Finish out MVP level detector node + Various fixes

 * Fix issue with oversampling in FM synth that was causing audio artifacts for sine waves and maybe others.
   * It sounds so much better now it's crazy...
   * Make the oversampling impl more unified across the board for the different waveforms
 * Build out level detector UI
   * Show cur detected level (if available) using `SharedArrayBuffer`
   * Show detected value as dB
 * Delete all the old equalizer code
   * It doesn't even work anymore and never worked well, and filter designer can do a decent job of providing that functionality anyway
 * Hide wavetable from the graph editor add module search since it's not meant to be used by itself
 * Add Jemalloc for the backend

backend/Cargo.toml

@@ -47,3 +47,6 @@ base64 = "0.21"
 rust-s3 = { version = "0.33", features = [] }
 aws-region = { version = "0.25.0", features = ["serde"] }
 urlencoding = "2.1"
+
+[target.'cfg(not(target_env = "msvc"))'.dependencies]
+tikv-jemallocator = "0.5"

backend/src/main.rs

@@ -19,6 +19,13 @@ use rocket::{
     Request, Response,
 };
 
+#[cfg(not(target_env = "msvc"))]
+use tikv_jemallocator::Jemalloc;
+
+#[cfg(not(target_env = "msvc"))]
+#[global_allocator]
+static GLOBAL: Jemalloc = Jemalloc;
+
 pub mod conf;
 pub mod db_util;
 pub mod models;

engine/dsp/src/oscillator.rs

@@ -5,6 +5,7 @@ pub trait PhasedOscillator {
 
   fn set_phase(&mut self, new_phase: f32);
 
+  #[inline(always)]
   fn compute_new_phase(phase: f32, frequency: f32) -> f32 {
     let mut new_phase = (phase + (1. / (SAMPLE_RATE as f32 / frequency))).fract();
     if new_phase < 0. {
@@ -13,19 +14,17 @@ pub trait PhasedOscillator {
     new_phase
   }
 
+  #[inline(always)]
   fn compute_new_phase_oversampled(phase: f32, oversample_multiplier: f32, frequency: f32) -> f32 {
     Self::compute_new_phase(phase, frequency / oversample_multiplier)
   }
 
+  #[inline(always)]
   fn update_phase(&mut self, frequency: f32) {
     // 1 phase corresponds to 1 period of the waveform.  1 phase is passed every (SAMPLE_RATE /
     // frequency) samples.
     let phase = self.get_phase();
     let new_phase = Self::compute_new_phase(phase, frequency);
     self.set_phase(new_phase);
   }
-
-  fn update_phase_oversampled(&mut self, oversample_multiplier: f32, frequency: f32) {
-    self.update_phase(frequency / oversample_multiplier)
-  }
 }

engine/dsp/src/rms_level_detector.rs

@@ -40,7 +40,7 @@ impl<const TEND_TOWARDS_ZERO: bool> RMSLevelDetector<TEND_TOWARDS_ZERO> {
 
     // To deal with floating point precision issues, we tend the sum towards zero slightly so
     // that it doesn't get stuck at a non-zero value when the input is silent.
-    if TEND_TOWARDS_ZERO {
+    if TEND_TOWARDS_ZERO && sample.abs() < 0.001 {
       self.sum *= 0.999999;
     }
 

engine/level_detector/src/lib.rs

@@ -13,7 +13,7 @@ impl Default for LevelDetectorCtx {
   fn default() -> Self {
     Self {
       io_buffer: [0.0; FRAME_SIZE],
-      detector: RMSLevelDetector::new(10), // Will be set dynamically during processing
+      detector: RMSLevelDetector::new(10), // Window size will be set dynamically during processing
     }
   }
 }

engine/wavetable/src/fm/mod.rs

@@ -95,26 +95,21 @@ impl Oscillator for SineOscillator {
     _base_frequency: f32,
   ) -> f32 {
     let sine_lookup_table = dsp::lookup_tables::get_sine_lookup_table();
-    if frequency.abs() < 1000. {
-      self.update_phase(frequency);
-      return dsp::read_interpolated(
-        sine_lookup_table,
-        self.phase * (sine_lookup_table.len() - 2) as f32,
-      );
-    }
 
-    // 2x oversampling to avoid aliasing
+    // 4x oversampling to avoid aliasing
     let mut out = 0.;
-    let oversample_ratio = 2usize;
+    let mut phase = self.phase;
+    let oversample_ratio = 4usize;
     for _ in 0..oversample_ratio {
-      self.update_phase_oversampled(oversample_ratio as f32, frequency);
+      phase = Self::compute_new_phase_oversampled(phase, oversample_ratio as f32, frequency);
       out += dsp::read_interpolated(
         sine_lookup_table,
-        self.phase * (sine_lookup_table.len() - 2) as f32,
-      ) * (1. / (oversample_ratio as f32));
+        phase * (sine_lookup_table.len() - 2) as f32,
+      );
     }
 
-    out
+    self.phase = phase;
+    out / oversample_ratio as f32
   }
 }
 
@@ -139,21 +134,20 @@ impl Oscillator for SquareOscillator {
     _sample_ix_within_frame: usize,
     _base_frequency: f32,
   ) -> f32 {
-    if frequency.abs() < 1000. {
-      self.update_phase(frequency);
-      return if self.phase < 0.5 { 1. } else { -1. };
-    }
-
     // 4x oversampling to avoid aliasing
     let mut out = 0.;
-    self.update_phase_oversampled(4., frequency);
-    out += if self.phase < 0.5 { 0.25 } else { -0.25 };
-    self.update_phase_oversampled(4., frequency);
-    out += if self.phase < 0.5 { 0.25 } else { -0.25 };
-    self.update_phase_oversampled(4., frequency);
-    out += if self.phase < 0.5 { 0.25 } else { -0.25 };
-    self.update_phase_oversampled(4., frequency);
-    out += if self.phase < 0.5 { 0.25 } else { -0.25 };
+    let mut phase = self.phase;
+
+    phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
+    out += if phase < 0.5 { 0.25 } else { -0.25 };
+    phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
+    out += if phase < 0.5 { 0.25 } else { -0.25 };
+    phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
+    out += if phase < 0.5 { 0.25 } else { -0.25 };
+    phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
+    out += if phase < 0.5 { 0.25 } else { -0.25 };
+
+    self.phase = phase;
 
     out
   }
@@ -181,10 +175,11 @@ impl Oscillator for TriangleOscillator {
     _base_frequency: f32,
   ) -> f32 {
     // 4x oversampling to avoid aliasing
+    let oversample_factor = 4usize;
     let mut out = 0.;
     let mut phase = self.phase;
-    for _ in 0..4 {
-      phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
+    for _ in 0..oversample_factor {
+      phase = Self::compute_new_phase_oversampled(phase, oversample_factor as f32, frequency);
       out += if phase < 0.25 {
         4. * phase
       } else if phase < 0.5 {
@@ -196,11 +191,11 @@ impl Oscillator for TriangleOscillator {
       } else {
         let adjusted_phase = phase - 0.75;
         -1. + (adjusted_phase * 4.)
-      } * 0.25;
+      }
     }
 
     self.phase = phase;
-    out
+    out / oversample_factor as f32
   }
 }
 
@@ -226,19 +221,20 @@ impl Oscillator for SawtoothOscillator {
     _base_frequency: f32,
   ) -> f32 {
     // 4x oversampling to reduce aliasing
+    let oversample_factor = 4usize;
     let mut out = 0.;
     let mut phase = self.phase;
-    for _ in 0..4 {
-      phase = Self::compute_new_phase_oversampled(phase, 4., frequency);
-      out += if self.phase < 0.5 {
-        2. * self.phase
+    for _ in 0..oversample_factor {
+      phase = Self::compute_new_phase_oversampled(phase, oversample_factor as f32, frequency);
+      out += if phase < 0.5 {
+        2. * phase
       } else {
-        -1. + (2. * (self.phase - 0.5))
-      } * 0.25;
+        -1. + (2. * (phase - 0.5))
+      };
     }
 
     self.phase = phase;
-    out
+    out / oversample_factor as f32
   }
 }
 
@@ -500,15 +496,19 @@ impl Oscillator for WaveTableHandle {
     ];
 
     // 4x oversampling to avoid aliasing
+    let oversample_factor = 4usize;
     let mut sample = 0.;
-    for _ in 0..4 {
-      self.update_phase_oversampled(4., frequency);
+    let mut phase = self.phase;
+    for _ in 0..oversample_factor {
+      phase = Self::compute_new_phase_oversampled(phase, oversample_factor as f32, frequency);
       sample += wavetable.get_sample(
-        self.phase * (wavetable.settings.waveform_length - 1) as f32,
+        phase * (wavetable.settings.waveform_length - 1) as f32,
         &mixes,
       );
     }
-    sample * 0.25
+
+    self.phase = phase;
+    sample / oversample_factor as f32
   }
 }