndex = '9001';
    eggbug.style.userSelect = 'none';
    eggbug.style.cursor = 'pointer';

    eggbug.onclick = () => {
        vy = -gravity;
        spin = randomSign() * 200;
        setJuggle(juggle + 1);
    };
}

makeEggbug();
move();