PKHeX/PKHeX.Core/Saves/SAV3GCMemoryCard.cs
2018-05-12 08:41:29 -07:00

321 lines
13 KiB
C#

using System;
using System.Linq;
using System.Text;
namespace PKHeX.Core
{
/* GameCube memory card format data, checksum and code to extract files based on Dolphin code, adapted from C++ to C#
* https://github.com/dolphin-emu/dolphin/
*/
/// <summary>
/// Flags for indicating what data is present in the Memory Card
/// </summary>
public enum GCMemoryCardState
{
Invalid,
NoPkmSaveGame,
SaveGameCOLO,
SaveGameXD,
SaveGameRSBOX,
MultipleSaveGame,
DuplicateCOLO,
DuplicateXD,
DuplicateRSBOX,
}
/// <summary>
/// GameCube save container which may or may not contain Generation 3 <see cref="SaveFile"/> objects.
/// </summary>
public sealed class SAV3GCMemoryCard
{
private const int BLOCK_SIZE = 0x2000;
private const int MBIT_TO_BLOCKS = 0x10;
private const int DENTRY_STRLEN = 0x20;
private const int DENTRY_SIZE = 0x40;
private static int NumEntries_Directory => BLOCK_SIZE / DENTRY_SIZE;
private static readonly int[] validMCSizes =
{
0x80000, // 512KB 59 Blocks Memory Card
0x100000, // 1MB
0x200000, // 2MB
0x400000, // 4MB 251 Blocks Memory Card
0x800000, // 8MB
0x1000000, // 16MB 1019 Blocks Default Dolphin Memory Card
0x2000000, // 64MB
0x4000000 // 128 MB
};
public static bool IsMemoryCardSize(long Size) => validMCSizes.Contains((int)Size);
public static bool IsMemoryCardSize(byte[] Data) => IsMemoryCardSize(Data.Length);
private readonly byte[] RawEmpty_DEntry = { 0xFF, 0xFF, 0xFF, 0xFF };
// Control blocks
private const int Header_Block = 0;
private const int Directory_Block = 1;
private const int DirectoryBackup_Block = 2;
private const int BlockAlloc_Block = 3;
private const int BlockAllocBackup_Block = 4;
private static int Header => BLOCK_SIZE * Header_Block;
private static int Directory => BLOCK_SIZE * Directory_Block;
private static int DirectoryBAK => BLOCK_SIZE * DirectoryBackup_Block;
private static int BlockAlloc => BLOCK_SIZE * BlockAlloc_Block;
private static int BlockAllocBAK => BLOCK_SIZE * BlockAlloc_Block;
// Checksums
private void GetChecksum(int block, int offset, int length, out ushort csum, out ushort inv_csum)
{
csum = inv_csum = 0;
var ofs = block * BLOCK_SIZE + offset;
for (int i = 0; i < length; i++)
{
var val = BigEndian.ToUInt16(Data, ofs + i*2);
csum += val;
inv_csum += (ushort)(val ^ 0xffff);
}
if (csum == 0xffff)
csum = 0;
if (inv_csum == 0xffff)
inv_csum = 0;
}
private uint VerifyChecksums()
{
uint results = 0;
GetChecksum(Header_Block, 0, 0xFE, out ushort csum, out ushort csum_inv);
if (Header_Checksum != csum || (Header_Checksum_Inv != csum_inv))
results |= 1;
GetChecksum(Directory_Block, 0, 0xFFE, out csum, out csum_inv);
if (Directory_Checksum != csum || (Directory_Checksum_Inv != csum_inv))
results |= 2;
GetChecksum(DirectoryBackup_Block, 0, 0xFFE, out csum, out csum_inv);
if (DirectoryBAK_Checksum != csum || (DirectoryBAK_Checksum_Inv != csum_inv))
results |= 4;
GetChecksum(BlockAlloc_Block, 4, 0xFFE, out csum, out csum_inv);
if (BlockAlloc_Checksum != csum || (BlockAlloc_Checksum_Inv != csum_inv))
results |= 8;
GetChecksum(BlockAllocBackup_Block, 4, 0xFFE, out csum, out csum_inv);
if ((BlockAllocBAK_Checksum != csum) || BlockAllocBAK_Checksum_Inv != csum_inv)
results |= 16;
return results;
}
// Structure
private int Header_Size => BigEndian.ToUInt16(Data, Header + 0x0022);
private ushort Header_Checksum => BigEndian.ToUInt16(Data, Header + 0x01fc);
private ushort Header_Checksum_Inv => BigEndian.ToUInt16(Data, Header + 0x01fe);
// Encoding (Windows-1252 or Shift JIS)
private int Header_Encoding => BigEndian.ToUInt16(Data, Header + 0x0024);
private bool Header_Japanese => Header_Encoding == 1;
private Encoding EncodingType => Header_Japanese ? Encoding.GetEncoding(1252) : Encoding.GetEncoding(932);
private int Directory_UpdateCounter => BigEndian.ToUInt16(Data, Directory + 0x1ffa);
private int Directory_Checksum => BigEndian.ToUInt16(Data, Directory + 0x1ffc);
private int Directory_Checksum_Inv => BigEndian.ToUInt16(Data, Directory + 0x1ffe);
private int DirectoryBAK_UpdateCounter => BigEndian.ToUInt16(Data, DirectoryBAK + 0x1ffa);
private int DirectoryBAK_Checksum => BigEndian.ToUInt16(Data, DirectoryBAK + 0x1ffc);
private int DirectoryBAK_Checksum_Inv => BigEndian.ToUInt16(Data, DirectoryBAK + 0x1ffe);
private int BlockAlloc_Checksum => BigEndian.ToUInt16(Data, BlockAlloc + 0x0000);
private int BlockAlloc_Checksum_Inv => BigEndian.ToUInt16(Data, BlockAlloc + 0x0002);
private int BlockAllocBAK_Checksum => BigEndian.ToUInt16(Data, BlockAllocBAK + 0x0000);
private int BlockAllocBAK_Checksum_Inv => BigEndian.ToUInt16(Data, BlockAllocBAK + 0x0002);
private int DirectoryBlock_Used;
private int NumBlocks => Data.Length/BLOCK_SIZE - 5;
private int EntryCOLO = -1;
private int EntryXD = -1;
private int EntryRSBOX = -1;
private int EntrySelected = -1;
public bool HasCOLO => EntryCOLO > -1;
public bool HasXD => EntryXD > -1;
public bool HasRSBOX => EntryRSBOX > -1;
public int SaveGameCount;
private bool IsCorruptedMemoryCard()
{
uint csums = VerifyChecksums();
if ((csums & 0x1) == 1) // Header checksum failed
return true;
if ((csums & 0x2) == 1) // directory checksum error!
{
if ((csums & 0x4) == 1) // backup is also wrong
return true; // Directory checksum and directory backup checksum failed
RestoreBackup(); // backup is correct, restore
csums = VerifyChecksums(); // update checksums
}
if ((csums & 0x8) != 1)
return false;
if ((csums & 0x10) == 1) // backup is also wrong
return true;
// backup is correct, restore
RestoreBackup();
return false;
}
private void RestoreBackup()
{
Array.Copy(Data, DirectoryBackup_Block*BLOCK_SIZE, Data, Directory_Block*BLOCK_SIZE, BLOCK_SIZE);
Array.Copy(Data, BlockAllocBackup_Block*BLOCK_SIZE, Data, BlockAlloc_Block*BLOCK_SIZE, BLOCK_SIZE);
}
public GCMemoryCardState LoadMemoryCardFile(byte[] data)
{
Data = data;
if (!IsMemoryCardSize(Data))
// Invalid size
return GCMemoryCardState.Invalid;
// Size in megabits, not megabytes
int m_sizeMb = Data.Length / BLOCK_SIZE / MBIT_TO_BLOCKS;
if (m_sizeMb != Header_Size) // Memory card file size does not match the header size
return GCMemoryCardState.Invalid;
if (IsCorruptedMemoryCard())
return GCMemoryCardState.Invalid;
// Use the most recent directory block
DirectoryBlock_Used = DirectoryBAK_UpdateCounter > Directory_UpdateCounter
? DirectoryBackup_Block
: Directory_Block;
string Empty_DEntry = EncodingType.GetString(RawEmpty_DEntry, 0, 4);
// Search for pokemon savegames in the directory
for (int i = 0; i < NumEntries_Directory; i++)
{
int offset = DirectoryBlock_Used*BLOCK_SIZE + i*DENTRY_SIZE;
string GameCode = EncodingType.GetString(Data, offset, 4);
if (GameCode == Empty_DEntry)
continue;
int FirstBlock = BigEndian.ToUInt16(Data, offset + 0x36);
int BlockCount = BigEndian.ToUInt16(Data, offset + 0x38);
// Memory card directory contains info for deleted files with boundaries beyond memory card size, ignore
if (FirstBlock + BlockCount > NumBlocks)
continue;
if (SaveUtil.HEADER_COLO.Contains(GameCode))
{
if (EntryCOLO > -1) // another entry already exists
return GCMemoryCardState.DuplicateCOLO;
EntryCOLO = i;
SaveGameCount++;
}
if (SaveUtil.HEADER_XD.Contains(GameCode))
{
if (EntryXD > -1) // another entry already exists
return GCMemoryCardState.DuplicateXD;
EntryXD = i;
SaveGameCount++;
}
if (SaveUtil.HEADER_RSBOX.Contains(GameCode))
{
if (EntryRSBOX > -1) // another entry already exists
return GCMemoryCardState.DuplicateRSBOX;
EntryRSBOX = i;
SaveGameCount++;
}
}
if (SaveGameCount == 0)
return GCMemoryCardState.NoPkmSaveGame;
if (SaveGameCount > 1)
return GCMemoryCardState.MultipleSaveGame;
if (EntryCOLO > -1)
{
EntrySelected = EntryCOLO;
return GCMemoryCardState.SaveGameCOLO;
}
if (EntryXD > -1)
{
EntrySelected = EntryXD;
return GCMemoryCardState.SaveGameXD;
}
EntrySelected = EntryRSBOX;
return GCMemoryCardState.SaveGameRSBOX;
}
public GameVersion SelectedGameVersion
{
get
{
if (EntryCOLO > -1 && EntrySelected == EntryCOLO)
return GameVersion.COLO;
if (EntryXD > -1 && EntrySelected == EntryXD)
return GameVersion.XD;
if (EntryRSBOX > -1 && EntrySelected == EntryRSBOX)
return GameVersion.RSBOX;
return GameVersion.Any; //Default for no game selected
}
}
public void SelectSaveGame(GameVersion Game)
{
switch (Game)
{
case GameVersion.COLO: if (EntryCOLO > -1) EntrySelected = EntryCOLO; break;
case GameVersion.XD: if (EntryXD > -1) EntrySelected = EntryXD; break;
case GameVersion.RSBOX: if (EntryRSBOX > -1) EntrySelected = EntryRSBOX; break;
}
}
public string GCISaveName => GCISaveGameName();
public byte[] SelectedSaveData { get => ReadSaveGameData(); set => WriteSaveGameData(value); }
public byte[] Data { get; private set; }
private string GCISaveGameName()
{
int offset = DirectoryBlock_Used*BLOCK_SIZE + EntrySelected*DENTRY_SIZE;
string GameCode = EncodingType.GetString(Data, offset, 4);
string Makercode = EncodingType.GetString(Data, offset + 0x04, 2);
string FileName = EncodingType.GetString(Data, offset + 0x08, DENTRY_STRLEN);
return $"{Makercode}-{GameCode}-{FileName.Replace("\0", "")}.gci";
}
private byte[] ReadSaveGameData()
{
if (EntrySelected == -1)
// Not selected any entry
return null;
int offset = DirectoryBlock_Used*BLOCK_SIZE + EntrySelected*DENTRY_SIZE;
int FirstBlock = BigEndian.ToUInt16(Data, offset + 0x36);
int BlockCount = BigEndian.ToUInt16(Data, offset + 0x38);
byte[] SaveData = new byte[BlockCount * BLOCK_SIZE];
Array.Copy(Data, FirstBlock * BLOCK_SIZE, SaveData, 0, BlockCount * BLOCK_SIZE);
return SaveData;
}
private void WriteSaveGameData(byte[] SaveData)
{
if (EntrySelected == -1) // Can't write anywhere
return;
int offset = DirectoryBlock_Used*BLOCK_SIZE + EntrySelected*DENTRY_SIZE;
int FirstBlock = BigEndian.ToUInt16(Data, offset + 0x36);
int BlockCount = BigEndian.ToUInt16(Data, offset + 0x38);
if (SaveData.Length != BlockCount * BLOCK_SIZE) // Invalid File Size
return;
Array.Copy(SaveData, 0, Data, FirstBlock * BLOCK_SIZE, BlockCount * BLOCK_SIZE);
}
}
}