Struct VelocityTracker 

pub struct VelocityTracker { /* private fields */ }

A rolling history of pointer positions that can be asked for a velocity.

Adding a position is cheap; asking for the estimate is not free (the regression strategy solves a small system), so ask once, at the release.

Implementations

impl VelocityTracker

pub fn new(strategy: VelocityStrategy) -> Self

A tracker using strategy.

pub fn strategy(&self) -> VelocityStrategy

The strategy in force.

pub fn add_position(&mut self, time: f32, point: Point)

Records where the pointer was, and when (in seconds).

pub fn clear(&mut self)

Forgets everything — a new gesture starts from nothing.

pub fn estimate(&self, now: f32) -> Option<VelocityEstimate>

The estimate as of now (seconds, same clock as the samples), or None when not a single position has been recorded.

pub fn velocity(&self, now: f32) -> Velocity

The estimated velocity as of now, or Velocity::ZERO if there is nothing to go on.

Trait Implementations

impl Clone for VelocityTracker

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VelocityTracker

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

Formats the value using the given formatter.

impl Default for VelocityTracker

fn default() -> Self

The base tracker, a fitted curve (VelocityStrategy::Regression). Which one a scroll reads its flings with is its scroll behaviour’s choice (milestone 616).