Add support for SAS5 engine patch format

This commit is contained in:
scientificworld
2025-11-29 13:22:29 +08:00
parent 7d655ee6d1
commit 12d5ed1a66

View File

@@ -76,7 +76,7 @@ namespace GameRes.Formats.Sas5
return new BinMemoryStream (code, entry.Name);
}
static void DecryptCodeSection (byte[] code)
protected static void DecryptCodeSection (byte[] code)
{
byte key = 0;
for (int i = 0; i < code.Length; ++i)
@@ -180,6 +180,198 @@ namespace GameRes.Formats.Sas5
using (var resr = new Res2Reader (input))
return resr.Read();
}
static internal Entry GetEntryBySectionName (ArcView file, string section_name)
{
if (file == null)
return null;
uint offset = 8;
while (offset < file.MaxOffset)
{
string name = file.View.ReadString (offset, 4, Encoding.ASCII);
if ("ENDS" == name)
break;
uint section_size = file.View.ReadUInt32 (offset+4);
offset += 8;
if (section_name == name)
{
var entry = new Entry {
Name = name,
Offset = offset,
Size = section_size,
};
return entry;
}
offset += section_size;
}
return null;
}
}
internal class Sep5Archive : ArcFile
{
private ArcView m_sec5;
public ArcView Sec5File { get { return m_sec5; } }
public Sep5Archive (ArcView arc, ArcView sec5, ArchiveFormat impl, ICollection<Entry> dir)
: base (arc, impl, dir)
{
m_sec5 = sec5;
}
}
internal class Sep5Entry : PackedEntry
{
public byte PType;
}
[Export(typeof(ArchiveFormat))]
public class Sep5Opener : Sec5Opener
{
public override string Tag { get { return "SEP5"; } }
public override string Description { get { return "SAS5 engine patched resource index file"; } }
public override uint Signature { get { return 0x35504553; } } // 'SEP5'
public override bool IsHierarchic { get { return false; } }
public override bool CanWrite { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
uint offset = 8;
var dir = new List<Entry>();
ArcView sec5 = null;
while (offset < file.MaxOffset)
{
string name = file.View.ReadString (offset, 4, Encoding.ASCII);
if ("ENDS" == name)
break;
uint section_size = file.View.ReadUInt32 (offset + 4);
offset += 8;
if ("OLDF" == name)
sec5 = new ArcView (file.View.ReadString (offset + 0x18, section_size - 0x18, Encoding.ASCII));
else
{
byte patch_type = file.View.ReadByte (offset);
uint size;
switch (patch_type)
{
case 0:
if (section_size != 1) return null;
var ent = GetEntryBySectionName (sec5, name);
if (ent == null) return null;
size = ent.Size;
break;
case 1:
size = section_size - 1;
break;
case 2:
var tmp = new byte[0x1D];
file.View.Read (offset + 1, tmp, 0, 0x1D);
DecryptCodeSection (tmp);
size = BitConverter.ToUInt32 (tmp, 0x19);
break;
default:
return null;
}
var entry = new Sep5Entry {
Name = name,
Offset = offset + 1,
Size = section_size - 1,
UnpackedSize = size,
PType = patch_type,
};
dir.Add (entry);
}
offset += section_size;
}
if (dir.Count > 0 && sec5 != null)
return new Sep5Archive (file, sec5, this, dir);
return null;
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var sent = entry as Sep5Entry;
var sep5 = arc as Sep5Archive;
var ent = GetEntryBySectionName (sep5.Sec5File, sent.Name);
var patch = new byte[sent.Size];
sep5.File.View.Read (sent.Offset, patch, 0, sent.Size);
var src = new byte[ent.Size];
sep5.Sec5File.View.Read (ent.Offset, src, 0, ent.Size);
if (sent.Name == "CODE")
{
DecryptCodeSection (src);
DecryptCodeSection (patch);
}
if (sent.PType == 0)
return new BinMemoryStream (src, sent.Name);
if (sent.PType == 1)
return new BinMemoryStream (patch, sent.Name);
var data = new byte[sent.UnpackedSize];
using (var mem = new MemoryStream (patch))
using (var reader = new BinaryReader (mem))
{
byte compressed_flag = reader.ReadByte();
var psizes = new uint[3];
var usizes = new uint[3];
var buffers = new byte[3][];
for (int i = 0; i < 3; ++i)
psizes[i] = reader.ReadUInt32();
for (int i = 0; i < 3; ++i)
usizes[i] = reader.ReadUInt32();
reader.ReadUInt32();
for (int i = 0; i < 3; ++i)
{
var packed = new byte[psizes[i]];
var unpacked = new byte[usizes[i]];
reader.Read (packed, 0, packed.Length);
if ((compressed_flag & (1 << i)) != 0)
{
using (var stream = new BinMemoryStream (packed))
using (var decompressor = new IarDecompressor (stream))
decompressor.Unpack (unpacked);
buffers[i] = unpacked;
}
else
buffers[i] = packed;
}
ApplyPatch (src, data, buffers[0], buffers[1], buffers[2]);
}
return new BinMemoryStream (data, sent.Name);
}
protected static void ApplyPatch (byte[] original, byte[] output, byte[] control, byte[] basic, byte[] append)
{
int original_index = 0, output_index = 0, basic_index = 0, append_index = 0;
using (var mem = new MemoryStream (control))
using (var reader = new BinaryReader (mem))
{
int base_size, tail_size, offset;
for (int i = 0; i < control.Length / 12; ++i)
{
base_size = reader.ReadInt32();
tail_size = reader.ReadInt32();
offset = reader.ReadInt32();
Buffer.BlockCopy (basic, basic_index, output, output_index, base_size);
for (int j = 0; j < base_size; j++)
output[output_index + j] += original[original_index + j];
Buffer.BlockCopy (append, append_index, output, output_index + base_size, tail_size);
basic_index += base_size;
append_index += tail_size;
original_index += base_size + offset;
output_index += base_size + tail_size;
}
}
}
}
internal sealed class Res2Reader : IDisposable