Update files from notes

[rbdr/r.bdr.sh] / js / animation.js

(function () {

if (window.matchMedia('(prefers-reduced-motion: reduce)').matches) return

var K=document.querySelector('canvas'),
{random:R,PI,cos:C,sin:S,atan2:A} = Math,
id = p => p,
spn = r => p => ({
    x: p.x + r * C(l),
    y: p.y + r * S(l)
}),
X = K.getContext('2d'), F = X.fill.bind(X), B = X.beginPath.bind(X),
f = 24, l = 0, s = 1, z = 5 + r(10),
k = R() > 0.5, c = R() > 0.5,
I = Array(r(10) + 6).fill().map(() => ({
  x: r(64), y: r(64),
  a: R() * 2 * PI, c: r(100)
})),
H = [sqr, crc, hrt, chs, lch], P = [id, spn(5), spn(15)],
dr = H[r(H.length)], pos = P[r(P.length)],
Z = 1

function r(x) {
  return ~~(R() * x)
}
function sqr(i) {
  var p = pos(i)
  X.fillRect(p.x, p.y, z, z)
}
function crc(i) {
  var p = pos(i)
  B()
  X.arc(p.x, p.y, z / 2, 0, 2 * PI)
  F()
}
function chs(i) {
  var {x, y} = pos(i)
  B()
  X.moveTo(x, y)
  X.lineTo(x * 10 * C(i.a), y * 10 * S(i.a))
  X.lineTo(r(64), r(64))
  F()
}
function lch(i) {
  var {x, y} = pos(i)
  B()
  X.lineWidth = 5
  X.strokeStyle = `hsl(0,0%,${i.c}%)`
  X.moveTo(x, y)
  X.lineTo(x * 10 * C(i.a), y * 10 * S(i.a))
  X.stroke()
}
function hrt(i) {
  var {x, y} = pos(i)
  X.fillRect(x, y, z, z)

  B()
  X.arc(x + z / 2, y, z / 2, 0, 2 * PI, false)
  F()
  X.closePath()

  B()
  X.arc(x + z, y + z / 2, z / 2, 0, 2 * PI, false)
  F()
  X.closePath()
}
function mv(i) {
  i.x = i.x + s * C(i.a)
  i.y = i.y + s * S(i.a)

  if (i.x < 0 || i.x > 64) {
    i.a = A(S(i.a), -C(i.a))
  }
  if (i.y < 0 || i.y > 64) {
    i.a = A(-S(i.a), C(i.a))
  }
}
function ucl(i) {i.c = (i.c + 2) % 101}
function frm(t) {
  if (Z) requestAnimationFrame(frm)
  var dt = t - l
  if (dt > 1000 / f) {
    k && X.clearRect(0, 0, 64, 64)
    for (var i of I) {
      X.fillStyle = `hsl(0,0%,${i.c}%)`
      dr(i)
      c && ucl(i)
      mv(i)
    }

    l = t
  }
}

K.addEventListener('click', () => ((Z=Z?0:1)&&frm()))
frm()
})()