Unity array, get current index -x or +x

Question

How I can achieve getting the current index -5 for example. I know how to get the current index and I can subtract or add to that index, but this will cause Array out of bounds errors. Let's say the array has 15 items (index 0/14) and my current index is 2 if I will subtract 5 it will return -3. And this doesn't exist in the array. Now what I want is that when the index is 2 and I substract 5 it returns 11, so it should always loop through the array. The same applies for adding 5 obviously.

Answer 1

You can create an extenstion method like this:

public static int ComputeCircularIndex(this Array arr, int i) 
{
   int N = arr.GetLength(0);
   if (i < 0) 
   {
       i = N + (i % N);
   } 
   else 
   {
       i = i % N;
   }
   return i;
}