void sound_update(int line)
{
int16 *fm[2], *psg[2];
if(!snd.enabled)
return;
/* Finish buffers at end of frame */
if(line == smptab_len - 1)
{
psg[0] = psg_buffer[0] + snd.done_so_far;
psg[1] = psg_buffer[1] + snd.done_so_far;
fm[0] = fm_buffer[0] + snd.done_so_far;
fm[1] = fm_buffer[1] + snd.done_so_far;
/* Generate SN76489 sample data */
SN76489_Update(0, psg, snd.sample_count - snd.done_so_far);
/* Generate YM2413 sample data */
FM_Update(fm, snd.sample_count - snd.done_so_far);
/* Mix streams into output buffer */
snd.mixer_callback(snd.stream, snd.output, snd.sample_count);
/* Reset */
snd.done_so_far = 0;
}
else
{
int tinybit;
tinybit = smptab[line] - snd.done_so_far;
/* Do a tiny bit */
psg[0] = psg_buffer[0] + snd.done_so_far;
psg[1] = psg_buffer[1] + snd.done_so_far;
fm[0] = fm_buffer[0] + snd.done_so_far;
fm[1] = fm_buffer[1] + snd.done_so_far;
/* Generate SN76489 sample data */
SN76489_Update(0, psg, tinybit);
/* Generate YM2413 sample data */
FM_Update(fm, tinybit);
/* Sum total */
snd.done_so_far += tinybit;
}
}
/* Run PSG chip for required M-cycles */
INLINE void psg_update(unsigned int cycles)
{
if (cycles > psg_cycles_count)
{
/* clocks to run */
unsigned int clocks = (cycles - psg_cycles_count + psg_cycles_ratio - 1) / psg_cycles_ratio;
/* update cycle count */
psg_cycles_count += clocks * psg_cycles_ratio;
/* run PSG chip & get samples */
snd.psg.pos += SN76489_Update(snd.psg.pos, clocks);
}
}
void sn764xx_stream_update(UINT8 ChipID, stream_sample_t **outputs, int samples)
{
sn764xx_state *info = &SN764xxData[ChipID];
switch(EMU_CORE)
{
case EC_MAME:
SN76496Update(info->chip, outputs, samples);
break;
#ifdef ENABLE_ALL_CORES
case EC_MAXIM:
SN76489_Update((SN76489_Context*)info->chip, outputs, samples);
break;
#endif
}
}
void sn764xx_stream_update(void *_info, stream_sample_t **outputs, int samples)
{
sn764xx_state* info = (sn764xx_state*)_info;
switch(info->EMU_CORE)
{
case EC_MAME:
SN76496Update(info->chip, outputs, samples);
break;
#ifdef ENABLE_ALL_CORES
case EC_MAXIM:
SN76489_Update((SN76489_Context*)info->chip, outputs, samples);
break;
#endif
}
}
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]);
}
