metaforce/Runtime/IOStreams.cpp

97 lines
2.4 KiB
C++

#include "IOStreams.hpp"
#include "CMemory.hpp"
namespace urde
{
/*!
* \brief CBitStreamReader::ReadBit
* Reads and decodes an encoded value from a bitstream.
* \param bitCount How many bits to read
* \return s32 The encoded value
*/
s32 CBitStreamReader::ReadEncoded(u32 bitCount)
{
s32 ret = 0;
if (bitCount < x20_bitOffset)
{
u32 diff = 0x20 - bitCount;
u32 baseVal = -1;
if (x20_bitOffset != 0x20)
baseVal = (1 << bitCount) - 1;
x20_bitOffset -= bitCount;
ret = baseVal & (x1c_val >> diff);
x1c_val <<= bitCount;
}
else
{
u32 diff = bitCount - x20_bitOffset;
u32 baseVal = -1;
if (x20_bitOffset != 32)
baseVal = (1 << x20_bitOffset) - 1;
u32 bit = diff & 7;
baseVal &= (x1c_val >> (32 - x20_bitOffset));
baseVal <<= diff;
x20_bitOffset = 0;
u32 count = (diff >> 3) + ((-bit | bit) >> 31);
readUBytesToBuf(&x1c_val, count);
/* The game uses Big Endian, which doesn't work for us */
/* Little Endian sucks */
athena::utility::BigUint32(x1c_val);
u32 baseVal2 = -1;
if (diff != 32)
baseVal2 = (1 << diff) - 1;
ret = baseVal | (baseVal2 & (x1c_val >> (32 - diff))) << x20_bitOffset;
x20_bitOffset = (count << 3) - diff;
x1c_val <<= diff;
}
return ret;
}
class CZipSupport
{
public:
static void* Alloc(void*, u32 c, u32 n)
{
return new u8[c*n];
}
static void Free(void*, void* buf)
{
delete[] static_cast<u8*>(buf);
}
};
CZipInputStream::CZipInputStream(std::unique_ptr<CInputStream>&& strm)
: x24_compBuf(new u8[4096]), x28_strm(std::move(strm))
{
x30_zstrm.next_in = x24_compBuf.get();
x30_zstrm.avail_in = 0;
x30_zstrm.zalloc = CZipSupport::Alloc;
x30_zstrm.zfree = CZipSupport::Free;
inflateInit(&x30_zstrm);
}
CZipInputStream::~CZipInputStream()
{
inflateEnd(&x30_zstrm);
}
atUint64 CZipInputStream::readUBytesToBuf(void *buf, atUint64 len)
{
x30_zstrm.next_out = (Bytef*)buf;
x30_zstrm.avail_out = len;
if (!x30_zstrm.avail_in)
{
atUint64 readSz = x28_strm->readUBytesToBuf(x24_compBuf.get(), 4096);
x30_zstrm.avail_in = readSz;
x30_zstrm.next_in = x24_compBuf.get();
}
inflate(&x30_zstrm, Z_NO_FLUSH);
return x30_zstrm.total_out;
}
}