在不考虑旋转的情况下拖动旋转元素的子元素，同时保持旋转

// 获取父元素和子元素
var parent = document.getElementById('parent');
var child = document.getElementById('child');

// 初始化变量
var isDragging = false;
var mouseX = 0;
var mouseY = 0;
var initialChildX = 0;
var initialChildY = 0;

// 鼠标按下事件监听器
parent.addEventListener('mousedown', function(e) {
  isDragging = true;
  mouseX = e.clientX;
  mouseY = e.clientY;
  initialChildX = child.offsetLeft;
  initialChildY = child.offsetTop;
});

// 鼠标移动事件监听器
document.addEventListener('mousemove', function(e) {
  if (isDragging) {
    var deltaX = e.clientX - mouseX;
    var deltaY = e.clientY - mouseY;

    // 计算子元素的新位置
    var newChildX = initialChildX + deltaX;
    var newChildY = initialChildY + deltaY;

    // 获取父元素的旋转角度
    var parentRotation = getRotation(parent);

    // 将子元素的相对移动距离逆向旋转
    var reverseDelta = rotate(deltaX, deltaY, -parentRotation);

    // 将逆向旋转后的距离应用到子元素的位置
    child.style.left = newChildX + reverseDelta.x + 'px';
    child.style.top = newChildY + reverseDelta.y + 'px';

    // 确保子元素在父元素的范围内
    var parentRect = parent.getBoundingClientRect();
    var childRect = child.getBoundingClientRect();
    if (childRect.left < parentRect.left) {
      child.style.left = parentRect.left - parentRect.left + 'px';
    }
    if (childRect.right > parentRect.right) {
      child.style.left = parentRect.right - childRect.width - parentRect.left + 'px';
    }
    if (childRect.top < parentRect.top) {
      child.style.top = parentRect.top - parentRect.top + 'px';
    }
    if (childRect.bottom > parentRect.bottom) {
      child.style.top = parentRect.bottom - childRect.height - parentRect.top + 'px';
    }
  }
});

// 鼠标松开事件监听器
document.addEventListener('mouseup', function() {
  isDragging = false;
});

// 获取元素的旋转角度（单位：度）
function getRotation(element) {
  var st = window.getComputedStyle(element, null);
  var tr = st.getPropertyValue('transform');
  var values = tr.split('(')[1].split(')')[0].split(',');
  var a = values[0];
  var b = values[1];
  var angle = Math.round(Math.atan2(b, a) * (180 / Math.PI));
  return (angle < 0 ? angle + 360 : angle);
}

// 对坐标点进行逆向旋转变换
function rotate(x, y, angle) {
  var newX = x * Math.cos(angle) + y * Math.sin(angle);
  var newY = -x * Math.sin(angle) + y * Math.cos(angle);
  return {
    x: newX,
    y: newY
  };
}