Native (C++) plug-ins for Android

Unity supports native plug-ins for Android written in C/C++ and packaged in a shared library (.so).

To build a C++ plug-in for Android, use the Android NDK and get yourself familiar with the steps required to build a shared library.

If you are using C++ to implement the plug-in, you must ensure the methods are declared with C linkage to avoid name mangling issues.

extern "C" {
  float Foopluginmethod ();
}

After building the library, copy the output .so file(s) into your Unity project. In the Inspector, mark your .so files as compatible with Android, and set the required CPU architecture in the dropdown box:

To call the methods in your native plug-in from within your C# scripts, use the following code:

[DllImport ("pluginName")]
private static extern float Foopluginmethod();

Note that pluginName should not include the prefix (‘lib’) or the extension (‘.so’) of the filename. It is recommended to wrap all the native plug-in method calls with an additional C# code layer. This code checks Application.platform and calls native methods only when the app is running on the actual device; dummy values are returned from the C# code when running in the Editor. Use platform defines to control platform dependent code compilation.

Native (C++) plug-in Sample

The AndroidNativePlugin.unitypackage zip file contains a simple example of a native code plug-in distributed as Unity package.

The sample shows how to invoke C++ code from a Unity application. The package includes a scene which displays the sum of two values as calculated by the native plug-in. To compile the plug-in must install the Android NDK.

To install the sample:

1. Download the the zip file.
2. Extract the AndroidNativePlugin.unitypackage file.
3. Open the Unity Editor.
4. Create a new Project.
5. In the new project click Assets > Import Package > Custom Package.
6. In the Import Package file dialog, navigate to the location in which you extracted the file and select it.

• Updated features in 5.5