  In earlier work, the planar diagrams of $SU(N_c)$ gauge theory have been
regulated on the light-cone by a scheme involving both discrete $p^+$ and
$\tau=ix^+$. The transverse coordinates remain continuous, but even so all
diagrams are rendered finite by this procedure. In this scheme quartic
interactions are represented as two cubics mediated by short lived fictitious
particles whose detailed behavior could be adjusted to retain properties of the
continuum theory, at least at one loop. Here we use this setup to calculate the
one loop three gauge boson triangle diagram, and so complete the calculation of
diagrams renormalizing the coupling to one loop. In particular, we find that
the cubic vertex is correctly renormalized once the couplings to the fictitious
particles are chosen to keep the gauge bosons massless.
