Port polygon computation updates

Port:

• https://gitlab.teklia.com/dla/yolo/-/commit/d55b6373bed1c4b8e55a5fafded2fe3b688660c9
• https://gitlab.teklia.com/dla/yolo/-/commit/f8a1dc6b9346ab90c22cf7e8a2cca6b1d91abb97