Mode names, in cycle order, around the ring.
Index of the current mode in labels.
Steps the ring has turned in total, +1 per forward and -1 per backward cycle. Always congruent to index modulo the number of labels, but not wrapped, so the ring keeps turning the way the reader turned it instead of spinning back the long way when the cycle wraps.
Which way the last cycle turned the ring: +1 forward, -1 backward.
Bumped on every cycle, so the dial reappears even on the same mode.
What the visual rotor dial draws: the modes around its ring, the current one, and how far the ring has turned.