householder

Author: lukeweston1234

crates/src/nodes/audio/householder.rs

@@ -0,0 +1,46 @@
+use crate::{
+    context::AudioContext,
+    node::{Inputs, Node},
+    ports::{PortBuilder, Ports},
+};
+
+/// As suggested in https://signalsmith-audio.co.uk/writing/2021/lets-write-a-reverb/
+///
+/// Allegedly a bit lower density than saw a hadamard mixer
+#[derive(Clone)]
+pub struct HouseholderMixer {
+    chans: usize,
+    ports: Ports,
+}
+
+impl HouseholderMixer {
+    pub fn new(chans: usize) -> Self {
+        Self {
+            chans,
+            ports: PortBuilder::default()
+                .audio_in(chans)
+                .audio_out(chans)
+                .build(),
+        }
+    }
+}
+
+impl Node for HouseholderMixer {
+    fn process(&mut self, _ctx: &mut AudioContext, inputs: &Inputs, outputs: &mut [&mut [f32]]) {
+        let block_size = outputs[0].len();
+        let multiplier = 2.0 / self.chans as f32;
+
+        for i in 0..block_size {
+            let sum: f32 = (0..self.chans)
+                .map(|c| inputs.get(c).and_then(|x| *x).map_or(0.0, |buf| buf[i]))
+                .sum();
+            for c in 0..self.chans {
+                let x = inputs.get(c).and_then(|x| *x).map_or(0.0, |buf| buf[i]);
+                outputs[c][i] = x - multiplier * sum;
+            }
+        }
+    }
+    fn ports(&self) -> &Ports {
+        &self.ports
+    }
+}

crates/src/nodes/audio/mod.rs

@@ -3,6 +3,8 @@ pub mod allpass;
 pub mod delay;
 pub mod external;
 pub mod fir;
+pub mod hadamard;
+pub mod householder;
 pub mod mixer;
 pub mod onepole;
 pub mod ops;

crates/src/registry.rs

@@ -14,6 +14,7 @@ use crate::{
             delay::{DelayRead, DelayWrite},
             external::ExternalInput,
             hadamard::HadamardMixer,
+            householder::HouseholderMixer,
             mixer::{MonoFanOut, TrackMixer},
             onepole::OnePole,
             ops::{ApplyOpKind, mult_node_factory},
@@ -382,6 +383,18 @@ pub fn audio_registry_factory() -> NodeRegistry {
                 Ok(Box::new(HadamardMixer::new(chans)))
             }
         ),
+        node_spec!(
+            "householder".into(),
+            required = ["chans"],
+            optional = [],
+            build = |_, p| {
+                let chans = p
+                    .get_usize("chans")
+                    .expect("Must provide chans to audio_input");
+
+                Ok(Box::new(HouseholderMixer::new(chans)))
+            }
+        ),
         node_spec!(
             "external".into(),
             required = ["interface_name", "chans"],