Where in the source code is the Durability Formula?

[133794m3r]

Ok, i'm on linux atm and since after looking over the formulas i've not found them just yet...

I've done a search for it but well there's a few random results with no clear pointing towards what it is.

For some reason today i was interested in how the durability loss was calculated in wow and since this is the only real project i know of that seems to do something close to real wow, i was thinking that i should come here and try to see if i can get any help with it.