phosphor-core 0.3.2

Index

• Overview
• Quick Start
• Instruments
• Features
• Architecture
• Controls
• Building from Source
• Project Structure
• Configuration
• Contributing
• License

Overview

Phosphor is a digital audio workstation that runs entirely in your terminal. It pairs a solarized-dark TUI with a real-time audio engine, giving you a DAW you can use over SSH, in a tiling window manager, or anywhere a terminal lives.

Each instrument track gets its own synthesizer instance with independent parameters. MIDI controllers are detected automatically on startup. The audio engine runs on a dedicated real-time thread with lock-free communication — no mutexes in the audio path, ever.

Quick Start

# Install from crates.io
cargo install phosphor-studio

# Or clone and build
git clone https://github.com/joshjetson/phosphor.git
cd phosphor
cargo build --release

# Run (TUI is the default)
cargo run --release

# Run with debug logging
PHOSPHOR_DEBUG=1 cargo run --release

# Run without audio (UI development)
cargo run --release -- --no-audio

# Run without MIDI
cargo run --release -- --no-midi

First steps once running:

1. Press Space to open the command menu
2. Press a to add an instrument track
3. Select an instrument and press Enter
4. Play your MIDI controller — sound comes out
5. Use j/k to navigate synth parameters, h/l to adjust values
6. Press Tab to cycle between Track FX, Synth params, Inst Config, Piano Roll

Instruments

Synthesizers

Drum Rack

Patch Highlights

DX7 (51 patches): E.Piano, Bass, Brass, Bells, Organ, Strings, Flute, Harpsichord, Marimba, Clavinet, Tubular Bells, Vibraphone, Koto, Synth Lead, Choir, Harmonica, Kalimba, Sitar, Oboe, Clarinet, Trumpet, Glockenspiel, Xylophone, Steel Pan, Slap Bass, Fretless Bass, Crystal, Ice Rain, Synth Pad, Digital Pad, Cello, Pizzicato, Log Drum, Tinkle Bell, Shakuhachi, Synth Brass, Voices, E.Piano 2, Accordion, Harp, Clav 2, Banjo, Guitar, Piano, Celeste, Cowbell, Synth Bass, Timpani, Pan Flute, Horns, Toy Piano

Jupiter-8 (42 patches): Pad, Brass, Bass, Sync Lead, Strings, Electric Piano, Pluck, Bell, Organ, PWM Pad, Unison Lead, Key Bass, Ambient, Sweep, Stab, Harp, Sync Bass, Sub Bass, Acid, Choir, Vox, Whistle, PWM Lead, XM Bell, Sequence, Resonant, Detune, Clav, Hollow Pad, Power Pluck, Lo Strings, Flute, Tuba, Saw Pad, Clarinet, Cello, Xylo, Funk Bass, Warm Lead, Noise, Cars Sync, and more

Odyssey (44 patches): Bass, Funk, Sync Lead, Bells, Pad, S&H, Zap, Hawkshaw Funk, Bennett Atmos, Numan Cars, Sci-Fi Wobble, Percussive Pluck, Thick Lead, Filter Sweep, Noise Hit, Duo Split, Snare Drum, Kick, Resonance, Squelch, Growl, Wind, Wah Bass, Stab, Buzz, Flute, Tremolo, Siren, Brass, Organ, Conga, Tom, Clap, PWM Bass, Violin, Oboe, Choir, Trombone, Marimba, Alarm, Robot, Whistler, Sitar, Theremin

Juno-60 (18 patches): Classic Pad, PWM Pad, Bass, Brass, Strings, Hoover, Acid, Warm Lead, Choir, Pluck, Organ, Synth Bass, Glass Bells, Resonant Pad, Wind, Clav, Sub Bass, Saw Pad

Features

Audio Engine

• Real-time audio via cpal (CoreAudio, WASAPI, ALSA)
• Lock-free audio thread — zero allocations, zero mutexes in the hot path
• Per-track instrument instances with independent processing
• Per-track and master VU metering via atomic shared state
• Configurable buffer size (default 64 samples, ~1.5ms latency at 44.1kHz)

Synthesizers

• Phosphor Synth: 16-voice polyphonic subtractive — dual oscillators, SVF filter, drive, ADSR
• DX7: 6-operator FM synthesis, all 32 algorithms, 4-rate/4-level envelopes, operator feedback
• Jupiter-8: Dual polyBLEP VCOs, IR3109 4-pole OTA ladder filter with tanh saturation, per-voice analog drift, 4 voice modes (Solo/Unison/Poly1/Poly2)
• ARP Odyssey: Duophonic split, 3 selectable filters (12dB SVF / 24dB Moog ladder / 24dB Norton), XOR ring mod, hard sync, Sample & Hold
• Juno-60: Single DCO per voice, BBD stereo chorus (Chorus I / II / I+II), sub-oscillator, 4-position HPF, single ADSR shared VCF+VCA
• Drum Rack: 10 kits including circuit-accurate 808/909/707/606, creative 777, warm tape-saturated tsty series, and resonator-based physical modeling

MIDI

• Auto-detection of MIDI controllers on startup
• Lock-free SPSC ring buffer for MIDI-to-audio routing
• Sample-accurate MIDI event processing
• Note-on/off, CC, pitch bend support
• Per-track MIDI routing — only the selected track receives input

TUI

• Solarized-dark theme with phosphor CRT aesthetic
• Vim-style navigation (j/k/h/l, Enter, Esc)
• Space menu (spacevim-inspired leader key)
• Per-track color coding, VU meters, mute/solo/arm controls
• Synth parameter panel with real-time adjustment and patch selection
• Instrument config tab for deeper parameter access
• Clip view with piano roll, automation, and FX panel
• Transport with BPM, loop region, metronome, recording
• Send A/B buses and master track

Architecture

• Workspace with 7 crates, clean dependency graph
• Shared domain models via atomics (no locks between threads)
• Command channel pattern for UI-to-audio communication
• Plugin trait for instruments and effects — same interface for built-in and third-party
• 214+ tests covering DSP, MIDI, engine, mixer, and navigation

Architecture

                    UI Thread                              Audio Thread
                    ---------                              ------------
                    NavState                               Mixer
                      |                                      |
                      +-- TrackState --Arc<TrackHandle>--> AudioTrack
                      |    muted ---> TrackConfig.muted      |
                      |    soloed --> TrackConfig.soloed      +-- instrument: Box<dyn Plugin>
                      |    volume --> TrackConfig.volume      +-- buf_l / buf_r
                      |    VU <----- TrackHandle.vu <------- +-- per-track VU
                      |
                      +-- MixerCommand --crossbeam--> Mixer.drain_commands()
                           AddTrack                     -> tracks.push()
                           SetInstrument                -> track.instrument = Some(plugin)
                           SetParameter                 -> plugin.set_parameter()

MIDI Controller --midir--> MidiRingSender --SPSC--> MidiRingReceiver
                                                        |
                                                   EngineAudio.process()
                                                        |
                                                   Mixer.process()
                                                        |
                                                   cpal audio callback --> speakers

Controls

Global

Space Menu

Tracks Pane

Clip View

Building from Source

Requirements

• Rust 1.75+ (install via rustup)
• System audio libraries:
  • macOS: CoreAudio (included with Xcode)
  • Linux: ALSA (sudo apt install libasound2-dev) and optionally JACK
  • Windows: WASAPI (included)
• MIDI support requires a connected MIDI device (optional)

Build

cargo build --release

Test

cargo test --workspace  # 214+ tests

Project Structure

phosphor/
├── Cargo.toml                 # Workspace root (phosphor-studio on crates.io)
├── src/main.rs                # CLI entry point
├── crates/
│   ├── phosphor-core/         # Audio engine, mixer, transport, metronome
│   ├── phosphor-dsp/          # Built-in instruments
│   │   └── src/
│   │       ├── synth.rs       # Phosphor Synth (subtractive)
│   │       ├── dx7.rs         # DX7 FM synthesizer (51 patches)
│   │       ├── jupiter.rs     # Jupiter-8 analog poly (42 patches)
│   │       ├── odyssey.rs     # ARP Odyssey duophonic (44 patches)
│   │       ├── juno.rs        # Juno-60 DCO + BBD chorus (18 patches)
│   │       ├── drum_rack.rs   # Drum machine (10 kits, 88 sounds each)
│   │       └── oscillator.rs  # Waveform oscillators
│   ├── phosphor-midi/         # MIDI I/O, message parsing, ring buffer
│   ├── phosphor-plugin/       # Plugin trait definitions
│   ├── phosphor-tui/          # Terminal UI frontend
│   │   └── src/
│   │       ├── app.rs         # Application loop, audio/MIDI wiring
│   │       ├── state/         # Navigation, track state, clip view, modals
│   │       ├── ui.rs          # Rendering
│   │       └── theme.rs       # Solarized-dark color palette
│   └── phosphor-gui/          # GUI frontend (planned)
└── architect.md               # Architecture plan and roadmap

Configuration

CLI Options

phosphor [OPTIONS]

Options:
    --tui                 Launch TUI frontend (default)
    --gui                 Launch GUI frontend (not yet implemented)
    --buffer-size <N>     Audio buffer size in samples [default: 64]
    --sample-rate <N>     Sample rate in Hz [default: 44100]
    --no-audio            Disable audio output
    --no-midi             Disable MIDI input
    -h, --help            Print help
    -V, --version         Print version

Debug Logging

PHOSPHOR_DEBUG=1 cargo run --release

Creates phosphor_debug.log with timestamped user actions and system responses. Includes a panic handler that captures full backtraces to the log.

Contributing

Phosphor uses a modular plugin architecture. The Plugin trait in phosphor-plugin is the contract for all instruments and effects:

pub trait Plugin: Send {
    fn info(&self) -> PluginInfo;
    fn init(&mut self, sample_rate: f64, max_buffer_size: usize);
    fn process(&mut self, inputs: &[&[f32]], outputs: &mut [&mut [f32]], midi_events: &[MidiEvent]);
    fn parameter_count(&self) -> usize;
    fn parameter_info(&self, index: usize) -> Option<ParameterInfo>;
    fn get_parameter(&self, index: usize) -> f32;
    fn set_parameter(&mut self, index: usize, value: f32);
    fn reset(&mut self);
}

To add a new instrument:

1. Create a struct that implements Plugin
2. Add it to phosphor-dsp (or your own crate)
3. Add the variant to InstrumentType in phosphor-tui/src/state/menu.rs
4. Wire it into create_instrument_track() in app.rs

License

MIT