using System.Collections.Generic;
namespace PKHeX.Core
{
public static class FrameFinder
{
///
/// Checks a to see if any encounter frames can generate the spread. Requires further filtering against matched Encounter Slots and generation patterns.
///
/// Matched containing info and .
/// object containing various accessible information required for the encounter.
/// to yield possible encounter details for further filtering
public static IEnumerable GetFrames(PIDIV pidiv, PKM pk)
{
if (pidiv.RNG == null)
yield break;
FrameGenerator info = new FrameGenerator(pidiv, pk);
if (info.FrameType == FrameType.None)
yield break;
info.Nature = pk.EncryptionConstant % 25;
// gather possible nature determination seeds until a same-nature PID breaks the unrolling
IEnumerable seeds = SeedInfo.GetSeedsUntilNature(pidiv, info);
var frames = pidiv.Type == PIDType.CuteCharm
? FilterCuteCharm(seeds, pidiv, info)
: FilterNatureSync(seeds, pidiv, info);
var refined = RefineFrames(frames, info);
foreach (var z in refined)
yield return z;
}
private static IEnumerable RefineFrames(IEnumerable frames, FrameGenerator info)
{
return info.FrameType == FrameType.MethodH
? RefineFrames3(frames, info)
: RefineFrames4(frames, info);
}
private static IEnumerable RefineFrames3(IEnumerable frames, FrameGenerator info)
{
// ESV
// Level
// Nature
// Current Seed of the frame is the Level Calc (frame before nature)
var list = new List();
foreach (var f in frames)
{
// Current Seed of the frame is the Level Calc
var prev = info.RNG.Prev(f.Seed); // ESV
var rand = prev >> 16;
{
f.ESV = rand;
yield return f;
}
if (f.Lead != LeadRequired.None || !info.AllowLeads) // Emerald
continue;
// Generate frames for other slots after the regular slots
list.Add(f);
}
// Check leads -- none in list if leads are not allowed
// Certain leads inject a RNG call
// 3 different rand places
foreach (var f in list)
{
LeadRequired lead;
var prev0 = f.Seed; // 0
var prev1 = info.RNG.Prev(f.Seed); // -1
var prev2 = info.RNG.Prev(prev1); // -2
// Modify Call values
var p0 = prev0 >> 16;
var p1 = prev1 >> 16;
var p2 = prev2 >> 16;
// Pressure, Hustle, Vital Spirit = Force Maximum Level from slot
// -2 ESV
// -1 Level
// 0 LevelMax proc (Random() & 1)
// 1 Nature
bool max = p0 % 2 == 1;
lead = max ? LeadRequired.PressureHustleSpirit : LeadRequired.PressureHustleSpiritFail;
yield return info.GetFrame(prev2, lead, p2);
// Keen Eye, Intimidate
// -2 ESV
// -1 Level
// 0 Level Adequate Check !(Random() % 2 == 1) rejects -- rand%2==1 is adequate
// 1 Nature
// Note: if this check fails, the encounter generation routine is aborted.
if (max) // same result as above, no need to recalculate
{
lead = LeadRequired.IntimidateKeenEye;
yield return info.GetFrame(prev2, lead, p2);
}
// Cute Charm
// -2 ESV
// -1 CC Proc (Random() % 3 != 0)
// 0 Level
// 1 Nature
bool cc = p1 % 3 != 0;
lead = cc ? LeadRequired.CuteCharm : LeadRequired.CuteCharmFail;
yield return info.GetFrame(prev2, lead, p2);
// Static or Magnet Pull
// -2 SlotProc (Random % 2 == 0)
// -1 ESV (select slot)
// 0 Level
// 1 Nature
bool force = p2 % 2 == 0;
if (force)
{
// Since a failed proc is indistinguishable from the default frame calls, only generate if it succeeds.
lead = LeadRequired.StaticMagnet;
yield return info.GetFrame(prev2, lead, p1);
}
}
}
private static IEnumerable RefineFrames4(IEnumerable frames, FrameGenerator info)
{
var list = new List();
foreach (var f in frames)
{
// Current Seed of the frame is the ESV.
var rand = f.Seed >> 16;
{
f.ESV = rand;
yield return f;
}
if (f.Lead != LeadRequired.None)
continue;
// Generate frames for other slots after the regular slots
list.Add(f);
}
foreach (var f in list)
{
// Level Modifiers between ESV and Nature
var prev = info.RNG.Prev(f.Seed);
var p16 = prev >> 16;
yield return info.GetFrame(prev, LeadRequired.IntimidateKeenEye, p16);
yield return info.GetFrame(prev, LeadRequired.PressureHustleSpirit, p16);
// Slot Modifiers before ESV
var force = (info.DPPt ? p16 >> 15 : p16 & 1) == 1;
if (!force)
continue;
var rand = f.Seed >> 16;
yield return info.GetFrame(prev, LeadRequired.StaticMagnet, rand);
}
}
///
/// Filters the input according to a Nature Lock frame generation pattern.
///
/// Seed Information for the frame
/// PIDIV Info for the frame
/// Search Info for the frame
/// Possible matches to the Nature Lock frame generation pattern
private static IEnumerable FilterNatureSync(IEnumerable seeds, PIDIV pidiv, FrameGenerator info)
{
foreach (var seed in seeds)
{
var s = seed.Seed;
var rand = s >> 16;
bool sync = info.AllowLeads && !seed.Charm3 && (info.DPPt ? rand >> 15 : rand & 1) == 0;
bool reg = (info.DPPt ? rand / 0xA3E : rand % 25) == info.Nature;
if (!sync && !reg) // doesn't generate nature frame
continue;
uint prev = pidiv.RNG.Prev(s);
if (info.AllowLeads && reg) // check for failed sync
{
var failsync = (info.DPPt ? prev >> 31 : (prev >> 16) & 1) != 1;
if (failsync)
yield return info.GetFrame(pidiv.RNG.Prev(prev), LeadRequired.SynchronizeFail);
}
if (sync)
yield return info.GetFrame(prev, LeadRequired.Synchronize);
if (reg)
{
if (seed.Charm3)
yield return info.GetFrame(prev, LeadRequired.CuteCharm);
else
yield return info.GetFrame(prev, LeadRequired.None);
}
}
}
///
/// Filters the input according to a Cute Charm frame generation pattern.
///
/// Seed Information for the frame
/// PIDIV Info for the frame
/// Search Info for the frame
/// Possible matches to the Cute Charm frame generation pattern
private static IEnumerable FilterCuteCharm(IEnumerable seeds, PIDIV pidiv, FrameGenerator info)
{
foreach (var seed in seeds)
{
var s = seed.Seed;
var rand = s >> 16;
var nature = info.DPPt ? rand / 0xA3E : rand % 25;
if (nature != info.Nature)
continue;
var prev = pidiv.RNG.Prev(s);
var proc = prev >> 16;
bool charmProc = (info.DPPt ? proc / 0x5556 : proc % 3) != 0; // 2/3 odds
if (!charmProc)
continue;
yield return info.GetFrame(prev, LeadRequired.CuteCharm);
}
}
}
}