PKHeX/PKHeX.Core/Legality/RNG/MethodFinder.cs
Kurt d47bb1d297
Update .NET Runtime to .NET 8.0 (#4082)
With the new version of Visual Studio bringing C# 12, we can revise our logic for better readability as well as use new methods/APIs introduced in the .NET 8.0 BCL.
2023-12-03 20:13:20 -08:00

826 lines
28 KiB
C#

using System;
using System.Runtime.CompilerServices;
using static PKHeX.Core.PIDType;
namespace PKHeX.Core;
/// <summary>
/// Class containing logic to obtain a PKM's PIDIV method.
/// </summary>
public static class MethodFinder
{
/// <summary>
/// Analyzes a <see cref="PKM"/> to find a matching PIDIV method.
/// </summary>
/// <param name="pk">Input <see cref="PKM"/>.</param>
/// <returns><see cref="PIDIV"/> object containing seed and method info.</returns>
public static PIDIV Analyze(PKM pk)
{
if (pk.Format < 3)
return AnalyzeGB(pk);
var pid = pk.EncryptionConstant;
var top = pid & 0xFFFF0000;
var bot = pid << 16;
Span<uint> temp = stackalloc uint[6];
for (int i = 0; i < 6; i++)
temp[i] = (uint)pk.GetIV(i);
ReadOnlySpan<uint> IVs = temp;
// Between XDRNG and LCRNG, the LCRNG will have the most results.
// Reuse our temp buffer across all methods.
const int maxResults = LCRNG.MaxCountSeedsIV;
Span<uint> seeds = stackalloc uint[maxResults];
if (GetLCRNGMatch(seeds, top, bot, IVs, out PIDIV pidiv))
return pidiv;
if (pk.Species == (int)Species.Unown && GetLCRNGUnownMatch(seeds, top, bot, IVs, out pidiv)) // frlg only
return pidiv;
if (GetColoStarterMatch(seeds, pk, top, bot, IVs, out pidiv))
return pidiv;
if (GetXDRNGMatch(seeds, pk, top, bot, IVs, out pidiv))
return pidiv;
// Special cases
if (GetLCRNGRoamerMatch(seeds, top, bot, IVs, out pidiv))
return pidiv;
if (GetChannelMatch(seeds, top, bot, IVs, out pidiv, pk))
return pidiv;
if (GetMG4Match(seeds, pid, IVs, out pidiv))
return pidiv;
if (GetBACDMatch(seeds, pk, pid, IVs, out pidiv))
return pidiv;
if (GetModifiedPIDMatch(seeds, pk, pid, IVs, out pidiv))
return pidiv;
return PIDIV.None; // no match
}
private static bool GetModifiedPIDMatch(Span<uint> seeds, PKM pk, uint pid, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
if (pk.IsShiny)
{
if (GetChainShinyMatch(seeds, pk, pid, IVs, out pidiv))
return true;
if (GetModified8BitMatch(pk, pid, out pidiv))
return true;
}
else
{
if (pid <= 0xFF && GetCuteCharmMatch(pk, pid, out pidiv))
return true;
}
return GetPokewalkerMatch(pk, pid, out pidiv);
}
private static bool GetModified8BitMatch(PKM pk, uint pid, out PIDIV pidiv)
{
return pk.Gen4
? (pid <= 0xFF && GetCuteCharmMatch(pk, pid, out pidiv)) || GetG5MGShinyMatch(pk, pid, out pidiv)
: GetG5MGShinyMatch(pk, pid, out pidiv) || (pid <= 0xFF && GetCuteCharmMatch(pk, pid, out pidiv));
}
private static bool GetLCRNGMatch(Span<uint> seeds, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
var count = LCRNGReversal.GetSeeds(seeds, bot, top);
var reg = seeds[..count];
var iv1 = GetIVChunk(IVs[..3]);
var iv2 = GetIVChunk(IVs[3..]);
foreach (var seed in reg)
{
// A and B are already used by PID
var B = LCRNG.Next2(seed);
// Method 1/2/4 can use 3 different RNG frames
var C = LCRNG.Next(B);
var ivC = C >> 16 & 0x7FFF;
if (iv1 == ivC)
{
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv2 == ivD) // ABCD
{
pidiv = new PIDIV(Method_1, seed);
return true;
}
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 == ivE) // ABCE
{
pidiv = new PIDIV(Method_4, seed);
return true;
}
}
else
{
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv1 != ivD)
continue;
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 == ivE) // ABDE
{
pidiv = new PIDIV(Method_2, seed);
return true;
}
}
}
count = LCRNGReversalSkip.GetSeeds(seeds, bot, top);
reg = seeds[..count];
foreach (var seed in reg)
{
// A and B are already used by PID
var C = LCRNG.Next3(seed);
// Method 3
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv1 != ivD)
continue;
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 != ivE)
continue;
pidiv = new PIDIV(Method_3, seed);
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetLCRNGUnownMatch(Span<uint> seeds, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
// this is an exact copy of LCRNG 1,2,4 matching, except the PID has its halves switched (BACD, BADE, BACE)
var count = LCRNGReversal.GetSeeds(seeds, top, bot); // reversed!
var reg = seeds[..count];
var iv1 = GetIVChunk(IVs[..3]);
var iv2 = GetIVChunk(IVs[3..]);
foreach (var seed in reg)
{
// A and B are already used by PID
var B = LCRNG.Next2(seed);
// Method 1/2/4 can use 3 different RNG frames
var C = LCRNG.Next(B);
var ivC = C >> 16 & 0x7FFF;
if (iv1 == ivC)
{
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv2 == ivD) // BACD
{
pidiv = new PIDIV(Method_1_Unown, seed);
return true;
}
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 == ivE) // BACE
{
pidiv = new PIDIV(Method_4_Unown, seed);
return true;
}
}
else
{
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv1 != ivD)
continue;
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 == ivE) // BADE
{
pidiv = new PIDIV(Method_2_Unown, seed);
return true;
}
}
}
count = LCRNGReversalSkip.GetSeeds(seeds, top, bot); // reversed!
reg = seeds[..count];
foreach (var seed in reg)
{
// A and B are already used by PID
var C = LCRNG.Next3(seed);
// Method 3
var D = LCRNG.Next(C);
var ivD = D >> 16 & 0x7FFF;
if (iv1 != ivD)
continue;
var E = LCRNG.Next(D);
var ivE = E >> 16 & 0x7FFF;
if (iv2 != ivE)
continue;
pidiv = new PIDIV(Method_3_Unown, seed);
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetLCRNGRoamerMatch(Span<uint> seeds, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
if (IVs is not [_, <= 7, 0, 0, 0, 0])
return GetNonMatch(out pidiv);
var iv1 = GetIVChunk(IVs[..3]);
var count = LCRNGReversal.GetSeeds(seeds, bot, top);
var reg = seeds[..count];
foreach (var seed in reg)
{
// Only the first 8 bits are kept
var ivC = LCRNG.Next3(seed) >> 16 & 0x00FF;
if (iv1 != ivC)
continue;
pidiv = new PIDIV(Method_1_Roamer, seed);
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetXDRNGMatch(Span<uint> seeds, PKM pk, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
var count = XDRNG.GetSeeds(seeds, top, bot);
var xdc = seeds[..count];
foreach (var seed in xdc)
{
var B = XDRNG.Prev(seed);
var A = XDRNG.Prev(B);
var hi = A >> 16;
var lo = B >> 16;
if (IVsMatch(hi, lo, IVs))
{
pidiv = new PIDIV(CXD, XDRNG.Prev(A));
return true;
}
// Check for anti-shiny against player TSV
var tsv = (uint)(pk.TID16 ^ pk.SID16) >> 3;
var psv = (top ^ bot) >> 3;
if (psv == tsv) // Already shiny, wouldn't be made anti-shiny
continue;
var p2 = seed;
var p1 = B;
psv = ((p2 ^ p1) >> 19);
if (psv != tsv) // The prior PID must be shiny!
continue;
do
{
B = XDRNG.Prev(A);
A = XDRNG.Prev(B);
hi = A >> 16;
lo = B >> 16;
if (IVsMatch(hi, lo, IVs))
{
pidiv = new PIDIV(CXDAnti, XDRNG.Prev(A));
return true;
}
p2 = XDRNG.Prev(p1);
p1 = XDRNG.Prev(p2);
psv = (p2 ^ p1) >> 19;
}
while (psv == tsv);
}
return GetNonMatch(out pidiv);
}
private static bool GetChannelMatch(Span<uint> seeds, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv, PKM pk)
{
var ver = pk.Version;
if (ver is not ((int)GameVersion.R or (int)GameVersion.S))
return GetNonMatch(out pidiv);
var undo = (top >> 16) ^ 0x8000;
if ((undo > 7 ? 0 : 1) != ((bot >> 16) ^ pk.SID16 ^ 40122))
top = (undo << 16);
var count = XDRNG.GetSeeds(seeds, top, bot);
var channel = seeds[..count];
foreach (var seed in channel)
{
var C = XDRNG.Next3(seed); // held item
// no checks, held item can be swapped
var D = XDRNG.Next(C); // Version
if ((D >> 31) + 1 != ver) // (0-Sapphire, 1-Ruby)
continue;
var E = XDRNG.Next(D); // OT Gender
if (E >> 31 != pk.OT_Gender)
continue;
if (!XDRNG.GetSequentialIVsUInt32(E, IVs))
continue;
if (seed >> 16 != pk.SID16)
continue;
pidiv = new PIDIV(Channel, XDRNG.Prev(seed));
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetMG4Match(Span<uint> seeds, uint pid, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
var currentPSV = getPSV(pid);
pid = ARNG.Prev(pid);
var originalPSV = getPSV(pid);
// ARNG shiny value must be different from the original shiny
// if we have a multi-rerolled PID, each re-roll must be from the same shiny value
if (originalPSV == currentPSV)
return GetNonMatch(out pidiv);
// ARNG can happen at most 3 times (checked all 2^32 seeds)
for (int i = 0; i < 3; i++)
{
var count = LCRNGReversal.GetSeeds(seeds, pid << 16, pid & 0xFFFF0000);
var mg4 = seeds[..count];
foreach (var seed in mg4)
{
var C = LCRNG.Next3(seed);
var D = LCRNG.Next(C);
if (!IVsMatch(C >> 16, D >> 16, IVs))
continue;
pidiv = new PIDIV(G4MGAntiShiny, seed);
return true;
}
// Continue checking for multi-rerolls
pid = ARNG.Prev(pid);
var prevPSV = getPSV(pid);
if (prevPSV != originalPSV)
break;
}
return GetNonMatch(out pidiv);
static uint getPSV(uint u32) => ((u32 >> 16) ^ (u32 & 0xFFFF)) >> 3;
}
private static bool GetG5MGShinyMatch(PKM pk, uint pid, out PIDIV pidiv)
{
var low = pid & 0xFFFF;
// generation 5 shiny PIDs
if (low <= 0xFF)
{
var av = (pid >> 16) & 1;
var genPID = PIDGenerator.GetMG5ShinyPID(low, av, pk.TID16, pk.SID16);
if (genPID == pid)
{
pidiv = PIDIV.G5MGShiny;
return true;
}
}
return GetNonMatch(out pidiv);
}
internal static bool GetCuteCharmMatch(PKM pk, uint pid, out PIDIV pidiv)
{
if (pid > 0xFF)
return GetNonMatch(out pidiv);
(var species, int genderValue) = GetCuteCharmGenderSpecies(pk, pid, pk.Species);
static byte getRatio(ushort species)
{
return species <= Legal.MaxSpeciesID_4
? PersonalTable.HGSS[species].Gender
: PKX.Personal[species].Gender;
}
switch (genderValue)
{
case 2: break; // can't cute charm a genderless pk
case 0: // male
var gr = getRatio(species);
if (gr >= PersonalInfo.RatioMagicFemale) // no modification for PID
break;
var rate = 25*((gr / 25) + 1); // buffered
var nature = pid % 25;
if (nature + rate != pid)
break;
pidiv = PIDIV.CuteCharm;
return true;
case 1: // female
if (pid >= 25)
break; // nope, this isn't a valid nature
if (getRatio(species) >= PersonalInfo.RatioMagicFemale) // no modification for PID
break;
pidiv = PIDIV.CuteCharm;
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetChainShinyMatch(Span<uint> seeds, PKM pk, uint pid, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
// 13 shiny bits
// PIDH & 7
// PIDL & 7
// IVs
var bot = GetIVChunk(IVs[..3]) << 16;
var top = GetIVChunk(IVs[3..]) << 16;
var count = LCRNGReversal.GetSeedsIVs(seeds, bot, top);
var reg = seeds[..count];
foreach (var seed in reg)
{
// check the individual bits
var s = seed;
int i = 15;
do
{
var bit = s >> 16 & 1;
if (bit != (pid >> i & 1))
break;
s = LCRNG.Prev(s);
}
while (--i != 2);
if (i != 2) // bit failed
continue;
// Shiny Bits of PID validated
var upper = s;
if ((upper >> 16 & 7) != (pid >> 16 & 7))
continue;
var lower = LCRNG.Prev(upper);
if ((lower >> 16 & 7) != (pid & 7))
continue;
var upid = (((pid & 0xFFFF) ^ pk.TID16 ^ pk.SID16) & 0xFFF8) | ((upper >> 16) & 0x7);
if (upid != pid >> 16)
continue;
s = LCRNG.Prev2(lower); // unroll one final time to get the origin seed
pidiv = new PIDIV(ChainShiny, s);
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetBACDMatch(Span<uint> seeds, PKM pk, uint pid, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
var bot = GetIVChunk(IVs[..3]) << 16;
var top = GetIVChunk(IVs[3..]) << 16;
var count = LCRNGReversal.GetSeedsIVs(seeds, bot, top);
var reg = seeds[..count];
PIDType type = BACD_U;
foreach (var seed in reg)
{
var B = seed;
var A = LCRNG.Prev(B);
var low = B >> 16;
var PID = (A & 0xFFFF0000) | low;
if (PID != pid)
{
uint idxor = (uint)(pk.TID16 ^ pk.SID16);
bool isShiny = (idxor ^ PID >> 16 ^ (PID & 0xFFFF)) < 8;
if (!isShiny)
{
if (!pk.IsShiny) // check for nyx antishiny
{
if (!IsBACD_U_AX(idxor, pid, low, A, ref type))
continue;
}
else // check for force shiny pk
{
if (!IsBACD_U_S(idxor, pid, low, ref A, ref type))
continue;
}
}
else if (!IsBACD_U_AX(idxor, pid, low, A, ref type))
{
if ((PID + 8 & 0xFFFFFFF8) != pid)
continue;
type = BACD_U_A;
}
}
var s = LCRNG.Prev(A);
// Check for prior Restricted seed
var sn = s;
for (int i = 0; i < 3; i++, sn = LCRNG.Prev(sn))
{
if ((sn & 0xFFFF0000) != 0)
continue;
// shift from unrestricted enum val to restricted enum val
pidiv = new PIDIV(--type, sn);
return true;
}
// no restricted seed found, thus unrestricted
pidiv = new PIDIV(type, s);
return true;
}
return GetNonMatch(out pidiv);
}
private static bool GetPokewalkerMatch(PKM pk, uint pid, out PIDIV pidiv)
{
// check surface compatibility
// Bits 8-24 must all be zero or all be one.
const uint midMask = 0x00FFFF00;
var mid = pid & midMask;
if (mid is not (0 or midMask))
return GetNonMatch(out pidiv);
// Quirky Nature is not possible with the algorithm.
var nature = pid % 25;
if (nature == 24)
return GetNonMatch(out pidiv);
// No Pokewalker Pokémon evolves into a different gender-ratio species.
// Besides Azurill, and Froslass
var gender = pk.Gender;
var gr = pk.PersonalInfo.Gender;
if (pk.Species == (int)Species.Froslass)
gr = 0x7F; // Snorunt
var expect = PokewalkerRNG.GetPID(pk.TID16, pk.SID16, nature, gender, gr);
if (expect != pid)
{
if (!(gender == 0 && IsAzurillEdgeCaseM(pk, nature, pid)))
return GetNonMatch(out pidiv);
}
pidiv = PIDIV.Pokewalker;
return true;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsAzurillEdgeCaseM(PKM pk, uint nature, uint oldpid)
{
// check for Azurill evolution edge case... 75% F-M is now 50% F-M; was this a Female->Male bend?
ushort species = pk.Species;
if (species is not ((int)Species.Marill or (int)Species.Azumarill))
return false;
const byte AzurillGenderRatio = 0xBF;
var gender = EntityGender.GetFromPIDAndRatio(pk.EncryptionConstant, AzurillGenderRatio);
if (gender != 1)
return false;
var pid = PokewalkerRNG.GetPID(pk.TID16, pk.SID16, nature, 1, AzurillGenderRatio);
return pid == oldpid;
}
private static bool GetColoStarterMatch(Span<uint> seeds, PKM pk, uint top, uint bot, ReadOnlySpan<uint> IVs, out PIDIV pidiv)
{
bool starter = pk.Version == (int)GameVersion.CXD && pk.Species switch
{
(int)Species.Espeon when pk.Met_Level >= 25 => true,
(int)Species.Umbreon when pk.Met_Level >= 26 => true,
_ => false,
};
if (!starter)
return GetNonMatch(out pidiv);
var iv1 = GetIVChunk(IVs[..3]);
var iv2 = GetIVChunk(IVs[3..]);
var count = XDRNG.GetSeeds(seeds, top, bot);
var xdc = seeds[..count];
foreach (var seed in xdc)
{
uint origin = seed;
if (!LockFinder.IsColoStarterValid(pk.Species, ref origin, pk.TID16, pk.SID16, pk.PID, iv1, iv2))
continue;
pidiv = new PIDIV(CXD_ColoStarter, origin);
return true;
}
return GetNonMatch(out pidiv);
}
/// <summary>
/// Returns false and no <see cref="PIDIV"/>.
/// </summary>
/// <param name="pidiv">Null</param>
/// <returns>False</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool GetNonMatch(out PIDIV pidiv)
{
pidiv = PIDIV.None;
return false;
}
/// <summary>
/// Checks if the PID is a <see cref="PIDType.BACD_U_S"></see> match.
/// </summary>
/// <param name="idxor"><see cref="PKM.TID16"/> ^ <see cref="PKM.SID16"/></param>
/// <param name="pid">Full actual PID</param>
/// <param name="low">Low portion of PID (B)</param>
/// <param name="A">First RNG call</param>
/// <param name="type">PID Type is updated if successful</param>
/// <returns>True/False if the PID matches</returns>
/// <remarks>First RNG call is unrolled once if the PID is valid with this correlation</remarks>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsBACD_U_S(uint idxor, uint pid, uint low, ref uint A, ref PIDType type)
{
// 0-Origin
// 1-PIDH
// 2-PIDL (ends up unused)
// 3-FORCEBITS
// PID = PIDH << 16 | (SID16 ^ TID16 ^ PIDH)
var X = LCRNG.Prev(A); // unroll once as there's 3 calls instead of 2
uint PID = (X & 0xFFFF0000) | (idxor ^ X >> 16);
PID &= 0xFFFFFFF8;
PID |= low & 0x7; // lowest 3 bits
if (PID != pid)
return false;
A = X; // keep the unrolled seed
type = BACD_U_S;
return true;
}
/// <summary>
/// Checks if the PID is a <see cref="PIDType.BACD_U_AX"></see> match.
/// </summary>
/// <param name="idxor"><see cref="PKM.TID16"/> ^ <see cref="PKM.SID16"/></param>
/// <param name="pid">Full actual PID</param>
/// <param name="low">Low portion of PID (B)</param>
/// <param name="A">First RNG call</param>
/// <param name="type">PID Type is updated if successful</param>
/// <returns>True/False if the PID matches</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsBACD_U_AX(uint idxor, uint pid, uint low, uint A, ref PIDType type)
{
if ((pid & 0xFFFF) != low)
return false;
// 0-Origin
// 1-ushort rnd, do until >8
// 2-PIDL
uint rnd = A >> 16;
if (rnd < 8)
return false;
uint PID = ((rnd ^ idxor ^ low) << 16) | low;
if (PID != pid)
return false;
type = BACD_U_AX;
return true;
}
private static PIDIV AnalyzeGB(PKM _)
{
// not implemented; correlation between IVs and RNG hasn't been converted to code.
return PIDIV.None;
}
/// <summary>
/// Generates IVs from 2 RNG calls using 15 bits of each to generate 6 IVs (5bits each).
/// </summary>
/// <param name="r1">First rand frame</param>
/// <param name="r2">Second rand frame</param>
/// <param name="IVs">IVs that should be the result</param>
/// <returns>IVs match random number IVs</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IVsMatch(uint r1, uint r2, ReadOnlySpan<uint> IVs)
{
if (IVs[0] != (r1 & 31))
return false;
if (IVs[1] != (r1 >> 5 & 31))
return false;
if (IVs[2] != (r1 >> 10 & 31))
return false;
if (IVs[3] != (r2 & 31))
return false;
if (IVs[4] != (r2 >> 5 & 31))
return false;
if (IVs[5] != (r2 >> 10 & 31))
return false;
return true;
}
/// <summary>
/// Generates IVs from 2 RNG calls using 15 bits of each to generate 6 IVs (5bits each).
/// </summary>
/// <param name="result">Result storage</param>
/// <param name="r1">First rand frame</param>
/// <param name="r2">Second rand frame</param>
/// <returns>Array of 6 IVs</returns>
internal static void GetIVsInt32(Span<int> result, uint r1, uint r2)
{
result[5] = (int)r2 >> 10 & 31;
result[4] = (int)r2 >> 5 & 31;
result[3] = (int)r2 & 31;
result[2] = (int)r1 >> 10 & 31;
result[1] = (int)r1 >> 5 & 31;
result[0] = (int)r1 & 31;
}
private static uint GetIVChunk(ReadOnlySpan<uint> arr)
{
uint result = 0;
for (int i = 0; i < arr.Length; i++)
result |= arr[i] << (5*i);
return result;
}
public static bool IsPokeSpotActivation(int slot, uint seed, out uint s)
{
s = seed;
var esv = (seed >> 16) % 100;
if (!IsPokeSpotSlotValid(slot, esv))
{
// todo
}
// check for valid activation
s = XDRNG.Prev(seed);
if ((s >> 16) % 3 != 0)
{
if ((s >> 16) % 100 < 10) // can't fail a Munchlax/Bonsly encounter check
{
// todo
}
s = XDRNG.Prev(s);
if ((s >> 16) % 3 != 0) // can't activate even if generous
{
// todo
}
}
return true;
}
private static bool IsPokeSpotSlotValid(int slot, uint esv) => slot switch
{
0 => esv < 50 , // [0,50)
1 => esv - 50 < 35, // [50,85)
2 => esv >= 85, // [85,100)
_ => false,
};
internal static bool IsCuteCharm4Valid(ISpeciesForm enc, PKM pk)
{
if (pk.Gender is not (0 or 1))
return false;
if (pk.Species is not ((int)Species.Marill or (int)Species.Azumarill))
return true;
if (!IsCuteCharmAzurillMale(pk.PID)) // recognized as not Azurill
return true;
return enc.Species == (int)Species.Azurill; // encounter must be male Azurill
}
private static bool IsCuteCharmAzurillMale(uint pid) => pid is >= 0xC8 and <= 0xE0;
/// <summary>
/// There are some edge cases when the gender ratio changes across evolutions.
/// </summary>
private static (ushort Species, int Gender) GetCuteCharmGenderSpecies(PKM pk, uint pid, ushort currentSpecies) => currentSpecies switch
{
// Nincada evo chain travels from M/F -> Genderless Shedinja
(int)Species.Shedinja => ((int)Species.Nincada, EntityGender.GetFromPID((int)Species.Nincada, pid)),
// These evolved species cannot be encountered with cute charm.
// 100% fixed gender does not modify PID; override this with the encounter species for correct calculation.
// We can assume the re-mapped species' [gender ratio] is what was encountered.
(int)Species.Wormadam => ((int)Species.Burmy, 1),
(int)Species.Mothim => ((int)Species.Burmy, 0),
(int)Species.Vespiquen => ((int)Species.Combee, 1),
(int)Species.Gallade => ((int)Species.Kirlia, 0),
(int)Species.Froslass => ((int)Species.Snorunt, 1),
// Azurill & Marill/Azumarill collision
// Changed gender ratio (25% M -> 50% M) needs special treatment.
// Double-check the encounter species with IsCuteCharm4Valid afterward.
(int)Species.Marill or (int)Species.Azumarill when IsCuteCharmAzurillMale(pid) => ((int)Species.Azurill, 0),
// Future evolutions
(int)Species.Sylveon => ((int)Species.Eevee, pk.Gender),
(int)Species.MrRime => ((int)Species.MimeJr, pk.Gender),
(int)Species.Kleavor => ((int)Species.Scyther, pk.Gender),
_ => (currentSpecies, pk.Gender),
};
public static PIDIV GetPokeSpotSeedFirst(PKM pk, byte slot)
{
// Activate (rand % 3)
// Munchlax / Bonsly (10%/30%)
// Encounter Slot Value (ESV) = 50%/35%/15% rarity (0-49, 50-84, 85-99)
Span<uint> seeds = stackalloc uint[XDRNG.MaxCountSeedsPID];
int count = XDRNG.GetSeeds(seeds, pk.EncryptionConstant);
var reg = seeds[..count];
foreach (var seed in reg)
{
// check for valid encounter slot info
if (IsPokeSpotActivation(slot, seed, out uint s))
return new PIDIV(PokeSpot, s);
}
return default;
}
}