phonic 0.16.0

Audio playback library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

use std::time::Duration;

// -------------------------------------------------------------------------------------------------

pub type SampleTime = u64;

// -------------------------------------------------------------------------------------------------

/// A clock that measures and converts wall-clock time in terms of sample frames at a fixed
/// sample rate. This clock tracks sample times directly as u64 values.
#[derive(Debug, Clone)]
pub struct SampleTimeClock {
    sample_rate: u32,
    start_time: SampleTime,
}

impl SampleTimeClock {
    /// Create a new SampleTimeClock with the given sample rate.
    pub fn new(sample_rate: u32) -> Self {
        assert!(sample_rate > 0, "Invalid sample rate");
        Self {
            sample_rate,
            start_time: 0,
        }
    }

    /// Convert a duration to sample frames with the given sample rate.
    pub fn duration_to_sample_time(duration: Duration, sample_rate: u32) -> SampleTime {
        debug_assert!(sample_rate > 0, "Invalid sample rate");
        if duration == Duration::MAX {
            SampleTime::MAX
        } else {
            (duration.as_secs_f64() * sample_rate as f64) as SampleTime
        }
    }

    /// Convert sample frames to a duration with the given sample rate.
    pub fn sample_time_to_duration(sample_time: SampleTime, sample_rate: u32) -> Duration {
        debug_assert!(sample_rate > 0, "Invalid sample rate");
        if sample_time == SampleTime::MAX {
            Duration::MAX
        } else {
            Duration::from_secs_f64(sample_time as f64 / sample_rate as f64)
        }
    }

    /// Reset the clock to start counting from the given sample time.
    pub fn reset(&mut self, current_time: SampleTime) {
        self.start_time = current_time;
    }

    /// Get the elapsed time since the last reset in sample frames.
    pub fn elapsed(&self, current_time: SampleTime) -> SampleTime {
        current_time.saturating_sub(self.start_time)
    }

    /// Get the elapsed time since the last reset as a duration.
    pub fn elapsed_duration(&self, current_time: u64) -> Duration {
        Self::sample_time_to_duration(self.elapsed(current_time), self.sample_rate)
    }
}