How to implement the "scissors" tool in an iOS application (swift) for photo processing?

Question

iOS

Good afternoon!
I hope that the essence of the question is clear from the title - you need to make a "scissors" tool in the application, when processing a photo. I am sure that this problem has been solved for a long time and more than one hundred times.
The problem is that I have good experience in programming, I already use swift confidently - but I have no experience in writing applications (except for tutorials from Apple / other lessons). So far, I'm just getting used to the IDE, the standard library (I'm actively studying the documentation).
Perhaps you know some library or project on GitHub that implements this functionality?
Now I want to try to implement a simple photo processor with this function myself, but I still don’t understand which way I should look.
I would be grateful for any useful (in my situation) tips/links/articles/projects, thanks in advance!

Answer 1

We draw a CGPath point by point, and using it we apply a mask to the image. We cut along it.

Answer 2

Libraries: ALCameraViewController ,
GKImagePicker
Response from stack: cropping-image-with-swift-and-put-it-on-center-position