This code allows you to use your Zoom R12/24 (R24) as a control surface for Bitwig Studio (BWS)

You can just download the latest version by selecting it from the list of releases to the right of this page, downloading the .bwextension file, and copying it into your Bitwig Studio Extensions directory.

You can also build this extension locally yourself (if you want to play around with the code or make some improvements or personalizations). This is not a JavaScript extension - the steps to install are more complicated that just copying the files. To install this extension, you need to compile it and copy the resulting .bwextension file to the Extensions directory of your BWS. I've tried to make this as easy as possible. There just a few steps, but this does assume that you have a Java Development Kit (JDK) installed that is version 12 or higher (this is required by the Java API provided by Bitwig). I strongly recommend you use sdkman to do this, if you don't already have a JDK installed.

Once installed, do the following:

1. Clone this repository to a directory on the same computer as your BWS.
2. In the base/root directory of the cloned repository, add a file called bitwig.properties. Use the provided bitwig.properties.example file, and update the single property inside to point at your BWS extensions directory (not the controller scripts directory - this is just for JavaScript) The provided example assumes a Linux installation so you may have to change it to point at your Documents folder if installing on Windows - see the Bitwig documentation for details.
3. From this base/root directory, run ./mvnw -Plocal-deploy clean install on Linux/MacOS or mvnw -Plocal-deploy clean install on Windows. This command will first download the Maven build tool, and then invoke it to build the project and copy it to the directory you configured in the properties file in step 2.

That's it - your extension should now be installed.

I'm going to assume you know how to use Bitwig to connect a controller. Just note that this controller will be found under the Zoom manufacturer, and is called Zoom R24 Controller.

The following diagram explains how the Zoom's faders, buttons and wheel can be used in BWS.

The following image might be useful when printed out and placed on the R12/24 meters. It maps the default colours that BWS uses to indicate controller elements (e.g. faders) to tracks or device parameters, onto those R24 strips (1-8). In this way, you have a visual guide to which fader corresponds to which parameter in the BWS UI.

• This extension requires API version 12 and upwards which corresponds to BWS 3.2.5 or later.
• This code is licensed under Apache 2.0, which allows it to be used for free but also potentially to be used in commercially licensed software.

This is a Java-based extension (as opposed to JavaScript), which is to say it runs on the Java Virtual Machine, which permits a number of languages, including the one I have chosen to use in this instance - Kotlin. Kotlin is a "better Java", facilitating more concise and reliable programming. This code makes use of a number of Kotlin-specific programming approaches, such as extension functions, data classes, sealed classes, null-safety, and pattern matching. The code trys to stick to idiomatic Kotlin concepts like using expressions whereever possible.

The design of the extension is based on the Elm Architecture, a pattern introduced by the Elm language, and widely copied by other web UI frameworks. The basic concept is that of a state machine: The extension models a state which represents a combined state of the controller (the R24) and the application (BWS). This state can only be updated by means of input events coming from either the controller or the application. Any input event can result in a change to the model, or an output event being emitted, or both. The way in which input events are interpreted depends on the current state.
Emitted events are converted into calls to the BWS API.

A good example of state is the 'shift' state. For as long as the F1 button is held down, the 'shift' property of the internal state will be true.

Only one event can be processed at a time. It is processed to completion before the next event is considered.

The state itself is an immutable object - it is not changed but atomically replaced with an updated version when state change is required.

If you want to adapt this code for your own needs (or create a Pull Request on this repo) see this useful guide for tips on how to develop Java-based extensions. I recommend using IntelliJ as an IDE.

Many of the ideas for this extension were based on reading the code of Dirk Schiller and by following the YouTube tutorials of Juergen Mossgraber.

If you have suggestions for improvements either to the code or the functionality, please raise an issue. Even better, create a Pull Request with suggested fixes.