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Fix pulse channel fails to clock lenght counter when silenced

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- Backported implementation from Mednafen-NES
- Reference test roms:
https://forums.nesdev.com/viewtopic.php?t=15346
https://github.com/christopherpow/nes-test-roms/tree/master/apu_mixer
This commit is contained in:
retro-wertz
2018-12-08 19:56:31 +08:00
parent 3b2511a8fe
commit fd5c95e60c
1 changed files with 50 additions and 52 deletions
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102
src/sound.c
View File

@@ -85,6 +85,9 @@ int32 nesincsize = 0;
uint32 soundtsinc = 0;
uint32 soundtsi = 0;
static int32 sqacc[2];
static uint32 lq_tcout;
static int32 lq_triacc;
static int32 lq_noiseacc;
/* LQ variables segment ends. */
static int32 lengthcount[4];
@@ -126,9 +129,9 @@ static const uint32 PALDMCTable[0x10] =
* $4013 - Size register: Size in bytes = (V+1)*64
*/
/*static*/ int32 DMCacc = 1;
static int32 DMCacc = 1;
static int32 DMCPeriod = 0;
/*static*/ uint8 DMCBitCount = 0;
static uint8 DMCBitCount = 0;
static uint8 DMCAddressLatch = 0, DMCSizeLatch = 0; /* writes to 4012 and 4013 */
static uint8 DMCFormat = 0; /* Write to $4010 */
@@ -176,13 +179,8 @@ static int FASTAPASS(2) CheckFreq(uint32 cf, uint8 sr) {
}
static void SQReload(int x, uint8 V) {
if (EnabledChannels & (1 << x)) {
if (x)
DoSQ2();
else
DoSQ1();
if (EnabledChannels & (1 << x))
lengthcount[x] = lengthtable[(V >> 3) & 0x1f];
}
curfreq[x] = curfreq[x] & 0xff | ((V & 7) << 8);
RectDutyCount[x] = 7;
@@ -211,6 +209,7 @@ static DECLFW(Write_PSG) {
curfreq[0] |= V;
break;
case 0x3:
DoSQ1();
SQReload(0, V);
break;
case 0x4:
@@ -231,6 +230,7 @@ static DECLFW(Write_PSG) {
curfreq[1] |= V;
break;
case 0x7:
DoSQ2();
SQReload(1, V);
break;
case 0xa:
@@ -532,54 +532,56 @@ static INLINE void RDoSQ(int x) {
int32 cf;
int32 rc;
if (curfreq[x] < 8 || curfreq[x] > 0x7ff)
goto endit;
if (!CheckFreq(curfreq[x], PSG[(x << 2) | 0x1]))
goto endit;
if (!lengthcount[x])
goto endit;
if (EnvUnits[x].Mode & 0x1)
amp = EnvUnits[x].Speed;
else
amp = EnvUnits[x].decvolume;
/* printf("%d\n",amp); */
/* Modify Square wave volume based on channel volume modifiers
* Note: the formulat x = x * y /100 does not yield exact results,
* but is "close enough" and avoids the need for using double values
* or implicit cohersion which are slower (we need speed here) */
/* TODO: Optimize this. */
if (FSettings.SquareVolume[x] != 256)
amp = (amp * FSettings.SquareVolume[x]) / 256;
amp <<= 24;
rthresh = RectDuties[(PSG[(x << 2)] & 0xC0) >> 6];
D = &WaveHi[ChannelBC[x]];
V = SOUNDTS - ChannelBC[x];
currdc = RectDutyCount[x];
cf = (curfreq[x] + 1) * 2;
rc = wlcount[x];
while (V > 0) {
if (currdc < rthresh)
*D += amp;
rc--;
if (!rc) {
rc = cf;
currdc = (currdc + 1) & 7;
/* added 2018/12/08 */
/* when pulse channel is silenced, resets length counters but not
* duty cycle, instead of resetting both */
if ((curfreq[x] < 8 || curfreq[x] > 0x7ff) ||
!CheckFreq(curfreq[x], PSG[(x << 2) | 0x1]) ||
!lengthcount[x]) {
rc -= V;
if (rc <= 0) {
rc = cf - (-rc % cf);
}
V--;
D++;
} else {
if (EnvUnits[x].Mode & 0x1)
amp = EnvUnits[x].Speed;
else
amp = EnvUnits[x].decvolume;
/* printf("%d\n",amp); */
/* Modify Square wave volume based on channel volume modifiers
* Note: the formulat x = x * y /100 does not yield exact results,
* but is "close enough" and avoids the need for using double values
* or implicit cohersion which are slower (we need speed here) */
/* TODO: Optimize this. */
if (FSettings.SquareVolume[x] != 256)
amp = (amp * FSettings.SquareVolume[x]) / 256;
amp <<= 24;
rthresh = RectDuties[(PSG[(x << 2)] & 0xC0) >> 6];
currdc = RectDutyCount[x];
D = &WaveHi[ChannelBC[x]];
while (V > 0) {
if (currdc < rthresh)
*D += amp;
rc--;
if (!rc) {
rc = cf;
currdc = (currdc + 1) & 7;
}
V--;
D++;
}
RectDutyCount[x] = currdc;
}
RectDutyCount[x] = currdc;
wlcount[x] = rc;
endit:
ChannelBC[x] = SOUNDTS;
}
@@ -724,10 +726,6 @@ static void RDoTriangle(void) {
ChannelBC[2] = SOUNDTS;
}
uint32 lq_tcout = 0;
int32 lq_triacc = 0;
int32 lq_noiseacc = 0;
static void RDoTriangleNoisePCMLQ(void) {
int32 V;
int32 start, end;