retrorust

Mini retro-vibe monophonic synthesizer.

Generates audio triangle and square waves at low resolution (like in good old retro times) using NES APU-like implementation and visualize resulting waveform in real-time.

Implementation

Main components used to generate a Pulse channel are:

envelope.rs : Manages volume envelope in increasing and decreasing fashion as well as looping.
lencounter.rs : Shutdown channel after specified length.
sequencer.rs : 8 values sequencer with 4 different duty cycles.
timer.rs : Trigger timer for others components.

The Pulse struct in pulse.rs uses all components in order to build a PWM channel.

For audio and video real-time playback:

audio.rs : Separate thread use to clock the signal and stream the audio signal.
main.rs : Main thread to display the waveform, communicating with audio thread to fetch signal data.
midi.rs : midi message input handling in separate thread.

How to use as standalone

Clone the repository.

gh clone alelouis/retrorust

Then run the main binary.

cargo run --bin main

Plug-in a midi keyboard and you will be prompted to select it at start of program.

How to use as VST

You can also build a VST version of this synthesizer.
The library is built from ./src/lib.rs which integrate the Pulse struct with VST host audio and events streams (not using graphics, cpal or midir).
First, install and then build for you target.

cargo build --target x86_64-apple-darwin --release

Then on OSX, bundle the .dylib target with the script bundle.sh.

./bundle.sh retrorust target/x86_64-apple-darwin/release/libretrorust.dylib

Then paste the retrorust.vst in your VST2 folder, e.g. on macOS:

cp -r retrorust.vst /Library/Audio/Plug-Ins/VST/