Fix BLZ decompression when the segment also has a uncompressed chunck

This commit is contained in:
gdkchan 2018-12-26 20:05:47 -03:00
commit ec19d87f5e
2 changed files with 34 additions and 34 deletions

View file

@ -1,5 +1,4 @@
using System; using System;
using System.IO;
namespace Ryujinx.HLE.Loaders.Compression namespace Ryujinx.HLE.Loaders.Compression
{ {
@ -7,22 +6,26 @@ namespace Ryujinx.HLE.Loaders.Compression
{ {
private class BackwardsReader private class BackwardsReader
{ {
private Stream _baseStream; private byte[] _data;
public BackwardsReader(Stream baseStream) private int _position;
public int Position => _position;
public BackwardsReader(byte[] data, int end)
{ {
_baseStream = baseStream; _data = data;
_position = end;
}
public void SeekCurrent(int offset)
{
_position += offset;
} }
public byte ReadByte() public byte ReadByte()
{ {
_baseStream.Seek(-1, SeekOrigin.Current); return _data[--_position];
byte value = (byte)_baseStream.ReadByte();
_baseStream.Seek(-1, SeekOrigin.Current);
return value;
} }
public short ReadInt16() public short ReadInt16()
@ -39,30 +42,24 @@ namespace Ryujinx.HLE.Loaders.Compression
} }
} }
public static byte[] Decompress(Stream input, int decompressedLength) public static void DecompressInPlace(byte[] buffer, int headerEnd)
{ {
long end = input.Position; BackwardsReader reader = new BackwardsReader(buffer, headerEnd);
BackwardsReader reader = new BackwardsReader(input);
int additionalDecLength = reader.ReadInt32(); int additionalDecLength = reader.ReadInt32();
int startOffset = reader.ReadInt32(); int startOffset = reader.ReadInt32();
int compressedLength = reader.ReadInt32(); int compressedLength = reader.ReadInt32();
input.Seek(12 - startOffset, SeekOrigin.Current); reader.SeekCurrent(12 - startOffset);
byte[] dec = new byte[decompressedLength]; int decBase = headerEnd - compressedLength;
int decompressedLengthUnpadded = compressedLength + additionalDecLength; int decPos = compressedLength + additionalDecLength;
int decompressionStart = decompressedLength - decompressedLengthUnpadded;
int decPos = dec.Length;
byte mask = 0; byte mask = 0;
byte header = 0; byte header = 0;
while (decPos > decompressionStart) while (decPos > 0)
{ {
if ((mask >>= 1) == 0) if ((mask >>= 1) == 0)
{ {
@ -72,7 +69,7 @@ namespace Ryujinx.HLE.Loaders.Compression
if ((header & mask) == 0) if ((header & mask) == 0)
{ {
dec[--decPos] = reader.ReadByte(); buffer[decBase + --decPos] = reader.ReadByte();
} }
else else
{ {
@ -81,25 +78,30 @@ namespace Ryujinx.HLE.Loaders.Compression
int length = (pair >> 12) + 3; int length = (pair >> 12) + 3;
int position = (pair & 0xfff) + 3; int position = (pair & 0xfff) + 3;
if (length > decPos)
{
length = decPos;
}
decPos -= length; decPos -= length;
int dstPos = decBase + decPos;
if (length <= position) if (length <= position)
{ {
int srcPos = decPos + position; int srcPos = dstPos + position;
Buffer.BlockCopy(dec, srcPos, dec, decPos, length); Buffer.BlockCopy(buffer, srcPos, buffer, dstPos, length);
} }
else else
{ {
for (int offset = 0; offset < length; offset++) for (int offset = 0; offset < length; offset++)
{ {
dec[decPos + offset] = dec[decPos + position + offset]; buffer[dstPos + offset] = buffer[dstPos + position + offset];
} }
} }
} }
} }
return dec;
} }
} }
} }

View file

@ -114,13 +114,11 @@ namespace Ryujinx.HLE.Loaders.Executables
private byte[] ReadSegment(SegmentHeader header, Stream input) private byte[] ReadSegment(SegmentHeader header, Stream input)
{ {
long end = input.Position + header.CompressedSize; byte[] data = new byte[header.DecompressedSize];
input.Seek(end, SeekOrigin.Begin); input.Read(data, 0, header.CompressedSize);
byte[] data = BackwardsLz.Decompress(input, header.DecompressedSize); BackwardsLz.DecompressInPlace(data, header.CompressedSize);
input.Seek(end, SeekOrigin.Begin);
return data; return data;
} }