ios - Detect if drawing a path is a circle/rectangle in xcode

Question

I want to implement a auto complete feature for a drawing app. Once a free hand object is drawn, I want to detect the type of object (circle/rectangle/triangle) and based on the result would want to plot a corresponding object.

I have read up a bit about OpenCV but then I would need to convert the user drawing into an image at real time. I am recording the number of points plotted/traced by the touch and also generate a UIBeizerPath of the corresponding path. How do I go about to detecting the shape type?

Answer 1

You can iterate through UIBezierPath points with CGPathApply(..) method. Look here for example.

But you should determine shape type somehow - it's mathematical task and approach depends on your input data.