the matrix:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
in row major:
float mat[16] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};
in column major:
float mat[16] = {1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16};
dGhlIG1hdHJpeDoKCiAxICAyICAzICA0CiA1ICA2ICA3ICA4CiA5IDEwIDExIDEyCjEzIDE0IDE1IDE2IAoKaW4gcm93IG1ham9yOgpmbG9hdCBtYXRbMTZdID0gezEsMiwzLDQsNSw2LDcsOCw5LDEwLDExLDEyLDEzLDE0LDE1LDE2fTsKCmluIGNvbHVtbiBtYWpvcjoKZmxvYXQgbWF0WzE2XSA9IHsxLDUsOSwxMywyLDYsMTAsMTQsMyw3LDExLDE1LDQsOCwxMiwxNn07