Algorithm of extruder in 3D printing (no replies)

Hi everyone, I'm a student in Hanoi university of technology and science. I took part in a small group to research about how the extrude of FDM printer work. I concern about the path of nozzle 3D printer in a surface to full a face and algorithm of this. I have seen a lot of video on Youtube but I cannot make any algorithm.

I hope you can give me some basic document to solve my problem.
Thanks everyone!

Mr. Crazy.