Version: 2018.2 (switch to 2018.1 or 2017.4)
Extending the UnityPlayerActivity Java Code
Customizing an Android Splash Screen
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Native (C++) plug-ins for Android

Unity supports native plug-ins for Android written in C/C++ and packaged in a shared library (.so) or a static library (.a). When using the IL2CPPA Unity-developed scripting back-end which you can use as an alternative to Mono when building projects for some platforms. More info
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scripting backendA framework that powers scripting in Unity. Unity supports three different scripting backends depending on target platform: Mono, .NET and IL2CPP. Universal Windows Platform, however, supports only two: .NET and IL2CPP. More info
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, you can use C/C++ source files as plug-ins and Unity compiles them along with IL2CPP generated files. This includes all C/C++ source files with extensions .c, .cc, .cpp and .h.

To buildThe process of compiling your project into a format that is ready to run on a specific platform or platforms. More info
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a C++ plug-in for Android, use the Android NDK and get yourself familiar with the steps required to build a shared library. The same applies to static libraries.

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. By default, only the C source files that have a .c file extension in the plug-ins have C linkage (not C++).

extern "C" {
  float Foopluginmethod ();
}

After building the library, copy the output .so file(s) into the Assets/Plugins/Android directory in your Unity project. In the InspectorA Unity window that displays information about the currently selected GameObject, Asset or Project Settings, alowing you to inspect and edit the values. More info
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, mark your .so files as compatible with Android, and set the required CPU architecture in the dropdown box:

Native(C++) plug-in import settings as displayed in the Inspector window
Native(C++) plug-in import settings as displayed in the Inspector window

To call the methods in your native plug-in from within your C# scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
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, 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.

When you use C/C++ source files as plug-ins, you call them from C# in the same way except that you use __Internal for plug-in name, for example:

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

Native (C++) plug-in Sample

This zip archive contains a simple example of a native code plug-in. This sample demonstrates how C++ code is invoked from a Unity application. The package includes a sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
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which displays the sum of two values as calculated by the native plug-in. You will need the Android NDK to compile the plug-in.



  • 2018–03–10 Page published with limited editorial review

  • Updated features in 5.5

  • Support for using C++ source files and static libraries as plug-ins on Android added in 2018.2 NewIn20182

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Extending the UnityPlayerActivity Java Code
Customizing an Android Splash Screen