[Fix] Avoid plugin notes from channels where we can't find a new NNA …

…channel with NNA=continue or force-reused NNA channels to linger on forever. The latter should in theory only have happened with notes triggered via CModDoc::PlayNote, which may force the first NNA channel to be used if no others are available.

[Imp] Allow NNA channels associated with MIDI-capable plugins to be reused even if they have NNA=continue set. The longer the NNA channel plays, the more likely it will be replaced.

git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@22602 56274372-70c3-4bfc-bfc3-4c3a0b034d27

mptrack/Moddoc.cpp

@@ -1073,6 +1073,7 @@ CHANNELINDEX CModDoc::PlayNote(PlayNoteParam &params, NoteToChannelMap *noteChan
 		// Find a channel to play on
 		channel = FindAvailableChannel();
 		ModChannel &chn = m_SndFile.m_PlayState.Chn[channel];
+		m_SndFile.StopOldNNA(chn, channel);
 
 		// reset channel properties; in theory the chan is completely unused anyway.
 		chn.Reset(ModChannel::resetTotal, m_SndFile, CHANNELINDEX_INVALID, CHN_MUTE);
@@ -1112,7 +1113,9 @@ CHANNELINDEX CModDoc::PlayNote(PlayNoteParam &params, NoteToChannelMap *noteChan
 		}
 
 		m_SndFile.NoteChange(chn, note, false, true, true, channel);
-		if(params.m_volume >= 0) chn.nVolume = std::min(params.m_volume, 256);
+		if(params.m_volume >= 0)
+			chn.nVolume = std::min(params.m_volume, 256);
+		chn.nnaChannelAge = 0;
 
 		// Handle sample looping.
 		// Changed line to fix http://forum.openmpt.org/index.php?topic=1700.0

soundlib/ModChannel.h

@@ -109,7 +109,11 @@ struct ModChannel
 	int16 nVolSwing, nPanSwing;
 	int16 nCutSwing, nResSwing;
 	uint16 volSlideDownRemain, volSlideDownTotal;
-	uint16 nRestorePanOnNewNote;  // If > 0, nPan should be set to nRestorePanOnNewNote - 1 on new note. Used to recover from pan swing and IT sample / instrument panning. High bit set = surround
+	union
+	{
+		uint16 nRestorePanOnNewNote;  // If > 0, nPan should be set to nRestorePanOnNewNote - 1 on new note. Used to recover from pan swing and IT sample / instrument panning. High bit set = surround
+		uint16 nnaChannelAge;         // If channel is moved to background (NNA), this counts up how old it is
+	};
 	uint16 nnaGeneration;         // For PlaybackTest implementation
 	CHANNELINDEX nMasterChn;
 	SAMPLEINDEX swapSampleIndex;  // Sample to swap to when current sample (loop) has finished playing

soundlib/Snd_fx.cpp

@@ -2271,7 +2271,10 @@ CHANNELINDEX CSoundFile::GetNNAChannel(CHANNELINDEX nChn) const
 		// Less priority to looped samples
 		if(c.dwFlags[CHN_LOOP])
 			v /= 2;
-		if((v < vol) || ((v == vol) && (c.VolEnv.nEnvPosition > envpos)))
+		// Less priority for channels potentially held for plugin notes with NNA=continue the older they get
+		if(!c.nLength && c.nMasterChn)
+			v -= std::min(static_cast<uint32>(c.nnaChannelAge) * c.nnaChannelAge, static_cast<uint32>(int32_max / 16)) * 16;
+		if((v < vol) || ((v == vol) && (c.VolEnv.nEnvPosition > envpos || !c.VolEnv.flags[ENV_ENABLED])))
 		{
 			envpos = c.VolEnv.nEnvPosition;
 			vol = v;
@@ -2326,6 +2329,7 @@ CHANNELINDEX CSoundFile::CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, boo
 		if(nnaChn == CHANNELINDEX_INVALID)
 			return CHANNELINDEX_INVALID;
 		ModChannel &chn = m_PlayState.Chn[nnaChn];
+		StopOldNNA(chn, nnaChn);
 		// Copy Channel
 		chn = srcChn;
 		chn.dwFlags.reset(CHN_VIBRATO | CHN_TREMOLO | CHN_MUTE | CHN_PORTAMENTO);
@@ -2336,6 +2340,7 @@ CHANNELINDEX CSoundFile::CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, boo
 		// Cut the note
 		chn.nFadeOutVol = 0;
 		chn.dwFlags.set(CHN_NOTEFADE | CHN_FASTVOLRAMP);
+		chn.nnaChannelAge = 0;
 		chn.nnaGeneration = ++srcChn.nnaGeneration;
 		// Stop this channel
 		srcChn.nLength = 0;
@@ -2477,6 +2482,8 @@ CHANNELINDEX CSoundFile::CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, boo
 	if(!srcChn.IsSamplePlaying() && !applyNNAtoPlug)
 		return CHANNELINDEX_INVALID;
 
+	const CHANNELINDEX nnaChn = GetNNAChannel(nChn);
+
 #ifndef NO_PLUGINS
 	if(applyNNAtoPlug)
 	{
@@ -2491,25 +2498,29 @@ CHANNELINDEX CSoundFile::CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, boo
 				srcChn.lastMidiNoteWithoutArp = NOTE_NONE;
 				break;
 			case NewNoteAction::Continue:
+				// If there's no NNA channels available, avoid the note lingering on forever
+				if(nnaChn == CHANNELINDEX_INVALID)
+					SendMIDINote(nChn, NOTE_KEYOFF, 0, m_playBehaviour[kMIDINotesFromChannelPlugin] ? pPlugin : nullptr);
+				else
+					pPlugin->MoveChannel(nChn, nnaChn);
 				break;
 		}
 	}
 #endif  // NO_PLUGINS
 
-	CHANNELINDEX nnaChn = GetNNAChannel(nChn);
 	if(nnaChn == CHANNELINDEX_INVALID)
 		return CHANNELINDEX_INVALID;
 
 	ModChannel &chn = m_PlayState.Chn[nnaChn];
-	if(chn.dwFlags[CHN_ADLIB] && m_opl)
-		m_opl->NoteCut(nnaChn);
+	StopOldNNA(chn, nnaChn);
 	// Copy Channel
 	chn = srcChn;
 	chn.dwFlags.reset(CHN_VIBRATO | CHN_TREMOLO | CHN_PORTAMENTO);
 	chn.nPanbrelloOffset = 0;
 
 	chn.nMasterChn = nChn < GetNumChannels() ? nChn + 1 : 0;
 	chn.nCommand = CMD_NONE;
+	chn.nnaChannelAge = 0;
 	chn.nnaGeneration = ++srcChn.nnaGeneration;
 
 	// Key Off the note
@@ -2564,6 +2575,31 @@ CHANNELINDEX CSoundFile::CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, boo
 }
 
 
+void CSoundFile::StopOldNNA(ModChannel &chn, CHANNELINDEX channel)
+{
+	if(chn.dwFlags[CHN_ADLIB] && m_opl)
+		m_opl->NoteCut(channel);
+
+#ifndef NO_PLUGINS
+	// Is a plugin note still associated with this old NNA channel? Stop it first.
+	if(chn.HasMIDIOutput() && ModCommand::IsNote(chn.nNote) && !chn.dwFlags[CHN_KEYOFF] && chn.lastMidiNoteWithoutArp != NOTE_NONE)
+	{
+		const PLUGINDEX plugin = GetBestPlugin(m_PlayState.Chn[channel], channel, PrioritiseInstrument, RespectMutes);
+		if(plugin > 0 && plugin <= MAX_MIXPLUGINS)
+		{
+			IMixPlugin *nnaPlugin = m_MixPlugins[plugin - 1].pMixPlugin;
+			// apply NNA to this plugin iff it is currently playing a note on this tracker channel
+			// (and if it is playing a note, we know that would be the last note played on this chan).
+			if(nnaPlugin && (chn.lastMidiNoteWithoutArp != NOTE_NONE) && nnaPlugin->IsNotePlaying(chn.lastMidiNoteWithoutArp, channel))
+			{
+				SendMIDINote(channel, chn.lastMidiNoteWithoutArp | IMixPlugin::MIDI_NOTE_OFF, 0, m_playBehaviour[kMIDINotesFromChannelPlugin] ? nnaPlugin : nullptr);
+			}
+		}
+	}
+#endif  // NO_PLUGINS
+}
+
+
 bool CSoundFile::ProcessEffects()
 {
 	m_PlayState.m_breakRow = ROWINDEX_INVALID;    // Is changed if a break to row command is encountered

soundlib/Sndfile.h

@@ -1006,6 +1006,7 @@ class CSoundFile
 	void SetupNextRow(PlayState &playState, const bool patternLoop) const;
 	CHANNELINDEX GetNNAChannel(CHANNELINDEX nChn) const;
 	CHANNELINDEX CheckNNA(CHANNELINDEX nChn, uint32 instr, int note, bool forceCut);
+	void StopOldNNA(ModChannel &chn, CHANNELINDEX channel);
 	void NoteChange(ModChannel &chn, int note, bool bPorta = false, bool bResetEnv = true, bool bManual = false, CHANNELINDEX channelHint = CHANNELINDEX_INVALID) const;
 	void InstrumentChange(ModChannel &chn, uint32 instr, bool bPorta = false, bool bUpdVol = true, bool bResetEnv = true) const;
 	void ApplyInstrumentPanning(ModChannel &chn, const ModInstrument *instr, const ModSample *smp) const;

soundlib/Sndmix.cpp

@@ -2169,6 +2169,9 @@ bool CSoundFile::ReadNote()
 			chn.nLength = 0;
 			chn.nROfs = chn.nLOfs = 0;
 		}
+		// Increment age of NNA channels
+		if(chn.nMasterChn && chn.nnaChannelAge < Util::MaxValueOfType(chn.nnaChannelAge))
+			chn.nnaChannelAge++;
 		// Check for unused channel
 		if(chn.dwFlags[CHN_MUTE] || (nChn >= GetNumChannels() && !chn.nLength))
 		{

soundlib/plugins/PlugInterface.cpp

@@ -1003,6 +1003,19 @@ bool IMidiPlugin::IsNotePlaying(uint8 note, CHANNELINDEX trackerChn)
 }
 
 
+void IMidiPlugin::MoveChannel(CHANNELINDEX from, CHANNELINDEX to)
+{
+	if(from >= std::size(m_MidiCh[GetMidiChannel(from)].noteOnMap[0]) || to >= std::size(m_MidiCh[GetMidiChannel(from)].noteOnMap[0]))
+		return;
+
+	for(auto &noteOnMap : m_MidiCh[GetMidiChannel(from)].noteOnMap)
+	{
+		noteOnMap[to] = noteOnMap[from];
+		noteOnMap[from] = 0;
+	}
+}
+
+
 void IMidiPlugin::ReceiveMidi(mpt::const_byte_span midiData)
 {
 	if(midiData.empty())

soundlib/plugins/PlugInterface.h

@@ -160,6 +160,7 @@ class IMixPlugin
 	virtual void MidiCommand(const ModInstrument &/*instr*/, uint16 /*note*/, uint16 /*vol*/, CHANNELINDEX /*trackChannel*/) { }
 	virtual void HardAllNotesOff() { }
 	virtual bool IsNotePlaying(uint8 /*note*/, CHANNELINDEX /*trackerChn*/) { return false; }
+	virtual void MoveChannel(CHANNELINDEX /*from*/, CHANNELINDEX /*to*/) { }
 
 	// Modify parameter by given amount. Only needs to be re-implemented if plugin architecture allows this to be performed atomically.
 	virtual void ModifyParameter(PlugParamIndex nIndex, PlugParamValue diff, PlayState &playState, CHANNELINDEX chn);
@@ -286,6 +287,7 @@ class IMidiPlugin : public IMixPlugin
 	void MidiVibrato(int32 depth, int8 pwd, CHANNELINDEX trackerChn) override;
 	void MidiCommand(const ModInstrument &instr, uint16 note, uint16 vol, CHANNELINDEX trackChannel) override;
 	bool IsNotePlaying(uint8 note, CHANNELINDEX trackerChn) override;
+	void MoveChannel(CHANNELINDEX from, CHANNELINDEX to) override;
 
 	// Get the MIDI channel currently associated with a given tracker channel
 	virtual uint8 GetMidiChannel(const ModChannel &chn, CHANNELINDEX trackChannel) const;