make js a bit smaller

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

(function () {

  var canvas = document.querySelector('canvas'),
      r = Math.random,
      pi = Math.PI,
      cos = Math.cos,
      sin = Math.sin,
      context = canvas.getContext('2d'),
      fps = 24,
      lastFrame = 0,
      speed = 1,
      size = 5 + rnd(10),
      clear = !!(r() > 0.5),
      changeColor = !!(r() > 0.5),
      items = Array(rnd(10) + 6).fill(null).map(() => ({
        x: rnd(64),
        y: rnd(64),
        angle: r() * 2 * pi,
        color: Array(3).fill(rnd(256))
      })),
      shapes = [sqr, crc, hrt, chs, lch],
      positions = [id, spn(5), spn(15)],
      draw = shapes[rnd(shapes.length)],
      pos = positions[rnd(positions.length)];

  function rnd (x) {
    return Math.floor(r() * x);
  }

  function sqr(i) {

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

  function crc(i) {

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

  function chs(i) {

    var p = pos(i);
    context.beginPath();
    context.moveTo(p.x, p.y);
    context.lineTo(p.x * 10 * cos(i.angle), p.y * 10 * sin(i.angle));
    context.lineTo(rnd(64), rnd(64));
    context.fill();
  }

  function lch(i) {

    var p = pos(i);
    context.beginPath();
    context.lineWidth = 5;
    context.strokeStyle = `rgb(${i.color.join(',')})`;
    context.moveTo(p.x, p.y);
    context.lineTo(p.x * 10 * cos(i.angle), p.y * 10 * sin(i.angle));
    context.stroke();
  }

  function sqr(i) {

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

  function hrt(i) {

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

    context.beginPath();
    context.arc(p.x + size / 2, p.y, size / 2, 0, 2 * pi, false);
    context.fill();
    context.closePath();

    context.beginPath();
    context.arc(p.x + size, p.y + size / 2, size / 2, 0, 2 * pi, false);
    context.fill();
    context.closePath();
  }

  function id(p) {

    return p;
  }

  function spn(rad) {
    return function (p) {

      return {
        x: p.x + rad * cos(lastFrame),
        y: p.y + rad * sin(lastFrame)
      }
    }
  }

  function mov(i) {

    i.x = i.x + speed * cos(i.angle);
    i.y = i.y + speed * sin(i.angle);

    if (i.x < 0 || i.x > 64) {
      i.angle = Math.atan2(sin(i.angle), -cos(i.angle))
    }

    if (i.y < 0 || i.y > 64) {
      i.angle = Math.atan2(-sin(i.angle), cos(i.angle))
    }
  }

  function updateColor(i) {

    i.color = i.color.map((c) => {
      c = c + 5;
      return c > 255 ? 0 : c;
    })
  }

  function frame(time) {

    window.requestAnimationFrame(frame);

    var delta = time - lastFrame;

    if (delta > 1000 / fps) {
      clear && context.clearRect(0, 0, 64, 64);
      for (var i of items) {
        context.fillStyle = `rgb(${i.color.join(',')})`;
        draw(i);
        changeColor && updateColor(i);
        mov(i);
      }

      lastFrame = time;
    }
  }

  frame();
}
)();