Dimension Swapper


I’ve been fiddling for quite some time with the “Dimension Swapper” node. Supposed to "e.g.: If you swap dimension X and Y, the Image will be rotated by 90 degress. ". The help guides don’t mention a thing about the first tab (which is usually the most relevant one). On the first tab, there’s a set of 0-4 buttons in yellow and another in purple. What are these supposed to mean? If you cross the 0 and 1s, the image is rotated (is swapped) 90 degrees (but not the way I’d like).

Could someone please elaborate on what the 0-4 represents?

Thanks in advance,