Implement ping-pong delay

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "maolan-plugins"
-version = "0.1.3"
+version = "0.1.4"
 edition = "2024"
 description = "Audio plugins for the Maolan ecosystem"
 license = "BSD-2-Clause"
@@ -22,8 +22,6 @@ dirs = "7.0.0"
 oxideav-core = "0.1.42"
 oxideav-basic = "0.0.11"
 oxideav-flac = "0.0.12"
-oxideav-mp3 = "0.1.3"
-oxideav-ogg = "0.1.9"
 pitch-detection = "0.3.0"
 symphonia = { version = "0.6.1", features = ["aac", "alac", "flac", "isomp4", "mp3", "ogg", "vorbis", "wav"] }
 maolan-baseview = { version = "0.1.1", features = ["canvas"] }

src/chorus/dsp.rs

@@ -40,8 +40,8 @@ impl Chorus {
         self.buf_r.fill(0.0);
         self.write_pos = 0;
         self.phases = [0.0; MAX_VOICES];
-        for i in 0..MAX_VOICES {
-            self.phases[i] = TWO_PI * i as f32 / MAX_VOICES as f32;
+        for (i, phase) in self.phases.iter_mut().enumerate() {
+            *phase = TWO_PI * i as f32 / MAX_VOICES as f32;
         }
     }
 

src/common/bus.rs

@@ -556,8 +556,8 @@ mod tests {
             valid_bins: 512,
             ..Default::default()
         };
-        for i in 0..512 {
-            fft.bins[i] = i as f32;
+        for (i, bin) in fft.bins.iter_mut().enumerate().take(512) {
+            *bin = i as f32;
         }
 
         let data = PluginSharedData::new(PluginType::Eq).with_fft(fft);

src/common/fft.rs

@@ -28,9 +28,9 @@ impl SpectrumAnalyzer {
             self.complex_buf[i].re = s;
             self.complex_buf[i].im = 0.0;
         }
-        for i in input.len()..n {
-            self.complex_buf[i].re = 0.0;
-            self.complex_buf[i].im = 0.0;
+        for complex in self.complex_buf.iter_mut().take(n).skip(input.len()) {
+            complex.re = 0.0;
+            complex.im = 0.0;
         }
 
         let scratch_len = fft.get_inplace_scratch_len();

src/common/modulated_oscillator.rs

@@ -18,46 +18,6 @@ impl FreqEnvMode {
     }
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::common::envelope::EnvPoint;
-
-    #[test]
-    fn changing_base_frequency_preserves_linear_freq_env_hz() {
-        let mut oscillator = ModulatedOscillator::new(48_000.0);
-        oscillator.set_base_freq_hz(1000.0);
-        oscillator.set_freq_env(Some(Envelope::new(vec![
-            EnvPoint::new(0.0, 0.5),
-            EnvPoint::new(1.0, 1.0),
-        ])));
-
-        oscillator.set_base_freq_hz_preserving_freq_env(2000.0);
-        let points = oscillator.freq_env().expect("frequency envelope").points();
-
-        assert_eq!(points[0].v, 0.25);
-        assert_eq!(points[1].v, 0.5);
-    }
-
-    #[test]
-    fn centered_stereo_oscillator_sums_to_mono_without_level_loss() {
-        let mut oscillator = ModulatedOscillator::new(48_000.0);
-        oscillator.set_base_freq_hz(100.0);
-        oscillator.set_amplitude(1.0);
-        let mut out = vec![0.0; 480];
-
-        oscillator.render(&mut out, 480, None);
-
-        let peak = out
-            .iter()
-            .fold(0.0f32, |peak, sample| peak.max(sample.abs()));
-        assert!(
-            peak > 0.9,
-            "mono summed oscillator should be near full scale, got {peak}"
-        );
-    }
-}
-
 #[derive(Debug, Clone)]
 pub struct ModulatedOscillator {
     oscillator: Oscillator,
@@ -497,3 +457,43 @@ impl ModulatedOscillator {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::common::envelope::EnvPoint;
+
+    #[test]
+    fn changing_base_frequency_preserves_linear_freq_env_hz() {
+        let mut oscillator = ModulatedOscillator::new(48_000.0);
+        oscillator.set_base_freq_hz(1000.0);
+        oscillator.set_freq_env(Some(Envelope::new(vec![
+            EnvPoint::new(0.0, 0.5),
+            EnvPoint::new(1.0, 1.0),
+        ])));
+
+        oscillator.set_base_freq_hz_preserving_freq_env(2000.0);
+        let points = oscillator.freq_env().expect("frequency envelope").points();
+
+        assert_eq!(points[0].v, 0.25);
+        assert_eq!(points[1].v, 0.5);
+    }
+
+    #[test]
+    fn centered_stereo_oscillator_sums_to_mono_without_level_loss() {
+        let mut oscillator = ModulatedOscillator::new(48_000.0);
+        oscillator.set_base_freq_hz(100.0);
+        oscillator.set_amplitude(1.0);
+        let mut out = vec![0.0; 480];
+
+        oscillator.render(&mut out, 480, None);
+
+        let peak = out
+            .iter()
+            .fold(0.0f32, |peak, sample| peak.max(sample.abs()));
+        assert!(
+            peak > 0.9,
+            "mono summed oscillator should be near full scale, got {peak}"
+        );
+    }
+}