Sending a NativeArray to be modified in a C++ Native Plugin

Hi!,

I was wondering if it is possible to send a NativeArray pointer to a C++ Native Plugin to be modified. What is the fastest way to do this? Since it is a NativeArray, I was wondering if there is a way that avoids any Marshalling/Copying.

This would be for an array of bytes.

 

I just found there is this thread about this already...
https://forum.unity.com/threads/how-to-pass-nativearray-byte-to-native-plugin.517015/

I will try to figure it out, however if anyone can provide a simple C++/C# side function definitions, that would be great.

 

OK, here it is:

Code (C++):

1.  
2. extern "C" {
3.    void UNITY_EXPORT SendBytes(void *bytes) {
4.        unsigned char *ptr = (unsigned char *)bytes;
5.        // do something
6.    }
7. }
8.  

Code (CSharp):

1.  
2. [DllImport("libraryName")]
3. unsafe public static extern void SendBytes(void* bytes);
4.  
5. // usage
6. void SomeFunction(NativeArray<byte> nativeByteArray) {
7.    unsafe {
8.       void* ptr = NativeArrayUnsafeUtility.GetUnsafePtr(nativeByteArray);
9.       SendBytes(ptr);
10.    }
11. }
12.  

 

GetUnsafePtr/GetUnsafeReadOnlyPtr extension methods of NativeArray.

 

note that you must also set the saftey handle
NativeArrayUnsafeUtility.SetAtomicSafetyHandle(ref arr, AtomicSafetyHandle.Create());