From ecb5bf2bb6058b785ae7732fe1a05598bd951ca1 Mon Sep 17 00:00:00 2001
From: monkey-w1n5t0n <w1n5t0n@lnfinitemonkeys.org>
Date: Sun, 28 Jun 2026 04:22:05 +0200
Subject: [PATCH] feat(backends): register VcvBackend in manager + roster; add
 defaultVcvSpec, feedback forwarding, input-vector streaming

---
 manifold/src/backends/index.ts    |  2 ++
 manifold/src/backends/manager.ts  | 35 +++++++++++++++++++++++++++++--
 manifold/src/dock/output-state.ts |  5 +++++
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/manifold/src/backends/index.ts b/manifold/src/backends/index.ts
index a0bea84..ca2431c 100644
--- a/manifold/src/backends/index.ts
+++ b/manifold/src/backends/index.ts
@@ -16,6 +16,8 @@ export { WebMidiBackend } from './midi-backend';
 export type { MidiBackendConfig } from './midi-backend';
 export { OscBridgeBackend } from './osc-backend';
 export type { OscBackendConfig } from './osc-backend';
+export { VcvBackend } from './vcv-backend';
+export type { VcvBackendConfig, VcvFeedbackOp } from './vcv-backend';
 export { NispsOscClient } from './osc-client';
 export { PassthroughBackend } from './passthrough-backend';
 export {
diff --git a/manifold/src/backends/manager.ts b/manifold/src/backends/manager.ts
index 4afe0c2..4112258 100644
--- a/manifold/src/backends/manager.ts
+++ b/manifold/src/backends/manager.ts
@@ -21,12 +21,19 @@ import type { BackendId } from '../dock/output-state';
 import { WebMidiBackend } from './midi-backend';
 import { OscBridgeBackend } from './osc-backend';
 import { PassthroughBackend } from './passthrough-backend';
+import { VcvBackend, type VcvFeedbackOp } from './vcv-backend';
 
 /** The slice of EngineApi the manager depends on (keeps it decoupled/testable). */
 export interface ManagerEngine {
   subscribe(cb: () => void): () => void;
   routedOutput(): Float32Array | null;
   audio: { setMuted(muted: boolean): void };
+  /**
+   * Current control input vector (2-D for the fixed 2→N MLP). Optional — when
+   * present the VCV backend streams it to the module so the browser drives the
+   * module's inputs in bridged mode.
+   */
+  inputVector?(): ReadonlyArray<number>;
 }
 
 export class BackendManager {
@@ -49,12 +56,17 @@ export class BackendManager {
       ['synth', backends?.synth ?? new PassthroughBackend('synth', 'Built-in Synth — audio plays in the engine')],
       ['particles', backends?.particles ?? new PassthroughBackend('particles', 'Particle visualiser')],
       ['cvgate', backends?.cvgate ?? new PassthroughBackend('cvgate', 'CV / gate (via VCV bridge)')],
-      ['vcv', backends?.vcv ?? new PassthroughBackend('vcv', 'VCV bridge')],
+      ['vcv', backends?.vcv ?? new VcvBackend()],
     ]);
 
-    // Single subscription to the spine: forward routed → active backend.
+    // Single subscription to the spine: forward routed → active backend. For the
+    // VCV backend we also stream the current input vector each tick so the
+    // browser drives the module's inputs in bridged mode.
     this.unsub = this.engine.subscribe(() => {
       if (!this.active) return;
+      if (this.active instanceof VcvBackend && this.engine.inputVector) {
+        this.active.setInputVector(this.engine.inputVector());
+      }
       const routed = this.engine.routedOutput();
       if (routed) this.active.send(routed);
     });
@@ -71,6 +83,25 @@ export class BackendManager {
     return b instanceof OscBridgeBackend ? b : null;
   }
 
+  vcv(): VcvBackend | null {
+    const b = this.backends.get('vcv');
+    return b instanceof VcvBackend ? b : null;
+  }
+
+  /**
+   * Forward a verdict op to the VCV module's embedded learner over the bridge.
+   * No-op unless the VCV backend is the ACTIVE one — the verdict loop only
+   * trains the module when Mode = VCV (otherwise the browser engine is the
+   * learner). Returns true if it was forwarded.
+   */
+  forwardFeedback(op: VcvFeedbackOp): boolean {
+    if (this.activeId !== 'vcv') return false;
+    const vcv = this.vcv();
+    if (!vcv) return false;
+    vcv.sendFeedback(op);
+    return true;
+  }
+
   get(id: BackendId): OutputBackend | undefined {
     return this.backends.get(id);
   }
diff --git a/manifold/src/dock/output-state.ts b/manifold/src/dock/output-state.ts
index 52c912d..b240a97 100644
--- a/manifold/src/dock/output-state.ts
+++ b/manifold/src/dock/output-state.ts
@@ -130,3 +130,8 @@ export function defaultMidiSpec(index: number): MidiCcSpec {
 export function defaultOscSpec(name: string): OscSpec {
   return { path: `/nisps/${name.toLowerCase()}`, rangeMin: 0, rangeMax: 1 };
 }
+
+/** Default VCV spec for an output — unipolar 0–10 V by default. */
+export function defaultVcvSpec(): VcvSpec {
+  return { bipolar: false };
+}