rodio/source/
zero.rs

1use std::marker::PhantomData;
2use std::time::Duration;
3
4use crate::{Sample, Source};
5
6use super::SeekError;
7
8/// An source that produces samples with value zero (silence). Depending on if
9/// it where created with [`Zero::new`] or [`Zero::new_samples`] it can be never
10/// ending or finite.
11#[derive(Clone, Debug)]
12pub struct Zero<S> {
13    channels: u16,
14    sample_rate: u32,
15    num_samples: Option<usize>,
16    marker: PhantomData<S>,
17}
18
19impl<S> Zero<S> {
20    /// Create a new source that never ends and produces total silence.
21    #[inline]
22    pub fn new(channels: u16, sample_rate: u32) -> Zero<S> {
23        Zero {
24            channels,
25            sample_rate,
26            num_samples: None,
27            marker: PhantomData,
28        }
29    }
30    /// Create a new source that never ends and produces total silence.
31    #[inline]
32    pub fn new_samples(channels: u16, sample_rate: u32, num_samples: usize) -> Zero<S> {
33        Zero {
34            channels,
35            sample_rate,
36            num_samples: Some(num_samples),
37            marker: PhantomData,
38        }
39    }
40}
41
42impl<S> Iterator for Zero<S>
43where
44    S: Sample,
45{
46    type Item = S;
47
48    #[inline]
49    fn next(&mut self) -> Option<S> {
50        if let Some(num_samples) = self.num_samples {
51            if num_samples > 0 {
52                self.num_samples = Some(num_samples - 1);
53                Some(S::zero_value())
54            } else {
55                None
56            }
57        } else {
58            Some(S::zero_value())
59        }
60    }
61}
62
63impl<S> Source for Zero<S>
64where
65    S: Sample,
66{
67    #[inline]
68    fn current_frame_len(&self) -> Option<usize> {
69        self.num_samples
70    }
71
72    #[inline]
73    fn channels(&self) -> u16 {
74        self.channels
75    }
76
77    #[inline]
78    fn sample_rate(&self) -> u32 {
79        self.sample_rate
80    }
81
82    #[inline]
83    fn total_duration(&self) -> Option<Duration> {
84        None
85    }
86
87    #[inline]
88    fn try_seek(&mut self, _: Duration) -> Result<(), SeekError> {
89        Ok(())
90    }
91}