rinth/rinth-synth/src/fm.rs
Ivan Bushchik 1aff34a06a
0.0.1: First alpha release
Signed-off-by: Ivan Bushchik <ivabus@ivabus.dev>
2024-01-19 09:59:08 +03:00

101 lines
2.5 KiB
Rust

use crate::shared::{add_delay, get_note};
use rinth_types::file::Channel;
use rinth_types::note::get_note_len;
use rinth_types::{file::ChannelType, note::Note, traits::Synth};
use std::f32::consts::PI;
use std::fs;
pub struct FM {
pub bpm: u16,
pub notes: Vec<(Note, ModulationFreq, FrequencyDeviation)>,
}
#[derive(Copy, Clone)]
pub struct ModulationFreq(f32);
#[derive(Copy, Clone)]
pub struct FrequencyDeviation(f32);
const FIGHT_CLICKS: usize = 128;
impl Synth for FM {
fn from_channel(channel: Channel, bpm: u16) -> Self
where
Self: Sized,
{
let channel = match channel {
Channel {
path,
channel_type: ChannelType::FM,
..
} => path,
_ => {
unreachable!()
}
};
let contents = fs::read(channel).unwrap();
let mut notes: Vec<(Note, ModulationFreq, FrequencyDeviation)> = vec![];
let mut current_tone = ModulationFreq(440.0);
let mut current_deviation = FrequencyDeviation(8.0);
for line in contents.split(|&x| x == b'\n') {
if line.is_empty() {
continue;
}
let s = String::from_utf8_lossy(line);
let l = s.split_ascii_whitespace().collect::<Vec<&str>>();
// Ignore comment
if l[0].as_bytes()[0] == b'/' {
continue;
}
// String in FM channel may be or carrier tone or note
if l[0].as_bytes()[0] == b'@' {
current_tone = ModulationFreq(l[0][1..].parse::<f32>().unwrap());
continue;
}
if l[0].as_bytes()[0] == b'#' {
current_deviation = FrequencyDeviation(l[0][1..].parse::<f32>().unwrap());
continue;
}
notes.push((get_note(l), current_tone, current_deviation))
}
FM {
bpm,
notes,
}
}
fn synthesise(&self, sample_rate: u32) -> Vec<f32> {
// t - time, m - modulating freq (carrier)
let y: fn(f32, f32, f32, f32) -> f32 =
|t: f32, f: f32, m: f32, d| (2_f32 * PI * m * t + d * (2_f32 * PI * f * t).sin()).cos();
let mut stream: Vec<f32> = vec![];
for (note, tone, deviation) in &self.notes {
if note.delay != 0_f32 {
add_delay(&mut stream, note.delay, self.bpm, sample_rate);
}
// Samples in _THIS_ note
let samples = (get_note_len(note.length, self.bpm) * sample_rate as f32) as usize;
for k in 0..samples {
stream.push(
y(k as f32 / sample_rate as f32, tone.0, note.tone.get_freq(), deviation.0)
// This makes a little linear fade-in-out so we don't get "clicks"
* if k <= FIGHT_CLICKS {
k as f32 / FIGHT_CLICKS as f32
} else if k
>= samples
- FIGHT_CLICKS
{
(samples
- k) as f32 / FIGHT_CLICKS as f32
} else {
1.0
},
)
}
}
stream
}
}