Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/robert-96/unity-swift

A simple Unity plug-in for iOS.
https://github.com/robert-96/unity-swift

csharp ios objective-c plugin swift unity

Last synced: 3 months ago
JSON representation

A simple Unity plug-in for iOS.

Awesome Lists containing this project

README 

        
# UnitySwift



A simple Unity plug-in for iOS designed to serve as a starting point for creating new plugins that bridge [Unity](http://unity3d.com/) and [Swift](https://swift.org/).



## Getting Started



Follow the instructions below to set up the plugin and integrate it into your Unity project.



### Prerequisites



* Unity 2019.x or later

* Xcode 11 or later



### Integration into Your Own Project



1. Clone or download this repository.

1. Open the Unity project where you want to integrate the Swift plugin.

1. Copy the entire `Assets/Plugins/iOS` folder from this repository into your Unity project's `Assets/Plugins` folder.



## Create a Unity plug-in from scratch



### How to call Swift methods from Unity



#### **Step 1**: Create your Swift classes



Add the following code into `Assets/Plugins/iOS/SwiftToUnity/Source/SwiftToUnity.swift`:



```swift

import Foundation



@objc public class SwiftToUnity: NSObject {

    @objc public static let shared = SwiftToUnity()



    /// Returns the "Hello, Swift!" string.

    ///

    /// - Returns: The "Hello, Swift!" string.

    @objc public func swiftHelloWorld() -> String {

        return "Hello, Swift!"

    }

}

```



Note that here `@obc` instructs Swift to make classes or methods available to Objective-C as well as Swift code.



#### **Step 2**: Create a `.mm` bridge file



Add the following code into `Assets/Plugins/iOS/SwiftToUnity/Source/SwiftToUnityBridge.mm`:



```objc

#import 

#import "UnityInterface.h"



extern "C"

{

    char* cStringCopy(const char* string) {

        if (string == NULL) {

            return NULL;

        }



        size_t length = strlen(string) + 1;

        char* res = (char*) malloc(length);



        if (res != NULL) {

            memcpy(res, string, length);

        }



        return res;

    }



    char* cHelloWorld()

    {

        NSString *returnString = [[SwiftToUnity shared] swiftHelloWorld];

        return cStringCopy([returnString UTF8String]);

    }

}

```



The `SwiftToUnityBridge.mm` file is the bridging medium between Swift and Unity.



#### **Step 3**: Add ``UnityFramework.modulemap``



Add the following code into `Assets/Plugins/iOS/SwiftToUnity/Source/UnityFramework.modulemap`:



```objc

framework module UnityFramework {

  umbrella header "UnityFramework.h"



  export *

  module * { export * }



  module UnityInterface {

      header "UnityInterface.h"



      export *

  }

}

```



#### **Step 4**: Add ``SwiftToUnityPostProcess.cs`` script



First, you will need to add the [PostProcessing](https://docs.unity3d.com/2022.3/Documentation/Manual/com.unity.postprocessing.html) package to your Unity project.



To install the package, go to **Window > Package Manager** and switch the view from **In Project** to **All**. Select **Post Processing** in the list. In the right panel you'll find information about the package and a button to install or update to the latest available version for the version of Unity you are running.



Now add the following code into `Assets/Plugins/iOS/SwiftToUnity/Editor/SwiftToUnityPostProcess.cs`:



```csharp

#if UNITY_IOS

using System.IO;

using UnityEngine;

using UnityEditor;

using UnityEditor.Callbacks;

using UnityEditor.iOS.Xcode;



public static class SwiftToUnityPostProcess

{

    [PostProcessBuild]

    public static void OnPostProcessBuild(BuildTarget buildTarget, string buildPath)

    {

        Debug.Log("OnPostProcessBuild: " + buildTarget);



        if (buildTarget == BuildTarget.iOS)

        {

            var projectPath = buildPath + "/Unity-iPhone.xcodeproj/project.pbxproj";



            var project = new PBXProject();

            project.ReadFromFile(projectPath);



            var unityFrameworkGuid = project.GetUnityFrameworkTargetGuid();



            // Modulemap

            project.AddBuildProperty(unityFrameworkGuid, "DEFINES_MODULE", "YES");



            var moduleFile = buildPath + "/UnityFramework/UnityFramework.modulemap";

            if (!File.Exists(moduleFile))

            {

                FileUtil.CopyFileOrDirectory("Assets/Plugins/iOS/SwiftToUnity/Source/UnityFramework.modulemap", moduleFile);

                project.AddFile(moduleFile, "UnityFramework/UnityFramework.modulemap");

                project.AddBuildProperty(unityFrameworkGuid, "MODULEMAP_FILE", "$(SRCROOT)/UnityFramework/UnityFramework.modulemap");

            }



            // Headers

            string unityInterfaceGuid = project.FindFileGuidByProjectPath("Classes/Unity/UnityInterface.h");

            project.AddPublicHeaderToBuild(unityFrameworkGuid, unityInterfaceGuid);



            string unityForwardDeclsGuid = project.FindFileGuidByProjectPath("Classes/Unity/UnityForwardDecls.h");

            project.AddPublicHeaderToBuild(unityFrameworkGuid, unityForwardDeclsGuid);



            string unityRenderingGuid = project.FindFileGuidByProjectPath("Classes/Unity/UnityRendering.h");

            project.AddPublicHeaderToBuild(unityFrameworkGuid, unityRenderingGuid);



            string unitySharedDeclsGuid = project.FindFileGuidByProjectPath("Classes/Unity/UnitySharedDecls.h");

            project.AddPublicHeaderToBuild(unityFrameworkGuid, unitySharedDeclsGuid);



            // Save project

            project.WriteToFile(projectPath);

        }



        Debug.Log("OnPostProcessBuild: Complete");

    }

}

#endif

```



Be sure to change the following line in ``SwiftPostProcess.cs`` script with the correct path to your `UnityFramework.modulemap` file:



```csharp

FileUtil.CopyFileOrDirectory("Assets/Plugins/iOS/SwiftToUnity/Source/UnityFramework.modulemap", moduleFile);

```



#### **Step 5**: Call your Swift methods from Unity



```csharp

using System.Runtime.InteropServices;

using UnityEngine;



public class CanvasScript : MonoBehaviour

{

    [DllImport("__Internal")]

    private static extern string cHelloWorld();



    private void Start()

    {

        cHelloWorld();

    }

}

```



### How to call Unity methods from Swift



To call Unity methods from Swift, use `UnitySendMessage` function like below:



```swift

// SwiftToUnity.swift

import Foundation



@objc public class SwiftToUnity: NSObject {

    @objc public static let shared = SwiftToUnity()



    /// Sends a "Hello World" message to the "Canvas" GameObject by calling the "OnMessageReceived" script method on that object with the "Hello World!" message.

    @objc public func swiftSendHelloWorldMessage() {

        // The UnitySendMessage function has three parameters: the name of the target GameObject, the script method to call on that object and the message string to pass to the called method.

        UnitySendMessage("Canvas", "OnMessageReceived", "Hello World!");

    }

}

```



See [SwiftToUnity.swift](Assets/Plugins/iOS/SwiftToUnity/Source/SwiftToUnity.swift).



For more information about `UnitySendMessage`, check out [Unity's Documentation](https://docs.unity3d.com/Manual/PluginsForIOS.html).



## License



This project is licensed under the [MIT License](LICENSE).