animate_core/tween/
alternate.rs

1use crate::{Alternate, Animate, TweenAnim, Tween, FRAME_TIME, IS_ANIMATING};
2use std::sync::atomic::Ordering;
3
4impl<T, E, I> Animate for Tween<T, E, I, Alternate>
5where
6    T: TweenAnim + PartialEq + Default,
7    E: Fn(f64) -> f64,
8    I: Fn(&T, &T, f64) -> T,
9{
10    type Value = T;
11
12    fn update(&mut self) {
13        if self.state.pending {
14            self.state.start = std::mem::take(&mut self.state.current);
15            self.state.pending = false;
16        }
17
18        if let Some(start_t) = self.state.started_at {
19            if self.state.duration > 0.0 {
20                let now = FRAME_TIME.load(Ordering::Relaxed);
21                let elapsed = now.saturating_sub(start_t) as f64;
22                let cycle = (elapsed / self.state.duration) as u64;
23                let t_raw = (elapsed % self.state.duration) / self.state.duration;
24                let t = if cycle % 2 == 0 { t_raw } else { 1.0 - t_raw };
25
26                self.state.current =
27                    (self.state.interp)(&self.state.start, &self.state.target, (self.state.easing)(t));
28            }
29            IS_ANIMATING.store(true, Ordering::Relaxed);
30        }
31    }
32
33    fn get(&self) -> &T {
34        &self.state.current
35    }
36
37    fn set(&mut self, target: T) {
38        let now = FRAME_TIME.load(Ordering::Relaxed);
39
40        self.state.target = target;
41        self.state.started_at = Some(now);
42        self.state.pending = true;
43    }
44
45    fn target(&self) -> &T {
46        &self.state.target
47    }
48}
animate_core/tween/alternate.rs

animate_core/tween/
alternate.rs
