PKHeX/PKHeX.Core/Legality/Learnset/EggMoves.cs
Kurt 9166d0eb64
Refactoring: Move Source (Legality) (#3560)
Rewrites a good amount of legality APIs pertaining to:
* Legal moves that can be learned
* Evolution chains & cross-generation paths
* Memory validation with forgotten moves

In generation 8, there are 3 separate contexts an entity can exist in: SW/SH, BD/SP, and LA. Not every entity can cross between them, and not every entity from generation 7 can exist in generation 8 (Gogoat, etc). By creating class models representing the restrictions to cross each boundary, we are able to better track and validate data.

The old implementation of validating moves was greedy: it would iterate for all generations and evolutions, and build a full list of every move that can be learned, storing it on the heap. Now, we check one game group at a time to see if the entity can learn a move that hasn't yet been validated. End result is an algorithm that requires 0 allocation, and a smaller/quicker search space.

The old implementation of storing move parses was inefficient; for each move that was parsed, a new object is created and adjusted depending on the parse. Now, move parse results are `struct` and store the move parse contiguously in memory. End result is faster parsing and 0 memory allocation.

* `PersonalTable` objects have been improved with new API methods to check if a species+form can exist in the game.
* `IEncounterTemplate` objects have been improved to indicate the `EntityContext` they originate in (similar to `Generation`).
* Some APIs have been extended to accept `Span<T>` instead of Array/IEnumerable
2022-08-03 16:15:27 -07:00

106 lines
3.2 KiB
C#

using System;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core;
public abstract class EggMoves
{
public readonly int[] Moves;
protected EggMoves(int[] moves) => Moves = moves;
public bool GetHasEggMove(int move) => Array.IndexOf(Moves, move) != -1;
}
public sealed class EggMoves2 : EggMoves
{
private EggMoves2(int[] moves) : base(moves) { }
public static EggMoves2[] GetArray(ReadOnlySpan<byte> data, int count)
{
var entries = new EggMoves2[count + 1];
var empty = entries[0] = new EggMoves2(Array.Empty<int>());
int baseOffset = ReadInt16LittleEndian(data) - (count * 2);
for (int i = 1; i < entries.Length; i++)
{
int start = ReadInt16LittleEndian(data[((i - 1) * 2)..]) - baseOffset;
var slice = data[start..];
int moveCount = slice.IndexOf((byte)0xFF);
if (moveCount == 0)
{
entries[i] = empty;
continue;
}
int[] moves = new int[moveCount];
for (int m = 0; m < moves.Length; m++)
moves[m] = slice[m];
entries[i] = new EggMoves2(moves);
}
return entries;
}
}
public sealed class EggMoves6 : EggMoves
{
private EggMoves6(int[] moves) : base(moves) { }
public static EggMoves6[] GetArray(BinLinkerAccessor entries)
{
var result = new EggMoves6[entries.Length];
var empty = result[0] = new EggMoves6(Array.Empty<int>());
for (int i = 1; i < result.Length; i++)
{
var data = entries[i];
int count = ReadInt16LittleEndian(data);
if (count == 0)
{
result[i] = empty;
continue;
}
var moves = new int[count];
var span = data[2..];
for (int j = 0; j < moves.Length; j++)
moves[j] = ReadInt16LittleEndian(span[(j * 2)..]);
result[i] = new EggMoves6(moves);
}
return result;
}
}
public sealed class EggMoves7 : EggMoves
{
public readonly int FormTableIndex;
private EggMoves7(int[] moves, int formIndex = 0) : base(moves) => FormTableIndex = formIndex;
public static EggMoves7[] GetArray(BinLinkerAccessor entries)
{
var result = new EggMoves7[entries.Length];
var empty = result[0] = new EggMoves7(Array.Empty<int>());
for (int i = 1; i < result.Length; i++)
{
var data = entries[i];
int count = ReadInt16LittleEndian(data[2..]);
int formIndex = ReadInt16LittleEndian(data);
if (count == 0)
{
// Might need to keep track of the Form Index for unavailable forms pointing to valid forms.
if (formIndex != 0)
result[i] = new EggMoves7(Array.Empty<int>(), formIndex);
else
result[i] = empty;
continue;
}
var moves = new int[count];
var span = data[4..];
for (int j = 0; j < moves.Length; j++)
moves[j] = ReadInt16LittleEndian(span[(j * 2)..]);
result[i] = new EggMoves7(moves, formIndex);
}
return result;
}
}