How to render the non-closure curbs in SD-Map

(I can only get a list of coordinate points like the red line above)

I am learning to draw simulated reality on autopilot, but when I draw the maps of lanes and roads, I only got a list of coordinate points, they are not a closure polygon, and I don’t know how to deal with the data to draw a closure polygon.

could someone give me some suggestions, please? thanks a lot.

Could you give specific example of what you get as an input - and what output you’d expect? Precise numbers / data format.