code: function addPathGuides($canvas, parent) {
  	var handles = parent._handles,
  		prevHandle, nextHandle, otherHandle,
  		handle, h,
  		guide, guideProps;
  	guideProps = $.extend({}, parent.guide, {
  		layer: true,
  		draggable: false,
  		type: 'line'
  	});
  	if (parent._method === $.fn.drawQuadratic) {
  		$canvas.addLayer(guideProps);
  		parent._guide = $canvas.getLayer(-1);
  		$canvas.moveLayer(parent._guide, -handles.length - 1);
  	} else if (parent._method === $.fn.drawBezier) {
  		parent._guides = [];
  		for (h = 0; h < handles.length; h += 1) {
  			handle = handles[h];
  			nextHandle = handles[h + 1];
  			prevHandle = handles[h - 1];
  			otherHandle = null;
  			if (nextHandle !== undefined) {
  				// If handle is a start/end point and next handle is a control point
  				if (handle._xProp.indexOf('x') === 0 && nextHandle._xProp.indexOf('cx') === 0) {
  					otherHandle = nextHandle;
  				}
  			} else if (prevHandle !== undefined) {
  				if (prevHandle._xProp.indexOf('cx') === 0 && handle._xProp.indexOf('x') === 0) {
  					otherHandle = prevHandle;
  				}
  			}
  			if (otherHandle !== null) {
  				$canvas.addLayer(guideProps);
  				guide = $canvas.getLayer(-1);
  				guide._handles = [handle, otherHandle];
  				parent._guides.push(guide);
  				$canvas.moveLayer(guide, -handles.length - 1);
  			}
  		}
  	}
  	updatePathGuides(parent);
  }
docs: Add guides to path layer