How do I create L Shaped Line

check reference video

https://www.awesomescreenshot.com/video/41931017?key=f408e3dcf4e8bf4892c499a3c0d02956

There's probably an easier and more efficient way, but here's my attempt:

dropbox.com/scl/fi/7mzkocw8vmpv94d58t8kg/drawLShapeLine.c3p

i look your attempt was, little hard to me

but what if when want to create 3rd line continues

i tweak the code , disabling else and create one more line with firstLineVertical is = 2. but line cant be created.

but what if when want to create 3rd line continues

Then it won't be L-shaped! You should've explained your task better. For multiple lines the solution would be different. If you just want to connect dots, then simply create a new line from dot to dot as the mouse moves.