PCE: Fixed PSG channels in DDA mode not immediately updating output w…

…hen a new output value was written
SourMesen · Dec 16, 2024 · f7c1beb · f7c1beb
1 parent 86cac32
commit f7c1beb
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Showing 3 changed files with 39 additions and 19 deletions.
diff --git a/Core/PCE/PcePsg.cpp b/Core/PCE/PcePsg.cpp
@@ -89,6 +89,8 @@ void PcePsg::Write(uint16_t addr, uint8_t value)
 		case 8: _state.LfoFrequency = value; break;
 		case 9: _state.LfoControl = value; break;
 	}
+
+	UpdateOutput(_emu->GetSettings()->GetPcEngineConfig());
 }
 
 void PcePsg::Run()
@@ -105,27 +107,14 @@ void PcePsg::Run()
 			}
 		}
 
-		int16_t leftOutput = 0;
-		int16_t rightOutput = 0;
 		for(int i = 0; i < 6; i++) {
-			PcePsgChannel& ch = _channels[i];
-			ch.Run(minTimer);
-			leftOutput += (int32_t)ch.GetOutput(true, _state.LeftVolume) * (int32_t)cfg.ChannelVol[i] / 100;
-			rightOutput += (int32_t)ch.GetOutput(false, _state.RightVolume) * (int32_t)cfg.ChannelVol[i] / 100;
+			_channels[i].Run(minTimer);
 		}
 
 		_clockCounter += minTimer;
 		clocksToRun -= minTimer * 6;
 
-		if(_prevLeftOutput != leftOutput) {
-			blip_add_delta(_leftChannel, _clockCounter, leftOutput - _prevLeftOutput);
-			_prevLeftOutput = leftOutput;
-		}
-
-		if(_prevRightOutput != rightOutput) {
-			blip_add_delta(_rightChannel, _clockCounter, rightOutput - _prevRightOutput);
-			_prevRightOutput = rightOutput;
-		}
+		UpdateOutput(cfg);
 	}
 
 	if(_clockCounter >= 20000) {
@@ -135,6 +124,27 @@ void PcePsg::Run()
 	_lastClock = clock - clocksToRun;
 }
 
+void PcePsg::UpdateOutput(PcEngineConfig& cfg)
+{
+	int16_t leftOutput = 0;
+	int16_t rightOutput = 0;
+	for(int i = 0; i < 6; i++) {
+		PcePsgChannel& ch = _channels[i];
+		leftOutput += (int32_t)ch.GetOutput(true, _state.LeftVolume) * (int32_t)cfg.ChannelVol[i] / 100;
+		rightOutput += (int32_t)ch.GetOutput(false, _state.RightVolume) * (int32_t)cfg.ChannelVol[i] / 100;
+	}
+
+	if(_prevLeftOutput != leftOutput) {
+		blip_add_delta(_leftChannel, _clockCounter, leftOutput - _prevLeftOutput);
+		_prevLeftOutput = leftOutput;
+	}
+
+	if(_prevRightOutput != rightOutput) {
+		blip_add_delta(_rightChannel, _clockCounter, rightOutput - _prevRightOutput);
+		_prevRightOutput = rightOutput;
+	}
+}
+
 void PcePsg::UpdateSoundOffset()
 {
 	uint8_t offset = _emu->GetSettings()->GetPcEngineConfig().UseHuC6280aAudio ? 0x10 : 0;

diff --git a/Core/PCE/PcePsg.h b/Core/PCE/PcePsg.h
@@ -8,6 +8,7 @@
 class Emulator;
 class PceConsole;
 class SoundMixer;
+struct PcEngineConfig;
 struct blip_t;
 
 class PcePsg final : public ISerializable
@@ -32,6 +33,7 @@ class PcePsg final : public ISerializable
 
 	uint32_t _clockCounter = 0;
 
+	void UpdateOutput(PcEngineConfig& cfg);
 	void UpdateSoundOffset();
 
 public:

diff --git a/Core/PCE/PcePsgChannel.cpp b/Core/PCE/PcePsgChannel.cpp
@@ -134,11 +134,15 @@ void PcePsgChannel::Write(uint16_t addr, uint8_t value)
 
 			_state.DdaEnabled = (value & 0x40) != 0;
 			_state.Amplitude = (value & 0x1F);
-
-			if(!_state.Enabled && _state.DdaEnabled) {
-				_state.WriteAddr = 0;
+
+			if(_state.DdaEnabled) {
+				if(_state.Enabled) {
+					//Update channel output immediately when DDA is enabled
+					_state.CurrentOutput = (int8_t)_state.DdaOutputValue - _outputOffset;
+				} else {
+					_state.WriteAddr = 0;
+				}
 			}
-
 			break;
 
 		case 5:
@@ -149,6 +153,10 @@ void PcePsgChannel::Write(uint16_t addr, uint8_t value)
 		case 6:
 			if(_state.DdaEnabled) {
 				_state.DdaOutputValue = value & 0x1F;
+				if(_state.Enabled) {
+					//Update channel output immediately with the new value when DDA is enabled
+					_state.CurrentOutput = (int8_t)_state.DdaOutputValue - _outputOffset;
+				}
 			} else if(!_state.Enabled) {
 				_state.WaveData[_state.WriteAddr] = value & 0x1F;
 				_state.WriteAddr = (_state.WriteAddr + 1) & 0x1F;