This is made back then when I was in grade 8 and was learning about functions. I was curious about what different functions look like so I made this shitty program (in today's view) and showed it to my class.

The program is written in Lua using Gnad which is based on Love2D. It supports zooming using the mouse wheel but does not support panning. The font is blurry because I didn't figure out how to use a larger font, instead I just scale up the small font after rendering. Also backspace deletes all the characters because I didn't know how to use subString in lua.

It works by evaling the function, meaning you can input any valid lua expression.