Hmmm weekend project?
Never use it, never distribute it in a way that someone else might mistakenly think it's a good idea to use it (so posting it on github would probably be a mistake!) and expect your implementation to have bugs you don't realize. (Even if you shove plaintext in and get the right ciphertext out doesn't mean you've found all the bugs, it gets tricky and in some cases different specific algorithmically correct implementations can have not just different performance characteristics, but different runtime security characteristics.)
Most people tend to find weekend projects more fulfilling if they have a way to put them to use. So while I don't mean to go all "this is dark arts that no one should practice uninitiated" on you, I would encourage you to stifle your tendency to find a use for any encryption code you write that isn't peer reviewed. View it as purely an artform; code never to be utilized.
This is the same advice most security researchers give to themselves and others.
It is not weekend project in any way.
I think that post you answer meant "weekend project on encryption algorithm animation".
The Rijndael algorithm itself is of course, very well reviewed and perhaps one of the most solid algorithms publicly available. Which is part of why it was chosen for AES. (Speed being the other factor.)
I think perhaps you misunderstood the conversation.
In your headers you should note that the code contained is for educational use only and is probably very flawed.
Please note: I'm not saying you're a terrible programmer and is guaranteed to botch this attempt. Encryption is a tricky beast. Best leave it to the maths geniuses.
Besides, the question 'Why does AES work the way it does?' is a completely different topic which should only be touched after the 'How does AES work?'.
So, the first step should be to NOT start with the "Advanced" standard :) look for block cyphers.
And if you found your self blocked on this little presentation during the non-sense (and not explained) column transformation step, this may help you:
Understanding AES Mix-Columns Transformation Calculation
Kit Choy Xintong
University of Wollongong,
However, I still don't agree with the OP that that makes this presentation pointless.
I should've just checked here first (includes an image of the slide in question): http://stackoverflow.com/questions/839479/what-does-a-circle...