Okay, maybe I was too fast on the decision...

So I tried moving everything only Irrlicht.

And noticed that my own implementation of... everything... is actually way faster (because of how I made it to work - plain simple and brute-forcy way). So I guess it means I have to switch from actually rewriting everything from scratch to... *sigh* refactoring everything I have right now...

Which may actually be way worse than rewriting it...

Don't worry. I'll make it better.

I hope.