I noticed You have source available, so I'll take a look later on

BUT ...

The most I'm interested of is the part that interprets the math function. Is this done by a lib or did You write something Yourself ?

What functions does it support ? etc...

I have an old old utility program, that visualizes some functions, but sofar the functions are hardcoded. I'd love to rewrite it so I could just dynamically input the equation.

I wrote it all myself, the code you would be interested is in PolishNotationFunction.java . It is mostly not specific to the game and would probably be easy to use on your own code with minimal modifications. The functions supported are:

sqrt()

log()

ln()

abs()

sin()

cos()

tan()

exp()

and the operators are: + - / * ^

Adding new functions would also be simple, I had actually a few more functions implemented but decided to remove from the game, like hyperbolic sines. Adding new operators would be much more complex.