C++ FileReader::GetPosition方法代码示例

VSTPresets::ErrorCode VSTPresets::LoadFile(FileReader &file, CVstPlugin &plugin)
//------------------------------------------------------------------------------
{
	const bool firstChunk = file.GetPosition() == 0;
	ChunkHeader header;
	if(!file.ReadConvertEndianness(header) || header.chunkMagic != cMagic)
	{
		return invalidFile;
	}
	if(header.fxID != plugin.GetUID())
	{
		return wrongPlugin;
	}

	if(header.fxMagic == fMagic || header.fxMagic == chunkPresetMagic)
	{
		// Program
		PlugParamIndex numParams = file.ReadUint32BE();

		VstPatchChunkInfo info;
		info.version = 1;
		info.pluginUniqueID = header.fxID;
		info.pluginVersion = header.fxVersion;
		info.numElements = numParams;
		MemsetZero(info.future);
		plugin.Dispatch(effBeginLoadProgram, 0, 0, &info, 0.0f);
		plugin.Dispatch(effBeginSetProgram, 0, 0, nullptr, 0.0f);

		char prgName[28];
		file.ReadString<mpt::String::maybeNullTerminated>(prgName, 28);
		plugin.Dispatch(effSetProgramName, 0, 0, prgName, 0.0f);

		if(header.fxMagic == fMagic)
		{
			if(plugin.GetNumParameters() != numParams)
			{
				return wrongParameters;
			}
			for(PlugParamIndex p = 0; p < numParams; p++)
			{
				plugin.SetParameter(p, file.ReadFloatBE());
			}
		} else
		{
			FileReader chunk = file.ReadChunk(file.ReadUint32BE());
			plugin.Dispatch(effSetChunk, 1, chunk.GetLength(), const_cast<char *>(chunk.GetRawData()), 0);
		}
		plugin.Dispatch(effEndSetProgram, 0, 0, nullptr, 0.0f);
	} else if((header.fxMagic == bankMagic || header.fxMagic == chunkBankMagic) && firstChunk)
	{
		// Bank - only read if it's the first chunk in the file, not if it's a sub chunk.
		uint32 numProgs = file.ReadUint32BE();
		uint32 currentProgram = file.ReadUint32BE();
		file.Skip(124);

		VstPatchChunkInfo info;
		info.version = 1;
		info.pluginUniqueID = header.fxID;
		info.pluginVersion = header.fxVersion;
		info.numElements = numProgs;
		MemsetZero(info.future);
		plugin.Dispatch(effBeginLoadBank, 0, 0, &info, 0.0f);

		if(header.fxMagic == bankMagic)
		{
			VstInt32 oldCurrentProgram = plugin.GetCurrentProgram();
			for(uint32 p = 0; p < numProgs; p++)
			{
				plugin.Dispatch(effBeginSetProgram, 0, 0, nullptr, 0.0f);
				plugin.Dispatch(effSetProgram, 0, 0, nullptr, 0.0f);
				ErrorCode retVal = LoadFile(file, plugin);
				if(retVal != noError)
				{
					return retVal;
				}
				plugin.Dispatch(effEndSetProgram, 0, 0, nullptr, 0.0f);
			}
			plugin.SetCurrentProgram(oldCurrentProgram);
		} else
		{
			FileReader chunk = file.ReadChunk(file.ReadUint32BE());
			plugin.Dispatch(effSetChunk, 0, chunk.GetLength(), const_cast<char *>(chunk.GetRawData()), 0);
		}
		if(header.version >= 2)
		{
			plugin.SetCurrentProgram(currentProgram);
		}
	}

	return noError;
}

OPENMPT_NAMESPACE_BEGIN


#if MPT_COMPILER_GCC
#if MPT_GCC_AT_LEAST(4,6,0)
#pragma GCC diagnostic push
#endif
#pragma GCC diagnostic ignored "-Wswitch"
#elif MPT_COMPILER_CLANG
#pragma clang diagnostic push
#if MPT_CLANG_AT_LEAST(3,3,0)
#pragma clang diagnostic ignored "-Wswitch"
#else
#pragma clang diagnostic ignored "-Wswitch-enum"
#endif
#endif

// Read a sample from memory
size_t SampleIO::ReadSample(ModSample &sample, FileReader &file) const
//--------------------------------------------------------------------
{
	if(sample.nLength < 1 || !file.IsValid())
	{
		return 0;
	}

	LimitMax(sample.nLength, MAX_SAMPLE_LENGTH);

	const char * const sourceBuf = file.GetRawData();
	const FileReader::off_t fileSize = file.BytesLeft(), filePosition = file.GetPosition();
	FileReader::off_t bytesRead = 0;	// Amount of memory that has been read from file

	sample.uFlags.set(CHN_16BIT, GetBitDepth() >= 16);
	sample.uFlags.set(CHN_STEREO, GetChannelFormat() != mono);
	size_t sampleSize = sample.AllocateSample();	// Target sample size in bytes

	if(sampleSize == 0)
	{
		sample.nLength = 0;
		return 0;
	}

	ASSERT(sampleSize >= sample.GetSampleSizeInBytes());

	//////////////////////////////////////////////////////
	// 8-Bit / Mono / PCM
	if(GetBitDepth() == 8 && GetChannelFormat() == mono)
	{
		switch(GetEncoding())
		{
		case signedPCM:		// 8-Bit / Mono / Signed / PCM
			bytesRead = CopyMonoSample<SC::DecodeInt8>(sample, sourceBuf, fileSize);
			break;
		case unsignedPCM:	// 8-Bit / Mono / Unsigned / PCM
			bytesRead = CopyMonoSample<SC::DecodeUint8>(sample, sourceBuf, fileSize);
			break;
		case deltaPCM:		// 8-Bit / Mono / Delta / PCM
		case MT2:
			bytesRead = CopyMonoSample<SC::DecodeInt8Delta>(sample, sourceBuf, fileSize);
			break;
		case PCM7to8:		// 7 Bit stored as 8-Bit with highest bit unused / Mono / Signed / PCM
			bytesRead = CopyMonoSample<SC::DecodeInt7>(sample, sourceBuf, fileSize);
			break;
		}
	}

	//////////////////////////////////////////////////////
	// 8-Bit / Stereo Split / PCM
	else if(GetBitDepth() == 8 && GetChannelFormat() == stereoSplit)
	{
		switch(GetEncoding())
		{
		case signedPCM:		// 8-Bit / Stereo Split / Signed / PCM
			bytesRead = CopyStereoSplitSample<SC::DecodeInt8>(sample, sourceBuf, fileSize);
			break;
		case unsignedPCM:	// 8-Bit / Stereo Split / Unsigned / PCM
			bytesRead = CopyStereoSplitSample<SC::DecodeUint8>(sample, sourceBuf, fileSize);
			break;
		case deltaPCM:		// 8-Bit / Stereo Split / Delta / PCM
		case MT2:
			bytesRead = CopyStereoSplitSample<SC::DecodeInt8Delta>(sample, sourceBuf, fileSize);
			break;
		}
	}

	//////////////////////////////////////////////////////
	// 8-Bit / Stereo Interleaved / PCM
	else if(GetBitDepth() == 8 && GetChannelFormat() == stereoInterleaved)
	{
		switch(GetEncoding())
		{
		case signedPCM:		// 8-Bit / Stereo Interleaved / Signed / PCM
			bytesRead = CopyStereoInterleavedSample<SC::DecodeInt8>(sample, sourceBuf, fileSize);
			break;
		case unsignedPCM:	// 8-Bit / Stereo Interleaved / Unsigned / PCM
			bytesRead = CopyStereoInterleavedSample<SC::DecodeUint8>(sample, sourceBuf, fileSize);
			break;
		case deltaPCM:		// 8-Bit / Stereo Interleaved / Delta / PCM
			bytesRead = CopyStereoInterleavedSample<SC::DecodeInt8Delta>(sample, sourceBuf, fileSize);
			break;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	}

	for(uint16 n = 0; n < fileHeader.smpnum; n++)
	{
		if(smpPos[n] > 0)
		{
			minPtr = std::min(minPtr, smpPos[n]);
		}
	}

	for(uint16 n = 0; n < fileHeader.patnum; n++)
	{
		if(patPos[n] > 0)
		{
			minPtr = std::min(minPtr, patPos[n]);
		}
	}

	if(fileHeader.special & ITFileHeader::embedSongMessage)
	{
		minPtr = std::min(minPtr, fileHeader.msgoffset);
	}

	// Reading IT Edit History Info
	// This is only supposed to be present if bit 1 of the special flags is set.
	// However, old versions of Schism and probably other trackers always set this bit
	// even if they don't write the edit history count. So we have to filter this out...
	// This is done by looking at the parapointers. If the history data end after
	// the first parapointer, we assume that it's actually no history data.
	if(fileHeader.special & ITFileHeader::embedEditHistory)
	{
		const uint16 nflt = file.ReadUint16LE();

		if(file.CanRead(nflt * sizeof(ITHistoryStruct)) && file.GetPosition() + nflt * sizeof(ITHistoryStruct) <= minPtr)
		{
			m_FileHistory.reserve(nflt);
			for(size_t n = 0; n < nflt; n++)
			{
				FileHistory mptHistory;
				ITHistoryStruct itHistory;
				file.ReadConvertEndianness(itHistory);
				itHistory.ConvertToMPT(mptHistory);
				m_FileHistory.push_back(mptHistory);
			}
		} else
		{
			// Oops, we were not supposed to read this.
			file.SkipBack(2);
		}
	} else if(fileHeader.highlight_major == 0 && fileHeader.highlight_minor == 0 && fileHeader.cmwt == 0x0214 && fileHeader.cwtv == 0x0214 && !memcmp(fileHeader.reserved, "\0\0\0\0", 4) && (fileHeader.special & (ITFileHeader::embedEditHistory | ITFileHeader::embedPatternHighlights)) == 0)
	{
		// Another non-conforming application is unmo3 < v2.4.0.1, which doesn't set the special bit
		// at all, but still writes the two edit history length bytes (zeroes)...
		if(file.ReadUint16LE() != 0)
		{
			// These were not zero bytes -> We're in the wrong place!
			file.SkipBack(2);
			madeWithTracker = "UNMO3";
		}
	}

	// Reading MIDI Output & Macros
	if(m_SongFlags[SONG_EMBEDMIDICFG] && file.Read(m_MidiCfg))
	{
			m_MidiCfg.Sanitize();
	}