DLL UINT array pointer

Hey everyone,

I was just trying to use an external DLL developed in flat assembly. I got everything nicely imported, except I am stuck on the "UINT pointer to an array of floats:

original:

UINT GetData(
UINT ptrFloatArray);

my version:

[DllImport ("dll")]
private static extern uint GetData( uint ptrFloatArray );


I have tried a lot the last couple of hours, but Unity keeps crashing (and I am totally the one to blame for that! ).

Most of the time I have been trying to use the GCHandle in various ways:

Code (csharp):

1.  
2.     private GCHandle _hGCFile;
3.     public float[] buffer;
4.  
5.         // get the legth of the file
6.         uint length = 512;
7.        
8.         // create the buffer which will keep the file in memory
9.         buffer = new float[length];
10.  
11.         _hGCFile = GCHandle.Alloc( buffer, GCHandleType.Pinned );
12.  

and then using GCHandle.ToIntPtr(_hGCFile) as parameter, or other variants including casts to uint, UInt32, Int32, etc. Or just passing the array as float[] to the function.

But nothing works, and if Unity does not crash, the array stays empty (which is not good as well ). Anyone have a simple suggestion on what I might be overlooking?

Thanks!

 

The TexturePlugin example helped me out a lot.

It's pretty much exactly what you want.
They parse Unity's Color (which is made of four floats) - so just take is as a reference and edit as needed.

 

This is a small snippet of some dll interface code I wrote. Maybe you can get some hints to your problem from that.

Code (csharp):

1.  
2. static extern int VcGetEncBytes(IntPtr pData, int maxLength, IntPtr pWrittenBytes);
3.  
4.  
5. public static bool GetEncodedBytes(ref byte[] array, ref int writtenBytes)
6. {
7.     GCHandle pArray = GCHandle.Alloc(array, GCHandleType.Pinned);
8.     GCHandle pWrittenBytes = GCHandle.Alloc(writtenBytes, GCHandleType.Pinned);
9.     if (VcGetEncBytes(pArray.AddrOfPinnedObject(), array.Length*sizeof(byte), pWrittenBytes.AddrOfPinnedObject()) == (int)VoiceComponentReturn.Success)
10.     {
11.         writtenBytes = (int)pWrittenBytes.Target;
12.         pArray.Free();
13.         pWrittenBytes.Free();
14.         return true;
15.     }
16.     writtenBytes = 0;
17.     pArray.Free();
18.     pWrittenBytes.Free();
19.     return false;
20. }
21.  

//perlohmann