如何计算DOM元素相对于指定父级的位置？

<div class="wrapper" id="wrapper">
    <div id="node-root">
        <div id="node-2">
            <div id="node-3"></div>
            <div id="node-3-1"></div>
            <div id="node-3-2"></div>
        </div>
        <div id="node-22">
            <div id="node-22-1"></div>
        </div>
        <div id="node-33">
            <div id="node-33-1"></div>
        </div>
    </div>
</div>

/**
 * 获取元素距浏览器最顶部及最左边的距离
 * @param ele dom元素
 * @returns {{top: number, left: number}}
 */
function offset(ele) {
  var position = {
    top: 0,
    left: 0
  };
  if (!ele || ele.nodetype != 1) {
    return position;
  }
  var offsetparent = ele.offsetparent;
  position.top = ele.offsettop;
  position.left = ele.offsetleft;
  while (offsetparent != null) {
    position.top += offsetparent.offsettop;
    position.left += offsetparent.offsetleft;
    offsetparent = offsetparent.offsetparent;
  }
  return position;
}

/**
 * 获取元素距指定父级元素最顶部及最左边的距离
 * @param ele dom元素
 * @param boundaryparent 边界父级元素，默认为null
 * @returns {{top: number, left: number}}
 */
function offsetinparent(ele, boundaryparent) {
  var position = {
    top: 0,
    left: 0
  };
  var eloffset = offset(ele);
  var parentoffset = {
    top: 0,
    left: 0
  };
  if (boundaryparent) {
    parentoffset = offset(boundaryparent);
  }
  position.top = eloffset.top - parentoffset.top;
  position.left = eloffset.left - parentoffset.left;
  return position;
}

console.log(offsetInParent(document.getElementById('node-22-1'), document.getElementById('wrapper')));