Apotheosis v0.1.0

Apotheosis is a lookahead brickwall true-peak limiter for the master bus, and the final plugin in the Basilica Audio heavy-music chain. It is the last gate before export: input gain drives an oversampled true-peak detector, a lookahead delay makes the resulting gain reduction instantaneous (no attack transient) rather than reactive, and a smooth release relaxes it back once the peak has passed. The output's true (inter-sample) peak never exceeds the Ceiling.

This is the first tagged release (v0.1.0), covering the M1 milestone: core DSP completion and broadened test coverage.

What's new in 0.1.0

Added

• Project bootstrap: README, license, contributing guide, architecture and build docs, ADRs, and CI workflow.
• DSP core: initial working Apotheosis signal path (Input Gain, 4x-oversampled true-peak detection, lookahead gain-reduction envelope, release smoothing, ceiling clamp) with unit tests.
• Release Curve parameter (Exponential/Linear/Smooth, default Exponential): shapes the release (increasing-gain) phase only - attack always stays instantaneous via the lookahead minimum, regardless of curve. Exponential matches the original v0.1 one-pole behaviour exactly.
• Clip Mix parameter (0-100%, default 0%): blends the transparent gain-reduction limiter path with an alternate tanh soft-clip "clipper" path, applied directly to the lookahead-delayed signal. Both paths (and every blend between them) pass through the same final hard ceiling clamp, so the never-exceed-ceiling guarantee holds at any Clip Mix setting; 0% is bit-identical to the pure limiter path.
• Dither parameter (Off/16-bit/24-bit, default Off): TPDF dither added after downsampling, at the output word length. Off is bit-identical to the pre-dither signal path.
• Metering (engine-side): gain reduction, output true peak, and Momentary (400 ms)/Short-Term (3 s)/Integrated LUFS loudness (K-weighted per a documented, real-time-safe approximation of ITU-R BS.1770-4), published via relaxed atomics on TruePeakLimiterEngine/ApotheosisAudioProcessor for a future GUI (roadmap M3) or any host/test consumer. No visual display yet - this is the DSP computation and readout API.
• Editor controls for the new Release Curve/Dither/Clip Mix parameters (two combo boxes + one knob), so every automatable parameter has a working v0.1 control.
• docs/manual.md: full user manual (what Apotheosis is, where it sits in a chain, signal flow, complete parameter reference, usage tips).
• Broadened Catch2 suite (19 -> 44 test cases): Release Curve/Dither/Clip Mix unit and regression tests, metering tests (idle defaults, gain-reduction/true-peak/LUFS behaviour, reset semantics), sample-rate sweep (44.1-192 kHz) with true-peak-ceiling verification at every rate, mono/stereo/rejected bus-layout coverage, long-run (several-second) NaN/Inf stability including the new metering state, and rapid automation of every parameter.

Changed

• docs/architecture.md, README.md, and CLAUDE.md updated to describe the full v0.1.0 signal path (Release Curve, Clip Mix, Dither, metering) and parameter table; README's roadmap table corrected to match the repository's actual GitHub milestones (M1 DSP & tests, M2 presets/state, M3 GUI & a11y, M4 release).

Supported formats

• Plugin formats: AU, VST3, Standalone
• Platforms: macOS (Universal Binary: arm64 + x86_64), Windows (x64)

Installation

Download the zip for your OS below, unzip, and copy the plugin into your system's plugin folder:

• macOS: AU -> ~/Library/Audio/Plug-Ins/Components/, VST3 -> ~/Library/Audio/Plug-Ins/VST3/. Standalone app can be run directly from wherever you unzip it (or moved to /Applications).
• Windows: VST3 -> C:\Program Files\Common Files\VST3\. Standalone app can be run directly from wherever you unzip it.

Rescan plugins in your DAW after installing.

Important: unsigned binaries

These macOS and Windows binaries are UNSIGNED and NOT notarized. Code signing and notarization are tracked as roadmap milestone M4 and are not part of this release.

• On macOS, Gatekeeper will block or warn on first launch. You will need to allow the app/plugin manually (System Settings -> Privacy & Security -> "Open Anyway", or remove the quarantine attribute via xattr -dr com.apple.quarantine <path>).
• On Windows, SmartScreen may warn that the publisher is unknown.

Use at your own discretion until a signed release ships.

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Warning

Known issue in v0.1.0: The Release Curve and Dither dropdown menus in the plugin editor render empty (the parameters themselves work via host automation). Fixed in v0.1.1 — please update.