MouseMove节流

const line=()=>
{
  let points=[]
  map.on('mousemove',throttleMouseMove((e:any) => {
  points.push(e.latlng)
}, 400));
}
function throttleMouseMove(callback:any, delay:any) {
  let lastTime = 0;

  return function (event:any) {
    const now = Date.now();
    if (now - lastTime > delay) {
      callback(event);
      lastTime = now;
    }
  };
}

时间戳的比较