Struct WheelAccelerator 

pub struct WheelAccelerator { /* private fields */ }

Cadence-based wheel accelerator over discrete line notches.

State is tiny (Copy); keep one per scroll surface. The accelerator never touches rendering or scroll state — callers apply WheelAccelerator::line_notch’s returned distance themselves.

Implementations

impl WheelAccelerator

pub fn new() -> Self

Creates an accelerator at rest.

pub fn line_notch(&mut self, dy: f32, fast: bool) -> Pixels

Processes one discrete wheel notch and returns the extra scroll distance to apply beyond the base scroll the framework already made.

Sign follows wheel convention: negative means scroll down. The boost ramps linearly over WHEEL_ACCEL_NOTCHES_TO_FULL same-direction notches toward WHEEL_ACCEL_MAX_MULTIPLIER, so the first notch of a burst contributes a small ramp-in boost and later ones contribute up to the full multiplier minus one. A pause longer than WHEEL_ACCEL_DECAY_SECONDS (see WheelAccelerator::rest) or a direction reversal restarts the ramp. fast applies the WHEEL_FAST_SENSITIVITY Alt-multiplier instead of WHEEL_SENSITIVITY.

pub fn rest(&mut self)

Marks the accelerator idle after a pause between gestures, resetting its cadence. Call this when input handling notices elapsed time rather than relying solely on per-notch decay checks.

pub fn cadence(&self) -> f32

Current signed notch cadence (positive scrolling up).

Trait Implementations

impl Clone for WheelAccelerator

fn clone(&self) -> WheelAccelerator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for WheelAccelerator

impl Debug for WheelAccelerator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for WheelAccelerator

fn default() -> Self

Returns the “default value” for a type.