PKHeX/PKHeX.Core/Editing/NatureAmp.cs
Kurt 998b8f1ce0 Minor tweaks
Add unit test for VC kata/hiragana edge case
De-duplicate some slot change notifications
Span in more spots
2023-04-22 17:51:32 -07:00

115 lines
3.5 KiB
C#

using System;
using static PKHeX.Core.NatureAmpRequest;
namespace PKHeX.Core;
/// <summary>
/// Logic for mutating a nature to amplify certain stats.
/// </summary>
public static class NatureAmp
{
/// <summary>
/// Mutate the nature amp indexes to match the request
/// </summary>
/// <param name="type">Request type to modify the provided <see cref="statIndex"/></param>
/// <param name="statIndex">Stat Index to mutate</param>
/// <param name="currentNature">Current nature to derive the current amps from</param>
/// <returns>New nature value</returns>
public static int GetNewNature(this NatureAmpRequest type, int statIndex, int currentNature)
{
if (currentNature > (int)Nature.Quirky)
return -1;
var (up, dn) = GetNatureModification(currentNature);
return GetNewNature(type, statIndex, up, dn);
}
/// <inheritdoc cref="GetNewNature(NatureAmpRequest,int,int)"/>
public static int GetNewNature(NatureAmpRequest type, int statIndex, int up, int dn)
{
//
switch (type)
{
case Increase when up != statIndex:
up = statIndex;
break;
case Decrease when dn != statIndex:
dn = statIndex;
break;
case Neutral when up != statIndex && dn != statIndex:
up = dn = statIndex;
break;
default:
return -1; // failure
}
return CreateNatureFromAmps(up, dn);
}
/// <summary>
/// Recombine the stat amps into a nature value.
/// </summary>
/// <param name="up">Increased stat</param>
/// <param name="dn">Decreased stat</param>
/// <returns>Nature</returns>
public static int CreateNatureFromAmps(int up, int dn)
{
if ((uint)up > 5 || (uint)dn > 5)
return -1;
return (up * 5) + dn;
}
/// <summary>
/// Decompose the nature to the two stat indexes that are modified
/// </summary>
public static (int up, int dn) GetNatureModification(int nature)
{
var up = (nature / 5);
var dn = (nature % 5);
return (up, dn);
}
/// <summary>
/// Checks if the nature is out of range or the stat amplifications are not neutral.
/// </summary>
/// <param name="nature">Nature</param>
/// <param name="up">Increased stat</param>
/// <param name="dn">Decreased stat</param>
/// <returns>True if nature modification values are equal or the Nature is out of range.</returns>
public static bool IsNeutralOrInvalid(int nature, int up, int dn)
{
return up == dn || nature >= 25; // invalid
}
/// <inheritdoc cref="IsNeutralOrInvalid(int, int, int)"/>
public static bool IsNeutralOrInvalid(int nature)
{
var (up, dn) = GetNatureModification(nature);
return IsNeutralOrInvalid(nature, up, dn);
}
/// <summary>
/// Updates stats according to the specified nature.
/// </summary>
/// <param name="stats">Current stats to amplify if appropriate</param>
/// <param name="nature">Nature</param>
public static void ModifyStatsForNature(Span<ushort> stats, int nature)
{
var (up, dn) = GetNatureModification(nature);
if (IsNeutralOrInvalid(nature, up, dn))
return;
ref var upStat = ref stats[up + 1];
ref var dnStat = ref stats[dn + 1];
upStat = (ushort)((upStat * 11) / 10);
dnStat = (ushort)((dnStat * 9) / 10);
}
}
public enum NatureAmpRequest
{
Neutral,
Increase,
Decrease,
}