/* End of frame update, return the number of samples run so far. */
int sound_update(unsigned int cycles)
{
int size, avail;
/* run PSG & FM chips until end of frame */
cycles <<= 11;
psg_update(cycles);
fm_update(cycles);
/* check number of available FM samples */
if (config.hq_fm)
{
size = Fir_Resampler_avail();
}
else
{
size = (snd.fm.pos - snd.fm.buffer) >> 1;
}
#ifdef LOGSOUND
error("%d FM samples available\n",size);
#endif
/* check number of available PSG samples */
avail = snd.psg.pos - snd.psg.buffer;
#ifdef LOGSOUND
error("%d PSG samples available\n", avail);
#endif
/* resynchronize FM & PSG chips */
if (size > avail)
{
/* FM chip is ahead */
fm_cycles_count += SN76489_Clocks(size - avail) * psg_cycles_ratio;
/* return number of available samples */
size = avail;
}
else
{
/* PSG chip is ahead */
psg_cycles_count += SN76489_Clocks(avail - size) * psg_cycles_ratio;
}
#ifdef LOGSOUND
error("%lu PSG cycles run\n",psg_cycles_count);
error("%lu FM cycles run \n",fm_cycles_count);
#endif
/* adjust PSG & FM cycle counts for next frame */
psg_cycles_count -= cycles;
fm_cycles_count -= cycles;
#ifdef LOGSOUND
error("%lu PSG cycles left\n",psg_cycles_count);
error("%lu FM cycles left\n",fm_cycles_count);
#endif
return size;
}
unsigned int fm_read(unsigned int cycles, unsigned int address)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* read FM status (YM2612 only) */
return YM2612Read();
}
void fm_reset(unsigned int cycles)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* reset FM chip */
YM_Reset();
}
void fm_write(unsigned int cycles, unsigned int address, unsigned int data)
{
/* synchronize FM chip with CPU (on data port write only) */
if (address & 1)
{
fm_update(cycles);
}
/* write FM register */
YM_Write(address, data);
}
int sound_update(unsigned int cycles)
{
int delta, preamp, time, l, r, *ptr;
/* Run PSG & FM chips until end of frame */
SN76489_Update(cycles);
fm_update(cycles);
/* FM output pre-amplification */
preamp = config.fm_preamp;
/* FM frame initial timestamp */
time = fm_cycles_start;
/* Restore last FM outputs from previous frame */
l = fm_last[0];
r = fm_last[1];
/* FM buffer start pointer */
ptr = fm_buffer;
/* flush FM samples */
if (config.hq_fm)
{
/* high-quality Band-Limited synthesis */
do
{
/* left channel */
delta = ((*ptr++ * preamp) / 100) - l;
l += delta;
blip_add_delta(snd.blips[0][0], time, delta);
/* right channel */
delta = ((*ptr++ * preamp) / 100) - r;
r += delta;
blip_add_delta(snd.blips[0][1], time, delta);
/* increment time counter */
time += fm_cycles_ratio;
}
while (time < cycles);
}
else
{
/* faster Linear Interpolation */
do
{
/* left channel */
delta = ((*ptr++ * preamp) / 100) - l;
l += delta;
blip_add_delta_fast(snd.blips[0][0], time, delta);
/* right channel */
delta = ((*ptr++ * preamp) / 100) - r;
r += delta;
blip_add_delta_fast(snd.blips[0][1], time, delta);
/* increment time counter */
time += fm_cycles_ratio;
}
while (time < cycles);
}
/* reset FM buffer pointer */
fm_ptr = fm_buffer;
/* save last FM output for next frame */
fm_last[0] = l;
fm_last[1] = r;
/* adjust FM cycle counters for next frame */
fm_cycles_count = fm_cycles_start = time - cycles;
/* end of blip buffers time frame */
blip_end_frame(snd.blips[0][0], cycles);
blip_end_frame(snd.blips[0][1], cycles);
/* return number of available samples */
return blip_samples_avail(snd.blips[0][0]);
}
/* Read FM status (YM2612 only) */
unsigned int fm_read(unsigned int cycles, unsigned int address)
{
fm_update(cycles << 11);
return YM2612Read();
}
/* Write FM chip */
void fm_write(unsigned int cycles, unsigned int address, unsigned int data)
{
if (address & 1) fm_update(cycles << 11);
YM_Write(address, data);
}
/* Reset FM chip */
void fm_reset(unsigned int cycles)
{
fm_update(cycles << 11);
YM_Reset();
}
