Since rB3bd4f229beb, mirror elements are no longer` TransData`.
Thus, some values computed with the TransData array now ignore mirror elements.
The solution is to duplicate the logic to use mirror elements in each case.
I don't like the idea of duplicating code but this solution has advantages in peformanse and memory.
The best solution would be to rearrange and make separate arrays for each case (instead of adding more members to TransData).
But that would be a huge refactor.