Internally a transformation is stored in a 4x3 matrix.
The left-top 3x3 submatrix
provides rotation, scaling and skewing.
Post translation is stored in
A separate vector containing the pretranslation, with an implicit
column
at the end when 4x4 multiplies are required.
The 'center of rotation' is NOT implemented as a separate vector, but as a combination of pre and post translations.