Some convenient functions related to transformations.
Conjugate one transformation by another.
conjugate t1 t2 is the
transformation which performs first
t2, then the
Carry out some transformation "under" another one:
f ` first applies
f, then the inverse of
equivalent to a rotation by 120 degrees about the point
rotateBy (1/3) `
(-1,0) (you may have to think about this for a minute =).
(transform t2) `under` t1 == transform (conjugate t1 t2)
for all transformations