tx, ty = pmatrix:TransformDistance(dx, dy)

This is similar to pmatrix:TransformPoint(), except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:

dx2 = dx1 * xx + dy1 * xy; dy2 = dx1 * yx + dy1 * yy;

Affine transformations are position invariant, so the same vector always transforms to the same vector. If (x1,y1) transforms to (x2,y2) then (x1+§dx1,y1+§dy1) will transform to (x1+§dx2,y1+§dy2) for all values of x1 and x2.

dx

X component of a distance vector

dy

Y component of a distance vector

tx

transformed X component of a distance vector

ty

transformed Y component of a distance vector