Rename math functions

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

(function () {

  var K = document.querySelector('canvas'),
      { random: R, PI, cos: C, sin: S, floor, atan2: A } = Math,
      x = K.getContext('2d'),
      f = 24,
      l = 0,
      spd = 1,
      siz = 5 + r(10),
      clr = R() > 0.5,
      ccl = R() > 0.5,
      I = Array(r(10) + 6).fill().map(() => ({
        x: r(64),
        y: r(64),
        a: R() * 2 * PI,
        c: Array(3).fill(r(256))
      })),
      S = [sqr, crc, hrt, chs, lch],
      P = [id, spn(5), spn(15)],
      draw = S[r(S.length)],
      pos = P[r(P.length)];

  function r(x) {
    return floor(R() * x);
  }

  function sqr(i) {

    var p = pos(i);
    x.fillRect(p.x, p.y, siz, siz);
  }

  function crc(i) {

    var p = pos(i);
    x.beginPath();
    x.arc(p.x, p.y, siz / 2, 0, 2 * PI);
    x.fill();
  }

  function chs(i) {

    var p = pos(i);
    x.beginPath();
    x.moveTo(p.x, p.y);
    x.lineTo(p.x * 10 * C(i.a), p.y * 10 * S(i.a));
    x.lineTo(r(64), r(64));
    x.fill();
  }

  function lch(i) {

    var p = pos(i);
    x.beginPath();
    x.lineWidth = 5;
    x.strokeStyle = `rgb(${i.c.join(',')})`;
    x.moveTo(p.x, p.y);
    x.lineTo(p.x * 10 * C(i.a), p.y * 10 * S(i.a));
    x.stroke();
  }

  function hrt(i) {

    var p = pos(i);
    x.fillRect(p.x, p.y, siz, siz);

    x.beginPath();
    x.arc(p.x + siz / 2, p.y, siz / 2, 0, 2 * PI, false);
    x.fill();
    x.closePath();

    x.beginPath();
    x.arc(p.x + siz, p.y + siz / 2, siz / 2, 0, 2 * PI, false);
    x.fill();
    x.closePath();
  }

  function id(p) {

    return p;
  }

  function spn(rad) {
    return (p) => ({
        x: p.x + rad * C(l),
        y: p.y + rad * S(l)
    })
  }

  function mov(i) {

    i.x = i.x + spd * C(i.a);
    i.y = i.y + spd * 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.map((c) => {
      c = c + 5;
      return c > 255 ? 0 : c;
    })
  }

  function frm(t) {

    window.requestAnimationFrame(frm);

    var dt = t - l;

    if (dt > 1000 / f) {
      clr && x.clearRect(0, 0, 64, 64);
      for (var i of I) {
        x.fillStyle = `rgb(${i.c.join(',')})`;
        draw(i);
        ccl && ucl(i);
        mov(i);
      }

      l = t;
    }
  }

  frm();
}
)();