sm-26/README.md

# SM-26

A self-contained **subtractive synthesizer** written in modern C++ on top of
[JUCE](https://juce.com). It ships as a **VST3** on macOS and Linux plus a
macOS **Audio Unit**, with a hand-rolled DSP core, 52 factory presets and an
embedded 4x80 HD44780-style LCD driven by a cascaded on-screen menu.

## Why this is pretty good

* **One real dependency, always fetchable.** JUCE is the only external thing
  this project needs, and the build fetches it automatically into `./build/`
  on the first `make`. Your source tree stays clean: no vendored JUCE, no
  submodules to go stale, no manual setup.
* **A tiny, readable DSP core with real character.** Twelve voices, two
  oscillators with gliding, a self-oscillating state-variable filter with
  drive, an ADSR, and a tempo-synced delay — all in one focused
  `SynthEngine` with no external DSP libraries. Easy to read, easy to hack.
* **A UI people actually look at.** A 4x80 pixel LCD renderer with a real
  menu (PRESETS / OSCILLATORS / FILTER / ENVELOPE / DELAY / SYSTEM) navigated
  with a diamond of arrow keys plus ENTER/ESC. A DAW-native plugin that wears
  its own little OS.
* **Knobs that mean something.** Four front-panel knobs that change meaning
  per preset (`KnobView`) — every preset ships with a curated mapping and a
  sensible value range, not just raw MIDI CCs.
* **Reproducible from a single command.** `make` = fetch JUCE → configure →
  build → you're done. `make install` even ad-hoc-signs and un-quarantines
  the macOS bundles so your DAW and `auval` accept them immediately.

## Features

* 12-voice polyphonic engine with voice stealing and glide
* 52 factory presets across Bass / Lead / Pad / Keys / Pluck / FX / Stab / Arp
* Dual-waveform oscillator section (sine / tri / saw / square / noise …)
* SVF low-pass filter with resonance **and** drive
* ADSR with a per-voice envelope and cutoff modulation
* Tempo-synced delay with rhythmic subdivision, locked to host BPM
* 4x80 LCD with live knob values, active preset, voice count and transport
* Footer that shows the exact git revision and build time

## Requirements

* C++17 compiler (Apple Clang or GCC)
* CMake >= 3.22
* Git (to fetch JUCE on the first build)
* Linux: X11/ALSA development headers

## Build

```sh
make            # fetches JUCE into build/ (once), configures and builds
make install    # installs + ad-hoc signs + un-quarantines the plugin bundles
make uninstall  # removes the installed plugins
make clean      # removes compiled artefacts only
make distclean  # wipes build/ entirely (including the fetched JUCE)
```

* macOS installs to `~/Library/Audio/Plug-Ins/` (AU + **VST3**).
* Linux installs to `~/.vst3/`.

> Jumping straight into CMake also works: `cmake -S . -B build` builds a
> Release plugin and grabs JUCE from the same `build/juce` location.

If a freshly installed AU is not visible to `auval` / your DAW:

```sh
sudo killall -HUP coreaudiod
```

(or just restart the host).

## Usage

* Feed the plugin MIDI; the four front-panel knobs drive whichever parameters
  the current preset maps them to (cutoff, resonance, envelope, delay — and a
  wide range of other routings).
* Navigate with the **arrow diamond + ENTER/ESC**:
  * root → PRESETS / OSCILLATORS / FILTER / ENVELOPE / DELAY / SYSTEM
  * up/down move, left/right adjust, ENTER opens/confirms, ESC goes back
* The LCD shows the active preset, knob mappings with live values, host BPM
  and voice count. The delay's SYNC mode locks to the host tempo and lets you
  pick rhythmic subdivisions.

## Layout

```
Build: Makefile -> CMake -> JUCE (fetched into build/juce, never committed)
Source/
  PluginProcessor.*  audio processor + DSP shell
  SynthEngine.*      osc/filter/ADSR/delay voice engine (12 voices)
  Presets.*          52 preset definitions + per-preset knob routings
  SynthParams.*      parameter model + formatting
  PluginEditor.*     panel, knobs, nav diamond, status footer
  LcdDisplay.*       4x80 HD44780-style display renderer
  MenuSystem.*       cascaded menu state machine
tools/gen_buildinfo.sh  generates git-revision + build-time header
```

Everything the project needs at build time lives under `./build/`, which is
git-ignored — the only things committed are your sources, this README and
the build glue.