Waves does not include sampler context rect and ux,uy effect in left,right,top,bottom AreaFilter computation
On my laptop, running:
GEGL_THREADS=8 gegl -o tmp.8.ppm -- checkerboard crop width=6000 height=1080 waves
produces a different result than
GEGL_THREADS=1 gegl -o tmp.1.ppm -- checkerboard crop width=6000 height=1080 waves
it is because left,right,top,bottom computation does not include the
effect of ux
and uy
and of the area sampler
requires