Re-express a raw turn fraction as the value NEAREST near, by shifting it a
whole turn either way.
A pointer angle only ever reads back in [0, 1), so it wraps at the 12
o'clock seam: nudging a handle sitting at 0 anticlockwise reads 0.99, not
-0.01. Taken literally that sends the handle right around the dial. Picking
the representative closest to where the handle already is keeps a drag
continuous, so the caller can then clamp it into the allowed arc instead of
having it teleport across the seam.
Re-express a raw turn fraction as the value NEAREST
near, by shifting it a whole turn either way.A pointer angle only ever reads back in
[0, 1), so it wraps at the 12 o'clock seam: nudging a handle sitting at 0 anticlockwise reads0.99, not-0.01. Taken literally that sends the handle right around the dial. Picking the representative closest to where the handle already is keeps a drag continuous, so the caller can then clamp it into the allowed arc instead of having it teleport across the seam.