# SerumAlt

A modern, commercial-quality wavetable synthesiser plugin (VST3 / AU / Standalone)
built with **JUCE 7**, **CMake** and **C++17**. SerumAlt is a self-contained synth
inspired by the workflow of Serum/Vital: two morphing wavetable oscillators, a full
filter section, four envelopes and LFOs, a modulation matrix, a reorderable FX rack,
four macros and a one-click **RAVE** button.

![SerumAlt](Source/Resources/logo.svg)

## Features

- **Two wavetable oscillators** — 256 frames × 2048 samples, bilinear morphing,
  8 warp modes (Bend+/-, Sync, PWM, Asym, Mirror, Fold), unison 1–16 with phase
  spread/detune/width.
- **10 factory wavetables** (Basic Shapes, Saw PWM, Square Sync, Triangle Fold,
  Vowel, Organ, Warm Saw, Digital, Glass, Bass), generated lazily and RAM-resident.
- **Sub oscillator** (sine/triangle, −2/−1/0 oct) and **noise** (white/pink).
- **Filter section** — two slots, 7 models (Ladder LP/HP/BP, Diode, Comb, Formant,
  Screamer), 6/12/24 dB slopes, drive, keytrack, and serial/parallel/split routing.
- **4 ADSR envelopes** with curve tension and live preview.
- **4 LFOs** — tempo-sync, 7 shapes (sine/tri/saw/square/S&H/step/freehand),
  editable step-sequencer and freehand drawing, fade-in and start delay.
- **Modulation matrix** — direct source→destination connections with bipolar depth.
- **FX rack** — 9 effects (Hyper/OTT, Chorus, Flanger, Phaser, Distortion, EQ,
  Compressor, Delay, Reverb) in 8 reorderable slots.
- **4 macros** (Energy, Width, Drive, Atmosphere) with assignable destinations.
- **RAVE** — one-click boost (unison, width, drive, OTT, reverb) with snapshot/restore.
- **16 factory presets** with production-quality values.
- **Scalable GUI** (75% / 100% / 125% / 150% / 200%) — dark modern vector look,
  Path-drawn controls, SVG logo/background, real-time waveform/filter/envelope/LFO
  displays.

## Architecture

```
Source/
  PluginProcessor.{h,cpp}     APVTS, presets, state, RAVE/UI-scale glue
  PluginEditor.{h,cpp}        Tabbed dark GUI, scaling, visualisations
  Params.{h,cpp}              Parameter IDs, enums, mod sources/targets, mappings
  Wavetable.{h,cpp}           256×2048 tables + lazy library
  Oscillator.{h,cpp}          Morph/warp/unison oscillator
  SubOscillator.{h,cpp}       Sine/triangle sub
  NoiseOscillator.{h,cpp}     White/pink noise
  Filter.{h,cpp}              7 filter models
  FilterBank.{h,cpp}          2 slots + routing
  Envelope.{h,cpp}            ADSR with curve
  LFO.{h,cpp}                 Synced LFO + shape editing
  ModulationMatrix.{h,cpp}    Connections
  FXProcessor.{h,cpp}         Reorderable rack
  EffectUnits/                Hyper, Chorus, Flanger, Phaser, Distortion, EQ,
                              Compressor, Delay, Reverb
  MacroControls.{h,cpp}       4 assignable macros
  RAVEButton.{h,cpp}          RAVE snapshot/boost
  SynthVoice.{h,cpp}          32-voice pool render path
  Engine.{h,cpp}              Per-block DSP + MIDI + FX + limiting
  GUI/                        Knob, Slider, ToggleButton, Display, Panel,
                              Waveform/Filter/Envelope/LFO displays
  Presets/FactoryPresets.cpp  16 factory presets
  Resources/                  SVG assets
```

Key architectural decisions: a fixed 32-voice pool with pre-allocated unison
sub-voices (max 16/osc), scalar processing (SIMD deferred), control-rate modulation
(one level, no modulation-of-modulation), and a `juce::AudioProcessorValueTreeState`
backed parameter store that survives preset save/load together with the mod matrix,
macro assignments and LFO shape data.

## Building

Requirements: CMake ≥ 3.22, a C++17 compiler, and the Linux dev libraries
(`libasound2-dev`, `libjack-dev`, `libfreetype-dev`, `libcurl`, X11, OpenGL).
JUCE 7.0.12 is vendored under `third_party/JUCE`.

```bash
cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
```

Outputs:

- `build/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3` — VST3
- `build/SerumAlt_artefacts/Release/Standalone/SerumAlt` — standalone app
- (on macOS, the `AU` target is produced automatically)

Cross-compilation for Windows/macOS is handled by JUCE: configure with the relevant
toolchain and add `-DCMAKE_TOOLCHAIN_FILE=...` as usual.

## Headless QA harness

A console app drives the processor through every factory preset, plays a chord,
verifies finite (non-NaN) output and non-silence, and exercises the RAVE toggle.
Build and run with:

```bash
cmake --build build --target SerumAltTest
./build/SerumAltTest_artefacts/Release/SerumAltTest
```

(Disable it with `-DSERUMALT_BUILD_TESTS=OFF`.)

## License

JUCE is licensed separately (see `third_party/JUCE/LICENSE.md`). This project is
provided for evaluation/development purposes.