public void TestKingRingMasks()
{
// King on e8.
// Inner Ring
var square = "e8";
var mask = Board.InnerRingMasks[(int)Board.GetSquare(square)];
WriteMessageLine($"King on {square} inner ring mask = ");
WriteMessageLine(Position.ToString(mask));
Assert.That(Bitwise.IsBitSet(mask, Square.D8), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.D7), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.E7), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.F7), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.F8), Is.EqualTo(true));
mask &= Bitwise.CreateULongUnmask(Square.D8) & Bitwise.CreateULongUnmask(Square.D7) & Bitwise.CreateULongUnmask(Square.E7) & Bitwise.CreateULongUnmask(Square.F7) & Bitwise.CreateULongUnmask(Square.F8);
Assert.That(mask & Bitwise.CreateULongMask((int)Square.A8, (int)Square.H1), Is.EqualTo(0));
// Outer Ring
mask = Board.OuterRingMasks[(int)Board.GetSquare(square)];
WriteMessageLine($"King on {square} outer ring mask = ");
WriteMessageLine(Position.ToString(mask));
Assert.That(Bitwise.IsBitSet(mask, Square.C8), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.C7), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.C6), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.D6), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.E6), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.F6), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.G6), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.G7), Is.EqualTo(true));
Assert.That(Bitwise.IsBitSet(mask, Square.G8), Is.EqualTo(true));
mask &= Bitwise.CreateULongUnmask(Square.C8) & Bitwise.CreateULongUnmask(Square.C7) & Bitwise.CreateULongUnmask(Square.C6) & Bitwise.CreateULongUnmask(Square.D6) & Bitwise.CreateULongUnmask(Square.E6) &
Bitwise.CreateULongUnmask(Square.F6) & Bitwise.CreateULongUnmask(Square.G6) & Bitwise.CreateULongUnmask(Square.G7) & Bitwise.CreateULongUnmask(Square.G8);
Assert.That(mask & Bitwise.CreateULongMask((int)Square.A8, (int)Square.H1), Is.EqualTo(0));
// King on c3.
square = "c3";
mask = Board.InnerRingMasks[(int)Board.GetSquare(square)];
WriteMessageLine($"King on {square} inner ring mask = ");
WriteMessageLine(Position.ToString(mask));
mask = Board.OuterRingMasks[(int)Board.GetSquare(square)];
WriteMessageLine($"King on {square} outer ring mask = ");
WriteMessageLine(Position.ToString(mask));
}
// 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
// 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
// To Horizon |Best From |Best To |BMP |Dynamic Score |DSP|Last
// Best From = Best Move From (one extra bit for illegal square)
// Best To = Best Move To (one extra bit for illegal square)
// BMP = Best Move Promoted Piece
// DSP = Dynamic Score Precision
// Last = Last Accessed
static CachedPositionData()
{
// Create bit shifts and masks.
_toHorizonShift = 58;
_toHorizonMask = Bitwise.CreateULongMask(58, 63);
_toHorizonUnmask = Bitwise.CreateULongUnmask(58, 63);
_bestMoveFromShift = 51;
_bestMoveFromMask = Bitwise.CreateULongMask(51, 57);
_bestMoveFromUnmask = Bitwise.CreateULongUnmask(51, 57);
_bestMoveToShift = 44;
_bestMoveToMask = Bitwise.CreateULongMask(44, 50);
_bestMoveToUnmask = Bitwise.CreateULongUnmask(44, 50);
_bestMovePromotedPieceShift = 40;
_bestMovePromotedPieceMask = Bitwise.CreateULongMask(40, 43);
_bestMovePromotedPieceUnmask = Bitwise.CreateULongUnmask(40, 43);
_dynamicScoreShift = 10;
_dynamicScoreMask = Bitwise.CreateULongMask(10, 39);
_dynamicScoreUnmask = Bitwise.CreateULongUnmask(10, 39);
_scorePrecisionShift = 8;
_scorePrecisionMask = Bitwise.CreateULongMask(8, 9);
_scorePrecisionUnmask = Bitwise.CreateULongUnmask(8, 9);
_lastAccessedMask = Bitwise.CreateULongMask(0, 7);
_lastAccessedUnmask = Bitwise.CreateULongUnmask(0, 7);
}
// Move Bits
// Higher priority moves have higher ulong value.
// 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
// 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
// B|CapV |CapA |Promo |Kil|History |!|O|K|E|2|P|To |From |Piece
// B = Best Move
// CapV = Capture Victim
// CapA = Capture Attacker (inverted)
// Promo = Promoted Piece
// Kil = Killer Move
// ! = Played
// O = Castling
// K = King Move
// E = En Passant Capture
// 2 = Double Pawn Move
// P = Pawn Move
// From = From (one extra bit for illegal square)
// To = To (one extra bit for illegal square)
static Move()
{
// Create bit masks and shifts.
_bestShift = 63;
_bestMask = Bitwise.CreateULongMask(63);
_bestUnmask = Bitwise.CreateULongUnmask(63);
_captureVictimShift = 59;
_captureVictimMask = Bitwise.CreateULongMask(59, 62);
_captureVictimUnmask = Bitwise.CreateULongUnmask(59, 62);
_captureAttackerShift = 55;
_captureAttackerMask = Bitwise.CreateULongMask(55, 58);
_captureAttackerUnmask = Bitwise.CreateULongUnmask(55, 58);
_promotedPieceShift = 51;
_promotedPieceMask = Bitwise.CreateULongMask(51, 54);
_promotedPieceUnmask = Bitwise.CreateULongUnmask(51, 54);
_killerShift = 49;
_killerMask = Bitwise.CreateULongMask(49, 50);
_killerUnmask = Bitwise.CreateULongUnmask(49, 50);
_historyShift = 24;
_historyMask = Bitwise.CreateULongMask(24, 48);
_historyUnmask = Bitwise.CreateULongUnmask(24, 48);
_playedShift = 23;
_playedMask = Bitwise.CreateULongMask(23);
_playedUnmask = Bitwise.CreateULongUnmask(23);
_castlingShift = 22;
_castlingMask = Bitwise.CreateULongMask(22);
_castlingUnmask = Bitwise.CreateULongUnmask(22);
_kingMoveShift = 21;
_kingMoveMask = Bitwise.CreateULongMask(21);
_kingMoveUnmask = Bitwise.CreateULongUnmask(21);
_enPassantShift = 20;
_enPassantMask = Bitwise.CreateULongMask(20);
_enPassantUnmask = Bitwise.CreateULongUnmask(20);
_doublePawnMoveShift = 19;
_doublePawnMoveMask = Bitwise.CreateULongMask(19);
_doublePawnMoveUnmask = Bitwise.CreateULongUnmask(19);
_pawnMoveShift = 18;
_pawnMoveMask = Bitwise.CreateULongMask(18);
_pawnMoveUnmask = Bitwise.CreateULongUnmask(18);
_toShift = 11;
_toMask = Bitwise.CreateULongMask(11, 17);
_toUnmask = Bitwise.CreateULongUnmask(11, 17);
_fromShift = 4;
_fromMask = Bitwise.CreateULongMask(4, 10);
_fromUnmask = Bitwise.CreateULongUnmask(4, 10);
_pieceMask = Bitwise.CreateULongMask(0, 3);
_pieceUnmask = Bitwise.CreateULongUnmask(0, 3);
// Set null move.
Null = 0;
SetIsBest(ref Null, false);
SetCaptureVictim(ref Null, Game.Piece.None);
SetCaptureAttacker(ref Null, Game.Piece.None);
SetPromotedPiece(ref Null, Game.Piece.None);
SetKiller(ref Null, 0);
SetHistory(ref Null, 0);
SetPlayed(ref Null, false);
SetIsCastling(ref Null, false);
SetIsKingMove(ref Null, false);
SetIsEnPassantCapture(ref Null, false);
SetIsDoublePawnMove(ref Null, false);
SetIsPawnMove(ref Null, false);
SetTo(ref Null, Square.Illegal);
SetFrom(ref Null, Square.Illegal);
SetPiece(ref Null, Game.Piece.None);
}