Reference: pmTransform
pmTransform(pm, M) returns the image of the pixmap after being transformed by the linear transformation (i.e., a 2×2 square matrix) M. pmTransform(pm, a11, a12, a21, a22) returns the image of the pixmap after being transformed by the linear transformation (i.e., a 2×2 square matrix) ❨❨a11, a12❩, ❨a21, a22❩❩.