  We discuss influence of modulation of gap function and anisotropy of Fermi
velocity to field angle dependences of upper critical field, $H_{c2}$, and
specific heat, $C$, on the basis of the approximate analytic solution in the
quasiclassical formalism. Using 4-fold modulation of the gap function and the
Fermi velocity in the single-band model, we demonstrate field and temperature
dependence of oscillatory amplitude of $H_{c2}$ and $C$. We apply the method to
the effective two-band model to discuss the gap structure of Sr$_2$RuO$_4$,
focusing on recent field angle-resolved experiments. It is shown that the gap
structures with the intermediate magnitude of minima in $[100]$ direction for
$\gamma$ band, and tiny minima of gaps in $[110]$ directions for $\alpha$ and
$\beta$ bands give consistent behaviors with experiments. The interplay of the
above two gaps also explains the anomalous temperature dependence of in-plane
$H_{c2}$ anisotropy, where the opposite contribution from the passive
$\alpha\beta$ band is pronounced near $T_c$.
