Thank you, I understand your intent better now. I wonder if maintaining a buffer in software that counts for each pixel how many times it has been dirty, combi

Thank you, I understand your intent better now. I wonder if maintaining a buffer in software that counts for each pixel how many times it has been dirty, combined with, say, the kind of quadtree one would normally use for hit detection, would let one do "local" refreshes and make this a generic solution. It sounds like the kind of thing that someone already must have thought of (let's hope it's not one of the software patents holding e-ink back)