PKHeX/PKHeX.Core/Legality/Evolutions/EvolutionChain.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

55 lines
2 KiB
C#

using System;
using static PKHeX.Core.Legal;
namespace PKHeX.Core;
public static class EvolutionChain
{
internal static EvolutionHistory GetEvolutionChainsAllGens(PKM pk, IEncounterTemplate enc)
{
var origin = new EvolutionOrigin((ushort)enc.Species, (byte)enc.Version, (byte)enc.Generation, enc.LevelMin, (byte)pk.CurrentLevel);
if (!pk.IsEgg && enc is not EncounterInvalid)
return GetEvolutionChainsSearch(pk, origin);
var history = new EvolutionHistory();
var group = EvolutionGroupUtil.GetCurrentGroup(pk);
var chain = group.GetInitialChain(pk, origin, (ushort)pk.Species, (byte)pk.Form);
history.Set(pk.Context, chain);
return history;
}
internal static EvolutionHistory GetEvolutionChainsSearch(PKM pk, EvolutionOrigin enc)
{
var group = EvolutionGroupUtil.GetCurrentGroup(pk);
ReadOnlySpan<EvoCriteria> chain = group.GetInitialChain(pk, enc, (ushort)pk.Species, (byte)pk.Form);
var history = new EvolutionHistory();
while (true)
{
var any = group.Append(pk, history, ref chain, enc);
if (!any)
break;
var previous = group.GetPrevious(pk, enc);
if (previous is null)
break;
group = previous;
}
return history;
}
internal static EvoCriteria[] GetValidPreEvolutions(PKM pk, int maxspeciesorigin = -1, int maxLevel = -1, int minLevel = 1, bool skipChecks = false)
{
if (maxLevel < 0)
maxLevel = pk.CurrentLevel;
if (maxspeciesorigin == -1 && pk.InhabitedGeneration(2) && pk.Format <= 2 && pk.Generation == 1)
maxspeciesorigin = MaxSpeciesID_2;
var context = pk.Context;
if (context < EntityContext.Gen2)
context = EntityContext.Gen2;
var et = EvolutionTree.GetEvolutionTree(context);
return et.GetValidPreEvolutions(pk, levelMax: (byte)maxLevel, maxSpeciesOrigin: maxspeciesorigin, skipChecks: skipChecks, levelMin: (byte)minLevel);
}
}