[nicknash]

A fun fact: Each point in the XOR texture is the smallest integer not appearing above it, or to its left

(Ducking while posting my own blog: https://nicknash.me/2012/10/26/happy-halloween/)

[lilyball]

The row starting with 5 in your example matrix is wrong, it should look like

  5 4 7 6 1 0 3 2