It seems that there's actually a bug here: the same var (idx) is used
as an index for vertical and horizontal scaling arrays. However,
there are 4 elements on the h arrays, and only 3 at the v ones.
On the first loop, it may select index 4 for the horizontal array.
In this case, if the second loop fails to select an index, the
code would keep using 4 for the vertical array, with is past of
the array sizes.
The intent here seems to use index 0, if the scale is not found.