利用者・トーク:Nazg-gul/MaskEditor
About ZanQdo's comment and the solution you propose. I think, because the transformation apply to the entire spline and not to a single point, it would be better to use:
float transform_matrix[3][3];
instead of
float offset[2];
that would permit to fine tune rotation, scaling and possibly shear/skew instead of just an position offset.