How would I know if the clipped children is fully visible?

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:bust_in_silhouette: Asked By nanto2016

What I want to do is make the player peel a potato; for this I have a Line2D which has Clip Children enabled and a potato image (Sprite2D) as a child. I detect when there is a MouseMotionEvent with _input() and if the mouse is pressed, I add a new segment. For now this works, I can make the potato image appear when I draw over it. The problem is that I do not know how to know when the image has been fully (or almost fully) revealed. Do I need to use an array of some sort that I update when I draw? Thanks for any help!