Let user draw/trace outline of shape

For a project I’m on the user have to be able to draw/trace outlines of different shapes. So for example an “S” shape is on the screen, and the user needs to try to draw OVER that shape. So it’s not just mouse recognition, it has to see if the user draw over that shape good enough. So it’s kind of like a colorbook but you only draw the outline of the shape, if you know what I mean.

I’ve been searching the web and haven’t found any pre made solution for this, but I thought that before I try to make it all from scratch I could ask you guys here about it.

Anyone ever seen a ready solution for this or know how a good solution would work and could point me in the right direction?