Dll not found error

Hello

I am trying to use FFTW dll for C# but i get the error:

Code (CSharp):

1. DllNotFoundException: libfftw3-3.dll

The dll is in Assets > Plugins



I used this repository: https://github.com/tszalay/FFTWSharp

And followed this tutorial:

I made this script trying to use it, but i get the error so it won't run:

Code (CSharp):

1.  
2. using System;
3. using System.Runtime.InteropServices;
4. using FFTWSharp;
5. using UnityEngine;
6.  
7. public class Test : MonoBehaviour
8.     {
9.         [SerializeField,Range(0,10)] private int _size;
10.  
11.         [SerializeField] private float[] data;
12.         [SerializeField] private float[] result;
13.  
14.         void Awake()
15.         {
16.             result = Ifft(data);
17.         }
18.  
19.         private static float[] Ifft(float[] data)
20.         {
21.             // Get the length of the array
22.             int n = data.Length;
23.             /* Allocate an unmanaged memory block for the input and output data.
24.              * (The input and output are of the same length in this case,
25.              * so we can use just one memory block.) */
26.             IntPtr ptr = fftw.malloc(n * sizeof(double));
27.             // Pass the managed input data to the unmanaged memory block
28.             Marshal.Copy(data, 0, ptr, n);
29.             // Plan the IFFT and execute it (n/2 because
30.             // complex numbers are stored as pairs of doubles)
31.             IntPtr plan = fftw.dft_1d(n / 2, ptr, ptr, fftw_direction.Backward, fftw_flags.Estimate);
32.             fftw.execute(plan);
33.             // Create an array to store the output values
34.             float[] ifft = new float[n];
35.             // Pass the unmanaged output data to the managed array
36.             Marshal.Copy(ptr, ifft, 0, n);
37.             // Do some cleaning
38.             fftw.destroy_plan(plan);
39.             fftw.free(ptr);
40.             fftw.cleanup();
41.             // Scale the output values
42.             for (int i = 0, nh = n / 2; i < n; i++) ifft[i] /= nh;
43.             // Return the IFFT output
44.             return ifft;
45.         }
46.     }

What have i done wrong here?

 

are you getting the error in Unity, or Visual Studio?

 

I fixed the error, i had a 32 bit dll instead ot the 64 bit version. But since fixing that - now unity immediately crashes to desktop when i press play every time i run my script.

I checked editor logs and it does not show any errors relating to my dll so i am a bit stuck on why that might be happening.

 

You should be able to import both 32-bit and 64-bit. Then mark each one in the inspector accordingly.

Try changing your compile settings in player settings under configuration. That may help if it is a compatibility issue.

 

Thats not the issue at the moment. At the moment it just crashes to desktop when i press play. And i have no idea how to debug it.

 

How do you know it is not a comparability issue, have you done any testing to check/confirm this?

You can use visual studio to debug. If you add a break-point when the script first starts getting called, then use visual studio to start the game. You can step down until something causes the crash.

 

I don't know - am new to using DLLs for unity that are not written in C#. But step through does nothing since unity crashes and VS will lock up if i use breakpoints. If i don't run the script that uses the DLL then unity runs fine.

 

Can you upload a slim version of your project. I can open it up and take a look for you.