text: /*
   * ITTools.cpp
   * -----------
   * Purpose: Definition of IT file structures and helper functions
   * Notes  : (currently none)
   * Authors: OpenMPT Devs
   * The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
   */
  
  
  #include "stdafx.h"
  #include "Loaders.h"
  #include "ITTools.h"
  #include "Tables.h"
  #include "../common/mptStringBuffer.h"
  #include "../common/version.h"
  
  
  OPENMPT_NAMESPACE_BEGIN
  
  
  // Convert OpenMPT's internal envelope format into an IT/MPTM envelope.
  void ITEnvelope::ConvertToIT(const InstrumentEnvelope &mptEnv, uint8 envOffset, uint8 envDefault)
  {
  	// Envelope Flags
  	if(mptEnv.dwFlags[ENV_ENABLED]) flags |= ITEnvelope::envEnabled;
  	if(mptEnv.dwFlags[ENV_LOOP]) flags |= ITEnvelope::envLoop;
  	if(mptEnv.dwFlags[ENV_SUSTAIN]) flags |= ITEnvelope::envSustain;
  	if(mptEnv.dwFlags[ENV_CARRY]) flags |= ITEnvelope::envCarry;
  
  	// Nodes and Loops
  	num = (uint8)std::min(mptEnv.size(), uint32(25));
  	lpb = (uint8)mptEnv.nLoopStart;
  	lpe = (uint8)mptEnv.nLoopEnd;
  	slb = (uint8)mptEnv.nSustainStart;
  	sle = (uint8)mptEnv.nSustainEnd;
  
  	// Envelope Data
  	MemsetZero(data);
  	if(!mptEnv.empty())
  	{
  		// Attention: Full MPTM envelope is stored in extended instrument properties
  		for(uint32 ev = 0; ev < num; ev++)
  		{
  			data[ev].value = static_cast<int8>(mptEnv[ev].value) - envOffset;
  			data[ev].tick = mptEnv[ev].tick;
  		}
  	} else
  	{
  		// Fix non-existing envelopes so that they can still be edited in Impulse Tracker.
  		num = 2;
  		data[0].value = data[1].value = envDefault - envOffset;
  		data[1].tick = 10;
  	}
  }
  
  
  // Convert IT/MPTM envelope data into OpenMPT's internal envelope format - To be used by ITInstrToMPT()
  void ITEnvelope::ConvertToMPT(InstrumentEnvelope &mptEnv, uint8 envOffset, uint8 maxNodes) const
  {
  	// Envelope Flags
  	mptEnv.dwFlags.set(ENV_ENABLED, (flags & ITEnvelope::envEnabled) != 0);
  	mptEnv.dwFlags.set(ENV_LOOP, (flags & ITEnvelope::envLoop) != 0);
  	mptEnv.dwFlags.set(ENV_SUSTAIN, (flags & ITEnvelope::envSustain) != 0);
  	mptEnv.dwFlags.set(ENV_CARRY, (flags & ITEnvelope::envCarry) != 0);
  
  	// Nodes and Loops
  	mptEnv.resize(std::min(num, maxNodes));
  	mptEnv.nLoopStart = std::min(lpb, maxNodes);
  	mptEnv.nLoopEnd = Clamp(lpe, mptEnv.nLoopStart, maxNodes);
  	mptEnv.nSustainStart = std::min(slb, maxNodes);
  	mptEnv.nSustainEnd = Clamp(sle, mptEnv.nSustainStart, maxNodes);
  
  	// Envelope Data
  	// Attention: Full MPTM envelope is stored in extended instrument properties
  	for(uint32 ev = 0; ev < std::min(uint8(25), num); ev++)
  	{
  		mptEnv[ev].value = Clamp<int8, int8>(data[ev].value + envOffset, 0, 64);
  		mptEnv[ev].tick = data[ev].tick;
  		if(ev > 0 && mptEnv[ev].tick < mptEnv[ev - 1].tick && !(mptEnv[ev].tick & 0xFF00))
  		{
  			// Fix broken envelopes... Instruments 2 and 3 in NoGap.it by Werewolf have envelope points where the high byte of envelope nodes is missing.
  			// NoGap.it was saved with MPT 1.07 - 1.09, which *normally* doesn't do this in IT files.
  			// However... It turns out that MPT 1.07 omitted the high byte of envelope nodes when saving an XI instrument file, and it looks like
  			// Instrument 2 and 3 in NoGap.it were loaded from XI files.
  			mptEnv[ev].tick |= mptEnv[ev - 1].tick & 0xFF00;
  			if(mptEnv[ev].tick < mptEnv[ev - 1].tick)
  				mptEnv[ev].tick += 0x100;
  		}
  	}
  }
  
  
  // Convert an ITOldInstrument to OpenMPT's internal instrument representation.
  void ITOldInstrument::ConvertToMPT(ModInstrument &mptIns) const
  {
  	// Header
  	if(memcmp(id, "IMPI", 4))
  	{
  		return;
  	}
  
  	mptIns.name = mpt::String::ReadBuf(mpt::String::spacePadded, name);
  	mptIns.filename = mpt::String::ReadBuf(mpt::String::nullTerminated, filename);
  
  	// Volume / Panning
  	mptIns.nFadeOut = fadeout << 6;
  	mptIns.nGlobalVol = 64;
  	mptIns.nPan = 128;
  
  	// NNA Stuff
  	mptIns.nNNA = static_cast<NewNoteAction>(nna.get());
  	mptIns.nDCT = static_cast<DuplicateCheckType>(dnc.get());
  
  	// Sample Map
  	for(size_t i = 0; i < 120; i++)
  	{
  		uint8 note = keyboard[i * 2];
  		SAMPLEINDEX ins = keyboard[i * 2 + 1];
  		if(ins < MAX_SAMPLES)
  		{
  			mptIns.Keyboard[i] = ins;
  		}
  		if(note < 120)
  		{
  			mptIns.NoteMap[i] = note + 1u;
  		} else
  		{
  			mptIns.NoteMap[i] = static_cast<uint8>(i + 1);
  		}
  	}
  
  	// Volume Envelope Flags
  	mptIns.VolEnv.dwFlags.set(ENV_ENABLED, (flags & ITOldInstrument::envEnabled) != 0);
  	mptIns.VolEnv.dwFlags.set(ENV_LOOP, (flags & ITOldInstrument::envLoop) != 0);
  	mptIns.VolEnv.dwFlags.set(ENV_SUSTAIN, (flags & ITOldInstrument::envSustain) != 0);
  
  	// Volume Envelope Loops
  	mptIns.VolEnv.nLoopStart = vls;
  	mptIns.VolEnv.nLoopEnd = vle;
  	mptIns.VolEnv.nSustainStart = sls;
  	mptIns.VolEnv.nSustainEnd = sle;
  	mptIns.VolEnv.resize(25);
  
  	// Volume Envelope Data
  	for(uint32 i = 0; i < 25; i++)
  	{
  		if((mptIns.VolEnv[i].tick = nodes[i * 2]) == 0xFF)
  		{
  			mptIns.VolEnv.resize(i);
  			break;
  		}
  		mptIns.VolEnv[i].value = nodes[i * 2 + 1];
  	}
  
  	if(std::max(mptIns.VolEnv.nLoopStart, mptIns.VolEnv.nLoopEnd) >= mptIns.VolEnv.size()) mptIns.VolEnv.dwFlags.reset(ENV_LOOP);
  	if(std::max(mptIns.VolEnv.nSustainStart, mptIns.VolEnv.nSustainEnd) >= mptIns.VolEnv.size()) mptIns.VolEnv.dwFlags.reset(ENV_SUSTAIN);
  }
  
  
  // Convert OpenMPT's internal instrument representation to an ITInstrument.
  uint32 ITInstrument::ConvertToIT(const ModInstrument &mptIns, bool compatExport, const CSoundFile &sndFile)
  {
  	MemsetZero(*this);
  
  	// Header
  	memcpy(id, "IMPI", 4);
  	trkvers = 0x5000 | static_cast<uint16>(Version::Current().GetRawVersion() >> 16);
  
  	mpt::String::WriteBuf(mpt::String::nullTerminated, filename) = mptIns.filename;
  	mpt::String::WriteBuf(mpt::String::nullTerminated, name) = mptIns.name;
  
  	// Volume / Panning
  	fadeout = static_cast<uint16>(std::min(mptIns.nFadeOut >> 5, uint32(256)));
  	gbv = static_cast<uint8>(std::min(mptIns.nGlobalVol * 2u, uint32(128)));
  	dfp = static_cast<uint8>(std::min(mptIns.nPan / 4u, uint32(64)));
  	if(!mptIns.dwFlags[INS_SETPANNING]) dfp |= ITInstrument::ignorePanning;
  
  	// Random Variation
  	rv = std::min(mptIns.nVolSwing, uint8(100));
  	rp = std::min(mptIns.nPanSwing, uint8(64));
  
  	// NNA Stuff
  	nna = mptIns.nNNA;
  	dct = (mptIns.nDCT < DCT_PLUGIN || !compatExport) ? mptIns.nDCT : DCT_NONE;
  	dca = mptIns.nDNA;
  
  	// Pitch / Pan Separation
  	pps = mptIns.nPPS;
  	ppc = mptIns.nPPC;
  
  	// Filter Stuff
  	ifc = mptIns.GetCutoff() | (mptIns.IsCutoffEnabled() ? ITInstrument::enableCutoff : 0x00);
  	ifr = mptIns.GetResonance() | (mptIns.IsResonanceEnabled() ? ITInstrument::enableResonance : 0x00);
  
  	// MIDI Setup
  	if(mptIns.nMidiProgram > 0)
  		mpr = mptIns.nMidiProgram - 1u;
  	else
  		mpr = 0xFF;
  	if(mptIns.wMidiBank > 0)
  	{
  		mbank[0] = static_cast<uint8>((mptIns.wMidiBank - 1) & 0x7F);
  		mbank[1] = static_cast<uint8>((mptIns.wMidiBank - 1) >> 7);
  	} else
  	{
  		mbank[0] = 0xFF;
  		mbank[1] = 0xFF;
  	}
  	if(mptIns.nMidiChannel != MidiNoChannel || mptIns.nMixPlug == 0 || mptIns.nMixPlug > 127 || compatExport)
  	{
  		// Default. Prefer MIDI channel over mixplug to keep the semantics intact.
  		mch = mptIns.nMidiChannel;
  	} else
  	{
  		// Keep compatibility with MPT 1.16's instrument format if possible, as XMPlay / BASS also uses this.
  		mch = mptIns.nMixPlug + 128;
  	}
  
  	// Sample Map
  	nos = 0;	// Only really relevant for ITI files
  	std::vector<bool> smpCount(sndFile.GetNumSamples(), false);
  	for(int i = 0; i < 120; i++)
  	{
  		keyboard[i * 2] = (mptIns.NoteMap[i] >= NOTE_MIN && mptIns.NoteMap[i] <= NOTE_MAX) ? (mptIns.NoteMap[i] - NOTE_MIN) : static_cast<uint8>(i);
  
  		const SAMPLEINDEX smp = mptIns.Keyboard[i];
  		if(smp < MAX_SAMPLES && smp < 256)
  		{
  			keyboard[i * 2 + 1] = static_cast<uint8>(smp);
  
  			if(smp && smp <= sndFile.GetNumSamples() && !smpCount[smp - 1])
  			{
  				// We haven't considered this sample yet. Update number of samples.
  				smpCount[smp - 1] = true;
  				nos++;
  			}
  		}
  	}
  
  	// Writing Volume envelope
  	volenv.ConvertToIT(mptIns.VolEnv, 0, 64);
  	// Writing Panning envelope
  	panenv.ConvertToIT(mptIns.PanEnv, 32, 32);
  	// Writing Pitch Envelope
  	pitchenv.ConvertToIT(mptIns.PitchEnv, 32, 32);
  	if(mptIns.PitchEnv.dwFlags[ENV_FILTER]) pitchenv.flags |= ITEnvelope::envFilter;
  
  	return sizeof(ITInstrument);
  }
  
  
  // Convert an ITInstrument to OpenMPT's internal instrument representation. Returns size of the instrument data that has been read.
  uint32 ITInstrument::ConvertToMPT(ModInstrument &mptIns, MODTYPE modFormat) const
  {
  	if(memcmp(id, "IMPI", 4))
  	{
  		return 0;
  	}
  
  	mptIns.name = mpt::String::ReadBuf(mpt::String::spacePadded, name);
  	mptIns.filename = mpt::String::ReadBuf(mpt::String::nullTerminated, filename);
  
  	// Volume / Panning
  	mptIns.nFadeOut = fadeout << 5;
  	mptIns.nGlobalVol = gbv / 2;
  	LimitMax(mptIns.nGlobalVol, 64u);
  	mptIns.nPan = (dfp & 0x7F) * 4;
  	if(mptIns.nPan > 256) mptIns.nPan = 128;
  	mptIns.dwFlags.set(INS_SETPANNING, !(dfp & ITInstrument::ignorePanning));
  
  	// Random Variation
  	mptIns.nVolSwing = std::min(static_cast<uint8>(rv), uint8(100));
  	mptIns.nPanSwing = std::min(static_cast<uint8>(rp), uint8(64));
  
  	// NNA Stuff
  	mptIns.nNNA = static_cast<NewNoteAction>(nna.get());
  	mptIns.nDCT = static_cast<DuplicateCheckType>(dct.get());
  	mptIns.nDNA = static_cast<DuplicateNoteAction>(dca.get());
  
  	// Pitch / Pan Separation
  	mptIns.nPPS = pps;
  	mptIns.nPPC = ppc;
  
  	// Filter Stuff
  	mptIns.SetCutoff(ifc & 0x7F, (ifc & ITInstrument::enableCutoff) != 0);
  	mptIns.SetResonance(ifr & 0x7F, (ifr & ITInstrument::enableResonance) != 0);
  
  	// MIDI Setup
  
  	// MPT used to have a slightly different encoding of MIDI program and banks which we are trying to fix here.
  	// Impulse Tracker / Schism Tracker will set trkvers to 0 in IT files,
  	// and we won't care about correctly importing MIDI programs and banks in ITI files.
  	// Chibi Tracker sets trkvers to 0x214, but always writes mpr=mbank=0 anyway.
  	// Old BeRoTracker versions set trkvers to 0x214 or 0x217.
  	//        <= MPT 1.07          <= MPT 1.16       OpenMPT 1.17-?      <= OpenMPT 1.26     definitely not MPT
  	if((trkvers == 0x0202 || trkvers == 0x0211 || trkvers == 0x0220 || trkvers == 0x0214) && mpr != 0xFF)
  	{
  		if(mpr <= 128)
  		{
  			mptIns.nMidiProgram = mpr;
  		}
  		uint16 bank = mbank[0] | (mbank[1] << 8);
  		// These versions also ignored the high bank nibble (was only handled correctly in OpenMPT instrument extensions)
  		if(bank <= 128)
  		{
  			mptIns.wMidiBank = bank;
  		}
  	} else
  	{
  		if(mpr < 128)
  		{
  			mptIns.nMidiProgram = mpr + 1;
  		}
  		uint16 bank = 0;
  		if(mbank[0] < 128)
  			bank = mbank[0] + 1;
  		if(mbank[1] < 128)
  			bank += (mbank[1] << 7);
  		mptIns.wMidiBank = bank;
  	}
  	mptIns.nMidiChannel = mch;
  	if(mptIns.nMidiChannel >= 128)
  	{
  		// Handle old format where MIDI channel and Plugin index are stored in the same variable
  		mptIns.nMixPlug = mptIns.nMidiChannel - 128;
  		mptIns.nMidiChannel = 0;
  	}
  
  	// Envelope point count. Limited to 25 in IT format.
  	const uint8 maxNodes = (modFormat & MOD_TYPE_MPT) ? MAX_ENVPOINTS : 25;
  
  	// Volume Envelope
  	volenv.ConvertToMPT(mptIns.VolEnv, 0, maxNodes);
  	// Panning Envelope
  	panenv.ConvertToMPT(mptIns.PanEnv, 32, maxNodes);
  	// Pitch Envelope
  	pitchenv.ConvertToMPT(mptIns.PitchEnv, 32, maxNodes);
  	mptIns.PitchEnv.dwFlags.set(ENV_FILTER, (pitchenv.flags & ITEnvelope::envFilter) != 0);
  
  	// Sample Map
  	for(int i = 0; i < 120; i++)
  	{
  		uint8 note = keyboard[i * 2];
  		SAMPLEINDEX ins = keyboard[i * 2 + 1];
  		if(ins < MAX_SAMPLES)
  		{
  			mptIns.Keyboard[i] = ins;
  		}
  		if(note < 120)
  		{
  			mptIns.NoteMap[i] = note + NOTE_MIN;
  		} else
  		{
  			mptIns.NoteMap[i] = static_cast<uint8>(i + NOTE_MIN);
  		}
  	}
  
  	return sizeof(ITInstrument);
  }
  
  
  // Convert OpenMPT's internal instrument representation to an ITInstrumentEx. Returns amount of bytes that need to be written to file.
  uint32 ITInstrumentEx::ConvertToIT(const ModInstrument &mptIns, bool compatExport, const CSoundFile &sndFile)
  {
  	uint32 instSize = iti.ConvertToIT(mptIns, compatExport, sndFile);
  
  	if(compatExport)
  	{
  		return instSize;
  	}
  
  	// Sample Map
  	bool usedExtension = false;
  	iti.nos = 0;
  	std::vector<bool> smpCount(sndFile.GetNumSamples(), false);
  	for(int i = 0; i < 120; i++)
  	{
  		const SAMPLEINDEX smp = mptIns.Keyboard[i];
  		keyboardhi[i] = 0;
  		if(smp < MAX_SAMPLES)
  		{
  			if(smp >= 256)
  			{
  				// We need to save the upper byte for this sample index.
  				iti.keyboard[i * 2 + 1] = static_cast<uint8>(smp & 0xFF);
  				keyboardhi[i] = static_cast<uint8>(smp >> 8);
  				usedExtension = true;
  			}
  
  			if(smp && smp <= sndFile.GetNumSamples() && !smpCount[smp - 1])
  			{
  				// We haven't considered this sample yet. Update number of samples.
  				smpCount[smp - 1] = true;
  				iti.nos++;
  			}
  		}
  	}
  
  	if(usedExtension)
  	{
  		// If we actually had to extend the sample map, update the magic bytes and instrument size.
  		memcpy(iti.dummy, "XTPM", 4);
  		instSize = sizeof(ITInstrumentEx);
  	}
  
  	return instSize;
  }
  
  
  // Convert an ITInstrumentEx to OpenMPT's internal instrument representation. Returns size of the instrument data that has been read.
  uint32 ITInstrumentEx::ConvertToMPT(ModInstrument &mptIns, MODTYPE fromType) const
  {
  	uint32 insSize = iti.ConvertToMPT(mptIns, fromType);
  
  	// Is this actually an extended instrument?
  	// Note: OpenMPT 1.20 - 1.22 accidentally wrote "MPTX" here (since revision 1203), while previous versions wrote the reversed version, "XTPM".
  	if(insSize == 0 || (memcmp(iti.dummy, "MPTX", 4) && memcmp(iti.dummy, "XTPM", 4)))
  	{
  		return insSize;
  	}
  
  	// Olivier's MPT Instrument Extension
  	for(int i = 0; i < 120; i++)
  	{
  		mptIns.Keyboard[i] |= ((SAMPLEINDEX)keyboardhi[i] << 8);
  	}
  
  	return sizeof(ITInstrumentEx);
  }
  
  
  // Convert OpenMPT's internal sample representation to an ITSample.
  void ITSample::ConvertToIT(const ModSample &mptSmp, MODTYPE fromType, bool compress, bool compressIT215, bool allowExternal)
  {
  	MemsetZero(*this);
  
  	// Header
  	memcpy(id, "IMPS", 4);
  
  	mpt::String::WriteBuf(mpt::String::nullTerminated, filename) = mptSmp.filename;
  	//mpt::String::WriteBuf(mpt::String::nullTerminated, name) = m_szNames[nsmp];
  
  	// Volume / Panning
  	gvl = static_cast<uint8>(mptSmp.nGlobalVol);
  	vol = static_cast<uint8>(mptSmp.nVolume / 4);
  	dfp = static_cast<uint8>(mptSmp.nPan / 4);
  	if(mptSmp.uFlags[CHN_PANNING]) dfp |= ITSample::enablePanning;
  
  	// Sample Format / Loop Flags
  	if(mptSmp.HasSampleData())
  	{
  		flags = ITSample::sampleDataPresent;
  		if(mptSmp.uFlags[CHN_LOOP]) flags |= ITSample::sampleLoop;
  		if(mptSmp.uFlags[CHN_SUSTAINLOOP]) flags |= ITSample::sampleSustain;
  		if(mptSmp.uFlags[CHN_PINGPONGLOOP]) flags |= ITSample::sampleBidiLoop;
  		if(mptSmp.uFlags[CHN_PINGPONGSUSTAIN]) flags |= ITSample::sampleBidiSustain;
  
  		if(mptSmp.uFlags[CHN_STEREO])
  		{
  			flags |= ITSample::sampleStereo;
  		}
  		if(mptSmp.uFlags[CHN_16BIT])
  		{
  			flags |= ITSample::sample16Bit;
  		}
  		cvt = ITSample::cvtSignedSample;
  
  		if(compress)
  		{
  			flags |= ITSample::sampleCompressed;
  			if(compressIT215)
  			{
  				cvt |= ITSample::cvtDelta;
  			}
  		}
  	} else
  	{
  		flags = 0x00;
  	}
  
  	// Frequency
  	C5Speed = mptSmp.nC5Speed ? mptSmp.nC5Speed : 8363;
  
  	// Size and loops
  	length = mpt::saturate_cast<uint32>(mptSmp.nLength);
  	loopbegin = mpt::saturate_cast<uint32>(mptSmp.nLoopStart);
  	loopend = mpt::saturate_cast<uint32>(mptSmp.nLoopEnd);
  	susloopbegin = mpt::saturate_cast<uint32>(mptSmp.nSustainStart);
  	susloopend = mpt::saturate_cast<uint32>(mptSmp.nSustainEnd);
  
  	// Auto Vibrato settings
  	vit = AutoVibratoXM2IT[mptSmp.nVibType & 7];
  	vis = std::min(mptSmp.nVibRate, uint8(64));
  	vid = std::min(mptSmp.nVibDepth, uint8(32));
  	vir = std::min(mptSmp.nVibSweep, uint8(255));
  
  	if((vid | vis) != 0 && (fromType & MOD_TYPE_XM))
  	{
  		// Sweep is upside down in XM
  		vir = 255 - vir;
  	}
  
  	if(mptSmp.uFlags[CHN_ADLIB])
  	{
  		length = 12;
  		cvt = ITSample::cvtOPLInstrument;
  	} else if(mptSmp.uFlags[SMP_KEEPONDISK])
  	{
  #ifndef MPT_EXTERNAL_SAMPLES
  		MPT_UNREFERENCED_PARAMETER(allowExternal);
  #else
  		// Save external sample (filename at sample pointer)
  		if(allowExternal && mptSmp.HasSampleData())
  		{
  			cvt = ITSample::cvtExternalSample;
  		} else
  #endif // MPT_EXTERNAL_SAMPLES
  		{
  			length = loopbegin = loopend = susloopbegin = susloopend = 0;
  		}
  	}
  }
  
  
  // Convert an ITSample to OpenMPT's internal sample representation.
  uint32 ITSample::ConvertToMPT(ModSample &mptSmp) const
  {
  	if(memcmp(id, "IMPS", 4))
  	{
  		return 0;
  	}
  
  	mptSmp.Initialize(MOD_TYPE_IT);
  	mptSmp.filename = mpt::String::ReadBuf(mpt::String::nullTerminated, filename);
  
  	// Volume / Panning
  	mptSmp.nVolume = vol * 4;
  	LimitMax(mptSmp.nVolume, uint16(256));
  	mptSmp.nGlobalVol = gvl;
  	LimitMax(mptSmp.nGlobalVol, uint16(64));
  	mptSmp.nPan = (dfp & 0x7F) * 4;
  	LimitMax(mptSmp.nPan, uint16(256));
  	if(dfp & ITSample::enablePanning) mptSmp.uFlags.set(CHN_PANNING);
  
  	// Loop Flags
  	if(flags & ITSample::sampleLoop) mptSmp.uFlags.set(CHN_LOOP);
  	if(flags & ITSample::sampleSustain) mptSmp.uFlags.set(CHN_SUSTAINLOOP);
  	if(flags & ITSample::sampleBidiLoop) mptSmp.uFlags.set(CHN_PINGPONGLOOP);
  	if(flags & ITSample::sampleBidiSustain) mptSmp.uFlags.set(CHN_PINGPONGSUSTAIN);
  
  	// Frequency
  	mptSmp.nC5Speed = C5Speed;
  	if(!mptSmp.nC5Speed) mptSmp.nC5Speed = 8363;
  	if(mptSmp.nC5Speed < 256) mptSmp.nC5Speed = 256;
  
  	// Size and loops
  	mptSmp.nLength = length;
  	mptSmp.nLoopStart = loopbegin;
  	mptSmp.nLoopEnd = loopend;
  	mptSmp.nSustainStart = susloopbegin;
  	mptSmp.nSustainEnd = susloopend;
  	mptSmp.SanitizeLoops();
  
  	// Auto Vibrato settings
  	mptSmp.nVibType = static_cast<VibratoType>(AutoVibratoIT2XM[vit & 7]);
  	mptSmp.nVibRate = vis;
  	mptSmp.nVibDepth = vid & 0x7F;
  	mptSmp.nVibSweep = vir;
  
  	if(cvt == ITSample::cvtOPLInstrument)
  	{
  		// FM instrument in MPTM
  		mptSmp.uFlags.set(CHN_ADLIB);
  	} else if(cvt == ITSample::cvtExternalSample)
  	{
  		// Read external sample (filename at sample pointer)
  		mptSmp.uFlags.set(SMP_KEEPONDISK);
  	}
  
  	return samplepointer;
  }
  
  
  // Retrieve the internal sample format flags for this instrument.
  SampleIO ITSample::GetSampleFormat(uint16 cwtv) const
  {
  	SampleIO sampleIO(
  		(flags & ITSample::sample16Bit) ? SampleIO::_16bit : SampleIO::_8bit,
  		SampleIO::mono,
  		SampleIO::littleEndian,
  		(cvt & ITSample::cvtSignedSample) ? SampleIO::signedPCM: SampleIO::unsignedPCM);
  
  	// Some old version of IT didn't clear the stereo flag when importing samples. Luckily, all other trackers are identifying as IT 2.14+, so let's check for old IT versions.
  	if((flags & ITSample::sampleStereo) && cwtv >= 0x214)
  	{
  		sampleIO |= SampleIO::stereoSplit;
  	}
  
  	if(flags & ITSample::sampleCompressed)
  	{
  		// IT 2.14 packed sample
  		sampleIO |= (cvt & ITSample::cvtDelta) ? SampleIO::IT215 : SampleIO::IT214;
  	} else
  	{
  		// MODPlugin :(
  		if(!(flags & ITSample::sample16Bit) && cvt == ITSample::cvtADPCMSample)
  		{
  			sampleIO |= SampleIO::ADPCM;
  		} else
  		{
  			// ITTECH.TXT says these convert flags are "safe to ignore". IT doesn't ignore them, though, so why should we? :)
  			if(cvt & ITSample::cvtBigEndian)
  			{
  				sampleIO |= SampleIO::bigEndian;
  			}
  			if(cvt & ITSample::cvtDelta)
  			{
  				sampleIO |= SampleIO::deltaPCM;
  			}
  			if((cvt & ITSample::cvtPTM8to16) && (flags & ITSample::sample16Bit))
  			{
  				sampleIO |= SampleIO::PTM8Dto16;
  			}
  		}
  	}
  
  	return sampleIO;
  }
  
  
  // Convert an ITHistoryStruct to OpenMPT's internal edit history representation
  void ITHistoryStruct::ConvertToMPT(FileHistory &mptHistory) const
  {
  	// Decode FAT date and time
  	MemsetZero(mptHistory.loadDate);
  	if(fatdate != 0 || fattime != 0)
  	{
  		mptHistory.loadDate.tm_year = ((fatdate >> 9) & 0x7F) + 80;
  		mptHistory.loadDate.tm_mon = Clamp((fatdate >> 5) & 0x0F, 1, 12) - 1;
  		mptHistory.loadDate.tm_mday = Clamp(fatdate & 0x1F, 1, 31);
  		mptHistory.loadDate.tm_hour = Clamp((fattime >> 11) & 0x1F, 0, 23);
  		mptHistory.loadDate.tm_min = Clamp((fattime >> 5) & 0x3F, 0, 59);
  		mptHistory.loadDate.tm_sec = Clamp((fattime & 0x1F) * 2, 0, 59);
  	}
  	mptHistory.openTime = static_cast<uint32>(runtime * (HISTORY_TIMER_PRECISION / 18.2));
  }
  
  
  // Convert OpenMPT's internal edit history representation to an ITHistoryStruct
  void ITHistoryStruct::ConvertToIT(const FileHistory &mptHistory)
  {
  	// Create FAT file dates
  	if(mptHistory.HasValidDate())
  	{
  		fatdate = static_cast<uint16>(mptHistory.loadDate.tm_mday | ((mptHistory.loadDate.tm_mon + 1) << 5) | ((mptHistory.loadDate.tm_year - 80) << 9));
  		fattime = static_cast<uint16>((mptHistory.loadDate.tm_sec / 2) | (mptHistory.loadDate.tm_min << 5) | (mptHistory.loadDate.tm_hour << 11));
  	} else
  	{
  		fatdate = 0;
  		fattime = 0;
  	}
  	runtime = static_cast<uint32>(mptHistory.openTime * (18.2 / HISTORY_TIMER_PRECISION));
  }
  
  
  uint32 DecodeITEditTimer(uint16 cwtv, uint32 editTime)
  {
  	if((cwtv & 0xFFF) >= 0x0208)
  	{
  		editTime ^= 0x4954524B;  // 'ITRK'
  		editTime = (editTime >> 7) | (editTime << (32 - 7));
  		editTime = ~editTime + 1;
  		editTime = (editTime << 4) | (editTime >> (32 - 4));
  		editTime ^= 0x4A54484C;  // 'JTHL'
  	}
  	return editTime;
  }
  
  
  OPENMPT_NAMESPACE_END
  