sketch.js

Copyright (C) 2013 Justin Windle

soulwire.co.uk 


        
<div id="sketch"></div>
<script src="//code.jquery.com/jquery-3.4.1.min.js"></script>
<script src="sketch.js"></script>
<script>
  const COLOURS = ['#EEE'];
  let radius = 0;

  Sketch.create({
    container: document.getElementById('sketch'),
    autoclear: false,
    retina: 'auto',

    setup: function() {
      console.log('setup');
    },
    update: function() {
      radius = 2 + abs(sin(this.millis * 0.002) * 25);
    },

    touchmove: function() {

      for (let i = this.touches.length - 1, touch; i >= 0; i--) {
        touch = this.touches[i];
        this.lineCap = 'round';
        this.lineJoin = 'round';
        this.fillStyle = this.strokeStyle = COLOURS[i % COLOURS.length];
        this.lineWidth = radius;

        this.beginPath();
        this.moveTo(touch.ox, touch.oy);
        this.lineTo(touch.x, touch.y);
        this.stroke();
      }
    }
  });
</script>