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/*
* Load_ims.cpp
* ------------
* Purpose: Images Music System (IMS) module loader
* 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 "MODTools.h"
OPENMPT_NAMESPACE_BEGIN
struct IMSFileHeader
{
std::array<char, 20> songName;
std::array<MODSampleHeader, 31> sampleHeaders;
MODFileHeader order;
uint32be sampleDataOffset;
bool IsValid() const
{
if(CountInvalidChars(songName))
return false;
uint16 hasSampleLength = 0;
for(const auto &sampleHeader : sampleHeaders)
{
if(sampleHeader.length > 0x8000 || sampleHeader.finetune || sampleHeader.GetInvalidByteScore())
return false;
hasSampleLength |= sampleHeader.length;
}
if(!hasSampleLength)
return false;
if(!order.numOrders || order.numOrders > 128 || order.restartPos > order.numOrders)
return false;
if(sampleDataOffset <= 1084)
return false;
const auto patternDiv = std::div(sampleDataOffset - 1084, 768);
if(patternDiv.rem)
return false;
const uint8 numPatterns = mpt::saturate_cast<uint8>(patternDiv.quot);
if(numPatterns > 128)
return false;
for(const auto pat : order.orderList)
{
if(pat >= numPatterns)
return false;
}
return true;
}
};
MPT_BINARY_STRUCT(IMSFileHeader, 1084)
CSoundFile::ProbeResult CSoundFile::ProbeFileHeaderIMS(MemoryFileReader file, const uint64 *pfilesize)
{
IMSFileHeader fileHeader;
if(!file.ReadStruct(fileHeader))
return ProbeWantMoreData;
if(pfilesize && *pfilesize < fileHeader.sampleDataOffset)
return ProbeFailure;
if(!fileHeader.IsValid())
return ProbeFailure;
return ProbeSuccess;
}
bool CSoundFile::ReadIMS(FileReader &file, ModLoadingFlags loadFlags)
{
file.Rewind();
IMSFileHeader fileHeader;
if(!file.ReadStruct(fileHeader))
return false;
if(!fileHeader.IsValid())
return false;
if(!file.LengthIsAtLeast(fileHeader.sampleDataOffset))
return false;
if(loadFlags == onlyVerifyHeader)
return true;
InitializeGlobals(MOD_TYPE_MOD, 4);
m_SongFlags.set(SONG_IMPORTED | SONG_FORMAT_NO_VOLCOL);
Order().SetDefaultTempoInt(125);
Order().SetDefaultSpeed(6);
Order().SetRestartPos(fileHeader.order.restartPos);
m_nMinPeriod = 113 * 4;
m_nMaxPeriod = 1712 * 4;
m_nSamples = 31;
m_songName = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.songName);
ReadOrderFromArray(Order(), fileHeader.order.orderList, fileHeader.order.numOrders);
file.Seek(20);
for(SAMPLEINDEX smp = 1; smp <= m_nSamples; smp++)
{
const auto &sampleHeader = fileHeader.sampleHeaders[smp - 1];
sampleHeader.ConvertToMPT(Samples[smp], true);
m_szNames[smp] = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, sampleHeader.name);
}
if(loadFlags & loadPatternData)
{
file.Seek(1084);
const PATTERNINDEX numPatterns = static_cast<PATTERNINDEX>((fileHeader.sampleDataOffset - 1084u) / 768u);
for(PATTERNINDEX pat = 0; pat < numPatterns; pat++)
{
if(!Patterns.Insert(pat, 64))
return false;
for(ModCommand &m : Patterns[pat])
{
const auto data = file.ReadArray<uint8, 3>();
if(const uint8 note = (data[0] & 0x3F); note < 48)
m.note = NOTE_MIDDLEC - 24 + note;
else if(note != 63)
return false;
m.instr = ((data[0] & 0xC0) >> 2) | (data[1] >> 4);
if(m.instr > 31)
return false;
ConvertModCommand(m, data[1] & 0x0F, data[2]);
}
}
}
if(loadFlags & loadSampleData)
{
file.Seek(fileHeader.sampleDataOffset);
for(SAMPLEINDEX smp = 1; smp <= m_nSamples; smp++)
{
if(!Samples[smp].nLength)
continue;
SampleIO(
SampleIO::_8bit,
SampleIO::mono,
SampleIO::littleEndian,
SampleIO::signedPCM)
.ReadSample(Samples[smp], file);
}
}
m_modFormat.formatName = UL_("Images Music System");
m_modFormat.type = UL_("ims");
m_modFormat.charset = mpt::Charset::Amiga_no_C1;
return true;
}
OPENMPT_NAMESPACE_END
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