Space Dust - JUCE Synthesizer Plugin

A pure CMake-based polyphonic synthesizer VST3 plugin built with JUCE 8. Cosmic particles of sound.

Repository: github.com/gadalleore/Space_Dust_Synthesizer

git clone https://github.com/gadalleore/Space_Dust_Synthesizer.git
cd Space_Dust_Synthesizer

Known Good With: Ableton Live 10, 11, and 12 (heavily tested for stability as of 2026).

Features

• VST3 format – VST3-only plugin
• 8-voice polyphony – Dual oscillators (with sub oscillator), filter, and ADSR per voice; voice modes Poly / Mono / Legato (last-note priority stack)
• Effects chain – Reverb, delay (with filter), phaser, flanger, trance gate (post-effect), grain delay, parametric EQ, bitcrusher, soft clipper, compressor, transient shaper, lo-fi (with Analog Drift: subtle per-note pitch/filter variation and slow wander when Lo-Fi is enabled)
• Modulation – Two LFOs with On toggles; LFO1 targets filter, LFO2 targets pitch (25% depth default)
• Master volume – 0–2.0 range for headroom
• MIDI input – Full MIDI note and control support, including MPE (per-note pitch bend, pressure, and timbre via Lower Zone or Legacy modes — see MPE Support)
• Custom UI – SpaceDust look and feel with compact tabbed layout (Main, Modulation, Effects, Saturation Color, Spectral) and meter-linked glow
• Real-time safe – Parameter updates without allocations in the audio thread
• Ableton stability focus – Significant hardening against common VST3 crash patterns in Ableton (state restore, automation, editor lifecycle). Includes automated QA checks and runtime safety logging (optional).

MPE Support

Space Dust is a fully MPE-aware synth: per-note pitch bend goes to the oscillators, channel pressure / aftertouch modulates amplitude, and CC74 / slide ("timbre") sweeps the filter cutoff. The MPE controls live on the Modulation tab (Mode: Legacy / Lower Zone, Bend Range, Pressure depth, Timbre depth).

Important: No DAW currently auto-enables MPE for third-party VST3 instruments — you have to flip a per-track toggle once per project. The plugin handles the rest.

Ableton Live 11 / 12

1. Right-click the Space Dust title bar in the device chain → Enable MPE Mode. The header will show "MPE" on the right side once enabled.
2. (Optional) Right-click again → MPE Channel Settings to configure zone (Lower / Upper) and member-channel count.
3. In Space Dust's Modulation tab → MPE strip, set Mode = Lower Zone for the standard MPE spec, or leave on Legacy for non-MPE keyboards / classic pitch-wheel + aftertouch.
4. Drive it from a Seaboard/LinnStrument, the Attila Magyar MPE Emulator VST3 (MIDI effect placed before Space Dust on the track), or Live's per-clip MPE envelopes ("E" button → category MPE → Pitch / Pressure / Slide).

Bitwig Studio

1. Click the Space Dust device's small triangle → Enable Note Expressions (or use the per-track MPE toggle on the track header).
2. In Space Dust set Mode = Lower Zone.
3. Per-note PB/AT/timbre from a Seaboard/LinnStrument or Bitwig's note expression editor will flow through.

Cubase / Studio One

• External MPE controllers (Seaboard, LinnStrument, Sensel, etc.) plug in and work out of the box — Space Dust accepts MIDI on all 16 channels and routes per-note expression internally.
• Cubase's native "Note Expression" inspector does not surface per-note curves for Space Dust because the plugin does not expose INoteExpressionController (a separate VST3 interface, not the same as MPE-over-MIDI). Hardware MPE controllers and MPE-emulator plugins still work fully.

Verifying it's working

Hold a note and move your controller's pitch wheel — pitch should glide; move pressure / aftertouch — amplitude should swell; move CC74 / slide — the filter should brighten or darken. Lower / raise the Pressure and Timbre knobs in the Modulation tab to confirm the attenuation.

Prerequisites

• Visual Studio 2022 or newer with "Desktop development with C++" workload
• CMake 3.22 or newer
• JUCE 8 – juce.com or GitHub

Setup

juce_path.local is gitignored—create it only on your machine (it may contain a local filesystem path to JUCE). Never commit it.

1. Install JUCE and point the project to it (choose one):

   • Copy juce_path.local.example to juce_path.local and put your JUCE path in it, or
   • Set the JUCE_DIR environment variable, or
   • Pass -DJUCE_DIR=... when running CMake

2. Generate and build (recommended): The easiest and most reliable way is to use the provided build script:

   .\build-and-launch.ps1
   # Use -NoLaunch to skip launching Ableton
   .\build-and-launch.ps1 -NoLaunch
   

   This script will:

   • Configure with the correct Visual Studio generator (with fallback between 2022 and 2026)
   • Build the Release VST3
   • Automatically copy the plugin to all common VST3 locations (system folder + Ableton User Library, etc.)

   Manual alternative:

   cmake -B build -G "Visual Studio 17 2022" -A x64
   cmake --build build --config Release
   

   (Use Visual Studio 18 2026 if you have VS 2026 installed.)

3. Plugin output: build\SpaceDust_artefacts\Release\VST3\Space Dust.vst3 (when building manually)

Building the Windows installer

Critical: Before building any installer or final Release binary, you must produce a completely clean build with all logging compiled out.

Run this first (it forces ENABLE_MEMORY_SAFETY_LOGGING=OFF, turns off VLD/ASAN, and does a binary scan as a safety net):

.\disable-all-logging-for-release.ps1

Then continue with packaging:

A signed-and-sealed Inno Setup script ships in installer/SpaceDust-Setup.iss.

1. Install Inno Setup 6 (one time).
2. Save the factory presets you want to ship from inside the plug-in UI. They land in %USERPROFILE%\Documents\Space Dust\Presets\ (or wherever you configured via the installer wizard / %ProgramData%\Space Dust\config.xml).
3. Run the packaging script:

   # Recommended full flow (ensures zero logging leaks):
   .\disable-all-logging-for-release.ps1
   .\package-installer.ps1
   
   # Or for fast iteration on installer-only tweaks (assumes you already ran disable):
   .\package-installer.ps1 -SkipBuild
   

   The script rebuilds the Release VST3, syncs your *.xml presets into installer/Files/Presets/, and compiles installer/Output/SpaceDust-Synthesizer-1.0-Setup.exe.
4. Test the produced .exe. Customer-side, the installer:
   • Prompts for a VST3 folder and a presets folder.
   • Writes %ProgramData%\Space Dust\config.xml so the plug-in finds the chosen presets folder on first run.
   • Ships the factory presets with onlyifdoesntexist, so re-installing or upgrading never overwrites a user's modified copies.

The installer's UAC prompt shows "Publisher: Unknown" because the .exe isn't code-signed; that's expected for indie distributions. See installer/Files/Presets/README.md for more on the preset workflow.

Project Structure

Source/
├── PluginProcessor.*        # Main audio processor
├── PluginEditor.*           # Plugin UI (tabbed: Main, Modulation, Effects, Saturation Color, Spectral)
├── SynthVoice.*             # Voice implementation
├── SynthSound.*             # Sound definition
├── SpaceDustSynthesiser.*   # Synth engine
├── MemorySafetyLogger.*     # Runtime safety & crash diagnostics logging (optional)
├── PresetManager.*          # Preset saving/loading system
├── Goniometer.*             # Stereo correlation meter
├── OscilloscopeComponent.*  # Lissajous / waveform display
├── SpectrumAnalyserComponent.*  # Spectrum analyzer
├── SpaceDustReverb.*        # Reverb
├── SpaceDustGrainDelay.*    # Grain delay
├── SpaceDustPhaser.*        # Phaser
├── SpaceDustFlanger.*       # Flanger
├── SpaceDustTranceGate.*    # Trance gate (post-effect)
├── SpaceDustBitCrusher.*    # Bitcrusher effect
├── SpaceDustSoftClipper.*   # KClip-style soft clipper (Saturation Color tab)
├── SpaceDustCompressor.*    # SSL/1176/LA-2A style compressor (Saturation Color tab)
├── SpaceDustTransient.*     # 808/909 transient shaper (Saturation Color tab)
├── SpaceDustLofi.*          # Lo-fi effect (Saturation Color tab)
├── SpaceDustParametricEQ.*  # Parametric EQ
├── SpaceDustFinalEQ.*       # Final mastering EQ (DSP)
├── FinalEQComponent.*       # Final EQ UI component
├── VoidVerbReverb.*         # Additional reverb (Dattorro plate)
├── SpaceDustLookAndFeel.*   # Custom UI styling
└── CheezeGuyGame.h          # Easter egg (optional)

Recent fixes

• Ableton stability hardening (2026): Major pass to eliminate classes of crashes that could occur during session restore, preset loading, and rapid automation. Key changes:
  • Introduced safeGetParam() helper on the editor (and equivalent helpers in the processor) to safely read parameters without risking null dereferences when IDs are missing or during state restore.
  • Replaced dozens of direct *getRawParameterValue() and getParameter()->getValue() calls throughout the UI with the safe wrappers.
  • Hardened Grain Delay read buffer against floating-point index drift (common with pitch shifting + automation), preventing potential out-of-bounds reads into the delay buffer.
• Build & deployment reliability: build-and-launch.ps1 now reliably copies the VST3 to all common locations (system VST3, Ableton User Library, etc.) and includes fallback logic between Visual Studio 2022 and 2026 generators.
• Host automation vs. Link to Master (filter): When LFO filter sections follow the main filter, the editor previously mixed normalized APVTS values with convertTo0to1 as if they were Hz, and called setValueNotifyingHost on the master when mod-filter parameters changed (including from host automation). That could corrupt cutoff and fight automation on the main filter. Link toggles now copy master→mod using normalized getValue(); while linked, the mod page mirrors the main filter visually without extra host notifications, and user edits on the mod page update the master through normal control gestures.
• Pink noise generator: The Voss–McCartney implementation uses 16 filter rows; the row index must stay in range. The counter is now wrapped so it cannot produce an out-of-bounds row (which could cause rare harsh digital glitches after sustained play, for example on long chords with pink noise). Non-finite oscillator frequencies and filter outputs are also clamped or zeroed; developers can read SpaceDustAudioProcessor::getDspSanitizeEventCount() if investigating edge cases.

Additional documentation

• docs/FIX_SUMMARY.md — detailed history of stability hardening, crash prevention work, and assertion fixes
• docs/REVERB_RESEARCH.md

Development & Testing

This project includes significant tooling focused on stability and quality:

• run-full-qa.ps1 — Runs static analysis checks, pluginval validation, installer smoke tests, and crash-marker hygiene.
• enable-safety-logging.ps1 / disable-all-logging-for-release.ps1 — Toggles the built-in MemorySafetyLogger for detailed runtime diagnostics (voices, grains, buffer access, audio-thread safety, etc.).
• The plugin has undergone extensive hardening specifically against common Ableton Live VST3 crash patterns (state restore crashes, dangling parameter listeners, etc.).

See QA-README.md for details on the QA suite.

References

• JUCE Documentation
• JUCE CMake API

License

MIT License - see LICENSE for details.