gilzoide / FSharp-Unity

Instructions for using F# with Unity

How to use F# libraries with Unity

The IDE project way

Note: this has only been tested out with Xamarin Studio on Mac OS X

1. Create a Unity Project
2. In the Unity 'Assets' folder, create a folder called 'Frameworks' and add the FSharp.Core.dll to it
3. Create a F# project (lib) and put it in the root of the Unity project
4. Open the preferences for the F# project and change the 'Target Framework' to 'Mono / .NET 3.5'
5. Remove all References in the project, except FSharp.Core (2.3.0), System and System.Core
6. Add the unity mscorlib.dll to somewhere in the F# project folder, and then to the project References
7. Make a custom build command (working dir: ${TargetDir}) that copies the resulting dll to the Unity 'Frameworks' folder

    cp MyFsharpLib.dll ../../../../Assets/Frameworks/

The command line way

Note: this has only been tested out on Linux (fsharpc command, which calls fsc.exe)

1. Create a Unity Project
2. Clone this repo in the root folder of your Unity Project
3. Call the prepare.sh script, that'll create the 'Assets/Frameworks' and 'Assets/Editor' folder, and copy the needed files
4. Put your F# source code (.fs file) in the 'Assets/Scripts' folder, edit it with your favorite text editor
5. Open the F# Compiler Window (from the 'F#/Compiler' menu, or with Shift+Ctrl+3)
6. Click the 'Compile F#s' button. Build errors are logged in the Editor's Console
7. Wait until complete. Dlls will be put in the 'Assets/Frameworks' folder

• You can access namespaces/classes from C# components just like you'd expect
• The component will show up under the DLL in Unity's Project view, click the little arrow to fold it out (or just add it to a game object using the Add Component menu)

How to write Unity components in F#

• Set the namespace as the file name

namespace MyFsharpLib

• Import the Unity namespace

open UnityEngine

• Inherit from MonoBehaviour, as usual

type SimpleComponent() =
    inherit MonoBehaviour()
    member this.stuff = 42

• To show properties in the inspector, make them mutable and serializable

    [<SerializeField>]
    let mutable changeSpeed = 2.0f

• Override member functions

    member this.Start () = 
        this.transform.Translate(1.0f, -1.0f, 2.0f)

• Mutate members

    this.renderer.material.color <- Color.red