Is a bug or misunderstanding the source code?

[mmlyj]

Hi ,Dear author, When I was reading the c_non_max_suppression_inds function, I notice the area_from_path funcion was used to calcualte the area of ploygon, and I also notice that the clip variable was created to store the coordinates of the vertx for one ploygon. I was confused about the way the code caculating the area.(if I understand it rightly) in the area_from_path function, the area accumulated the results of each small trigangle by caculating the cross product of two vector, but the clip variable store the coordinates which means the two vector start from (0,0), not the center of ploygon, I didn't found any minus operation in that piece of code, not sure I undertand it correctly, It would be grateful if your group could reply me.