The previoius behavior was that entirely black pixels were treated as
white, and anything else as black. That's at least counter-intuitive.
This patch changes the behavior to actually look at the color values and
use a cutoff around medium gray: darker colors are treated as black, and
lighter colors are treated as white.
This is a backwards incompatible change, but I think this behavior makes
a lot more sense.
This commit updates rotation behavior to match other displays.
For more information, see: https://github.com/tinygo-org/drivers/pull/550
This changes the signature of `SetRotation` but I don't think any
existing code will be affected by this change.