rg3d_sound/dsp/
mod.rs

1// Clippy is being stupid here again, filters cannot be empty and there is no
2// need to define is_empty() method.
3#![allow(clippy::len_without_is_empty)]
4
5//! Digital signal processing module. Provides basic elements to process signal sample-by-sample.
6//!
7//! # Abbreviations
8//!
9//! `fc` - normalized frequency, i.e. `fc = 0.2` with `sample rate = 44100 Hz` will be `f = 8820 Hz`
10
11use rg3d_core::visitor::{Visit, VisitResult, Visitor};
12
13pub mod filters;
14
15/// See more info here <https://ccrma.stanford.edu/~jos/pasp/Delay_Lines.html>
16#[derive(Debug, Clone)]
17pub struct DelayLine {
18    samples: Vec<f32>,
19    last: f32,
20    pos: u32,
21}
22
23impl DelayLine {
24    /// Creates new instance of delay line of given length in samples.
25    pub fn new(len: usize) -> Self {
26        Self {
27            samples: vec![0.0; len],
28            last: 0.0,
29            pos: 0,
30        }
31    }
32
33    /// Returns length of delay line in samples.
34    pub fn len(&self) -> usize {
35        self.samples.len()
36    }
37
38    /// Processes single sample.
39    pub fn feed(&mut self, sample: f32) -> f32 {
40        self.last = self.samples[self.pos as usize];
41        self.samples[self.pos as usize] = sample;
42        self.pos += 1;
43        if self.pos >= self.samples.len() as u32 {
44            self.pos -= self.samples.len() as u32
45        }
46        self.last
47    }
48
49    /// Returns last processed sample.
50    pub fn last(&self) -> f32 {
51        self.last
52    }
53}
54
55impl Default for DelayLine {
56    fn default() -> Self {
57        Self {
58            samples: vec![0.0],
59            last: 0.0,
60            pos: 0,
61        }
62    }
63}
64
65impl Visit for DelayLine {
66    fn visit(&mut self, name: &str, visitor: &mut Visitor) -> VisitResult {
67        visitor.enter_region(name)?;
68
69        self.last.visit("Last", visitor)?;
70        self.pos.visit("Pos", visitor)?;
71        self.samples.visit("Samples", visitor)?;
72
73        visitor.leave_region()
74    }
75}
76
77/// Calculates single coefficient of Hamming window.
78/// <https://en.wikipedia.org/wiki/Window_function#Hamming_window>
79pub fn hamming_window(i: usize, sample_count: usize) -> f32 {
80    0.54 - 0.46 * (2.0 * std::f32::consts::PI * i as f32 / (sample_count - 1) as f32).cos()
81}
82
83/// Calculates single coefficient of Hann window.
84/// <https://en.wikipedia.org/wiki/Hann_function>
85pub fn hann_window(i: usize, sample_count: usize) -> f32 {
86    0.5 - 0.5 * (2.0 * std::f32::consts::PI * i as f32 / (sample_count - 1) as f32).cos()
87}
88
89/// Creates new window using specified window function.
90/// <https://en.wikipedia.org/wiki/Window_function>
91pub fn make_window<W: Fn(usize, usize) -> f32>(sample_count: usize, func: W) -> Vec<f32> {
92    (0..sample_count).map(|i| func(i, sample_count)).collect()
93}
rg3d_sound/dsp/mod.rs

rg3d_sound/dsp/
mod.rs
