Add MVP safety limiter impl

 * I seem to be able to understand how compressors work much better now than when I was working on the multi-band compressor.  Probably because this one is way simpler in multiple ways and totally static.
 * Fix issue loading idential wavetables in fm synth
 * Remove code in faust AWP that clips values to [-1,1]

.gitignore

@@ -55,3 +55,4 @@ public/midi_renderer.wasm
 public/oscilloscope.wasm
 public/spectrum_viz_full.wasm
 public/sampler.wasm
+public/safety_limiter.wasm

Justfile

@@ -87,6 +87,7 @@ build-all:
   cp ./engine/target/wasm32-unknown-unknown/release/oscilloscope.wasm ./public
   cp ./engine/target/wasm32-unknown-unknown/release/spectrum_viz_full.wasm ./public
   cp ./engine/target/wasm32-unknown-unknown/release/sampler.wasm ./public
+  cp ./engine/target/wasm32-unknown-unknown/release/safety_limiter.wasm ./public
   cp ./engine/build/* ./src
 
   just build-sinsy
@@ -319,3 +320,7 @@ build-sampler:
 debug-sampler:
   cd ./engine/sampler && cargo build --target wasm32-unknown-unknown && \
     cp ../target/wasm32-unknown-unknown/debug/sampler.wasm ../../public
+
+debug-safety-limiter:
+  cd ./engine/safety_limiter && cargo build --target wasm32-unknown-unknown && \
+    cp ../target/wasm32-unknown-unknown/debug/safety_limiter.wasm ../../public

engine/Cargo.toml

@@ -31,7 +31,8 @@ members = [
   "midi_renderer",
   "oscilloscope",
   "canvas_utils",
-  "sampler"
+  "sampler",
+  "safety_limiter"
 ]
 
 [profile.release]

engine/compressor/Cargo.toml

@@ -9,3 +9,7 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 dsp = { path = "../dsp" }
+
+[features]
+exports = []
+default = ["exports"]

engine/compressor/src/lib.rs

@@ -1,3 +1,5 @@
+#![feature(const_float_methods)]
+
 use dsp::{
   circular_buffer::CircularBuffer,
   db_to_gain,
@@ -224,7 +226,7 @@ fn detect_level_peak(
 
 /// Given the attack time in milliseconds, compute the coefficient for a one-pole lowpass filter to
 /// be used in the envelope follower.
-fn compute_attack_coefficient(attack_time_ms: f32) -> f32 {
+pub const fn compute_attack_coefficient(attack_time_ms: f32) -> f32 {
   let attack_time_s = (attack_time_ms * 0.001).max(0.0001);
   let attack_time_samples = attack_time_s * SAMPLE_RATE;
   let attack_coefficient = 1. - 1. / attack_time_samples;
@@ -233,7 +235,7 @@ fn compute_attack_coefficient(attack_time_ms: f32) -> f32 {
 
 /// Given the release time in milliseconds, compute the coefficient for a one-pole highpass filter
 /// to be used in the envelope follower.
-fn compute_release_coefficient(release_time_ms: f32) -> f32 {
+pub const fn compute_release_coefficient(release_time_ms: f32) -> f32 {
   let release_time_s = (release_time_ms * 0.001).max(0.0001);
   let release_time_samples = release_time_s * SAMPLE_RATE;
   let release_coefficient = 1. / release_time_samples;
@@ -547,6 +549,7 @@ impl MultibandCompressor {
   }
 }
 
+#[cfg(feature = "exports")]
 #[no_mangle]
 pub extern "C" fn init_compressor() -> *mut MultibandCompressor {
   use std::fmt::Write;
@@ -561,24 +564,28 @@ pub extern "C" fn init_compressor() -> *mut MultibandCompressor {
   Box::into_raw(Box::new(compressor))
 }
 
+#[cfg(feature = "exports")]
 #[no_mangle]
 pub extern "C" fn get_compressor_input_buf_ptr(compressor: *mut MultibandCompressor) -> *mut f32 {
   let compressor = unsafe { &mut *compressor };
   compressor.input_buffer.as_mut_ptr()
 }
 
+#[cfg(feature = "exports")]
 #[no_mangle]
 pub extern "C" fn get_compressor_output_buf_ptr(compressor: *mut MultibandCompressor) -> *mut f32 {
   let compressor = unsafe { &mut *compressor };
   compressor.output_buffer.as_mut_ptr()
 }
 
+#[cfg(feature = "exports")]
 #[no_mangle]
 pub extern "C" fn get_sab_ptr(compressor: *mut MultibandCompressor) -> *mut f32 {
   let compressor = unsafe { &mut *compressor };
   compressor.sab.as_mut_ptr()
 }
 
+#[cfg(feature = "exports")]
 #[no_mangle]
 pub extern "C" fn process_compressor(
   compressor: *mut MultibandCompressor,

engine/waveform_renderer/src/lib.rs

@@ -76,7 +76,7 @@ pub fn get_waveform_buf_ptr(ctx: *mut WaveformRendererCtx) -> *mut f32 {
 }
 
 #[inline(always)]
-fn ms_to_samples(sample_rate: f32, ms: f32) -> u32 { ((ms * sample_rate) / 1000.) as u32 }
+const fn ms_to_samples(sample_rate: f32, ms: f32) -> u32 { ((ms * sample_rate) / 1000.) as u32 }
 
 #[inline(always)]
 fn sample_to_y_val(sample: f32, half_height: f32, max_distance_from_0: f32) -> u32 {

engine/wavetable/src/fm/mod.rs

@@ -2699,7 +2699,8 @@ pub extern "C" fn fm_synth_get_wavetable_data_ptr(
     ctx.wavetables[wavetable_ix] = new_wavetable;
   } else if ctx.wavetables.len() != wavetable_ix {
     panic!(
-      "Tried to set wavetable index {} but only {} wavetables exist",
+      "Tried to set wavetable index {} but only {} wavetables exist.  Wavetable bank indices are \
+       managed by the JS code in `FmSynth.tsx`; it's not our fault!",
       wavetable_ix,
       ctx.wavetables.len()
     );

engine/wavetable/src/lib.rs

@@ -1,4 +1,4 @@
-#![feature(const_maybe_uninit_assume_init, get_mut_unchecked)]
+#![feature(get_mut_unchecked)]
 
 pub mod fm;
 

faust-compiler/FaustWorkletModuleTemplate.template.js

@@ -274,11 +274,7 @@ class FaustAudioWorkletProcessor extends AudioWorkletProcessor {
     for (let i = 0; i < Math.min(outputs.length, this.dspOutChannels.length); i++) {
       const dspOutput = this.dspOutChannels[i];
       for (let channelIx = 0; channelIx < outputs[i].length; channelIx++) {
-        // If we send NaNs or out-of-range values, computer gets very upset and destroys
-        // my entire system audio on Linux until I shut down this AWP.
-        for (let sampleIx = 0; sampleIx < outputs[i][channelIx].length; sampleIx++) {
-          outputs[i][channelIx][sampleIx] = clamp(-1.0, 1.0, dspOutput[sampleIx]);
-        }
+        outputs[i][channelIx].set(dspOutput);
       }
     }
 

src/graphEditor/nodes/CustomAudio/FMSynth/FMSynth.tsx

@@ -466,6 +466,7 @@ export default class FMSynth implements ForeignNode {
       samples: bank.samples,
     };
     if (
+      this.lastSetWavetableData.wavetableIx === setWavetableData.wavetableIx &&
       this.lastSetWavetableData.baseFrequency === setWavetableData.baseFrequency &&
       this.lastSetWavetableData.waveformsPerDimension === setWavetableData.waveformsPerDimension &&
       this.lastSetWavetableData.waveformLength === setWavetableData.waveformLength &&