PKHeX/PKHeX.Core/Saves/Util/StadiumUtil.cs
Kurt 47071b41f3
Refactoring: Span-based value writes and method signatures (#3361)
Existing `get`/`set` logic is flawed in that it doesn't work on Big Endian operating systems, and it allocates heap objects when it doesn't need to.

`System.Buffers.Binary.BinaryPrimitives` in the `System.Memory` NuGet package provides both Little Endian and Big Endian methods to read and write data; all the `get`/`set` operations have been reworked to use this new API. This removes the need for PKHeX's manual `BigEndian` class, as all functions are already covered by the BinaryPrimitives API.

The `StringConverter` has now been rewritten to accept a Span to read from & write to, no longer requiring a temporary StringBuilder.

Other Fixes included:
- The Super Training UI for Gen6 has been reworked according to the latest block structure additions.
- Cloning a Stadium2 Save File now works correctly (opening from the Folder browser list).
- Checksum & Sanity properties removed from parent PKM class, and is now implemented via interface.
2022-01-02 21:35:59 -08:00

81 lines
2.8 KiB
C#

using System;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core
{
/// <summary>
/// Logic pertaining to Pokémon Stadium Save Files.
/// </summary>
public static class StadiumUtil
{
/// <summary>
/// Checks if the <see cref="magic"/> value is present either with or without byte-swapping.
/// </summary>
public static bool IsMagicPresentEither(ReadOnlySpan<byte> data, int size, uint magic)
{
if (IsMagicPresent(data, size, magic))
return true;
if (IsMagicPresentSwap(data, size, magic))
return true;
return false;
}
/// <summary>
/// Checks if the <see cref="magic"/> value is present without byte-swapping.
/// </summary>
public static bool IsMagicPresent(ReadOnlySpan<byte> data, int size, uint magic)
{
// Check footers of first few teams to see if the magic value is there.
for (int i = 0; i < 10; i++)
{
var footer = data[(size - 6 + (i * size))..];
if (ReadUInt32LittleEndian(footer) != magic)
return false;
}
return true;
}
/// <summary>
/// Checks if the <see cref="magic"/> value is present either with byte-swapping.
/// </summary>
public static bool IsMagicPresentSwap(ReadOnlySpan<byte> data, int size, uint magic)
{
// Check footers of first few teams to see if the magic value is there.
var left = (ushort)magic;
var right = (ushort)(magic >> 16);
left = (ushort)((left >> 8) | (left << 8));
right = (ushort)((right >> 8) | (right << 8));
for (int i = 0; i < 10; i++)
{
var ofs = size - 6 + (i * size);
if (ReadUInt16LittleEndian(data[(ofs - 2)..]) != left) // OP
return false;
if (ReadUInt16LittleEndian(data[(ofs + 4)..]) != right) // EK
return false;
}
return true;
}
public static bool IsMagicPresentAbsolute(ReadOnlySpan<byte> data, int offset, uint magic)
{
var actual = ReadUInt32LittleEndian(data[offset..]);
if (actual == magic) // POKE
return true;
var left = (ushort)magic;
var right = (ushort)(magic >> 16);
left = (ushort)((left >> 8) | (left << 8));
right = (ushort)((right >> 8) | (right << 8));
if (ReadUInt16LittleEndian(data[(offset - 2)..]) != left) // OP
return false;
if (ReadUInt16LittleEndian(data[(offset + 4)..]) != right) // EK
return false;
return true;
}
}
}