[utils, sosten] move delay to utils lib

crates/sosten/Cargo.toml

@@ -9,3 +9,5 @@ crate-type = ["cdylib"]
 [dependencies]
 baseplug = { git = "https://github.com/wrl/baseplug.git", rev = "9cec68f31cca9c0c7a1448379f75d92bbbc782a8" }
 serde = "1.0.126"
+
+utils = { path = "../utils" }

crates/sosten/src/delay.rs

@@ -1,30 +0,0 @@
-pub struct DelayLine<const LEN: usize> {
-    buffer: [f32; LEN],
-    index: usize,
-}
-
-impl<const LEN: usize> DelayLine<LEN> {
-    pub fn new() -> Self {
-        Self {
-            buffer: [0.0; LEN],
-            index: 0,
-        }
-    }
-
-    pub fn read_slice(&self, slice: &mut [f32]) {
-        // Copy values in order
-        for i in 0..LEN {
-            slice[i] = self.buffer[(self.index + i - LEN) % LEN];
-        }
-    }
-
-    pub fn write_and_advance(&mut self, value: f32) {
-        self.buffer[self.index] = value;
-
-        if self.index == LEN - 1 {
-            self.index = 0;
-        } else {
-            self.index += 1;
-        }
-    }
-}

crates/sosten/src/lib.rs

@@ -4,8 +4,7 @@
 use baseplug::{Plugin, ProcessContext};
 use serde::{Deserialize, Serialize};
 
-mod delay;
-use delay::DelayLine;
+use utils::delay::*;
 
 // If you change this remember to change the max on the model
 const LEN: usize = 48000;

crates/utils/src/delay.rs

@@ -0,0 +1,78 @@
+pub struct DelayLine<const LEN: usize> {
+    buffer: [f32; LEN],
+    index: usize,
+}
+impl<const LEN: usize> DelayLine<LEN> {
+    pub fn new() -> Self {
+        Self {
+            buffer: [0.0; LEN],
+            index: 0,
+        }
+    }
+
+    pub fn read_slice(&self, slice: &mut [f32]) {
+        // Copy values in order
+        for i in 0..LEN {
+            slice[i] = self.wrapped_index(self.index + i);
+        }
+    }
+
+    pub fn write_and_advance(&mut self, value: f32) {
+        self.buffer[self.index] = value;
+
+        if self.index == LEN - 1 {
+            self.index = 0;
+        } else {
+            self.index += 1;
+        }
+    }
+
+    /// Returns the sample at idx after taking modulo LEN
+    pub fn wrapped_index(&self, idx: usize) -> f32 {
+        self.buffer[idx % LEN]
+    }
+
+    /// Indexes the buffer but interpolates between the current and the next sample
+    pub fn floating_index(&self, val: f32) -> f32 {
+        let idx = val.trunc() as usize;
+        let a = val.fract();
+
+        let one = self.wrapped_index(idx);
+        let two = self.wrapped_index(idx + 1);
+
+        (1.0 - a) * one + a * two
+    }
+
+    /// Get a reference to the delay line's index.
+    pub fn idx(&self) -> &usize {
+        &self.index
+    }
+
+    /// Get a reference to the delay line's buffer.
+    pub fn buffer(&self) -> &[f32; LEN] {
+        &self.buffer
+    }
+}
+
+pub struct DelayLines<const LEN: usize> {
+    pub l: DelayLine<LEN>,
+    pub r: DelayLine<LEN>,
+}
+impl<const LEN: usize> DelayLines<LEN> {
+    pub fn new() -> Self {
+        Self {
+            l: DelayLine::<LEN>::new(),
+            r: DelayLine::<LEN>::new(),
+        }
+    }
+
+    pub fn read_slices(&self, l: &mut [f32], r: &mut [f32]) {
+        self.l.read_slice(l);
+        self.r.read_slice(r);
+    }
+
+    pub fn write_and_advance(&mut self, l: f32, r: f32) {
+        self.l.write_and_advance(l);
+        self.r.write_and_advance(r);
+    }
+}

crates/utils/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod buffers;
+pub mod delay;
 pub mod logs;
 pub mod pitch;
 pub mod threeband;