Is there a utility method for faster copying of NativeArray?

Is there a better method other looping through arrays and copying each element?

 

Where you copying too?
What you try to do?

 

I'm trying to expand an existing array. I'm copying to an array with bigger length.

 

I have stumbled upon same problem at some point.
Didn't have to comback to it, as I change approach.
But questions still stays.

 

We have nativeArray.CopyTo(nativeArray) but I am not sure of the behaviour where the target is larger/smaller than the current one. One thing for sure it use UnsafeUtility.MemCpy which should be faster than manual looping.

But you can also try NativeList instead. Each add might be slower than directly assigning to NativeArray but maybe the expansion cost is cheaper than making a new bigger NativeArray depending on your situation. The expansion rule is the initial capacity will *2 when you go over it.

 

Can you share the code of NativeArray.CopyTo()?

 

Isn't it just like this :

Code (CSharp):

1.  
2.         NativeArray<int> one = new NativeArray<int>(5, Allocator.Temp);
3.         NativeArray<int> two = new NativeArray<int>(10, Allocator.Temp);
4.         one[0] = 10;
5.         one[1] = 10;
6.         one.CopyTo(two);
7.         Assert.That(two[0], Is.EqualTo(10));
8.  

 

It doesn't work. They need to have the same length.

 

You can use NativeSlice

Code (CSharp):

1.             var array1 = new NativeArray<int>(100, Allocator.Temp);
2.             var array2 = new NativeArray<int>(50, Allocator.Temp);
3.        
4.             var slice1 = new NativeSlice<int>(array1, 25, 50);
5.             var slice2 = new NativeSlice<int>(array2);
6.        
7.             slice1.CopyFrom(slice2);
8.        
9.             // array1 index from 25 -> 75 is now equal to array 2

It's very fast.
To create a slice it just grabs the pointer from the NativeArray and offsets it.
CopyFrom/CopyTo uses MemCopy.

 

This works. Thanks!

 

Hey Joachim. Is this available in the beta? I need a fast copy from NativeArray to .NET array.