How does the bezier_fill shader render shapes?

[TheCyberWeaver]

I'm currently working on a personal project that tries to render shapes defined by bezier curves onto the screen. I encountered some problems when trying to implement the bezier_fill part. My original thought was to trianglulate inner part of a shape using ear clipping algorithm, and fill the rest outer part with short bezier curves (two anchors two handles). Like the graph shown below:

However, this method does not work when the inner part of the shape is a self-intersecting polygon. Like the Like the graph shown below:(the blue lines connect all the anchors and the red lines connect all the anchor and the handles)(this shape should look like a ring)

I believe manim has used a different method to implement this. Can someone help me to explain how it can be done?
I have spent hours trying to understand the codes in vectorized_mobject.py and shaders under quadratic_bezier_fill and still could not get a single clue.