本文整理汇总了C++中FileReader::SkipBack方法的典型用法代码示例。如果您正苦于以下问题：C++ FileReader::SkipBack方法的具体用法？C++ FileReader::SkipBack怎么用？C++ FileReader::SkipBack使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类FileReader的用法示例。
在下文中一共展示了FileReader::SkipBack方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: IMAADPCMUnpack16
// Note: Only works for mono samples.
bool IMAADPCMUnpack16(int16 *target, SmpLength sampleLen, FileReader file, uint16 blockAlign)
//-------------------------------------------------------------------------------------------
{
static const int32 IMAIndexTab[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
static const int32 IMAUnpackTable[90] =
{
7, 8, 9, 10, 11, 12, 13, 14,
16, 17, 19, 21, 23, 25, 28, 31,
34, 37, 41, 45, 50, 55, 60, 66,
73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658,
724, 796, 876, 963, 1060, 1166, 1282, 1411,
1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
32767, 0
};
if((sampleLen < 4) || (!target) || (blockAlign < 5) || (blockAlign > file.GetLength()))
return false;
SmpLength nPos = 0;
while((nPos < sampleLen) && file.CanRead(5))
{
int32 value = file.ReadIntLE<int16>();
int32 nIndex = file.ReadIntLE<uint8>();
nIndex = Clamp(nIndex, 0, 89);
file.Skip(1);
target[nPos++] = (int16)value;
for(uint32 i = 0; (i < (blockAlign - 4u) * 2u) && (nPos < sampleLen) && file.AreBytesLeft(); i++)
{
uint8 delta;
if(i & 1)
{
delta = (file.ReadIntLE<uint8>() >> 4) & 0x0F;
} else
{
delta = file.ReadIntLE<uint8>() & 0x0F;
file.SkipBack(1);
}
int32 v = IMAUnpackTable[nIndex] >> 3;
if (delta & 1) v += IMAUnpackTable[nIndex] >> 2;
if (delta & 2) v += IMAUnpackTable[nIndex] >> 1;
if (delta & 4) v += IMAUnpackTable[nIndex];
if (delta & 8) value -= v; else value += v;
nIndex += IMAIndexTab[delta & 7];
nIndex = Clamp(nIndex, 0, 88);
target[nPos++] = static_cast<int16>(Clamp(value, -32768, 32767));
}示例2: ReadITQ
//.........这里部分代码省略.........
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();
}
// Ignore MIDI data. Fixes some files like denonde.it that were made with old versions of Impulse Tracker (which didn't support Zxx filters) and have Zxx effects in the patterns.
if(fileHeader.cwtv < 0x0214)
{
MemsetZero(m_MidiCfg.szMidiSFXExt);
MemsetZero(m_MidiCfg.szMidiZXXExt);
m_SongFlags.set(SONG_EMBEDMIDICFG);
}
if(file.ReadMagic("MODU"))
{
madeWithTracker = "BeRoTracker";
}