chuck-max

A project which embeds the ChucK 1.5.4.2-dev (chai) engine in a Max/MSP external.

This repository is itself a Max package which includes one external (chuck~) with the following features and limitations:

• Generate and process audio by running chuck files and evaluating chuck code with global parameters controlled and adjusted in realtime by Max messages.

• Layer sounds from a single instance by running multiple chuck files concurrently.

• Add, remove, replace audio and audio processes on the fly using chuck messages via Max messages.

• Interact with Max via MIDI and OSC protocols.

The package also includes the following:

• The complete set of current chuck examples

• Most of the base CCRMA chugins including WarpBuf and Fauck or Faust except for Fluidsynth and Ladspa.

• Many Max patchers to test and demonstrate usage.

• Contributed patchers and code examples.

For the impatient: download the chuck-max package with pre-compiled externals and chugins from the the project's Releases section and check out the cheatsheat.

Note that chuck-max has a sibling in the pd-chuck project.

Overview

• The chuck~ object can take the following arguments:

  • [chuck~] : single channel in/out, no default chuck file
  • [chuck~ <N>] : N channel in/out, no default chuck file
  • [chuck~ <filename>] : single channel in/out with default chuck file
  • [chuck~ <N> <filename>] : N channels with default chuck file

It's recommended to choose 2 channels for stereo audio.

If a <filename> argument is given it will be searched for according to the following rules:

1. Assume it's an absolute path, use it if it exists.

2. Assume that it's a partial path with the package's examples folder as a prefix. So if stk/flute.ck is given as <filename>, the absolute path of the package examples folder is prepended to it and if the resulting path exists, it is used.

3. Assume <filename> exists in the parent patcher's directory. Test that this is the case and if it is, use it. This is useful if you want to package patchers and chuck files together.

4. Use Max's locatefile_extended search function to search for the <filename> in the Max search path. The first successul result will be used.

Core Messages

As of the current version, chuck~ implements the core Chuck vm messages as Max messages:

Action	Max msg	Max msg (alias)
Add shred from file	add <file> [arg1 arg2 .. ]	+ <filepath> [args]
Run chuck file (save last used)	run <file>
Eval code as shred	eval <code>
Remove shred	remove <shredID>	- <shredID>
Remove last shred	remove last
Remove all shreds	remove all
Replace shred	replace <shredID> <file>	= <shredID> <file>
List running shreds	status
Clear vm	clear vm	reset
Clear globals	clear globals
Reset id	reset id
Time	time

It's worth reading the ChucK Language Specification's section on Concurrency and Shreds to get a sense of what the above means. The first paragraph will be quoted here since it's quite informative:

ChucK is able to run many processes concurrently (the process behave as if they are running in parallel). A ChucKian process is called a shred. To spork a shred means creating and adding a new process to the virtual machine. Shreds may be sporked from a variety of places, and may themselves spork new shreds.

Utility Messages

The core set of chuck vm messesages is also extended in chuck-max with the following utility messages:

Action	Max msg
Set file attribute (does not run)	file <path>
Set full path to editor attribute	editor <path>
Prevent running shreds when dsp is off	run_needs_audio
Open file in external editor	edit <path>
Probe chugins	chugins
Get/set loglevel (0-10)	loglevel & loglevel <n>
Get state of chuck vm	vm
Launch chuck docs in a browser	docs
Clear Max console	clear console

Parameter Messages

Once a shred is running you can change its parameters by sending values from Max to the chuck~ object. To this end, ChucK makes available three mechanisms: global variables, global events, and callbacks which are triggered by events. chuck~ maps these chuck language elements to corresponding Max/MSP constructs as per the following table:

Action	ChucK	Max msg
Change param value (untyped)	global variable	<name> <value>
Dump global variables to console	global variable	globals
Trigger named event	global event	sig <name>
Trigger named event all shreds	global event	broadcast <name>

You change a global variable by sending a <variable-name> <value> message to a chuck~ instance where the value can be an int, float, string, array of ints or floats, etc. You can also trigger events by sending sig or signal messages, broadcast messages as per the above table.

Note: You can't use the ChucK types of dur or time in Max. Also, while in the above case, the Max msg seems untyped, it must match the type of the chuck global variable. So if you connect a Max number or flownum object to a message box, it needs to match the type of the global variable (int/float).

See help/chuck~.maxhelp and patchers in the patchers/tests directory for a demonstration of current features.

Parameter Messages using Callbacks (Advanced Usage)

In addition to the typical way of changing parameters there is also an extensive callback system which includes listening / stop-listening for events associated with callbacks, triggering them via sig and broadcast messages and also setting typed global variables via messages and symmetrically getting their values via typed callbacks:

Action	ChucK	Max msg
Listen to event (one shot)	global event	listen <name> or listen <name> 0
Listen to event (forever)	global event	listen <name> 1
Stop listening to event	global event	unlisten <name>
Trigger named callback	global event	sig <name>
Trigger named callback all shreds	global event	broadcast <name>
Get int variable	global variable	get int <name>
Get float variable	global variable	get float <name>
Get string variable	global variable	get string <name>
Get int array	global variable	get int[] <name>
Get float array	global variable	get float[] <name>
Get int array indexed value	global variable	get int[i] <name> <index>
Get float array indexed value	global variable	get float[i] <name> <index>
Get int associative array value	global variable	get int[k] <name> <key>
Get float associative array value	global variable	get float[k] <name> <key>
Set int variable	global variable	set int <name> <value>
Set float variable	global variable	set float <name> <value>
Set string variable	global variable	set string <name> <value>
Set int array	global variable	set int[] <name> v1, v2, ..
Set float array	global variable	set float[] <name> v1, v2, ..
Set int array indexed value	global variable	set int[i] <name> <index> <value>
Set float array indexed value	global variable	set float[i] <name> <index> <value>
Set int associative array value	global variable	set int[k] <name> <key> <value>
Set float associative array value	global variable	set float[k] <name> <key> <value>

Build Requirements and Options

Please note that this external is currently only developed and tested on macOS, although a Windows version is on the TODO list (any help on this front would be much appreciated).

A number of build variants have been made available to address platform-specific changes and library compatibility issues and also to provide for different levels of usage.

The following matrix shows feature coverage and also differences in compatibility among the different macOS versions:

feature/variant	native	universal	brew	full	nomp3	light
External	x	x	x	x	x	x
Base chugins	x	x	x	x	x	x
Faust.chug			x	x	x	x
WarpBuf.chug			x	x	x	x
FluidSynth.chug			x
.wav	x	x	x	x	x	x
.mp3			x	x
.flac			x	x	x
.ogg			x	x	x
.opus			x	x	x
.vorbis			x	x	x
macOS 15 (Sequoia)	x	x	x	x	x	x
macOS 14 (Sonoma)	x	x	x	x	x	x
macOS 13 (Ventura)	x	x	x	x	x	x
macOS 12 (Monterey)	x	x	x	x	x	x
macOS 11 (Big Sur)	x	x		x	x	x

A. The Base System

The base chuck-max system consists of a Max package with the chuck~ external, the base CCRMA chugins and extensive examples, tests and Max patchers.

Building it requires the following to be available on your machine:

1. Xcode from the App store or Xcode Command Line Tools via xcode-select –install

2. cmake

3. bison

4. flex

The last three can be installed using Homebrew as follows:

brew install cmake bison flex

The buildsystem consists of a minimal Makefile frontend with CMake driving the build on the backend.

To get up and running:

git clone https://github.com/shakfu/chuck-max.git
cd chuck-max
make setup

Note that make setup does two things: (1) retrieves max-sdk-base as a git submodule and makes the package and its contents available to be used by Max by creating a symlink of the chuck-max folder in $HOME/Documents/Max 8/Packages.

Now it should be possible to build the base system with either of the following two options:

• make or make native: builds the external using your machine's native architecture which is arm64 for Apple Silicon Macs and x86_64 for Intel Macs. This is the default build option.

• make universal: build the external as a universal binary making it compatible with both Mac architectural variants. This is useful if you want share the external with others in a custom Max package or standalone.

B. The Advanced System

The advanced system consists of the base system + two advanced chugins, Faust.chug and WarpBuf.chug:

1. The Fauck chugin contains the full llvm-based faust engine and dsp platform which makes it quite powerful and also quite large compared to other chugins (at around 45 MB stripped down). It requires at least 2 output channels to work properly. It also uses the libsndfile library.

2. The WarpBuf chugin makes it possible to time-stretch and independently transpose the pitch of an audio file. It uses the rubberband, libsndfile, and libsamplerate libraries.

To build these two chugins, you will need some additional dependencies which can also be installed via Homebrew as follows:

brew install autoconf autogen automake flac libogg libtool libvorbis opus mpg123 lame rubberband libsamplerate

After these are installed, it should be possible, subject to the compatibility matrix above, to build the advanced system with one of the following options:

• make brew: build the external using the previously installed homebrew dependencies, as well as downloaded faust headers and a downloaded pre-compiled libfaust (libfaustwithllvm) library. This is the newer, faster, recommended way of getting a full chuck-max system up and running.

• make brew2: preliminary experimental support (currently not working) for building FluidSynth.chug is provided with this make target but this requires additional dependencies to be installed via brew install glib portaudio gettext fluid-synth

• make full: build the external by manually building all of the dependencies except for libfaust from source. This is the previous way of building an advanced system. It is currently only for advanced developers who want maximum flexibility in their builds.

• make nomp3: same as make full except without support for the .mp3 format. Try this variant if you are unable to build using make full on Intel Macs or on older macOS versions.

• make light: Same as make full except for withouth libsndfile multi-file format support. This means that (.mp3, flac, vorbis, opus, ogg) formats are not supported in this build. Only .wav files can be used.

Usage

The chuck-max package consists of the following folders:

chuck-max
├── examples
│    ├── ai
│    ├── analysis
│    ├── ...
│    ├── **chugins**
│    ├── ...
│    ├── **fauck**
│    ├── **faust**
│    ├── ...
│    ├── **max**
│    ├── ...
│    ├── **test**
│    ├── ...
│    └── warpbuf
├── externals
│    └── chuck~.mxo
├── help
├── media
└── patchers
    ├── abstractions
    ├── contrib
    └── tests

Start with the chuck~.maxhelp file in the help folder for an overview of the external's features. The media folder also has a pdf cheatsheet of available chuck~ methods.

The examples directory contains all chuck examples from the chuck repo, and some additional folders: chugins containing chugin binaries, fauck, containing faust.chug examples, faust, containing the faust stdlib, max chuck files which are used by the max patchers, and test, chuck files used by max patcher test files.

In the patchers section, there are quite a few patchers demonstrating one feature or other in the tests folder, and the contrib folder contains excellents advanced examples of uses by chuck-max contributors.

Known Unresolved Bugs

• If a chuck file contains a custom event and the Max patch sends a clear vm or reset before running the chuck file while Max audio is turned off, it may cause Max to crash. The case is demonstrated in the patchers/tests/crash section. See github issue #11 for updates on this. The interim solution is to only run chuck files with Max audio on, and there's an attribute run_needs_audio to force this and prevent the crash. Thanks to @HighHarmonics2 for discovering this one.

Credits

This project thanks the following:

• Professors GE Wang and Perry Cook and all chuck and chuggin contributors for creating the amazing ChucK language and chuggin ecosystem!

• Professor Perry Cook for co-authoring Chuck and creating the Synthesis Toolkit which is integrated with chuck.

• Professor Brad Garton for creating the original chuck~ external for Max 5. My failure to build it and run it on Max 8 motivated me to start this project.

• David Braun, the author of the very cool and excellent DawDreamer project, for creating the excellent ChucKDesigner project which embeds chuck in a Touch Designer plugin. His project provided a super-clear blueprint on how to embed libchuck in another host or plugin system and was essential to this project.