code: function paperLoadedInit() {
    console.log('Paper ready!');
  
    // Set center adjusters based on size of canvas
    $('#hcenter').attr({
      value: 0,
      min: -(robopaint.canvas.width / 2),
      max: robopaint.canvas.width / 2
    });
  
    $('#vcenter').attr({
      value: 0,
      min: -(robopaint.canvas.height / 2),
      max: robopaint.canvas.height / 2
    });
  
    $(window).resize();
  
    // Use mode settings management on all "managed" class items. This
    // saves/loads settings from/into the elements on change/init.
    mode.settings.$manage('.managed');
  
    // With Paper ready, send a single up to fill values for buffer & pen.
    mode.run('up');
  }
docs: Callback that tells us that our Paper.js canvas is ready!