How is the rotation iou calculated 旋转iou是用什么方式计算的

[gejintaohua]

In this file mmrotate\core\bbox\iou_calculators\rotate_iou2d_calculator.py
box_iou_rotated is used to calculate iou.
This module use ext_module.box_iou_rotated to calculate rotated ious.
I want to know how to calcuate the iou. If the mmcv use skewiou or other method?
在这个文件rotate_iou2d_calculator.py中，用box_iou_rotated函数进行iou的计算，内部是调用了ext_module.box_iou_rotated 计算的旋转iou，我想知道内部是怎么实现的，是利用了skewiou吗？