A proof-of-concept JUCE 8 plugin (VST3 / AU / Standalone, macOS) that renders Prism's Spectrum scope inside a DAW. It reuses Prism's existing C++ DSP (native/src/spectrum.cpp, dsp_utils.cpp) and the existing React canvas UI (src/plugin-ui, which imports src/renderer/visualizers/SpectrumAnalyzer.ts).

How it fits together

DAW track audio
  → processBlock (RT thread): mix to mono, write to lock-free FIFO     [Source/PluginProcessor.cpp]
  → 60 Hz timer (message thread): drain FIFO → Visualizer::Spectrum    [Source/PluginEditor.cpp + native/src/spectrum.cpp]
  → emit "spectrumFrame" (base64 Float32 magnitudes) to the webview
  → juceBridge.ts decodes → BridgeSpectrumAnalyzer (a SpectrumNativeAnalyzer shim)
  → SpectrumAnalyzer.ts renders to canvas (unchanged Electron code)    [src/plugin-ui]

No DSP or allocation runs on the realtime audio thread; audio passes through unmodified.

Build & run (macOS)

Prereqs: CMake ≥ 3.22, Xcode command-line tools, Node.

Default: self-contained build (embedded UI)

The UI is bundled into the plugin binary and served via JUCE's resource provider — no dev server needed at runtime.

npm run plugin-ui:build                                   # build the webview bundle → plugin/webview-dist
cmake -B plugin/build -S plugin -DCMAKE_BUILD_TYPE=Release # embeds the bundle (reconfigure to pick up UI changes)
cmake --build plugin/build --config Release

COPY_PLUGIN_AFTER_BUILD installs into your user plugin folders:

AU: ~/Library/Audio/Plug-Ins/Components/Prism Spectrum.component
VST3: ~/Library/Audio/Plug-Ins/VST3/Prism Spectrum.vst3

Run the Standalone (plugin/build/.../Standalone/Prism Spectrum.app) or load the VST3/AU on a track in Ableton / FL / Logic / Reaper, play audio, and the spectrum animates. (To use a local JUCE checkout instead of fetching: add -DJUCE_PATH=/path/to/JUCE.)

UI development: dev-server mode (hot reload)

npm run plugin-ui:dev                                      # serve UI on :5174 with HMR
cmake -B plugin/build -S plugin -DPRISM_DEV_SERVER=ON      # editor loads http://localhost:5174
cmake --build plugin/build --config Release

Edit React → the plugin window hot-reloads. The UI also runs in a plain browser at http://localhost:5174 (no JUCE host → it shows a synthetic spectrum so the UI is developable outside a DAW). Reconfigure without -DPRISM_DEV_SERVER=ON to go back to embedded.

Notes

Refresh rate (macOS): frames are emitted on juce::VBlankAttachment (synced to the display, adapts to 60/120/144 Hz) and the webview renders via the display-sync FrameScheduler. WKWebView otherwise throttles requestAnimationFrame to 60 fps regardless of display — Source/WebViewFrameRate.mm lifts that by disabling WebKit's private PreferPageRenderingUpdatesNear60FPSEnabled feature on the live web view (no public API exists; fine for a non-App-Store FOSS plugin). To diagnose, set showFpsMeter on <SpectrumScope/> to overlay render / data fps.
Windows (later): bump NEEDS_WEBVIEW2 TRUE; the DSP is already cross-platform. The frame-rate workaround is macOS-only (WebView2 has its own rate behavior).