Fix iOS Safari audio silence by unlocking Web Audio during power button gesture

experiments/clarinet-synth/src/audio/ClarinetProcessor.js

@@ -18,7 +18,7 @@ export class ClarinetProcessor {
     async initialize() {
         console.log(`ClarinetProcessor.initialize()`)
         this.audioContext = new (window.AudioContext || window.webkitAudioContext)();
-        this._installIOSUnlock(this.audioContext);
+        await this._installIOSUnlock(this.audioContext);
 
         // Create gain node for volume control
         this.gainNode = this.audioContext.createGain();
@@ -80,7 +80,7 @@ export class ClarinetProcessor {
         }
     }
 
-    _installIOSUnlock(ctx) {
+    async _installIOSUnlock(ctx) {
         if (!ctx) return;
         let unlocked = ctx.state === 'running';
         const cleanup = () => {
@@ -110,6 +110,9 @@ export class ClarinetProcessor {
         document.addEventListener('touchstart', unlock, { capture: true, passive: true });
         document.addEventListener('keydown', unlock, { capture: true });
         ctx.onstatechange = () => console.log('[audio] state:', ctx.state);
+
+        // Try to unlock immediately if we're in a user gesture
+        await unlock();
     }
 
     noteOff() {

experiments/clarinet-synth/vite.config.js

@@ -16,7 +16,6 @@ export default defineConfig({
           return 'assets/[name]-[hash][extname]';
         }
       }
-    },
-    watch: {},
+    }
   }
 })

www/clarinet-synth/assets/clarinet-worklet-TGdX5pU9.js → www/clarinet-synth/assets/clarinet-worklet-BBK06oMB.js

@@ -1,6 +1,8 @@
 // clarinet-worklet.js
 // AudioWorklet processor for the clarinet engine
 
+const sampleRate = globalThis.sampleRate;
+
 class ClarinetWorkletProcessor extends AudioWorkletProcessor {
     constructor() {
         super();
@@ -73,12 +75,15 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
         if (scaled < -3) return -1;
 
         const x2 = scaled * scaled;
-        return scaled * (27 + x2) / (27 + 9 * x2);
+        const result = scaled * (27 + x2) / (27 + 9 * x2);
+        console.log(`[ClarinetWorkletProcessor] reedReflection: pressureDiff=${pressureDiff.toFixed(4)}, scaled=${scaled.toFixed(4)}, result=${result.toFixed(4)}`);
+        return result;
     }
 
     lowpass(input, cutoff) {
         const a = cutoff;
         this.lpf.y1 = a * input + (1 - a) * this.lpf.y1;
+        console.log(`[ClarinetWorkletProcessor] lowpass: input=${input.toFixed(4)}, cutoff=${cutoff.toFixed(4)}, output=${this.lpf.y1.toFixed(4)}`);
         return this.lpf.y1;
     }
 
@@ -103,11 +108,11 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
 
     updateEnvelope(deltaTime) {
         if (this.gate) {
-            const attackRate = 1.0 / (this.attackTime * this.sampleRate);
+            const attackRate = 1.0 / this.attackTime;
             this.envelope += attackRate * deltaTime;
             if (this.envelope > 1) this.envelope = 1;
         } else {
-            const releaseRate = 1.0 / (this.releaseTime * this.sampleRate);
+            const releaseRate = 1.0 / this.releaseTime;
             this.envelope -= releaseRate * deltaTime;
             if (this.envelope < 0) {
                 this.envelope = 0;
@@ -166,10 +171,11 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
         this.delayLine[this.writePos] = newSample;
         this.writePos = (this.writePos + 1) % this.delayLength;
 
-        return newSample * env * 0.5;
+        return newSample * env * 1.0;
     }
 
     noteOn(frequency) {
+        console.log(`[ClarinetWorkletProcessor] noteOn: ${frequency}`);
         this.setFrequency(frequency);
         this.gate = true;
         this.isPlaying = true;
@@ -187,6 +193,7 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
     }
 
     setParameter(param, value) {
+        console.log(`[ClarinetWorkletProcessor] setParameter: ${param}, ${value}`);
         switch(param) {
             case 'breath':
                 this.breathPressure = value * 0.8 + 0.2;
@@ -207,7 +214,7 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
                 this.lpf.cutoff = 0.3 + value * 0.69;
                 break;
             case 'brightness':
-                this.hpf.cutoff = value * 0.05;
+                this.hpf.cutoff = value * 0.5;
                 break;
             case 'vibrato':
                 this.vibratoAmount = value * 0.01;
@@ -223,6 +230,10 @@ class ClarinetWorkletProcessor extends AudioWorkletProcessor {
             channel[i] = this.processSample();
         }
 
+        if (this.isPlaying) {
+            console.log(`[ClarinetWorkletProcessor] process: output[0] = ${channel[0]}`);
+        }
+
         return true; // Keep processor alive
     }
 }