metaforce/Runtime/IOStreams.cpp

143 lines
3.7 KiB
C++

#include "IOStreams.hpp"
#include "hecl/hecl.hpp"
namespace urde {
#define DUMP_BITS 0
#if DUMP_BITS
static void PrintBinary(u32 val, u32 count) {
for (int i = 0; i < count; ++i) {
printf("%d", (val >> (count - i - 1)) & 0x1);
}
}
#endif
/*!
* \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) {
#if DUMP_BITS
auto pos = position();
auto boff = x20_bitOffset;
#endif
u32 ret = 0;
s32 shiftAmt = x20_bitOffset - s32(bitCount);
if (shiftAmt < 0) {
/* OR in remaining bits of cached value */
u32 mask = bitCount == 32 ? 0xffffffff : ((1 << bitCount) - 1);
ret |= (x1c_val << u32(-shiftAmt)) & mask;
/* Load in exact number of bytes remaining */
auto loadDiv = std::div(-shiftAmt, 8);
if (loadDiv.rem)
++loadDiv.quot;
readUBytesToBuf(reinterpret_cast<u8*>(&x1c_val) + 4 - loadDiv.quot, loadDiv.quot);
x1c_val = hecl::SBig(x1c_val);
/* New bit offset */
x20_bitOffset = loadDiv.quot * 8 + shiftAmt;
/* OR in next bits */
mask = (1 << u32(-shiftAmt)) - 1;
ret |= (x1c_val >> x20_bitOffset) & mask;
} else {
/* OR in bits of cached value */
u32 mask = bitCount == 32 ? 0xffffffff : ((1 << bitCount) - 1);
ret |= (x1c_val >> u32(shiftAmt)) & mask;
/* New bit offset */
x20_bitOffset -= bitCount;
}
#if DUMP_BITS
printf("READ ");
PrintBinary(ret, bitCount);
printf(" %d %d\n", int(pos), int(boff));
#endif
return ret;
}
void CBitStreamWriter::WriteEncoded(u32 val, u32 bitCount) {
#if DUMP_BITS
printf("WRITE ");
PrintBinary(val, bitCount);
printf(" %d %d\n", int(position()), int(x18_bitOffset));
#endif
s32 shiftAmt = x18_bitOffset - s32(bitCount);
if (shiftAmt < 0) {
/* OR remaining bits to cached value */
u32 mask = (1 << x18_bitOffset) - 1;
x14_val |= (val >> u32(-shiftAmt)) & mask;
/* Write out 32-bits */
x14_val = hecl::SBig(x14_val);
writeUBytes(reinterpret_cast<u8*>(&x14_val), 4);
/* Cache remaining bits */
x18_bitOffset = 0x20 + shiftAmt;
x14_val = val << x18_bitOffset;
} else {
/* OR bits to cached value */
u32 mask = bitCount == 32 ? 0xffffffff : ((1 << bitCount) - 1);
x14_val |= (val & mask) << u32(shiftAmt);
/* New bit offset */
x18_bitOffset -= bitCount;
}
}
void CBitStreamWriter::Flush() {
if (x18_bitOffset < 0x20) {
auto pos = std::div(0x20 - x18_bitOffset, 8);
if (pos.rem)
++pos.quot;
x14_val = hecl::SBig(x14_val);
writeUBytes(reinterpret_cast<u8*>(&x14_val), pos.quot);
x18_bitOffset = 0x20;
x14_val = 0;
}
}
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;
x30_zstrm.total_out = 0;
while (x30_zstrm.avail_out != 0) {
if (x30_zstrm.avail_in == 0) {
atUint64 readSz = x28_strm->readUBytesToBuf(x24_compBuf.get(), 4096);
x30_zstrm.avail_in = readSz;
x30_zstrm.next_in = x24_compBuf.get();
}
int inflateRet = inflate(&x30_zstrm, Z_NO_FLUSH);
if (inflateRet != Z_OK)
break;
}
return x30_zstrm.total_out;
}
} // namespace urde