T[] GetCollisionObjectsFromAChild(Vector2 checkPoint, float checkRadius, QuadtreeData <T> child)
 {
     if (child._field.PointToFieldDistance(checkPoint) <= _maxRadius + checkRadius)      //这里不光要考虑到检测半径,还要考虑到节点最大半径
     {
         return(child.DoCheckCollision(checkPoint, checkRadius));
     }
     return(new T[] { });
 }
 public T[] CheckCollision(Vector2 checkPoint, float checkRadius)
 {
     return(_root.DoCheckCollision(checkPoint, checkRadius));
 }