T[] GetCollisionObjectsFromAChild(Vector2 checkPoint, float checkRadius, QuadtreeRadius <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.CheckCollision(checkPoint, checkRadius));
}
return(new T[0]);
}
/*
* 构造方法增加一个父节点参数，默认值是null。
* 创建四叉树时不传参数，分割时传当前节点，这样根节点就没有父节点，其他节点都有父节点，向上更新半径就可以进行。
*/
public QuadtreeRadius(float top, float right, float bottom, float left, int maxLeafNumber, float minSideLength, QuadtreeRadius <T> parent = null)
{
_field = new QuadtreeWithRadiusField(top, right, bottom, left);
_maxLeafsNumber = maxLeafNumber;
_minSideLength = minSideLength;
_parent = parent;
DrawField(); //绘制节点范围，删除不影响功能
}
void Split()
{
Debug.Log("位置在((" + _field.top + "," + _field.right + "," + _field.bottom + "," + _field.left + "))的树梢节点达到分割条件，进行分割");
float xCenter = (_field.left + _field.right) / 2;
float yCenter = (_field.bottom + _field.top) / 2;
_upperRightChild = new QuadtreeRadius <T>(_field.top, _field.right, yCenter, xCenter, _maxLeafsNumber, _minSideLength, this);
_lowerRightChild = new QuadtreeRadius <T>(yCenter, _field.right, _field.bottom, xCenter, _maxLeafsNumber, _minSideLength, this);
_lowerLeftChild = new QuadtreeRadius <T>(yCenter, xCenter, _field.bottom, _field.left, _maxLeafsNumber, _minSideLength, this);
_upperLeftChild = new QuadtreeRadius <T>(_field.top, xCenter, yCenter, _field.left, _maxLeafsNumber, _minSideLength, this);
foreach (QuadtreeLeafRadius <T> leaf in _leafs) //因为这里向子节点存入所有叶子，最大半径的叶子依然在范围里，不需要对最大半径做特别处理
{
SetLeafToChildren(leaf);
}
_leafs = null;
}
private void Awake()
{
_quadtree = new QuadtreeRadius <GameObject>(_top, _right, _bottom, _left, _maxLeafsNumber, _minSideLength);
}