  A theory for surface transitions in the presence of a disordered pinning
potential is presented. Arbitrary disorder correlations are treated in the
framework of a dynamical functional renormalization group. The roughening
transition, where surface roughness and mobility behave discontinuously, is
shown to turn smoothly into the continuous superroughening transition, when the
range of disorder correlations is decreased. Implications for random-field
$XY$-models and vortex glasses are discussed.
