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-rw-r--r--audio/softsynth/mt32/Partial.cpp119
1 files changed, 60 insertions, 59 deletions
diff --git a/audio/softsynth/mt32/Partial.cpp b/audio/softsynth/mt32/Partial.cpp
index c7848f02d8..75e674074f 100644
--- a/audio/softsynth/mt32/Partial.cpp
+++ b/audio/softsynth/mt32/Partial.cpp
@@ -24,15 +24,10 @@
namespace MT32Emu {
-#ifdef INACCURATE_SMOOTH_PAN
-// Mok wanted an option for smoother panning, and we love Mok.
-static const float PAN_NUMERATOR_NORMAL[] = {0.0f, 0.5f, 1.0f, 1.5f, 2.0f, 2.5f, 3.0f, 3.5f, 4.0f, 4.5f, 5.0f, 5.5f, 6.0f, 6.5f, 7.0f};
-#else
-// CONFIRMED by Mok: These NUMERATOR values (as bytes, not floats, obviously) are sent exactly like this to the LA32.
-static const float PAN_NUMERATOR_NORMAL[] = {0.0f, 0.0f, 1.0f, 1.0f, 2.0f, 2.0f, 3.0f, 3.0f, 4.0f, 4.0f, 5.0f, 5.0f, 6.0f, 6.0f, 7.0f};
-#endif
-static const float PAN_NUMERATOR_MASTER[] = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f};
-static const float PAN_NUMERATOR_SLAVE[] = {0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 7.0f, 7.0f, 7.0f, 7.0f, 7.0f, 7.0f, 7.0f};
+static const Bit8u PAN_NUMERATOR_MASTER[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7};
+static const Bit8u PAN_NUMERATOR_SLAVE[] = {0, 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7};
+
+static const Bit32s PAN_FACTORS[] = {0, 18, 37, 55, 73, 91, 110, 128, 146, 165, 183, 201, 219, 238, 256};
Partial::Partial(Synth *useSynth, int useDebugPartialNum) :
synth(useSynth), debugPartialNum(useDebugPartialNum), sampleNum(0) {
@@ -116,24 +111,30 @@ void Partial::startPartial(const Part *part, Poly *usePoly, const PatchCache *us
structurePosition = patchCache->structurePosition;
Bit8u panSetting = rhythmTemp != NULL ? rhythmTemp->panpot : part->getPatchTemp()->panpot;
- float panVal;
if (mixType == 3) {
if (structurePosition == 0) {
- panVal = PAN_NUMERATOR_MASTER[panSetting];
+ panSetting = PAN_NUMERATOR_MASTER[panSetting] << 1;
} else {
- panVal = PAN_NUMERATOR_SLAVE[panSetting];
+ panSetting = PAN_NUMERATOR_SLAVE[panSetting] << 1;
}
// Do a normal mix independent of any pair partial.
mixType = 0;
pairPartial = NULL;
} else {
- panVal = PAN_NUMERATOR_NORMAL[panSetting];
+ // Mok wanted an option for smoother panning, and we love Mok.
+#ifndef INACCURATE_SMOOTH_PAN
+ // CONFIRMED by Mok: exactly bytes like this (right shifted?) are sent to the LA32.
+ panSetting &= 0x0E;
+#endif
}
- // FIXME: Sample analysis suggests that the use of panVal is linear, but there are some some quirks that still need to be resolved.
- // FIXME: I suppose this should be panVal / 8 and undoubtly integer, clarify ASAP
- stereoVolume.leftVol = panVal / 7.0f;
- stereoVolume.rightVol = 1.0f - stereoVolume.leftVol;
+ leftPanValue = synth->reversedStereoEnabled ? 14 - panSetting : panSetting;
+ rightPanValue = 14 - leftPanValue;
+
+#if !MT32EMU_USE_FLOAT_SAMPLES
+ leftPanValue = PAN_FACTORS[leftPanValue];
+ rightPanValue = PAN_FACTORS[rightPanValue];
+#endif
// SEMI-CONFIRMED: From sample analysis:
// Found that timbres with 3 or 4 partials (i.e. one using two partial pairs) are mixed in two different ways.
@@ -150,8 +151,8 @@ void Partial::startPartial(const Part *part, Poly *usePoly, const PatchCache *us
// For my personal taste, this behaviour rather enriches the sounding and should be emulated.
// Also, the current partial allocator model probably needs to be refined.
if (debugPartialNum & 8) {
- stereoVolume.leftVol = -stereoVolume.leftVol;
- stereoVolume.rightVol = -stereoVolume.rightVol;
+ leftPanValue = -leftPanValue;
+ rightPanValue = -rightPanValue;
}
if (patchCache->PCMPartial) {
@@ -230,39 +231,6 @@ Bit32u Partial::getCutoffValue() {
return (tvf->getBaseCutoff() << 18) + cutoffModifierRampVal;
}
-unsigned long Partial::generateSamples(Sample *partialBuf, unsigned long length) {
- if (!isActive() || alreadyOutputed) {
- return 0;
- }
- if (poly == NULL) {
- synth->printDebug("[Partial %d] *** ERROR: poly is NULL at Partial::generateSamples()!", debugPartialNum);
- return 0;
- }
- alreadyOutputed = true;
-
- for (sampleNum = 0; sampleNum < length; sampleNum++) {
- if (!tva->isPlaying() || !la32Pair.isActive(LA32PartialPair::MASTER)) {
- deactivate();
- break;
- }
- la32Pair.generateNextSample(LA32PartialPair::MASTER, getAmpValue(), tvp->nextPitch(), getCutoffValue());
- if (hasRingModulatingSlave()) {
- la32Pair.generateNextSample(LA32PartialPair::SLAVE, pair->getAmpValue(), pair->tvp->nextPitch(), pair->getCutoffValue());
- if (!pair->tva->isPlaying() || !la32Pair.isActive(LA32PartialPair::SLAVE)) {
- pair->deactivate();
- if (mixType == 2) {
- deactivate();
- break;
- }
- }
- }
- *(partialBuf++) = la32Pair.nextOutSample();
- }
- unsigned long renderedSamples = sampleNum;
- sampleNum = 0;
- return renderedSamples;
-}
-
bool Partial::hasRingModulatingSlave() const {
return pair != NULL && structurePosition == 0 && (mixType == 1 || mixType == 2);
}
@@ -305,19 +273,52 @@ bool Partial::produceOutput(Sample *leftBuf, Sample *rightBuf, unsigned long len
synth->printDebug("[Partial %d] *** ERROR: poly is NULL at Partial::produceOutput()!", debugPartialNum);
return false;
}
- Sample buffer[MAX_SAMPLES_PER_RUN];
- unsigned long numGenerated = generateSamples(buffer, length);
- for (unsigned int i = 0; i < numGenerated; i++) {
+ alreadyOutputed = true;
+
+ for (sampleNum = 0; sampleNum < length; sampleNum++) {
+ if (!tva->isPlaying() || !la32Pair.isActive(LA32PartialPair::MASTER)) {
+ deactivate();
+ break;
+ }
+ la32Pair.generateNextSample(LA32PartialPair::MASTER, getAmpValue(), tvp->nextPitch(), getCutoffValue());
+ if (hasRingModulatingSlave()) {
+ la32Pair.generateNextSample(LA32PartialPair::SLAVE, pair->getAmpValue(), pair->tvp->nextPitch(), pair->getCutoffValue());
+ if (!pair->tva->isPlaying() || !la32Pair.isActive(LA32PartialPair::SLAVE)) {
+ pair->deactivate();
+ if (mixType == 2) {
+ deactivate();
+ break;
+ }
+ }
+ }
+
+ // Although, LA32 applies panning itself, we assume here it is applied in the mixer, not within a pair.
+ // Applying the pan value in the log-space looks like a waste of unlog resources. Though, it needs clarification.
+ Sample sample = la32Pair.nextOutSample();
+
+ // FIXME: Sample analysis suggests that the use of panVal is linear, but there are some quirks that still need to be resolved.
#if MT32EMU_USE_FLOAT_SAMPLES
- *(leftBuf++) += buffer[i] * stereoVolume.leftVol;
- *(rightBuf++) += buffer[i] * stereoVolume.rightVol;
+ Sample leftOut = (sample * (float)leftPanValue) / 14.0f;
+ Sample rightOut = (sample * (float)rightPanValue) / 14.0f;
+ *(leftBuf++) += leftOut;
+ *(rightBuf++) += rightOut;
#else
- *leftBuf = Synth::clipBit16s((Bit32s)*leftBuf + Bit32s(buffer[i] * stereoVolume.leftVol));
- *rightBuf = Synth::clipBit16s((Bit32s)*rightBuf + Bit32s(buffer[i] * stereoVolume.rightVol));
+ // FIXME: Dividing by 7 (or by 14 in a Mok-friendly way) looks of course pointless. Need clarification.
+ // FIXME2: LA32 may produce distorted sound in case if the absolute value of maximal amplitude of the input exceeds 8191
+ // when the panning value is non-zero. Most probably the distortion occurs in the same way it does with ring modulation,
+ // and it seems to be caused by limited precision of the common multiplication circuit.
+ // From analysis of this overflow, it is obvious that the right channel output is actually found
+ // by subtraction of the left channel output from the input.
+ // Though, it is unknown whether this overflow is exploited somewhere.
+ Sample leftOut = Sample((sample * leftPanValue) >> 8);
+ Sample rightOut = Sample((sample * rightPanValue) >> 8);
+ *leftBuf = Synth::clipBit16s((Bit32s)*leftBuf + (Bit32s)leftOut);
+ *rightBuf = Synth::clipBit16s((Bit32s)*rightBuf + (Bit32s)rightOut);
leftBuf++;
rightBuf++;
#endif
}
+ sampleNum = 0;
return true;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 22:11:57 +0000