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https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-09-21 05:39:43 +02:00
[Core/Sound] fixed PSG noise channel bug
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EkeEke
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3a0ec7e895
commit
31906b20cf
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152
core/sound/psg.c
152
core/sound/psg.c
@ -151,7 +151,6 @@ int psg_context_save(uint8 *state)
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save_param(psg.freqInc,sizeof(psg.freqInc));
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save_param(psg.freqCounter,sizeof(psg.freqCounter));
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save_param(psg.polarity,sizeof(psg.polarity));
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save_param(psg.chanDelta,sizeof(psg.chanDelta));
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save_param(psg.chanOut,sizeof(psg.chanOut));
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return bufferptr;
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@ -159,34 +158,29 @@ int psg_context_save(uint8 *state)
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int psg_context_load(uint8 *state)
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{
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int chanOut[4][2], delta[2];
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int delta[2];
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int i, bufferptr = 0;
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/* get current tone channels output */
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/* initialize delta with current noise channel output */
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if (psg.noiseShiftValue & 1)
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{
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delta[0] = -psg.chanOut[3][0];
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delta[1] = -psg.chanOut[3][1];
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}
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else
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{
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delta[0] = 0;
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delta[1] = 0;
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}
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/* add current tone channels output */
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for (i=0; i<3; i++)
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{
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if (psg.polarity[i] > 0)
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{
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chanOut[i][0] = psg.chanOut[i][0];
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chanOut[i][1] = psg.chanOut[i][1];
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delta[0] -= psg.chanOut[i][0];
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delta[1] -= psg.chanOut[i][1];
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}
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else
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{
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chanOut[i][0] = 0;
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chanOut[i][1] = 0;
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}
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}
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/* get current noise channel output */
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if (psg.noiseShiftValue & 1)
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{
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chanOut[3][0] = psg.chanOut[3][0];
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chanOut[3][1] = psg.chanOut[3][1];
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}
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else
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{
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chanOut[3][0] = 0;
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chanOut[3][1] = 0;
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}
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load_param(&psg.clocks,sizeof(psg.clocks));
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@ -196,46 +190,22 @@ int psg_context_load(uint8 *state)
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load_param(psg.freqInc,sizeof(psg.freqInc));
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load_param(psg.freqCounter,sizeof(psg.freqCounter));
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load_param(psg.polarity,sizeof(psg.polarity));
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load_param(psg.chanDelta,sizeof(psg.chanDelta));
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load_param(psg.chanOut,sizeof(psg.chanOut));
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/* apply any pending channel volume variation */
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for (i=0; i<4; i++)
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{
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psg.chanOut[i][0] += psg.chanDelta[i][0];
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psg.chanOut[i][1] += psg.chanDelta[i][1];
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psg.chanDelta[i][0] = 0;
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psg.chanDelta[i][1] = 0;
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}
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/* calculate noise channel output variations */
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/* add noise channel output variation */
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if (psg.noiseShiftValue & 1)
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{
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/* channel output is high */
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delta[0] = psg.chanOut[3][0] - chanOut[3][0];
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delta[1] = psg.chanOut[3][0] - chanOut[3][1];
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}
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else
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{
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/* channel output is low */
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delta[0] = -chanOut[3][0];
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delta[1] = -chanOut[3][1];
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delta[0] += psg.chanOut[3][0];
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delta[1] += psg.chanOut[3][1];
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}
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/* add tone channels output variations */
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/* add tone channels output variation */
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for (i=0; i<3; i++)
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{
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if (psg.polarity[i] > 0)
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{
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/* channel output is high */
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delta[0] += (psg.chanOut[i][0] - chanOut[i][0]);
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delta[1] += (psg.chanOut[i][0] - chanOut[i][1]);
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}
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else
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{
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/* channel output is low */
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delta[0] -= chanOut[i][0];
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delta[1] -= chanOut[i][1];
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delta[0] += psg.chanOut[i][0];
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delta[1] += psg.chanOut[i][1];
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}
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}
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@ -317,7 +287,7 @@ void psg_write(unsigned int clocks, unsigned int data)
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case 6: /* Noise control */
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{
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/* noise signal generator frequency (----?xxx) */
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/* noise signal generator frequency (-----?xx) */
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int noiseFreq = (data & 0x03);
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if (noiseFreq == 0x03)
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@ -336,8 +306,8 @@ void psg_write(unsigned int clocks, unsigned int data)
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if (psg.noiseShiftValue & 1)
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{
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/* high to low transition will be applied at next internal cycle update */
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psg.chanDelta[3][0] = -psg.chanOut[3][0];
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psg.chanDelta[3][1] = -psg.chanOut[3][1];
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psg.chanDelta[3][0] -= psg.chanOut[3][0];
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psg.chanDelta[3][1] -= psg.chanOut[3][1];
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}
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/* reset noise shift register value (noise channel output is forced low) */
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@ -348,48 +318,56 @@ void psg_write(unsigned int clocks, unsigned int data)
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case 7: /* Noise channel attenuation */
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{
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int chanOut[2];
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/* convert 4-bit attenuation value (----xxxx) to 16-bit volume value */
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data = chanVolume[data & 0x0f];
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/* channel pre-amplification */
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chanOut[0] = (data * psg.chanAmp[3][0]) / 100;
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chanOut[1] = (data * psg.chanAmp[3][1]) / 100;
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/* check noise shift register output */
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if (psg.noiseShiftValue & 1)
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{
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/* channel output is high, volume variation will be applied at next internal cycle update */
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psg.chanDelta[3][0] = ((data * psg.chanAmp[3][0]) / 100) - psg.chanOut[3][0];
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psg.chanDelta[3][1] = ((data * psg.chanAmp[3][1]) / 100) - psg.chanOut[3][1];
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}
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else
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{
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/* channel output is low, volume variation will be applied at next transition */
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psg.chanOut[3][0] = (data * psg.chanAmp[3][0]) / 100;
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psg.chanOut[3][1] = (data * psg.chanAmp[3][1]) / 100;
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psg.chanDelta[3][0] += (chanOut[0] - psg.chanOut[3][0]);
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psg.chanDelta[3][1] += (chanOut[1] - psg.chanOut[3][1]);
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}
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/* update channel volume */
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psg.chanOut[3][0] = chanOut[0];
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psg.chanOut[3][1] = chanOut[1];
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break;
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}
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default: /* Tone channels attenuation */
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{
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int chanOut[2];
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/* channel number (0-2) */
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int i = index >> 1;
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/* convert 4-bit attenuation value (----xxxx) to 16-bit volume value */
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data = chanVolume[data & 0x0f];
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/* channel pre-amplification */
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chanOut[0] = (data * psg.chanAmp[i][0]) / 100;
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chanOut[1] = (data * psg.chanAmp[i][1]) / 100;
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/* check tone generator polarity */
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if (psg.polarity[i] > 0)
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{
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/* channel output is high, volume variation will be applied at next internal cycle update */
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psg.chanDelta[i][0] = ((data * psg.chanAmp[i][0]) / 100) - psg.chanOut[i][0];
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psg.chanDelta[i][1] = ((data * psg.chanAmp[i][1]) / 100) - psg.chanOut[i][1];
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}
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else
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{
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/* channel output is low, volume variation will be applied at next transition */
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psg.chanOut[i][0] = (data * psg.chanAmp[i][0]) / 100;
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psg.chanOut[i][1] = (data * psg.chanAmp[i][1]) / 100;
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psg.chanDelta[i][0] += (chanOut[0] - psg.chanOut[i][0]);
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psg.chanDelta[i][1] += (chanOut[1] - psg.chanOut[i][1]);
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}
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/* update channel volume */
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psg.chanOut[i][0] = chanOut[0];
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psg.chanOut[i][1] = chanOut[1];
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break;
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}
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}
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@ -428,14 +406,8 @@ void psg_config(unsigned int clocks, unsigned int preamp, unsigned int panning)
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if (psg.polarity[i] > 0)
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{
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/* channel output is high, volume variation will be applied at next internal cycle update */
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psg.chanDelta[i][0] = ((volume * psg.chanAmp[i][0]) / 100) - psg.chanOut[i][0];
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psg.chanDelta[i][1] = ((volume * psg.chanAmp[i][1]) / 100) - psg.chanOut[i][1];
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}
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else
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{
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/* channel output is low, volume variation will be applied at next transition*/
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psg.chanOut[i][0] = (volume * psg.chanAmp[i][0]) / 100;
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psg.chanOut[i][1] = (volume * psg.chanAmp[i][1]) / 100;
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psg.chanDelta[i][0] += (((volume * psg.chanAmp[i][0]) / 100) - psg.chanOut[i][0]);
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psg.chanDelta[i][1] += (((volume * psg.chanAmp[i][1]) / 100) - psg.chanOut[i][1]);
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}
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}
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@ -446,16 +418,14 @@ void psg_config(unsigned int clocks, unsigned int preamp, unsigned int panning)
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if (psg.noiseShiftValue & 1)
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{
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/* channel output is high, volume variation will be applied at next internal cycle update */
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psg.chanDelta[3][0] = ((volume * psg.chanAmp[3][0]) / 100) - psg.chanOut[3][0];
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psg.chanDelta[3][1] = ((volume * psg.chanAmp[3][1]) / 100) - psg.chanOut[3][1];
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}
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else
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{
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/* channel output is low, volume variation will be applied at next transition */
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psg.chanOut[3][0] = (volume * psg.chanAmp[3][0]) / 100;
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psg.chanOut[3][1] = (volume * psg.chanAmp[3][1]) / 100;
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psg.chanDelta[3][0] += (((volume * psg.chanAmp[3][0]) / 100) - psg.chanOut[3][0]);
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psg.chanDelta[3][1] += (((volume * psg.chanAmp[3][1]) / 100) - psg.chanOut[3][1]);
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}
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}
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/* update channel volume */
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psg.chanOut[i][0] = (volume * psg.chanAmp[i][0]) / 100;
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psg.chanOut[i][1] = (volume * psg.chanAmp[i][1]) / 100;
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}
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}
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@ -501,10 +471,6 @@ static void psg_update(unsigned int clocks)
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blip_add_delta_fast(snd.blips[0], psg.clocks, psg.chanDelta[i][0], psg.chanDelta[i][1]);
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}
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/* update channel volume */
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psg.chanOut[i][0] += psg.chanDelta[i][0];
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psg.chanOut[i][1] += psg.chanDelta[i][1];
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/* clear pending channel volume variations */
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psg.chanDelta[i][0] = 0;
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psg.chanDelta[i][1] = 0;
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@ -558,14 +524,14 @@ static void psg_update(unsigned int clocks)
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/* current shift register output */
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int shiftOutput = shiftValue & 0x01;
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/* White noise (----1xxx) */
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/* White noise (-----1xx) */
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if (psg.regs[6] & 0x04)
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{
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/* shift and apply XOR feedback network */
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shiftValue = (shiftValue >> 1) | (noiseFeedback[shiftValue & psg.noiseBitMask] << psg.noiseShiftWidth);
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}
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/* Periodic noise (----0xxx) */
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/* Periodic noise (-----0xx) */
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else
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{
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/* shift and feedback current output */
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