neko.js

// Based on oneko.js: https://github.com/adryd325/oneko.js

(function oneko() {
  const isReducedMotion =
    window.matchMedia(`(prefers-reduced-motion: reduce)`) === true ||
    window.matchMedia(`(prefers-reduced-motion: reduce)`).matches === true;

  let movementEnabled = false;

  const nekoEl = document.createElement("div");

  let nekoPosX = window.innerWidth - 32;
  let nekoPosY = window.innerHeight - 32;

  let mousePosX = 0;
  let mousePosY = 0;

  let frameCount = 0;
  let idleTime = 0;
  let idleAnimation = null;
  let idleAnimationFrame = 0;

  const nekoSpeed = 10;
  const spriteSets = {
    idle: [[-3, -3]],
    alert: [[-7, -3]],
    scratchSelf: [
      [-5, 0],
      [-6, 0],
      [-7, 0],
    ],
    scratchWallN: [
      [0, 0],
      [0, -1],
    ],
    scratchWallS: [
      [-7, -1],
      [-6, -2],
    ],
    scratchWallE: [
      [-2, -2],
      [-2, -3],
    ],
    scratchWallW: [
      [-4, 0],
      [-4, -1],
    ],
    tired: [[-3, -2]],
    sleeping: [
      [-2, 0],
      [-2, -1],
    ],
    N: [
      [-1, -2],
      [-1, -3],
    ],
    NE: [
      [0, -2],
      [0, -3],
    ],
    E: [
      [-3, 0],
      [-3, -1],
    ],
    SE: [
      [-5, -1],
      [-5, -2],
    ],
    S: [
      [-6, -3],