Rewrite more readable

I hope you don't take this the wrong way, but the existing code is horrible. It is extremely hard to read and understand, mostly thanks to the choice of cryptic variable names where the purpose is undocumented. 

I took my best shot with this approach: https://gist.github.com/oliversalzburg/99a755a8fc0b0e52b09fa54f1662d929

If there is any interest, I'd also happily open a PR.