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use crate::dsp::{
DspNode, GraphFun, LedPhaseVals, NodeContext, NodeGlobalRef, NodeId, ProcBuf, SAtom,
};
use crate::nodes::{NodeAudioContext, NodeExecContext};
use synfx_dsp::Rng;
#[macro_export]
macro_rules! fa_noise_mode {
($formatter: expr, $v: expr, $denorm_v: expr) => {{
let s = match ($v.round() as usize) {
0 => "Bipolar",
1 => "Unipolar",
_ => "?",
};
write!($formatter, "{}", s)
}};
}
#[derive(Debug, Clone)]
pub struct Noise {
seed: u64,
rng: Rng,
}
impl Noise {
pub fn new(nid: &NodeId, _node_global: &NodeGlobalRef) -> Self {
let mut rng = Rng::new();
rng.seed((0x193a67f4a8a6d769_u64).wrapping_add(0x131415 * (nid.instance() as u64 + 1)));
Self { seed: nid.instance() as u64, rng }
}
pub const atv: &'static str = "Attenuverter input, to attenuate or invert \
the noise";
pub const offs: &'static str = "Offset input, that is added to the output \
signal after attenuvertig it.";
pub const mode: &'static str = "You can switch between **Bipolar** noise, which \
uses the full range from **-1** to **1**, or **Unipolar** noise that \
only uses the range from **0** to **1**.";
pub const sig: &'static str = "The noise output.";
pub const DESC: &'static str = r#"Noise Oscillator
This is a very simple noise oscillator, which can be used for any kind of audio rate noise.
And as a source for sample & hold like nodes to generate low frequency modulation. The white
noise is uniformly distributed and not normal distributed (which could be a bit more natural
in some contexts). See also the `XNoise` node for more noise alternatives.
"#;
pub const HELP: &'static str = r#"A Simple Noise Oscillator
This is a very simple noise oscillator, which can be used for
any kind of audio rate noise. And as a source for sample & hold
like nodes to generate low frequency modulation.
The noise follows a uniform distribution. That means all amplitudes are equally likely to occur.
While it might sound similar, white noise is usually following a normal distribution, which makes
some amplitudes more likely to occur than others.
See also the `XNoise` node for more noise alternatives.
The ~~atv~~ attenuverter and ~~offs~~ parameters control the value range
of the noise, and the ~~mode~~ allows to switch the oscillator between
unipolar and bipolar output.
"#;
pub fn graph_fun() -> Option<GraphFun> {
None
}
}
impl DspNode for Noise {
fn set_sample_rate(&mut self, _srate: f32) {}
fn reset(&mut self) {
self.rng.seed((0x193a67f4a8a6d769_u64).wrapping_add(0x131415 * (self.seed + 1)));
}
#[inline]
fn process(
&mut self,
ctx: &mut dyn NodeAudioContext,
_ectx: &mut NodeExecContext,
_nctx: &NodeContext,
atoms: &[SAtom],
inputs: &[ProcBuf],
outputs: &mut [ProcBuf],
ctx_vals: LedPhaseVals,
) {
use crate::dsp::{at, denorm, inp, out};
let mode = at::Noise::mode(atoms);
let atv = inp::Noise::atv(inputs);
let offs = inp::Noise::offs(inputs);
let out = out::Noise::sig(outputs);
let rng = &mut self.rng;
if mode.i() == 0 {
for frame in 0..ctx.nframes() {
let s = (rng.next() * 2.0) - 1.0;
let s = s * denorm::Noise::atv(atv, frame) + denorm::Noise::offs(offs, frame);
out.write(frame, s);
}
} else {
for frame in 0..ctx.nframes() {
let s =
rng.next() * denorm::Noise::atv(atv, frame) + denorm::Noise::offs(offs, frame);
out.write(frame, s);
}
}
let last_frame = ctx.nframes() - 1;
ctx_vals[0].set(out.read(last_frame));
}
}
