void emu_run()
{
void *timer = sys_timer();
int delay;
vid_begin();
lcd_begin();
for (;;)
{
cpu_emulate(2280);
while (R_LY > 0 && R_LY < 144)
emu_step();
vid_end();
rtc_tick();
sound_mix();
if (!pcm_submit())
{
delay = framelen - sys_elapsed(timer);
sys_sleep(delay);
sys_elapsed(timer);
}
doevents();
vid_begin();
if (framecount) { if (!--framecount) die("finished\n"); }
if (!(R_LCDC & 0x80))
cpu_emulate(32832);
while (R_LY > 0) /* wait for next frame */
emu_step();
}
}
/*
Time intervals throughout the code, unless otherwise noted, are
specified in double-speed machine cycles (2MHz), each unit
roughly corresponds to 0.477us.
For CPU each cycle takes 2dsc (0.954us) in single-speed mode
and 1dsc (0.477us) in double speed mode.
Although hardware gbc LCDC would operate at completely different
and fixed frequency, for emulation purposes timings for it are
also specified in double-speed cycles.
line = 228 dsc (109us)
frame (154 lines) = 35112 dsc (16.7ms)
of which
visible lines x144 = 32832 dsc (15.66ms)
vblank lines x10 = 2280 dsc (1.08ms)
*/
void emu_run()
{
void *timer = sys_timer();
int delay;
vid_begin();
lcd_begin();
for (;;)
{
/* FRAME BEGIN */
/* FIXME: djudging by the time specified this was intended
to emulate through vblank phase which is handled at the
end of the loop. */
cpu_emulate(2280);
/* FIXME: R_LY >= 0; comparsion to zero can also be removed
altogether, R_LY is always 0 at this point */
while (R_LY > 0 && R_LY < 144)
{
/* Step through visible line scanning phase */
emu_step();
}
/* VBLANK BEGIN */
vid_end();
rtc_tick();
sound_mix();
/* pcm_submit() introduces delay, if it fails we use
sys_sleep() instead */
if (!pcm_submit())
{
delay = framelen - sys_elapsed(timer);
sys_sleep(delay);
sys_elapsed(timer);
}
doevents();
vid_begin();
if (framecount) { if (!--framecount) die("finished\n"); }
if (!(R_LCDC & 0x80)) {
/* LCDC operation stopped */
/* FIXME: djudging by the time specified, this is
intended to emulate through visible line scanning
phase, even though we are already at vblank here */
cpu_emulate(32832);
}
while (R_LY > 0) {
/* Step through vblank phase */
emu_step();
}
/* VBLANK END */
/* FRAME END */
}
}
// void *timer = sys_timer();
// int delay;
void emu_frame(void)
{
/* FRAME BEGIN */
/* FIXME: djudging by the time specified this was intended
to emulate through vblank phase which is handled at the
end of the loop. */
cpu_emulate(2280);
/* FIXME: R_LY >= 0; comparsion to zero can also be removed
altogether, R_LY is always 0 at this point */
while (R_LY > 0 && R_LY < 144)
{
/* Step through visible line scanning phase */
emu_step();
}
/* VBLANK BEGIN */
vid_end();
rtc_tick();
sound_mix();
pcm_submit();
/* pcm_submit() introduces delay, if it fails we use
sys_sleep() instead */
/* timebase is exclusively done with pcm submit. we shall sync with LCD !
if (!pcm_submit())
{
delay = framelen - sys_elapsed(timer);
sys_sleep(delay);
sys_elapsed(timer);
}*/
// doevents(); // does not handle extra events
gamepad_poll();
vid_begin();
if (!(R_LCDC & 0x80)) {
/* LCDC operation stopped */
/* FIXME: djudging by the time specified, this is
intended to emulate through visible line scanning
phase, even though we are already at vblank here */
cpu_emulate(32832);
}
while (R_LY > 0) {
/* Step through vblank phase */
emu_step();
}
/* VBLANK END */
/* FRAME END */
}
int main(void) {
emu_init();
emu_step();
return 0;
}