116 lines
3.5 KiB
Rust
116 lines
3.5 KiB
Rust
|
// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
|
||
|
// This is a part of HexoDSP. Released under (A)GPLv3 or any later.
|
||
|
// See README.md and COPYING for details.
|
||
|
|
||
|
use crate::nodes::{NodeAudioContext, NodeExecContext};
|
||
|
use crate::dsp::{NodeId, SAtom, ProcBuf, DspNode, LedPhaseVals, NodeContext};
|
||
|
|
||
|
#[macro_export]
|
||
|
macro_rules! fa_sfilter_type { ($formatter: expr, $v: expr, $denorm_v: expr) => { {
|
||
|
let s =
|
||
|
match ($v.round() as usize) {
|
||
|
0 => "LP(1p)",
|
||
|
1 => "HP(1p)",
|
||
|
_ => "?",
|
||
|
};
|
||
|
write!($formatter, "{}", s)
|
||
|
} } }
|
||
|
|
||
|
/// A simple amplifier
|
||
|
#[derive(Debug, Clone)]
|
||
|
pub struct SFilter {
|
||
|
israte: f64,
|
||
|
z: f64,
|
||
|
}
|
||
|
|
||
|
impl SFilter {
|
||
|
pub fn new(_nid: &NodeId) -> Self {
|
||
|
Self {
|
||
|
israte: 1.0 / 44100.0,
|
||
|
z: 0.0,
|
||
|
}
|
||
|
}
|
||
|
pub const inp : &'static str =
|
||
|
"SFilter inp\nSignal input\nRange: (-1..1)\n";
|
||
|
pub const freq : &'static str =
|
||
|
"SFilter freq\nFilter cutoff frequency.\nRange: (-1..1)\n";
|
||
|
pub const ftype : &'static str =
|
||
|
"SFilter ftype\nFilter type.";
|
||
|
pub const sig : &'static str =
|
||
|
"SFilter sig\nFiltered signal output.\nRange: (-1..1)\n";
|
||
|
pub const DESC : &'static str =
|
||
|
r#"Simple Audio Filter
|
||
|
|
||
|
This is a very simple collection of filters.
|
||
|
"#;
|
||
|
pub const HELP : &'static str =
|
||
|
r#"SFilter - Simple Audio Filter
|
||
|
|
||
|
"#;
|
||
|
}
|
||
|
|
||
|
impl DspNode for SFilter {
|
||
|
fn outputs() -> usize { 1 }
|
||
|
|
||
|
fn set_sample_rate(&mut self, srate: f32) {
|
||
|
self.israte = 1.0 / (srate as f64);
|
||
|
}
|
||
|
fn reset(&mut self) {
|
||
|
self.z = 0.0;
|
||
|
}
|
||
|
|
||
|
#[inline]
|
||
|
fn process<T: NodeAudioContext>(
|
||
|
&mut self, ctx: &mut T, _ectx: &mut NodeExecContext,
|
||
|
_nctx: &NodeContext,
|
||
|
atoms: &[SAtom], inputs: &[ProcBuf],
|
||
|
outputs: &mut [ProcBuf], ctx_vals: LedPhaseVals)
|
||
|
{
|
||
|
use crate::dsp::{out, inp, denorm, at};
|
||
|
|
||
|
let inp = inp::SFilter::inp(inputs);
|
||
|
let freq = inp::SFilter::freq(inputs);
|
||
|
let ftype = at::SFilter::ftype(atoms);
|
||
|
let out = out::SFilter::sig(outputs);
|
||
|
|
||
|
match ftype.i() {
|
||
|
// one pole lp from valley rack free:
|
||
|
// https://github.com/ValleyAudio/ValleyRackFree/blob/v1.0/src/Common/DSP/OnePoleFilters.cpp
|
||
|
0 => {
|
||
|
for frame in 0..ctx.nframes() {
|
||
|
let input = inp.read(frame) as f64;
|
||
|
let b =
|
||
|
(-std::f64::consts::TAU
|
||
|
* (denorm::SFilter::freq(freq, frame) as f64)
|
||
|
* self.israte).exp();
|
||
|
let a = 1.0 - b;
|
||
|
|
||
|
self.z = a * input + self.z * b;
|
||
|
out.write(frame, self.z as f32);
|
||
|
}
|
||
|
},
|
||
|
// one pole from:
|
||
|
// http://www.willpirkle.com/Downloads/AN-4VirtualAnalogFilters.pdf
|
||
|
// (page 5)
|
||
|
1 => {
|
||
|
for frame in 0..ctx.nframes() {
|
||
|
let input = inp.read(frame) as f64;
|
||
|
let g =
|
||
|
(std::f64::consts::PI
|
||
|
* (denorm::SFilter::freq(freq, frame) as f64)
|
||
|
* self.israte).tan();
|
||
|
let a1 = g / (1.0 + g);
|
||
|
|
||
|
let v1 = a1 * (input - self.z);
|
||
|
let v2 = v1 + self.z;
|
||
|
self.z = v2 + v1;
|
||
|
|
||
|
let (m0, m1) = (0.0, 1.0);
|
||
|
out.write(frame, (m0 * input + m1 * v2) as f32);
|
||
|
}
|
||
|
},
|
||
|
_ => {},
|
||
|
}
|
||
|
}
|
||
|
}
|