Unity Native Plugin Example for iOS & macOS using Swift

Unity supports native plugin, which are libraries of native code written in Swift.
Native plugin make possible for code written in C# to call functions from these libraries.
Check this document for detailed Native Plugin creation instructions.

Build Swift Libraries

Check Makefile for command details.

Build Framework for iOS

$ make framework

This should result in SwiftPmPlugin.framework being generated in Build.
Copy the built framework into your Unity project's Assets/Plugins/iOS.
Enable Add To Embedded Binaries in the Unity Inspector of SwiftPmPlugin.framework.

Build Bundle for macOS

$ make bundle

This should result in SwiftPmPlugin.bundle being generated in Build.
Copy the built bundle into your Unity project's Assets/Plugins/macOS.
Need to restart unity to load the new bundle.

Swift Interface Example for Unity

Check UnityInterface.swift for details.

@_cdecl("swiftPmPlugin_toNumber")
public func swiftPmPlugin_toNumber(_ stringPtr: UnsafePointer<CChar>?) -> Int64 {
    let str = String(cString: stringPtr!)
    return Int64(Int(str) ?? 0)
}

Call Swift Function in C#

Check SwiftPmPlugin.cs for details.

[DllImport(libName)]
private static extern long swiftPmPlugin_toNumber(string stringNumber);

public static long ToNumber(string stringNumber)
{
    return swiftPmPlugin_toNumber(stringNumber);
}