rodio/source/
fadein.rs

1use std::time::Duration;
2
3use super::{linear_ramp::linear_gain_ramp, LinearGainRamp, SeekError};
4use crate::common::{ChannelCount, SampleRate};
5use crate::Source;
6
7/// Internal function that builds a `FadeIn` object.
8pub fn fadein<I>(input: I, duration: Duration) -> FadeIn<I>
9where
10    I: Source,
11{
12    FadeIn {
13        input: linear_gain_ramp(input, duration, 0.0f32, 1.0f32, false),
14    }
15}
16
17/// Filter that modifies raises the volume from silence over a time period.
18#[derive(Clone, Debug)]
19pub struct FadeIn<I> {
20    input: LinearGainRamp<I>,
21}
22
23impl<I> FadeIn<I>
24where
25    I: Source,
26{
27    /// Returns a reference to the inner source.
28    #[inline]
29    pub fn inner(&self) -> &I {
30        self.input.inner()
31    }
32
33    /// Returns a mutable reference to the inner source.
34    #[inline]
35    pub fn inner_mut(&mut self) -> &mut I {
36        self.input.inner_mut()
37    }
38
39    /// Returns the inner source.
40    #[inline]
41    pub fn into_inner(self) -> I {
42        self.input.into_inner()
43    }
44}
45
46impl<I> Iterator for FadeIn<I>
47where
48    I: Source,
49{
50    type Item = I::Item;
51
52    #[inline]
53    fn next(&mut self) -> Option<I::Item> {
54        self.input.next()
55    }
56
57    #[inline]
58    fn size_hint(&self) -> (usize, Option<usize>) {
59        self.input.size_hint()
60    }
61}
62
63impl<I> ExactSizeIterator for FadeIn<I> where I: Source + ExactSizeIterator {}
64
65impl<I> Source for FadeIn<I>
66where
67    I: Source,
68{
69    #[inline]
70    fn current_span_len(&self) -> Option<usize> {
71        self.inner().current_span_len()
72    }
73
74    #[inline]
75    fn channels(&self) -> ChannelCount {
76        self.inner().channels()
77    }
78
79    #[inline]
80    fn sample_rate(&self) -> SampleRate {
81        self.inner().sample_rate()
82    }
83
84    #[inline]
85    fn total_duration(&self) -> Option<Duration> {
86        self.inner().total_duration()
87    }
88
89    #[inline]
90    fn try_seek(&mut self, pos: Duration) -> Result<(), SeekError> {
91        self.inner_mut().try_seek(pos)
92    }
93}
rodio/source/fadein.rs

rodio/source/
fadein.rs
