/*
 * ModSample.h
 * -----------
 * Purpose: Module Sample header class and helpers
 * 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 "ModSample.h"
#include "AudioCriticalSection.h"
#include "modsmp_ctrl.h"
#include "Sndfile.h"
#include "mpt/base/numbers.hpp"

#include <cmath>


OPENMPT_NAMESPACE_BEGIN


// Translate sample properties between two given formats.
void ModSample::Convert(MODTYPE fromType, MODTYPE toType)
{
	uFlags.reset(CHN_REVERSE);  // Not supported by any native formats yet

	// Convert between frequency and transpose values if necessary.
	if((!(toType & (MOD_TYPE_MOD | MOD_TYPE_XM))) && (fromType & (MOD_TYPE_MOD | MOD_TYPE_XM)))
	{
		TransposeToFrequency();
		RelativeTone = 0;
		nFineTune = 0;
		// TransposeToFrequency assumes NTSC middle-C frequency like FT2, but we play MODs with PAL middle-C!
		if(fromType == MOD_TYPE_MOD)
			nC5Speed = Util::muldivr_unsigned(nC5Speed, 8287, 8363);
	} else if((toType & (MOD_TYPE_MOD | MOD_TYPE_XM)) && (!(fromType & (MOD_TYPE_MOD | MOD_TYPE_XM))))
	{
		// FrequencyToTranspose assumes NTSC middle-C frequency like FT2, but we play MODs with PAL middle-C!
		if(toType == MOD_TYPE_MOD)
			nC5Speed = Util::muldivr_unsigned(nC5Speed, 8363, 8287);
		FrequencyToTranspose();
	}
	if(toType == MOD_TYPE_MOD)
	{
		if(RelativeTone == -1 && nFineTune == 0)
			nFineTune = -128;
		RelativeTone = 0;
		nFineTune &= ~0x0F;
	}

	// No ping-pong loop, panning and auto-vibrato for MOD / S3M samples
	if(toType & (MOD_TYPE_MOD | MOD_TYPE_S3M))
	{
		uFlags.reset(CHN_PINGPONGLOOP | CHN_PANNING);

		nVibDepth = 0;
		nVibRate = 0;
		nVibSweep = 0;
		nVibType = VIB_SINE;
	}

	// No global volume / sustain loops for MOD/S3M/XM
	if(toType & (MOD_TYPE_MOD | MOD_TYPE_XM | MOD_TYPE_S3M))
	{
		nGlobalVol = 64;
		// Sustain loops - convert to normal loops
		if(uFlags[CHN_SUSTAINLOOP])
		{
			// We probably overwrite a normal loop here, but since sustain loops are evaluated before normal loops, this is just correct.
			nLoopStart = nSustainStart;
			nLoopEnd = nSustainEnd;
			uFlags.set(CHN_LOOP);
			uFlags.set(CHN_PINGPONGLOOP, uFlags[CHN_PINGPONGSUSTAIN]);
		}
		nSustainStart = nSustainEnd = 0;
		uFlags.reset(CHN_SUSTAINLOOP | CHN_PINGPONGSUSTAIN);
	}

	// All XM samples have default panning, and XM's autovibrato settings are rather limited.
	if(toType & MOD_TYPE_XM)
	{
		if(!uFlags[CHN_PANNING])
		{
			uFlags.set(CHN_PANNING);
			nPan = 128;
		}

		LimitMax(nVibDepth, uint8(15));
		LimitMax(nVibRate, uint8(63));
	}

	// Autovibrato sweep setting is inverse in XM (0 = "no sweep") and IT (0 = "no vibrato")
	if(((fromType & MOD_TYPE_XM) && (toType & (MOD_TYPE_IT | MOD_TYPE_MPT))) || ((toType & MOD_TYPE_XM) && (fromType & (MOD_TYPE_IT | MOD_TYPE_MPT))))
	{
		if(nVibRate != 0 && nVibDepth != 0)
		{
			if(nVibSweep != 0)
				nVibSweep = mpt::saturate_cast<decltype(nVibSweep)>(Util::muldivr_unsigned(nVibDepth, 256, nVibSweep));
			else
				nVibSweep = 255;
		}
	}
	// Convert incompatible autovibrato types
	if(toType == MOD_TYPE_IT && nVibType == VIB_RAMP_UP)
	{
		nVibType = VIB_RAMP_DOWN;
	} else if(toType == MOD_TYPE_XM && nVibType == VIB_RANDOM)
	{
		nVibType = VIB_SINE;
	}

	// No external samples in formats other than MPTM.
	if(toType != MOD_TYPE_MPT)
	{
		uFlags.reset(SMP_KEEPONDISK);
	}

	// No Adlib instruments in formats that can't handle it.
	if(!CSoundFile::SupportsOPL(toType) && uFlags[CHN_ADLIB])
	{
		SetAdlib(false);
	} else if(toType == MOD_TYPE_S3M && uFlags[CHN_ADLIB])
	{
		// No support for OPL3 waveforms in S3M
		adlib[8] &= 0x03;
		adlib[9] &= 0x03;
	}
}


// Initialize sample slot with default values.
void ModSample::Initialize(MODTYPE type)
{
	FreeSample();
	nLength = 0;
	nLoopStart = nLoopEnd = 0;
	nSustainStart = nSustainEnd = 0;
	nC5Speed = 8363;
	nPan = 128;
	nVolume = 256;
	nGlobalVol = 64;
	uFlags.reset(CHN_PANNING | CHN_SUSTAINLOOP | CHN_LOOP | CHN_PINGPONGLOOP | CHN_PINGPONGSUSTAIN | CHN_REVERSE | CHN_ADLIB | SMP_MODIFIED | SMP_KEEPONDISK);
	if(type == MOD_TYPE_XM)
	{
		uFlags.set(CHN_PANNING);
	}
	RelativeTone = 0;
	nFineTune = 0;
	nVibType = VIB_SINE;
	nVibSweep = 0;
	nVibDepth = 0;
	nVibRate = 0;
	rootNote = 0;
	filename = "";

	if(type & (MOD_TYPE_DBM | MOD_TYPE_IMF | MOD_TYPE_MED))
	{
		for(SmpLength i = 1; i < 10; i++)
		{
			cues[i - 1] = Util::muldiv_unsigned(i, 255 * 256, 9);
		}
	} else
	{
		RemoveAllCuePoints();
	}
}


// Returns sample rate of the sample.
uint32 ModSample::GetSampleRate(const MODTYPE type) const
{
	uint32 rate;
	if(CSoundFile::UseFinetuneAndTranspose(type))
		rate = TransposeToFrequency(RelativeTone, nFineTune);
	else
		rate = nC5Speed;
	// TransposeToFrequency assumes NTSC middle-C frequency like FT2, but we play MODs with PAL middle-C!
	if(type == MOD_TYPE_MOD)
		rate = Util::muldivr_unsigned(rate, 8287, 8363);
	return (rate > 0) ? rate : 8363;
}


// Copies sample data from another sample slot and ensures that the 16-bit/stereo flags are set accordingly.
bool ModSample::CopyWaveform(const ModSample &smpFrom, SmpLength start, SmpLength end)
{
	LimitMax(start, smpFrom.nLength);
	LimitMax(end, smpFrom.nLength);
	if(!smpFrom.HasSampleData() || start >= end)
		return false;
	// If we duplicate a sample slot, avoid deleting the sample we just copy from
	if(smpFrom.sampleb() == sampleb())
		pData.pSample = nullptr;
	LimitMax(nLength, end - start);

	uFlags.set(CHN_16BIT, smpFrom.uFlags[CHN_16BIT]);
	uFlags.set(CHN_STEREO, smpFrom.uFlags[CHN_STEREO]);
	if(AllocateSample())
	{
		const auto bps = smpFrom.GetBytesPerSample();
		std::copy(smpFrom.sampleb() + start * bps, smpFrom.sampleb() + (start + nLength) * bps, sampleb());
		return true;
	}
	return false;
}


// Replace waveform with given data, keeping the currently chosen format of the sample slot.
void ModSample::ReplaceWaveform(void *newWaveform, const SmpLength newLength, CSoundFile &sndFile)
{
	auto oldWaveform = samplev();

	CriticalSection cs;

	ctrlChn::ReplaceSample(sndFile, *this, newWaveform, newLength);
	pData.pSample = newWaveform;
	nLength = newLength;
	FreeSample(oldWaveform);
}


// Allocate sample based on a ModSample's properties.
// Returns number of bytes allocated, 0 on failure.
size_t ModSample::AllocateSample()
{
	FreeSample();

	if((pData.pSample = AllocateSample(nLength, GetBytesPerSample())) == nullptr)
	{
		return 0;
	} else
	{
		return GetSampleSizeInBytes();
	}
}


// Allocate sample memory. On success, a pointer to the silenced sample buffer is returned. On failure, nullptr is returned.
// numFrames must contain the sample length, bytesPerSample the size of a sampling point multiplied with the number of channels.
void *ModSample::AllocateSample(SmpLength numFrames, size_t bytesPerSample)
{
	const size_t allocSize = GetRealSampleBufferSize(numFrames, bytesPerSample);

	if(allocSize != 0)
	{
		char *p = new(std::nothrow) char[allocSize];
		if(p != nullptr)
		{
			memset(p, 0, allocSize);
			return p + (InterpolationLookaheadBufferSize * MaxSamplingPointSize);
		}
	}
	return nullptr;
}


// Compute sample buffer size in bytes, including any overhead introduced by pre-computed loops and such. Returns 0 if sample is too big.
size_t ModSample::GetRealSampleBufferSize(SmpLength numSamples, size_t bytesPerSample)
{
	// Number of required lookahead samples:
	// * 1x InterpolationMaxLookahead samples before the actual sample start. This is set to MaxSamplingPointSize due to the way AllocateSample/FreeSample currently work.
	// * 1x InterpolationMaxLookahead samples of silence after the sample end (if normal loop end == sample end, this can be optimized out).
	// * 2x InterpolationMaxLookahead before the loop point (because we start at InterpolationMaxLookahead before the loop point and will look backwards from there as well)
	// * 2x InterpolationMaxLookahead after the loop point (for wrap-around)
	// * 4x InterpolationMaxLookahead for the sustain loop (same as the two points above)

	const SmpLength maxSize = Util::MaxValueOfType(numSamples);
	const SmpLength lookaheadBufferSize = (MaxSamplingPointSize + 1 + 4 + 4) * InterpolationLookaheadBufferSize;

	if(numSamples == 0 || numSamples > MAX_SAMPLE_LENGTH || lookaheadBufferSize > maxSize - numSamples)
	{
		return 0;
	}
	numSamples += lookaheadBufferSize;

	if(maxSize / bytesPerSample < numSamples)
	{
		return 0;
	}

	return numSamples * bytesPerSample;
}


void ModSample::FreeSample()
{
	FreeSample(pData.pSample);
	pData.pSample = nullptr;
}


void ModSample::FreeSample(void *samplePtr)
{
	if(samplePtr)
	{
		delete[](((char *)samplePtr) - (InterpolationLookaheadBufferSize * MaxSamplingPointSize));
	}
}


// Set loop points and update loop wrap-around buffer
void ModSample::SetLoop(SmpLength start, SmpLength end, bool enable, bool pingpong, CSoundFile &sndFile)
{
	nLoopStart = start;
	nLoopEnd = end;
	LimitMax(nLoopEnd, nLength);
	if(nLoopStart < nLoopEnd)
	{
		uFlags.set(CHN_LOOP, enable);
		uFlags.set(CHN_PINGPONGLOOP, pingpong && enable);
	} else
	{
		nLoopStart = nLoopEnd = 0;
		uFlags.reset(CHN_LOOP | CHN_PINGPONGLOOP);
	}
	PrecomputeLoops(sndFile, true);
}


// Set sustain loop points and update loop wrap-around buffer
void ModSample::SetSustainLoop(SmpLength start, SmpLength end, bool enable, bool pingpong, CSoundFile &sndFile)
{
	nSustainStart = start;
	nSustainEnd = end;
	LimitMax(nLoopEnd, nLength);
	if(nSustainStart < nSustainEnd)
	{
		uFlags.set(CHN_SUSTAINLOOP, enable);
		uFlags.set(CHN_PINGPONGSUSTAIN, pingpong && enable);
	} else
	{
		nSustainStart = nSustainEnd = 0;
		uFlags.reset(CHN_SUSTAINLOOP | CHN_PINGPONGSUSTAIN);
	}
	PrecomputeLoops(sndFile, true);
}


namespace  // Unnamed namespace for local implementation functions.
{

template <typename T>
class PrecomputeLoop
{
protected:
	T *target;
	const T *sampleData;
	SmpLength loopEnd;
	int numChannels;
	bool pingpong;
	bool ITPingPongMode;

public:
	PrecomputeLoop(T *target, const T *sampleData, SmpLength loopEnd, int numChannels, bool pingpong, bool ITPingPongMode)
	    : target(target), sampleData(sampleData), loopEnd(loopEnd), numChannels(numChannels), pingpong(pingpong), ITPingPongMode(ITPingPongMode)
	{
		if(loopEnd > 0)
		{
			CopyLoop(true);
			CopyLoop(false);
		}
	}

	void CopyLoop(bool direction) const
	{
		// Direction: true = start reading and writing forward, false = start reading and writing backward (write direction never changes)
		const int numSamples = 2 * InterpolationLookaheadBufferSize + (direction ? 1 : 0);  // Loop point is included in forward loop expansion
		T *dest = target + numChannels * (2 * InterpolationLookaheadBufferSize - 1);        // Write buffer offset
		SmpLength readPosition = loopEnd - 1;
		const int writeIncrement = direction ? 1 : -1;
		int readIncrement = writeIncrement;

		for(int i = 0; i < numSamples; i++)
		{
			// Copy sample over to lookahead buffer
			for(int c = 0; c < numChannels; c++)
			{
				dest[c] = sampleData[readPosition * numChannels + c];
			}
			dest += writeIncrement * numChannels;

			if(readPosition == loopEnd - 1 && readIncrement > 0)
			{
				// Reached end of loop while going forward
				if(pingpong)
				{
					readIncrement = -1;
					if(ITPingPongMode && readPosition > 0)
					{
						readPosition--;
					}
				} else
				{
					readPosition = 0;
				}
			} else if(readPosition == 0 && readIncrement < 0)
			{
				// Reached start of loop while going backward
				if(pingpong)
				{
					readIncrement = 1;
				} else
				{
					readPosition = loopEnd - 1;
				}
			} else
			{
				readPosition += readIncrement;
			}
		}
	}
};


template <typename T>
void PrecomputeLoopsImpl(ModSample &smp, const CSoundFile &sndFile)
{
	const int numChannels = smp.GetNumChannels();
	const int copySamples = numChannels * InterpolationLookaheadBufferSize;

	T *sampleData = static_cast<T *>(smp.samplev());
	T *afterSampleStart = sampleData + smp.nLength * numChannels;
	T *loopLookAheadStart = afterSampleStart + copySamples;
	T *sustainLookAheadStart = loopLookAheadStart + 4 * copySamples;

	// Hold sample on the same level as the last sampling point at the end to prevent extra pops with interpolation.
	// Do the same at the sample start, too.
	for(int i = 0; i < (int)InterpolationLookaheadBufferSize; i++)
	{
		for(int c = 0; c < numChannels; c++)
		{
			afterSampleStart[i * numChannels + c] = afterSampleStart[-numChannels + c];
			sampleData[-(i + 1) * numChannels + c] = sampleData[c];
		}
	}

	if(smp.uFlags[CHN_LOOP])
	{
		PrecomputeLoop<T>(loopLookAheadStart,
			sampleData + smp.nLoopStart * numChannels,
			smp.nLoopEnd - smp.nLoopStart,
			numChannels,
			smp.uFlags[CHN_PINGPONGLOOP],
			sndFile.m_playBehaviour[kITPingPongMode]);
	}
	if(smp.uFlags[CHN_SUSTAINLOOP])
	{
		PrecomputeLoop<T>(sustainLookAheadStart,
			sampleData + smp.nSustainStart * numChannels,
			smp.nSustainEnd - smp.nSustainStart,
			numChannels,
			smp.uFlags[CHN_PINGPONGSUSTAIN],
			sndFile.m_playBehaviour[kITPingPongMode]);
	}
}

}  // unnamed namespace


void ModSample::PrecomputeLoops(CSoundFile &sndFile, bool updateChannels)
{
	if(!HasSampleData())
		return;

	SanitizeLoops();

	// Update channels with possibly changed loop values
	if(updateChannels)
	{
		UpdateLoopPointsInActiveChannels(sndFile);
	}

	if(GetElementarySampleSize() == 2)
		PrecomputeLoopsImpl<int16>(*this, sndFile);
	else if(GetElementarySampleSize() == 1)
		PrecomputeLoopsImpl<int8>(*this, sndFile);
}


// Propagate loop point changes to player
bool ModSample::UpdateLoopPointsInActiveChannels(CSoundFile &sndFile)
{
	if(!HasSampleData())
		return false;

	CriticalSection cs;

	// Update channels with new loop values
	for(auto &chn : sndFile.m_PlayState.Chn)
	{
		if(chn.pModSample != this || chn.nLength == 0)
			continue;

		bool looped = false, bidi = false;
		if(nSustainStart < nSustainEnd && nSustainEnd <= nLength && uFlags[CHN_SUSTAINLOOP] && !chn.dwFlags[CHN_KEYOFF])
		{
			// Sustain loop is active
			chn.nLoopStart = nSustainStart;
			chn.nLoopEnd = nSustainEnd;
			chn.nLength = nSustainEnd;
			looped = true;
			bidi = uFlags[CHN_PINGPONGSUSTAIN];
		} else if(nLoopStart < nLoopEnd && nLoopEnd <= nLength && uFlags[CHN_LOOP])
		{
			// Normal loop is active
			chn.nLoopStart = nLoopStart;
			chn.nLoopEnd = nLoopEnd;
			chn.nLength = nLoopEnd;
			looped = true;
			bidi = uFlags[CHN_PINGPONGLOOP];
		}
		chn.dwFlags.set(CHN_LOOP, looped);
		chn.dwFlags.set(CHN_PINGPONGLOOP, looped && bidi);

		if(chn.position.GetUInt() > chn.nLength)
		{
			chn.position.Set(chn.nLoopStart);
			chn.dwFlags.reset(CHN_PINGPONGFLAG);
		}
		if(!bidi)
		{
			chn.dwFlags.reset(CHN_PINGPONGFLAG);
		}
		if(!looped)
		{
			chn.nLength = nLength;
		}
	}

	return true;
}


// Remove loop points if they're invalid.
void ModSample::SanitizeLoops()
{
	LimitMax(nSustainEnd, nLength);
	LimitMax(nLoopEnd, nLength);
	if(nSustainStart >= nSustainEnd)
	{
		nSustainStart = nSustainEnd = 0;
		uFlags.reset(CHN_SUSTAINLOOP | CHN_PINGPONGSUSTAIN);
	}
	if(nLoopStart >= nLoopEnd)
	{
		nLoopStart = nLoopEnd = 0;
		uFlags.reset(CHN_LOOP | CHN_PINGPONGLOOP);
	}
}


/////////////////////////////////////////////////////////////
// Transpose <-> Frequency conversions

uint32 ModSample::TransposeToFrequency(int transpose, int finetune)
{
	return mpt::saturate_round<uint32>(std::pow(2.0, (transpose * 128.0 + finetune) * (1.0 / (12.0 * 128.0))) * 8363.0);
}


void ModSample::TransposeToFrequency()
{
	nC5Speed = TransposeToFrequency(RelativeTone, nFineTune);
}


// Return a pair of {transpose, finetune}
std::pair<int8, int8> ModSample::FrequencyToTranspose(uint32 freq)
{
	if(!freq)
		return {};

	const auto f2t = mpt::saturate_round<int32>(std::log(freq * (1.0 / 8363.0)) * (12.0 * 128.0 * (1.0 / mpt::numbers::ln2)));
	const auto fine = std::div(Clamp(f2t, -16384, 16383), int32(128));
	return {static_cast<int8>(fine.quot), static_cast<int8>(fine.rem)};
}


void ModSample::FrequencyToTranspose()
{
	std::tie(RelativeTone, nFineTune) = FrequencyToTranspose(nC5Speed);
}


// Transpose the sample by amount specified in octaves (i.e. amount=1 transposes one octave up)
void ModSample::Transpose(double amount)
{
	nC5Speed = mpt::saturate_round<uint32>(nC5Speed * std::pow(2.0, amount));
}


// Check if the sample has any valid cue points
bool ModSample::HasAnyCuePoints() const
{
	if(uFlags[CHN_ADLIB])
		return false;
	for(auto pt : cues)
	{
		if(pt < nLength)
			return true;
	}
	return false;
}


// Check if the sample's cue points are the default cue point set.
bool ModSample::HasCustomCuePoints() const
{
	if(uFlags[CHN_ADLIB])
		return false;
	for(SmpLength i = 0; i < std::size(cues); i++)
	{
		const SmpLength defaultValue = (i + 1) << 11;
		if(cues[i] != defaultValue && (cues[i] < nLength || defaultValue < nLength))
			return true;
	}
	return false;
}


void ModSample::SetDefaultCuePoints()
{
	// Default cues compatible with old-style volume column offset
	for(int i = 0; i < 9; i++)
	{
		cues[i] = (i + 1) << 11;
	}
}


void ModSample::Set16BitCuePoints()
{
	// Cue points that are useful for extending regular offset command
	for(int i = 0; i < 9; i++)
	{
		cues[i] = (i + 1) << 16;
	}
}


void ModSample::RemoveAllCuePoints()
{
	if(!uFlags[CHN_ADLIB])
		cues.fill(MAX_SAMPLE_LENGTH);
}


void ModSample::SetAdlib(bool enable, OPLPatch patch)
{
	if(!enable && uFlags[CHN_ADLIB])
	{
		SetDefaultCuePoints();
	}
	uFlags.set(CHN_ADLIB, enable);
	if(enable)
	{
		// Bogus sample to make playback work
		uFlags.reset(CHN_16BIT | CHN_STEREO);
		nLength = 4;
		AllocateSample();
		adlib = patch;
	}
}


OPENMPT_NAMESPACE_END
