devalang_wasm/engine/audio/effects/processors/
vibrato.rs

1use crate::engine::audio::effects::processors::super_trait::EffectProcessor;
2
3#[derive(Debug, Clone)]
4pub struct VibratoProcessor {
5    pub rate: f32,
6    pub depth: f32,
7    pub sync: bool,
8    buf_l: Vec<f32>,
9    buf_r: Vec<f32>,
10    pos: usize,
11    phase: f32,
12}
13
14impl VibratoProcessor {
15    pub fn new(rate: f32, depth: f32, sync: bool) -> Self {
16        let max_delay = 2048usize;
17        Self {
18            rate: rate.clamp(0.1, 10.0),
19            depth: depth.clamp(0.0, 0.02),
20            sync,
21            buf_l: vec![0.0; max_delay],
22            buf_r: vec![0.0; max_delay],
23            pos: 0,
24            phase: 0.0,
25        }
26    }
27}
28
29impl Default for VibratoProcessor {
30    fn default() -> Self {
31        Self::new(5.0, 0.003, false)
32    }
33}
34
35impl EffectProcessor for VibratoProcessor {
36    fn process(&mut self, samples: &mut [f32], sr: u32) {
37        let sr_f = sr as f32;
38        let max_delay = (self.buf_l.len() - 2) as f32;
39        for i in (0..samples.len()).step_by(2) {
40            let in_l = samples[i];
41            let in_r = if i + 1 < samples.len() {
42                samples[i + 1]
43            } else {
44                in_l
45            };
46            // compute read position first (read from previous samples), then write current input into buffer
47            let lfo = (2.0 * std::f32::consts::PI * self.phase).sin();
48            let delay = ((self.depth * max_delay) * (lfo + 1.0) * 0.5).max(0.0);
49            let read_pos =
50                (self.pos as f32 - delay + self.buf_l.len() as f32) % self.buf_l.len() as f32;
51            let idx = read_pos.floor() as usize % self.buf_l.len();
52            let frac = read_pos - read_pos.floor();
53            let a = self.buf_l[idx];
54            let b = self.buf_l[(idx + 1) % self.buf_l.len()];
55            samples[i] = a * (1.0 - frac) + b * frac;
56
57            if i + 1 < samples.len() {
58                let a2 = self.buf_r[idx];
59                let b2 = self.buf_r[(idx + 1) % self.buf_r.len()];
60                samples[i + 1] = a2 * (1.0 - frac) + b2 * frac;
61            }
62
63            // now write current input into buffer (overwrite oldest)
64            let write_idx = self.pos % self.buf_l.len();
65            self.buf_l[write_idx] = in_l;
66            self.buf_r[write_idx] = in_r;
67            self.pos = (self.pos + 1) % self.buf_l.len();
68            self.phase += self.rate / sr_f;
69            if self.phase >= 1.0 {
70                self.phase -= 1.0;
71            }
72        }
73    }
74
75    fn reset(&mut self) {
76        self.pos = 0;
77        self.phase = 0.0;
78    }
79
80    fn name(&self) -> &str {
81        "Vibrato"
82    }
83}