Windows VST3/CLAP/ASIO Stability, Solaris UI, Autosave & Modulation Fixes — Omni Update May 6–11

Build: 2d2a75e | May 6 – 11, 2026

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🔌 Windows — VST3 & CLAP Plugin UI Stability

After extensive testing on Windows with Surge XT, Vital, u-he Hive and LSP Plugins, every known plugin window issue has been resolved:

• Plugin windows now hide on close instead of being destroyed — re-opening restores the same editor without a full reinitialisation cycle. The toggle button state is synced with IsWindowVisible on every frame
• Fixed plugin window reopen for both VST3 and CLAP on Win32: window state is no longer out of sync after the user closes and reopens the editor
• Enforced fixed-size editor windows on Win32: prevents some plugins from collapsing to 0 × 0 px on show
• VST3 initialisation on persistent GUI thread: IComponent::initialize and IEditController setup now run exclusively on the dedicated GUI thread — eliminates COM apartment violations and race conditions
• Message pumping while attached() runs: fixes Surge XT GUI hang where the plugin called back into the host during the attach sequence
• Per-monitor DPI awareness (PROCESS_DPI_UNAWARE → PROCESS_DPI_AWARE) set before any window is created; WS_CLIPCHILDREN prevents child overdraw
• Attach watchdog extended to 180 s; worker thread detaches cleanly on timeout — the UI never freezes waiting for a stuck plugin
• Step-by-step logging and a panic catcher around IComponent::initialize for easier debugging of misbehaving plugins

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🔊 Windows — WASAPI & ASIO Engine Fixes

• WASAPI DEVICE_INVALIDATED fix: the engine now negotiates the device's native mix format instead of the user-configured format — the leading cause of stream crashes on default-device change
• Panic catcher in the audio callback: any Rust panic is caught and logged; the stream is not killed, preventing full WASAPI session loss
• WASAPI buffer size regression fixed: a recent refactor accidentally wrote a hard-coded frame count; now correctly reads the device-reported period
• Unified settings path: all persisted settings (audio, MIDI, autosave, app prefs) now live under omni_config_dir() — consistent on Windows and Linux
• ASIO sample format conversion corrected: silence and noise artefacts on 24-bit and 32-bit ASIO devices (ASIO4ALL, RME, Focusrite) are eliminated
• ASIO4ALL control panel now launches correctly from the Settings → Audio dialog on Windows
• Windows builds now include ASIO SDK by default — ASIO is no longer an optional compile-time feature; any Windows build can use ASIO devices

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⚡ Engine — Auto-Restart on Stream Death

Previously, if the audio device was removed or WASAPI reported a fatal error, the engine would silently stop processing while Omni's UI remained up with no indication. This is fixed:

• A new stream_died: Arc<AtomicBool> is set by the cpal error callback on any fatal stream error
• The UI polls this flag once per frame; on detection it tears down and fully rebuilds the engine with the current audio settings
• Recovery is automatic — plug in a USB audio device, switch the Windows default output, or wake from sleep: Omni reconnects without a restart

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💾 Autosave — Complete System

Omni now has a full autosave implementation designed for crash recovery and session continuity:

• Configurable interval: 1–60 minutes; enabled by default at 5 minutes
• Snapshots stored in ~/.config/omni/autosave/ with ISO-8601 timestamps
• Automatic pruning: old autosaves beyond a configurable count are removed; storage stays bounded
• Extended Load menu: Open…, Recent Projects (last 10), and AutoSave Recovery sub-menus accessible from the top bar
• One-click recovery: open any autosave snapshot directly from the Recovery list
• Settings → AutoSave tab: enable/disable toggle, interval slider, Clear Autosaves button
• Recent projects list persisted in ~/.config/omni/app_settings.json; updated on every save and open

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🎛️ Modulation Routing — Engine Fix

A subtle but impactful bug in the modulation engine has been corrected:

• Add/remove/disable routes now correctly primes and resets the parameter base value for instrument and plugin targets — the value a modulator is added on top of
• Routing order bug fixed: a newly added route could read a stale base value on the very first audio callback, causing a one-buffer offset artefact
• Dead code removed; regression tests added for all three cases (add, remove, disable)

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🎨 Solaris UI — Universal Synth Panel Refactor

Every remaining synth in Omni has been migrated to the compact Solaris-style panel layout — the design system introduced with Bass Synth that maximises knob density and modulation visibility on a 15.6″ laptop screen.

TOMNIC Drum Synth

• OSCILLATORS section with OSC 1 / OSC 2 tabs
• NOISE section with NOISE 1 / NOISE 2 tabs
• LFOs section with LFO 1 / LFO 2 tabs
• CLICK as a separate narrow section
• FILTER uses the hardware filter_display widget, narrowed to 86 px
• FX split into individual vertical sections: DISTORTION, FREQ SHIFT, RING MOD, DELAY, REVERB, PHASER, CHORUS, EQ, WIDTH
• Main panel scroll eliminated — all sections fit without scrolling at full resolution

PolySynth

• Full compact Solaris layout — shared widgets and conventions with Bass Synth
• Modular code split; legacy polysynth_sections.rs removed

Alchemy — Chemistry Synth

• Modular code split: solaris_reaction.rs (reactor view) and solaris_visuals.rs (plasma orb, stoichiometry fill) extracted into dedicated files
• Ampoule panel rearranged to a 3×3 grid placed after the output section — more accessible, less visual clutter
• Periodic table resized and compacted; ScrollArea wrapper removed in favour of direct layout allocation — no horizontal scroll

Piano & Violin (Physical Models)

• Both instruments migrated to the shared modeled_synth_solaris panel module
• Preset combo, section headers and dynamic labels unified with Bass Synth conventions
• Piano UI reduced from ~760 lines to a compact shared implementation; Violin from ~443

Scratch Deck

• Compact Solaris layout applied to the sample loader and transport controls
• Live platter rotation visualiser added — the vinyl graphic rotates in real time at the current playback speed and direction

Bass Synth

• Modulation animation overlays fully restored for all Solaris widgets: knobs, faders, toggles, combo boxes
• All modulated parameters show animated rings, sweep dots and highlight lanes as before the Solaris migration
• Legacy bass_synth_sections.rs removed; imports cleaned up

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🐛 Bug Fixes

• Gate expander mode: soft-expander ratio was applied in the wrong direction at low ratio values — gain reduction is now correctly attenuated
• Windows debug stack overflow: .cargo/config.toml now sets a larger stack size for debug builds, preventing stack overflows in debug-mode recursive code paths
• Load toolbar button: now uses the same toolbar_button style as its neighbours — was inconsistently using a plain button style
• omni_midi_sim Windows build: added a stub main() for non-Unix targets so the crate compiles without virtual MIDI port support on Windows

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Omni is actively developed — the next update is coming soon. 🚀

VST3 finally stable on Windows, or the Solaris UI refresh — which one makes the biggest difference for your workflow? Let us know.