@rempt:

1. Why does the generator layer update it's visible content when you adjust the pixel-content? It doesn't do much if anything with the pixel-content beyond transparency. I am not sure why this would be much different from using a mask? (I can tell the content is being updated because it slows down like hell)
2. Why doesn't the generator layer use the koupdater that it's dragging along?

Like, it's one thing that my generator is slow, but Krita isn't very good at doing anything with that slowness, making it seem as if it has frozen, which is unlike the more complex filters.

I think that for both questions the answer is -- because nobody has really done a lot with generator layers yet. So when the other layers were connected to the in-the-layerbox updater, the generator layers might have been forgotten, and the same goes KisGeneratorLayer::update() -- it's really simple-minded at the moment.

I've tested your generator and it does seem to work pretty well, btw :-)