Ugh, I think this now needs to consider both `FillColor` *and* `FillTexture`, but the way I have it set up it can only handle doing one at a time. =(

One solution I suppose would be to make a second function akin to `splitFills` but acting on `FillTexture`.  It's just a bit annoying to have to do two passes, but it should only be a few extra lines of code (copy lines 551-566 here and change a few things).