OptionaldeadOptionallookPixel-equivalent units per second at full deflection. Default 800.
Optionalcurvepow() exponent on stick magnitude — >1 softens center, =1 is linear. Default 1.5.
OptionalinvertInvert vertical look. Default false.
OptionalonLook-delta callback. dx, dy are already scaled by lookScale * curve(mag) * dt.
Stick magnitude below this fraction reads as zero. Default 0.15.