From e000e30fcabdd18bbd5d5bcf8555351706d124d7 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sun, 2 Aug 2026 13:37:17 +0000
Subject: [PATCH] feat(web-synth): add Phase Inversion, Filter Bypass, DC
 Offset, and fix Reverb Mix

- Fixed Reverb Mix param wiring in store.ts
- Implemented Phase Inversion toggle in GainNode with UI
- Implemented true bypass mode for FilterNode using dry/wet gains with UI
- Added new DC Offset node and integrated it into the app
- Updated JOURNAL.md with new tasks and marked completed ones

Co-authored-by: kkd16 <112675076+kkd16@users.noreply.github.com>
---
 projects/web-synth-9x1a/JOURNAL.md            | 14 +++++
 projects/web-synth-9x1a/src/App.tsx           |  5 ++
 .../src/audio/nodes/processors.ts             | 62 ++++++++++++++++---
 .../web-synth-9x1a/src/audio/nodes/sources.ts | 14 +++++
 .../src/components/nodes/DcOffsetNode.tsx     | 38 ++++++++++++
 .../src/components/nodes/FilterNode.tsx       |  9 +++
 .../src/components/nodes/GainNode.tsx         |  9 +++
 projects/web-synth-9x1a/src/store.ts          | 11 +++-
 8 files changed, 152 insertions(+), 10 deletions(-)
 create mode 100644 projects/web-synth-9x1a/src/components/nodes/DcOffsetNode.tsx

diff --git a/projects/web-synth-9x1a/JOURNAL.md b/projects/web-synth-9x1a/JOURNAL.md
index 097010ba..d8f70d14 100644
--- a/projects/web-synth-9x1a/JOURNAL.md
+++ b/projects/web-synth-9x1a/JOURNAL.md
@@ -90,3 +90,17 @@
 - [ ] Add Volume meter to Output Node
 - [ ] Implement node collapsing/folding
 - [x] Add a "Reset to Default" button on nodes
+
+## Expansion Phase 8 (New Improvements)
+- [x] Fix Reverb Node Mix control wiring in store
+- [ ] Fix AudioCore to support separate input and output nodes for complex effects
+- [ ] Add Dry/Wet mix control to Delay Node
+- [x] Add Phase Inversion toggle to Gain Node
+- [x] Implement Node Bypassing for Filter Node
+- [ ] Add a Clipping Indicator to Output Node
+- [x] Add a DC Offset Node
+- [ ] Implement auto-pan LFO sync in Panning Node
+- [ ] Add an Invert Phase option to Oscillator Node
+- [ ] Add a "Randomize Parameters" button to node UIs
+- [ ] Implement Node Bypassing for Delay Node
+- [ ] Add a Drive/Saturation parameter to the Filter Node
diff --git a/projects/web-synth-9x1a/src/App.tsx b/projects/web-synth-9x1a/src/App.tsx
index 53e77aec..40a88f54 100644
--- a/projects/web-synth-9x1a/src/App.tsx
+++ b/projects/web-synth-9x1a/src/App.tsx
@@ -17,6 +17,7 @@ import { ReverbNode } from './components/nodes/ReverbNode';
 import { AnalyserNode } from './components/nodes/AnalyserNode';
 import { OutputNode } from './components/nodes/OutputNode';
 import { AdsrNode } from './components/nodes/AdsrNode';
+import { DcOffsetNode } from './components/nodes/DcOffsetNode';
 import { ChorusNode } from './components/nodes/ChorusNode';
 import { Settings, Waves, Sliders, AudioWaveform, Activity, MonitorPlay, X } from 'lucide-react';
 import { useState } from 'react';
@@ -37,6 +38,7 @@ const nodeTypes = {
   reverbNode: ReverbNode,
   analyserNode: AnalyserNode,
   adsrNode: AdsrNode,
+  dcOffsetNode: DcOffsetNode,
   chorusNode: ChorusNode,
   outputNode: OutputNode,
 };
@@ -71,6 +73,9 @@ export default function App() {
               <Waves size={18} className="mb-1 text-gray-400" />
               Noise
             </button>
+            <button onClick={() => handleAddNode('dcOffsetNode')} className="flex flex-col items-center justify-center p-3 bg-gray-700 hover:bg-gray-600 rounded-lg text-xs transition-colors">
+              DC Offset
+            </button>
             <button onClick={() => handleAddNode('lfoNode')} className="flex flex-col items-center justify-center p-3 bg-gray-700 hover:bg-gray-600 rounded-lg text-xs transition-colors col-span-2">
               <Activity size={18} className="mb-1 text-blue-400" />
               LFO
diff --git a/projects/web-synth-9x1a/src/audio/nodes/processors.ts b/projects/web-synth-9x1a/src/audio/nodes/processors.ts
index cec351a6..d985e61a 100644
--- a/projects/web-synth-9x1a/src/audio/nodes/processors.ts
+++ b/projects/web-synth-9x1a/src/audio/nodes/processors.ts
@@ -4,6 +4,7 @@ export class GainWrapper {
   public node: GainNode;
   private currentGain: number = 0.5;
   private isMuted: boolean = false;
+  private invertPhase: boolean = false;
 
   constructor(id: string) {
     const ctx = audioCore.getContext();
@@ -14,20 +15,24 @@ export class GainWrapper {
     audioCore.registerParam(`${id}.gain`, this.node.gain);
   }
 
+  public setInvertPhase(invert: boolean) {
+    this.invertPhase = invert;
+    this.applyGain();
+  }
+
   public setGain(value: number) {
     this.currentGain = value;
-    if (!this.isMuted) {
-      this.node.gain.setValueAtTime(value, audioCore.getContext().currentTime);
-    }
+    this.applyGain();
   }
 
   public setMute(mute: boolean) {
     this.isMuted = mute;
-    if (this.isMuted) {
-      this.node.gain.setValueAtTime(0, audioCore.getContext().currentTime);
-    } else {
-      this.node.gain.setValueAtTime(this.currentGain, audioCore.getContext().currentTime);
-    }
+    this.applyGain();
+  }
+
+  private applyGain() {
+    const val = this.isMuted ? 0 : (this.invertPhase ? -this.currentGain : this.currentGain);
+    this.node.gain.setValueAtTime(val, audioCore.getContext().currentTime);
   }
 
   public destroy(id: string) {
@@ -37,16 +42,45 @@ export class GainWrapper {
 }
 
 export class FilterWrapper {
+  public inputNode: GainNode;
   public node: BiquadFilterNode;
+  public dryGain: GainNode;
+  public wetGain: GainNode;
+  public outputNode: GainNode;
 
   constructor(id: string) {
     const ctx = audioCore.getContext();
+
+    this.inputNode = ctx.createGain();
     this.node = ctx.createBiquadFilter();
     this.node.type = 'lowpass';
     this.node.frequency.value = 1000;
     this.node.Q.value = 1;
+    this.dryGain = ctx.createGain();
+    this.dryGain.gain.value = 0;
+    this.wetGain = ctx.createGain();
+    this.wetGain.gain.value = 1;
+    this.outputNode = ctx.createGain();
 
-    audioCore.registerNode(id, this.node);
+    this.inputNode.connect(this.node);
+    this.inputNode.connect(this.dryGain);
+    this.node.connect(this.wetGain);
+    this.dryGain.connect(this.outputNode);
+    this.wetGain.connect(this.outputNode);
+
+    (this.inputNode as any).connect = (dest: any, output?: number, input?: number) => {
+      if (output !== undefined && input !== undefined) return this.outputNode.connect(dest, output, input);
+      if (output !== undefined) return this.outputNode.connect(dest, output);
+      return this.outputNode.connect(dest);
+    };
+    (this.inputNode as any).disconnect = (dest?: any, output?: number, input?: number) => {
+      if (dest && output !== undefined && input !== undefined) return this.outputNode.disconnect(dest, output, input);
+      if (dest && output !== undefined) return this.outputNode.disconnect(dest, output);
+      if (dest) return this.outputNode.disconnect(dest);
+      return this.outputNode.disconnect();
+    };
+
+    audioCore.registerNode(id, this.inputNode);
     audioCore.registerParam(`${id}.frequency`, this.node.frequency);
     audioCore.registerParam(`${id}.Q`, this.node.Q);
   }
@@ -63,7 +97,17 @@ export class FilterWrapper {
     this.node.Q.setValueAtTime(q, audioCore.getContext().currentTime);
   }
 
+  public setBypass(bypass: boolean) {
+    this.dryGain.gain.value = bypass ? 1 : 0;
+    this.wetGain.gain.value = bypass ? 0 : 1;
+  }
+
   public destroy(id: string) {
+    this.inputNode.disconnect();
+    this.node.disconnect();
+    this.dryGain.disconnect();
+    this.wetGain.disconnect();
+    this.outputNode.disconnect();
     audioCore.unregisterNode(id);
     audioCore.unregisterParam(`${id}.frequency`);
     audioCore.unregisterParam(`${id}.Q`);
diff --git a/projects/web-synth-9x1a/src/audio/nodes/sources.ts b/projects/web-synth-9x1a/src/audio/nodes/sources.ts
index efc60f28..098d905e 100644
--- a/projects/web-synth-9x1a/src/audio/nodes/sources.ts
+++ b/projects/web-synth-9x1a/src/audio/nodes/sources.ts
@@ -161,3 +161,17 @@ export class LfoWrapper {
     audioCore.unregisterParam(`${id}.depth`);
   }
 }
+
+export class DcOffsetWrapper {
+  public node: ConstantSourceNode;
+  constructor(id: string) {
+    const ctx = audioCore.getContext();
+    this.node = ctx.createConstantSource();
+    this.node.offset.value = 0;
+    this.node.start();
+    audioCore.registerNode(id, this.node);
+    audioCore.registerParam(`${id}.offset`, this.node.offset);
+  }
+  public setOffset(v: number) { this.node.offset.setValueAtTime(v, audioCore.getContext().currentTime); }
+  public destroy(id: string) { this.node.stop(); audioCore.unregisterNode(id); audioCore.unregisterParam(`${id}.offset`); }
+}
diff --git a/projects/web-synth-9x1a/src/components/nodes/DcOffsetNode.tsx b/projects/web-synth-9x1a/src/components/nodes/DcOffsetNode.tsx
new file mode 100644
index 00000000..603f4ab5
--- /dev/null
+++ b/projects/web-synth-9x1a/src/components/nodes/DcOffsetNode.tsx
@@ -0,0 +1,38 @@
+import { X } from 'lucide-react';
+import { Handle, Position } from '@xyflow/react';
+import { useStore } from '../../store';
+
+export function DcOffsetNode({ id, data }: { id: string, data: Record<string, any> }) {
+  const updateNodeData = useStore((state) => state.updateNodeData);
+  const removeNode = useStore((state) => state.removeNode);
+
+  return (
+    <div style={data.color ? { borderColor: data.color } : {}} className="bg-gray-800 border border-gray-700 rounded-md p-3 min-w-[150px] shadow-lg">
+      <div className="flex justify-between items-center mb-2 border-b border-gray-600 pb-1">
+        <div className="flex items-center">
+          <input
+            value={data.label || 'DC Offset'}
+            onChange={(e) => updateNodeData(id, { label: e.target.value })}
+            className={`bg-transparent outline-none w-24 text-sm font-bold ${data.color ? '' : 'text-gray-400'}`}
+            style={data.color ? { color: data.color } : {}}
+          />
+          <input
+            type="color"
+            value={data.color || '#ffffff'}
+            onChange={(e) => updateNodeData(id, { color: e.target.value })}
+            className="w-4 h-4 p-0 border-0 bg-transparent cursor-pointer ml-2 opacity-50 hover:opacity-100"
+            title="Custom Color"
+          />
+        </div>
+        <button onClick={() => removeNode(id)} className="text-gray-500 hover:text-red-400"><X size={14} /></button>
+      </div>
+      <div className="flex flex-col gap-2">
+        <label className="text-xs text-gray-300 flex flex-col">
+          Offset: {data.offset !== undefined ? data.offset.toFixed(2) : '0.00'}
+          <input type="range" min="-1" max="1" step="0.01" value={data.offset || 0} onChange={(e) => updateNodeData(id, { offset: Number(e.target.value) })} className="mt-1" />
+        </label>
+      </div>
+      <Handle type="source" position={Position.Right} id="out" className="w-3 h-3 bg-gray-500" />
+    </div>
+  );
+}
diff --git a/projects/web-synth-9x1a/src/components/nodes/FilterNode.tsx b/projects/web-synth-9x1a/src/components/nodes/FilterNode.tsx
index 775d431c..4b065af3 100644
--- a/projects/web-synth-9x1a/src/components/nodes/FilterNode.tsx
+++ b/projects/web-synth-9x1a/src/components/nodes/FilterNode.tsx
@@ -28,6 +28,15 @@ export function FilterNode({ id, data }: { id: string, data: Record<string, any>
       </div>
 
       <div className="flex flex-col gap-2">
+        <label className="text-xs text-gray-300 flex items-center justify-between mb-1">
+          Bypass
+          <input
+            type="checkbox"
+            checked={data.bypass || false}
+            onChange={(e) => updateNodeData(id, { bypass: e.target.checked })}
+            className="ml-2 accent-orange-500"
+          />
+        </label>
         <label className="text-xs text-gray-300 flex flex-col">
           Type
           <select
diff --git a/projects/web-synth-9x1a/src/components/nodes/GainNode.tsx b/projects/web-synth-9x1a/src/components/nodes/GainNode.tsx
index 9b5a297c..ccb14616 100644
--- a/projects/web-synth-9x1a/src/components/nodes/GainNode.tsx
+++ b/projects/web-synth-9x1a/src/components/nodes/GainNode.tsx
@@ -37,6 +37,15 @@ export function GainNode({ id, data }: { id: string, data: Record<string, any> }
             className="ml-2 accent-green-500"
           />
         </label>
+        <label className="text-xs text-gray-300 flex items-center justify-between mb-1">
+          Invert Phase
+          <input
+            type="checkbox"
+            checked={data.invertPhase || false}
+            onChange={(e) => updateNodeData(id, { invertPhase: e.target.checked })}
+            className="ml-2 accent-green-500"
+          />
+        </label>
         <label className="text-xs text-gray-300 flex flex-col">
           Level: {data.gain !== undefined ? data.gain.toFixed(2) : '0.50'}
           <input
diff --git a/projects/web-synth-9x1a/src/store.ts b/projects/web-synth-9x1a/src/store.ts
index e2b4e948..63bb4b24 100644
--- a/projects/web-synth-9x1a/src/store.ts
+++ b/projects/web-synth-9x1a/src/store.ts
@@ -16,7 +16,7 @@ import {
 } from '@xyflow/react';
 
 import { audioCore } from './audio/core';
-import { OscillatorWrapper, NoiseWrapper, LfoWrapper } from './audio/nodes/sources';
+import { OscillatorWrapper, NoiseWrapper, LfoWrapper, DcOffsetWrapper } from './audio/nodes/sources';
 import { GainWrapper, FilterWrapper, DelayWrapper, ReverbWrapper, PanningWrapper, DistortionWrapper, CompressorWrapper, ChorusWrapper, BitcrusherWrapper, TremoloWrapper, RingModulatorWrapper } from './audio/nodes/processors';
 import { AnalyserWrapper } from './audio/nodes/visualizers';
 import { AdsrWrapper } from './audio/nodes/control';
@@ -119,6 +119,10 @@ export const useStore = create<AppState>((set, get) => ({
       case 'noiseNode':
         wrapper = new NoiseWrapper(id);
         break;
+      case 'dcOffsetNode':
+        wrapper = new DcOffsetWrapper(id);
+        initialData = { offset: 0 };
+        break;
       case 'adsrNode':
         wrapper = new AdsrWrapper(id);
         initialData = { attack: 0.1, decay: 0.1, sustain: 0.5, release: 0.3 };
@@ -235,9 +239,12 @@ export const useStore = create<AppState>((set, get) => ({
 
     } else if (wrapper instanceof NoiseWrapper) {
       if (data.type !== undefined) wrapper.setType(data.type);
+    } else if (wrapper instanceof DcOffsetWrapper) {
+      if (data.offset !== undefined) wrapper.setOffset(data.offset);
     } else if (wrapper instanceof GainWrapper) {
       if (data.gain !== undefined) wrapper.setGain(data.gain);
       if (data.muted !== undefined) wrapper.setMute(data.muted);
+      if (data.invertPhase !== undefined) wrapper.setInvertPhase(data.invertPhase);
     } else if (wrapper instanceof CompressorWrapper) {
       if (data.threshold !== undefined) wrapper.setThreshold(data.threshold);
       if (data.knee !== undefined) wrapper.setKnee(data.knee);
@@ -252,6 +259,7 @@ export const useStore = create<AppState>((set, get) => ({
       if (data.frequency !== undefined) wrapper.setFrequency(data.frequency);
       if (data.Q !== undefined) wrapper.setQ(data.Q);
       if (data.type !== undefined) wrapper.setType(data.type);
+      if (data.bypass !== undefined) wrapper.setBypass(data.bypass);
     } else if (wrapper instanceof BitcrusherWrapper) {
       if (data.bits !== undefined) wrapper.setBitDepth(data.bits);
     } else if (wrapper instanceof TremoloWrapper) {
@@ -265,6 +273,7 @@ export const useStore = create<AppState>((set, get) => ({
       if (data.feedback !== undefined) wrapper.setFeedback(data.feedback);
     } else if (wrapper instanceof ReverbWrapper) {
 
+      if (data.mix !== undefined) wrapper.setMix(data.mix);
       if (data.decay !== undefined) wrapper.setDecay(data.decay);
     }
   },