/* This hook is called at the end of every frame. */
static void machine_vsync_hook(void)
{
CLOCK sub;
network_hook();
drive_vsync_hook();
autostart_advance();
screenshot_record();
sub = clk_guard_prevent_overflow(maincpu_clk_guard);
/* The drive has to deal both with our overflowing and its own one, so
it is called even when there is no overflowing in the main CPU. */
drivecpu_prevent_clk_overflow_all(sub);
}
/* Make sure the drive clock counters never overflow; return nonzero if
they have been decremented to prevent overflow. */
CLOCK drivecpu_prevent_clk_overflow(drive_context_t *drv, CLOCK sub)
{
if (sub != 0) {
/* First, get in sync with what the main CPU has done. Notice that
`clk' has already been decremented at this point. */
if (drv->drive->enable) {
if (drv->cpu->last_clk < sub) {
/* Hm, this is kludgy. :-( */
drive_cpu_execute_all(maincpu_clk + sub);
}
drv->cpu->last_clk -= sub;
} else {
drv->cpu->last_clk = maincpu_clk;
}
}
/* Then, check our own clock counters. */
return clk_guard_prevent_overflow(drv->cpu->clk_guard);
}