Free script/plugin for drawing a line with a collider?

I want to make a (2D) game and the user need to draw a line. Thereafter a rock will fall at it and launch another rock. Just like a catapult. But when I want to draw a line with linerenderer, it doesn’t look very well. Does anyone know a free script/plugin that makes the user able to draw a line with a 2D Collider? Now I’m using RageSpline for it, but it’s quite slow. (Sorry for my bad English, it’s not my native language)

I can give you my C# script for drawing a line, I as well am looking for how to add a collider