So today I kinda finished my branch for a new public filter API in #GIMP 3.0.
We used to have special-case code for specific filters. Now it will be generic code able to apply *any* GEGL operation as a filter in @GIMP, just like the GUI already allows!
Of course, it makes use of the non-destructive filter infrastructure so you can append filters non-destructively or merge them old-school!
Tonight my brain is foggy (too much code). I'll review again and will merge tomorrow.
@GIMP It's now merged! That was one of the 2 remaining major blockers before releasing RC2.