Each section below has two boxes, the top runs on the main thread, the bottom
on the compositor.
These boxes should start in the middle and finish at the end (both fill)
MT
CT
These boxes should start in the middle and finish at the start (backwards fill)
MT
CT
These boxes appear on the left and jump to the middle and finish at the end (forwards fill)
MT
CT
These boxes appear on the left and jump to the middle and finish at the start (none fill)
MT
CT
These boxes appear on the left and jump to the middle and finish at the start (auto fill)
MT
CT