winamp/Src/external_dependencies/openmpt-trunk/soundlib/Load_fmt.cpp
2024-09-24 14:54:57 +02:00

196 lines
5.1 KiB
C++

/*
* Load_fmt.cpp
* ------------
* Purpose: Davey W Taylor's FM Tracker 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"
OPENMPT_NAMESPACE_BEGIN
struct FMTChannelSetting
{
char name[8];
char settings[11];
};
MPT_BINARY_STRUCT(FMTChannelSetting, 19)
struct FMTFileHeader
{
char magic[11]; // Includes format version number for simplicity
char trackerName[20];
char songName[32];
FMTChannelSetting channels[8];
uint8 lastRow;
uint8 lastOrder;
uint8 lastPattern;
};
MPT_BINARY_STRUCT(FMTFileHeader, 218)
static uint64 GetHeaderMinimumAdditionalSize(const FMTFileHeader &fileHeader)
{
// Order list + pattern delays, pattern mapping + at least one byte per channel
return (fileHeader.lastOrder + 1u) * 2u + (fileHeader.lastPattern + 1u) * 9u;
}
static bool ValidateHeader(const FMTFileHeader &fileHeader)
{
if(memcmp(fileHeader.magic, "FMTracker\x01\x01", 11))
return false;
for(const auto &channel : fileHeader.channels)
{
// Reject anything that resembles OPL3
if((channel.settings[8] & 0xFC) || (channel.settings[9] & 0xFC) || (channel.settings[10] & 0xF0))
return false;
}
return true;
}
CSoundFile::ProbeResult CSoundFile::ProbeFileHeaderFMT(MemoryFileReader file, const uint64 *pfilesize)
{
FMTFileHeader fileHeader;
if(!file.Read(fileHeader))
return ProbeWantMoreData;
if(!ValidateHeader(fileHeader))
return ProbeFailure;
return ProbeAdditionalSize(file, pfilesize, GetHeaderMinimumAdditionalSize(fileHeader));
}
bool CSoundFile::ReadFMT(FileReader &file, ModLoadingFlags loadFlags)
{
file.Rewind();
FMTFileHeader fileHeader;
if(!file.Read(fileHeader))
return false;
if(!ValidateHeader(fileHeader))
return false;
if(!file.CanRead(mpt::saturate_cast<FileReader::off_t>(GetHeaderMinimumAdditionalSize(fileHeader))))
return false;
if(loadFlags == onlyVerifyHeader)
return true;
InitializeGlobals(MOD_TYPE_S3M);
InitializeChannels();
m_nChannels = 8;
m_nSamples = 8;
m_nDefaultTempo = TEMPO(45.5); // 18.2 Hz timer
m_playBehaviour.set(kOPLNoteStopWith0Hz);
m_SongFlags.set(SONG_IMPORTED);
m_songName = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.songName);
for(CHANNELINDEX chn = 0; chn < 8; chn++)
{
const auto name = mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.channels[chn].name);
ChnSettings[chn].szName = name;
ModSample &mptSmp = Samples[chn + 1];
mptSmp.Initialize(MOD_TYPE_S3M);
OPLPatch patch{{}};
memcpy(patch.data(), fileHeader.channels[chn].settings, 11);
mptSmp.SetAdlib(true, patch);
mptSmp.nC5Speed = 8215;
m_szNames[chn + 1] = name;
}
const ORDERINDEX numOrders = fileHeader.lastOrder + 1u;
ReadOrderFromFile<uint8>(Order(), file, numOrders);
std::vector<uint8> delays;
file.ReadVector(delays, numOrders);
for(uint8 delay : delays)
{
if(delay < 1 || delay > 8)
return false;
}
m_nDefaultSpeed = delays[0];
const PATTERNINDEX numPatterns = fileHeader.lastPattern + 1u;
const ROWINDEX numRows = fileHeader.lastRow + 1u;
std::vector<uint8> patternMap;
file.ReadVector(patternMap, numPatterns);
Patterns.ResizeArray(numPatterns);
for(PATTERNINDEX pat = 0; pat < numPatterns; pat++)
{
if(!(loadFlags & loadPatternData) || !Patterns.Insert(patternMap[pat], numRows))
break;
auto &pattern = Patterns[patternMap[pat]];
for(CHANNELINDEX chn = 0; chn < 8; chn++)
{
for(ROWINDEX row = 0; row < pattern.GetNumRows(); row++)
{
uint8 data = file.ReadUint8();
if(data & 0x80)
{
row += data & 0x7F;
} else
{
ModCommand &m = *pattern.GetpModCommand(row, chn);
if(data == 1)
{
m.note = NOTE_NOTECUT;
} else if(data >= 2 && data <= 97)
{
m.note = data + NOTE_MIN + 11u;
m.instr = static_cast<ModCommand::INSTR>(chn + 1u);
}
}
}
}
}
// Write song speed to patterns... due to a quirk in the original playback routine
// (delays is applied before notes are triggered, not afterwards), a pattern's delay
// already applies to the last row of the previous pattern.
// In case you wonder if anyone would ever notice: My own songs written with this tracker
// actively work around this issue and will sound wrong if tempo is changed on the first row.
for(ORDERINDEX ord = 0; ord < numOrders; ord++)
{
if(!Order().IsValidPat(ord))
{
if(PATTERNINDEX pat = Patterns.InsertAny(numRows); pat != PATTERNINDEX_INVALID)
Order()[ord] = pat;
else
continue;
}
auto m = Patterns[Order()[ord]].end() - 1;
auto delay = delays[(ord + 1u) % numOrders];
if(m->param == delay)
continue;
if(m->command == CMD_SPEED)
{
PATTERNINDEX newPat = Order().EnsureUnique(ord);
if(newPat != PATTERNINDEX_INVALID)
m = Patterns[newPat].end() - 1;
}
m->command = CMD_SPEED;
m->param = delay;
}
m_modFormat.formatName = U_("FM Tracker");
m_modFormat.type = U_("fmt");
m_modFormat.madeWithTracker = mpt::ToUnicode(mpt::Charset::CP437, mpt::String::ReadBuf(mpt::String::maybeNullTerminated, fileHeader.trackerName));
m_modFormat.charset = mpt::Charset::CP437;
return true;
}
OPENMPT_NAMESPACE_END