你好，如果想修改为支持：选中的区域为任意四边形（四个内角都不能大于180度）而不是矩形，需要修改哪里啊？

[jingweitao123]

[jingweitao123]

Hello, if you want to modify it to support: the selected area is any quadrilateral (no four inner corners can be greater than 180 degrees) instead of a rectangle, where do you need to modify it?