. . . x * * * (row 2, bit value 4) 
  . . . * * * * (row 1, bit value 2)
  . * * . . . * (row 0, bit value 1)

  0 1 1 2 6 6 7 (bitwise column values)

##</code><code>##

  . . . x * * * (still row 2)
  . * * . . . * (was row 0, now row 1)
  . . . * * * * (was row 1, now row 0)

  0 2 2 1 5 5 7 (new bitwise column values)

##</code><code>##

  . x . . * * *
  . . * * . . *
  . * . . * * *

  0 1 2 2 5 5 7 (new bitwise column values)