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AY: this sucks, part 3

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improve heuristics... noise is very slow
This commit is contained in:
tildearrow 2025-03-08 02:22:45 -05:00
parent ccf9277bfe
commit 42920b9101
2 changed files with 46 additions and 20 deletions
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52
src/engine/platform/ay.cpp
View file

@ -255,33 +255,59 @@ void DivPlatformAY8910::acquire_mame(blip_buffer_t** bb, size_t len) {
oscBuf[i]->begin(len);
}
//logV("%d, %d, %d",ay->noise_enable(0),ay->noise_enable(1),ay->noise_enable(2));
for (size_t i=0; i<len; i++) {
int advance=len-i;
bool careAboutEnv=false;
bool careAboutNoise=false;
// heuristic
for (int j=0; j<3; j++) {
// tone counter
const int period=MAX(1,ay->m_tone[j].period)*(ay->m_step_mul<<1);
const int remain=period-ay->m_tone[j].count;
if (remain<advance) advance=remain;
if (!ay->tone_enable(j) && ay->m_tone[j].volume!=0) {
const int period=MAX(1,ay->m_tone[j].period)*(ay->m_step_mul<<1);
const int remain=(period-ay->m_tone[j].count)>>1;
if (remain<advance) {
advance=remain;
}
}
// envelope
if (j<1) {
if (ay->m_envelope[j].holding==0) {
const int periodEnv=MAX(1,ay->m_envelope[j].period)*ay->m_env_step_mul;
const int remainEnv=periodEnv-ay->m_envelope[j].count;
if (remainEnv<advance) advance=remainEnv;
// count me in if I have noise enabled
if (!ay->noise_enable(j) && ay->m_tone[j].volume!=0) {
careAboutNoise=true;
}
// envelope check
if (ay->m_tone[j].volume&16) {
careAboutEnv=true;
}
}
// envelope
if (careAboutEnv) {
if (ay->m_envelope[0].holding==0) {
const int periodEnv=MAX(1,ay->m_envelope[0].period)*ay->m_env_step_mul;
const int remainEnv=periodEnv-ay->m_envelope[0].count;
if (remainEnv<advance) {
advance=remainEnv;
}
}
}
// noise
const int noisePeriod=((int)ay->noise_period())*ay->m_step_mul;
const int noiseRemain=noisePeriod-ay->m_count_noise;
if (noiseRemain<advance) advance=noiseRemain;
if (careAboutNoise) {
const int noisePeriod=((int)ay->noise_period())*ay->m_step_mul;
const int noiseRemain=noisePeriod-ay->m_count_noise;
if (noiseRemain<advance) {
advance=noiseRemain;
}
}
//runDAC();
//runTFX();
if (!writes.empty() || advance<1) advance=1;
if (!writes.empty() || advance<1) {
//logV("must write, advance is 1");
advance=1;
}
checkWrites();
ay->sound_stream_update(ayBuf,advance);

14
src/engine/platform/sound/ay8910.cpp
View file

@ -1060,21 +1060,21 @@ void ay8910_device::sound_stream_update(short* outputs, int advance)
tone = &m_tone[chan];
const int period = std::max<int>(1, tone->period) * (m_step_mul << 1);
tone->count += advance << (is_expanded_mode() ? 5 : ((m_feature & PSG_HAS_EXPANDED_MODE) ? 0 : 1));
if (tone->count>=period) {
tone->duty_cycle = (tone->duty_cycle - (tone->count/period)) & 0x1f;
tone->output = is_expanded_mode() ? BIT(duty_cycle[tone_duty(tone)], tone->duty_cycle) : BIT(tone->duty_cycle, 0);
tone->count = tone->count % period;
}
if (tone->count>=period) {
tone->duty_cycle = (tone->duty_cycle - (tone->count/period)) & 0x1f;
tone->output = is_expanded_mode() ? BIT(duty_cycle[tone_duty(tone)], tone->duty_cycle) : BIT(tone->duty_cycle, 0);
tone->count = tone->count % period;
}
}
const int period_noise = (int)(noise_period()) * m_step_mul;
m_count_noise+=advance;
while (m_count_noise >= period_noise)
if (m_count_noise >= period_noise)
{
/* toggle the prescaler output. Noise is no different to
* channels.
*/
m_count_noise -= period_noise;
m_count_noise = 0;
m_prescale_noise = (m_prescale_noise + 1) & ((m_feature & PSG_HAS_EXPANDED_MODE) ? 3 : 1);
if (is_expanded_mode()) // AY8930 noise generator rate is twice? compares as compatibility mode