1use std::fmt;
2use std::sync::atomic::{AtomicU64, Ordering};
3
4use super::tick;
5
6pub struct SystemClock {
11 pub sample_rate: f32,
13 position: AtomicU64,
15 bpm: AtomicU64,
17}
18
19impl SystemClock {
20 pub fn new(sample_rate: f32, initial_bpm: f64) -> Self {
22 Self {
23 sample_rate,
24 position: AtomicU64::new(0),
25 bpm: AtomicU64::new(initial_bpm.to_bits()),
26 }
27 }
28
29 pub fn with_sample_rate(sample_rate: f32) -> Self {
31 Self::new(sample_rate, 120.0)
32 }
33
34 pub fn next_tick(&mut self, block_size: usize) -> tick::ClockTick {
36 let samples = block_size as u32;
37 let pos = self.position.fetch_add(samples as u64, Ordering::Relaxed);
38
39 tick::ClockTick {
40 sample_pos: pos,
41 samples_since_last: samples,
42 is_new_block: true,
43 sample_rate: self.sample_rate,
44 tempo: Some(self.bpm() as f32),
45 }
46 }
47
48 pub fn bpm(&self) -> f64 {
50 f64::from_bits(self.bpm.load(Ordering::Relaxed))
51 }
52
53 pub fn set_bpm(&self, bpm: f64) {
55 self.bpm.store(bpm.to_bits(), Ordering::Relaxed);
56 }
57
58 pub fn position(&self) -> u64 {
60 self.position.load(Ordering::Relaxed)
61 }
62
63 pub fn reset(&self) {
65 self.position.store(0, Ordering::Relaxed);
66 }
67}
68
69impl fmt::Debug for SystemClock {
70 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
71 f.debug_struct("SystemClock")
72 .field("sample_rate", &self.sample_rate)
73 .field("position", &self.position.load(Ordering::Relaxed))
74 .field("bpm", &self.bpm())
75 .finish()
76 }
77}
78
79#[cfg(test)]
80mod tests {
81 use super::*;
82
83 #[test]
84 fn test_system_clock() {
85 let mut clock = SystemClock::new(44100.0, 120.0);
86
87 let tick = clock.next_tick(64);
88 assert_eq!(tick.sample_pos, 0);
89 assert_eq!(tick.samples_since_last, 64);
90 assert_eq!(tick.sample_rate, 44100.0);
91 assert_eq!(tick.tempo, Some(120.0));
92
93 let tick = clock.next_tick(64);
94 assert_eq!(tick.sample_pos, 64);
95 }
96}