native macos backend, reduce latency

src/preload/index.ts

@@ -1,5 +1,9 @@
 import { contextBridge, ipcRenderer } from 'electron'
-import type { CaptureBackendSupport } from '../types/capture'
+import type { CaptureBackendSupport, CaptureBackendSupportEntry } from '../types/capture'
+import type { NativeCaptureAPI } from '../types/nativeCapture'
+import type { VisualizerDSP } from '../renderer/audio/native/visualizer-dsp'
+
+type NativeAddonModule = VisualizerDSP & NativeCaptureAPI
 
 // Expose Electron API to renderer
 contextBridge.exposeInMainWorld('electronAPI', {
@@ -9,7 +13,13 @@ contextBridge.exposeInMainWorld('electronAPI', {
   toggleAlwaysOnTop: () => ipcRenderer.send('window:toggle-always-on-top'),
   isAlwaysOnTop: () => ipcRenderer.invoke('window:is-always-on-top'),
   getDesktopSources: () => ipcRenderer.invoke('audio:get-desktop-sources') as Promise<{ id: string; name: string }[]>,
-  getCaptureBackendSupport: () => ipcRenderer.invoke('capture:get-backend-support') as Promise<CaptureBackendSupport>,
+  getCaptureBackendSupport: async () => {
+    const support = await ipcRenderer.invoke('capture:get-backend-support') as CaptureBackendSupport
+    return {
+      ...support,
+      nativeBackend: resolveNativeCaptureSupport(support.nativeBackend),
+    } satisfies CaptureBackendSupport
+  },
   expandSettings: (panelHeight: number) => ipcRenderer.send('window:expand-settings', panelHeight),
   collapseSettings: (panelHeight: number) => ipcRenderer.send('window:collapse-settings', panelHeight),
   setSettingsHeight: (panelHeight: number) => ipcRenderer.send('window:set-settings-height', panelHeight),
@@ -36,15 +46,54 @@ contextBridge.exposeInMainWorld('electronAPI', {
 })
 
 // Native DSP module — load if available, gracefully degrade if not
-let visualizerDSP: unknown = null
+let nativeAddonModule: NativeAddonModule | null = null
 try {
   const isDev = process.env.NODE_ENV === 'development'
   const modulePath = isDev
     ? require('path').join(__dirname, '../../native/build/Release/visualizer_dsp.node')
     : require('path').join(process.resourcesPath!, 'native/visualizer_dsp.node')
-  visualizerDSP = require(modulePath)
+  nativeAddonModule = require(modulePath) as NativeAddonModule
 } catch {
   console.warn('Native DSP module not available — using JS fallback')
 }
 
-contextBridge.exposeInMainWorld('visualizerAPI', visualizerDSP)
+function resolveNativeCaptureSupport(
+  fallbackEntry: CaptureBackendSupportEntry,
+): CaptureBackendSupportEntry {
+  if (process.platform !== 'darwin') {
+    return fallbackEntry
+  }
+
+  const macosCapture = nativeAddonModule?.macosCapture
+  if (!macosCapture) {
+    return {
+      kind: 'native-macos',
+      available: false,
+      reason: 'Native capture module is not available in this build.',
+    }
+  }
+
+  const support = macosCapture.getSupport()
+  return {
+    kind: 'native-macos',
+    available: support.available,
+    reason: support.reason,
+  }
+}
+
+const visualizerAPI = nativeAddonModule
+  ? {
+      oscilloscope: nativeAddonModule.oscilloscope,
+      spectrum: nativeAddonModule.spectrum,
+      vectorscope: nativeAddonModule.vectorscope,
+    }
+  : null
+
+const nativeCaptureAPI = nativeAddonModule
+  ? {
+      macosCapture: nativeAddonModule.macosCapture,
+    }
+  : null
+
+contextBridge.exposeInMainWorld('visualizerAPI', visualizerAPI)
+contextBridge.exposeInMainWorld('nativeCaptureAPI', nativeCaptureAPI)