since we know that this is a matrix only used for 2D transforms,
we know that the last row of the matrix is always { 0, 0, 1 }.
Therefore, we don't need to store that information, and
we can simplify some of the computations.
Also remove operations like operator+ which are not legal for
such a matrix.
Change-Id: I482de9a45ebbedf79e3b6033575aab590e61c2d5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/151909
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Noel Grandin
fdd06037e0