animate_core/mode/
alternate.rs

1use crate::macros::impl_ops;
2use crate::{AnimateState, FRAME, IS_ANIMATING, Lerp};
3use std::sync::atomic::Ordering;
4use std::time::Instant;
5
6#[derive(Debug)]
7pub struct Alternate<T: Lerp + PartialEq>(pub(crate) AnimateState<T>);
8
9impl<T: Lerp + PartialEq + Default> Alternate<T> {
10    pub fn new(
11        initial: T,
12        duration: f64,
13        easing: fn(f64) -> f64,
14        interp: fn(&T, &T, f64) -> T,
15    ) -> Self {
16        Self(AnimateState::new(initial, duration, easing, interp))
17    }
18
19    pub fn set(&mut self, target: T) {
20        let current = std::mem::take(self.0.current.get_mut());
21        *self.0.start.get_mut() = current;
22        *self.0.target.get_mut() = target;
23        *self.0.started_at.get_mut() = Some(Instant::now());
24    }
25
26    pub fn get(&self) -> &T {
27        let frame = FRAME.load(Ordering::Relaxed);
28        unsafe {
29            let last_frame = self.0.last_frame.get();
30            let started_at = self.0.started_at.get();
31            if *last_frame != frame {
32                if let Some(started) = *started_at {
33                    let elapsed = started.elapsed().as_secs_f64() * 1000.0;
34                    let cycle = (elapsed / self.0.duration) as u64;
35                    let t_raw = (elapsed % self.0.duration) / self.0.duration;
36                    let t = if cycle % 2 == 0 { t_raw } else { 1.0 - t_raw };
37                    *self.0.current.get() = (self.0.interp)(
38                        &*self.0.start.get(),
39                        &*self.0.target.get(),
40                        (self.0.easing)(t),
41                    );
42                    *last_frame = frame;
43                    IS_ANIMATING.store(true, Ordering::Relaxed);
44                }
45            }
46            &*self.0.current.get()
47        }
48    }
49
50    pub fn target(&self) -> &T {
51        unsafe { &*self.0.target.get() }
52    }
53}
54
55impl_ops!(Alternate);
animate_core/mode/alternate.rs

animate_core/mode/
alternate.rs
