NINEIGHT - OPNA (YM2608) FM Synth VST v0.1.0(Beta)

C++ port of the NINEIGHT web app "NINEIGHT" as VST3 / AU / Standalone (JUCE 8).

• Audio: native ymfm::ym2608 — the same emulator the web app compiles to WASM. Register packing, voice allocation, resampler and rhythm-ROM init are line-for-line ports of @opna/core, so the plugin sounds identical.
• UI: the actual Phaser 3 web UI (PC-98 CRT aesthetic) embedded via JUCE 8 WebBrowserComponent, talking to the native engine over a JS↔C++ bridge (window.__JUCE__).
• 52 host-automatable parameters (algorithm, feedback, LFO, gain, pan, poly, 4 ops × 11); state = APVTS XML.

Build (Linux)

cmake -B build -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_C_COMPILER=clang-12 -DCMAKE_CXX_COMPILER=clang++-12   # gcc 9 breaks on JUCE 8 harfbuzz
cmake --build build --parallel

Outputs land in build/Nineight_artefacts/Release/{VST3,Standalone} and are copied to ~/.vst3.

Deps: libwebkit2gtk-4.0-dev + usual JUCE X11/ALSA packages.

Build (macOS — VST3 + AU + Standalone)

Requires Xcode (or Command Line Tools) and CMake ≥ 3.22. The FORMATS line i CMakeLists adds AU automatically on Darwin. The UI uses the system WKWebView — no extra dependencies.

# clone with submodules (JUCE)
git clone --recurse-submodules <repo-url> && cd nin8

# universal binary (Apple Silicon + Intel)
cmake -B build -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64"
cmake --build build --parallel

Outputs: build/Nineight_artefacts/Release/{VST3,AU,Standalone}; JUCE copies them to ~/Library/Audio/Plug-Ins/VST3 and ~/Library/Audio/Plug-Ins/Components. The AU only shows up in Logic/GarageBand after a plugin rescan; validate with:

auval -v aumu Opna Nin8

Note: unsigned builds may need Gatekeeper quarantine removed on other machines (xattr -dr com.apple.quarantine <plugin>), or proper codesign/notarization for distribution.

Build (Windows — VST3 + Standalone)

Requires Visual Studio 2022 (Desktop C++ workload), CMake, and git (the configure step applies the JUCE webview patch with git apply).

git clone --recurse-submodules <repo-url>
cd nin8
cmake -B build -G "Visual Studio 17 2022" -A x64
cmake --build build --config Release --parallel

Outputs: build/Nineight_artefacts/Release/{VST3,Standalone}; the VST3 is copied to %COMMONPROGRAMFILES%\VST3 (may need an elevated shell, or set COPY_PLUGIN_AFTER_BUILD FALSE and copy manually).

The UI needs the WebView2 Evergreen Runtime — preinstalled on Windows 11 and most updated Windows 10 machines; otherwise install it from the WebView2 download page. Without it the editor comes up blank (audio still works).

Note: the Linux-only pieces (webview patch behavior, HostEnvSanitizer) are no-ops on macOS/Windows; the same ui/webui.zip is embedded on all platforms.

Offline audio check

clang++-12 -O2 -std=c++17 -I third_party/ymfm/src -o build/render_test \
  tools/render_test.cpp third_party/ymfm/src/ymfm_{opn,adpcm,ssg}.cpp
build/render_test assets/ym2608_rhythm_rom.bin /tmp/c4.wav   # renders piano C4, fails if silent

Bridge protocol

JS → C++	Purpose
synthReady() (native fn, round-trip)	returns {sampleRate, nativeRate, patch} on UI boot
uiEvent (one-way emitEvent)	all hot-path traffic: {cmd: noteOn/noteOff/allNotesOff/setParam/setOpEnvelope/post, …} — no response roundtrip, so knob drags can't flood the message loop

Events (C++ → JS, 30 Hz while editor visible): paramChanged, noteOn/noteOff (host MIDI → key highlight), waveform (2048-byte AnalyserNode-format scope data).

Status / TODO

• Native engine, MIDI, params, state, WebView UI (verified in Standalone on Linux)
• Add SSG scene / rhythm pads
• Export instruments presets from PC-98 games
• Scene adopts DAW-restored patch on editor open (currently boots with default preset)
• Mono-mode portamento glide for host MIDI

Licenses: ymfm BSD-3 (Aaron Giles), JUCE 8 (GPLv3/commercial), UI assets from the opna repo.