You can call functions from your C, C++, or C# plug-insA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
See in Glossary in your Unity projects.
Unity uses Emscripten to compile your sources into WebAssembly from C/C++/C# code, so you can write plug-ins in C/C++/C# code and call these functions from your Unity 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
See in Glossary.
To call functions from your JavaScript plug-ins instead, refer to Call JavaScript functions from Unity C# scripts.
To allow your Unity project to call functions from your C/C++/C# plug-in code, you need to import your plug-in into your Unity project.
In your Unity project, put your plug-in files in the Assets/Plugin folder.
If you use C++ (.cpp) to implement the plug-in, you must declare the functions with C linkage (extern “C”) to avoid name mangling issues.
The following code is an example C++ plug-in with simple functions that you can call in your Unity project.
#include <stdio.h>
extern "C" void Hello ()
{
printf("Hello, world!\n");
}
extern "C" int AddNumbers (int x, int y)
{
return x + y;
}
Note: Unity uses the Emscripten version 2.0.19 toolchain.
Use the following Unity C# code in your Unity project to call the C++ functions.
using UnityEngine;
using System.Runtime.InteropServices;
public class NewBehaviourScript : MonoBehaviour {
[DllImport("__Internal")]
private static extern void Hello();
[DllImport("__Internal")]
private static extern int AddNumbers(int x, int y);
void Start() {
Hello();
int result = AddNumbers(5, 7);
Debug.Log(result);
}
}