Struct ScrollClock 

pub struct ScrollClock { /* private fields */ }

A Clock that derives delta-time from scroll position changes.

Instead of measuring wall time, ScrollClock converts position changes (in any unit — pixels, percentage, etc.) into normalised animation progress.

The delta() value represents the fraction of the scroll range that was traversed since the last call, which can be fed directly into Update::update().

Implementations

impl ScrollClock

pub fn new(start: f32, end: f32) -> Self

Create a new ScrollClock mapping position from start to end.

The animation progresses from 0.0 to 1.0 as position moves from start to end. Scrolling backwards produces negative delta.

pub fn set_position(&mut self, position: f32)

Set the current scroll position.

The difference from the previous position is accumulated and returned by the next Clock::delta call.

pub fn position(&self) -> f32

Current scroll position.

pub fn progress(&self) -> f32

Current progress in 0.0..=1.0 (clamped).

pub fn start(&self) -> f32

The start of the scroll range.

pub fn end(&self) -> f32

The end of the scroll range.

pub fn set_range(&mut self, start: f32, end: f32)

Update the scroll range at runtime.

Trait Implementations

impl Clock for ScrollClock

fn delta(&mut self) -> f32

Returns the accumulated scroll delta as a fraction of the total range.

For a scroll range of 0..1000, scrolling from 0 to 500 produces a delta of 0.5. The accumulator is reset after each call.

impl Clone for ScrollClock

fn clone(&self) -> ScrollClock

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScrollClock

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

Formats the value using the given formatter.