You are right Rodrigo. Sharing is sharing, so here is the source code. But beware, the patch is still in a mess. I think the gen~ part is a bit clearer. But I'm not sure it is a "lesson"... I would have to clean it to call it that way.
Sorry about the "Donationware", it's more for people who would use it professionnaly to make some sound without wanting to understand the programming behind.