PKHeX/PKHeX.Core/Saves/Util/Checksums.cs
Kurt 9855382b0a Misc encounter tweaks, annotations
EncounterEgg now indicates FixedBall(Poke) for Gen2-5
EncounterSlot2 now indicates Form Random for Gen2 Unown, database
EncounterStatic3 now generates FRLG Gen2 Roamers with correct location
EncounterCriteria now used more heavily for requested IVs
EncounterPossible3 now correctly skips Eggs if eggs are not requested
EncounterGift3Colo now generates Japanese Bonus disk gifts only in Japanese, doesn't validate non-Japanese
2023-08-17 00:07:54 -07:00

215 lines
11 KiB
C#

using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core;
/// <summary>
/// Checksum algorithms used by the games.
/// </summary>
public static class Checksums
{
/// <summary>Calculates the CRC16-CCITT checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
/// <returns>Checksum</returns>
public static ushort CRC16_CCITT(ReadOnlySpan<byte> data)
{
byte top = 0xFF;
byte bot = 0xFF;
foreach (var b in data)
{
var x = b ^ top;
x ^= (x >> 4);
top = (byte)(bot ^ (x >> 3) ^ (x << 4));
bot = (byte)(x ^ (x << 5));
}
return (ushort)((top << 8) | bot);
}
private static ReadOnlySpan<ushort> crc16 => new ushort[]
{
0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040,
};
private static ReadOnlySpan<uint> crc32 => new uint[]
{
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
};
/// <summary>Calculates the 16bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
/// <param name="initial">Initial value for checksum</param>
/// <returns>Checksum</returns>
private static ushort CRC16(ReadOnlySpan<byte> data, [ConstantExpected(Min = 0)] ushort initial)
{
ushort chk = initial;
foreach (var b in data)
chk = (ushort)(crc16[(byte)(b ^ chk)] ^ (chk >> 8));
return chk;
}
/// <summary>Calculates the 16bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
public static ushort CRC16Invert(ReadOnlySpan<byte> data) => (ushort)~CRC16(data, unchecked((ushort)~0));
/// <summary>Calculates the 16bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
public static ushort CRC16NoInvert(ReadOnlySpan<byte> data) => CRC16(data, 0);
/// <summary>Calculates the 32bit checksum over an input byte array. Used in GBA save files.</summary>
/// <param name="data">Input byte array</param>
/// <param name="initial">Initial value for checksum</param>
/// <returns>Checksum</returns>
public static ushort CheckSum32(ReadOnlySpan<byte> data, [ConstantExpected(Min = 0)] uint initial = 0)
{
uint chk = initial;
foreach (var u32 in MemoryMarshal.Cast<byte, uint>(data))
{
if (BitConverter.IsLittleEndian)
chk += u32;
else
chk += ReverseEndianness(u32);
}
return (ushort)(chk + (chk >> 16));
}
/// <summary>Calculates the 32bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
/// <param name="initial">Initial value for checksum</param>
/// <returns>Checksum</returns>
private static uint CRC32(ReadOnlySpan<byte> data, [ConstantExpected(Min = 0)] uint initial)
{
uint chk = initial;
foreach (var b in data)
chk = crc32[(byte)(b ^ chk)] ^ (chk >> 8);
return chk;
}
/// <summary>Calculates the 16bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
public static uint CRC32Invert(ReadOnlySpan<byte> data) => ~CRC32(data, unchecked((uint)~0));
/// <summary>Calculates the 16bit checksum over an input byte array.</summary>
/// <param name="data">Input byte array</param>
public static uint CRC32NoInvert(ReadOnlySpan<byte> data) => CRC32(data, 0);
/// <summary>Calculates the 16bit checksum over an input byte array. Used in N64 Stadium save files.</summary>
/// <param name="data">Input byte array</param>
/// <param name="initial">Initial value for checksum</param>
/// <returns>Checksum</returns>
public static ushort CheckSum16(ReadOnlySpan<byte> data, [ConstantExpected(Min = 0)] ushort initial = 0)
{
ushort acc = initial;
foreach (byte b in data)
acc += b;
return acc;
}
/// <summary>Calculates the 32bit checksum over an input byte array. Used in GC R/S BOX.</summary>
/// <param name="data">Input byte array</param>
/// <returns>Checksum</returns>
public static uint CheckSum16BigInvert(ReadOnlySpan<byte> data)
{
var chk = Add16BigEndian(data);
return (uint)((chk << 16) | (ushort)(0xF004u - chk));
}
/// <summary>
/// Gets the 16-bit checksum of a byte array reading as Little Endian.
/// </summary>
/// <param name="data">Input byte array</param>
/// <returns>Checksum</returns>
public static ushort Add16(ReadOnlySpan<byte> data)
{
ushort chk = 0;
foreach (var u16 in MemoryMarshal.Cast<byte, ushort>(data))
{
if (BitConverter.IsLittleEndian)
chk += u16;
else
chk += ReverseEndianness(u16);
}
return chk;
}
/// <summary>
/// Gets the 16-bit checksum of a byte array reading as Big Endian.
/// </summary>
/// <param name="data">Input byte array</param>
/// <returns>Checksum</returns>
public static ushort Add16BigEndian(ReadOnlySpan<byte> data)
{
ushort chk = 0;
foreach (var u16 in MemoryMarshal.Cast<byte, ushort>(data))
{
if (!BitConverter.IsLittleEndian)
chk += u16;
else
chk += ReverseEndianness(u16);
}
return chk;
}
}