/
move.go
456 lines (411 loc) · 10.9 KB
/
move.go
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package main
import (
"fmt"
)
var MOVE_KIND_MAP = [MOVE_KINDS]string{
"QUIET", "DOUBLE_PAWN_PUSH", "KING_CASTLE",
"QUEEN_CASTLE", "CAPTURE", "EP_CAPTURE",
"KNIGHT_PROMOTION", "BISHOP_PROMOTION",
"ROOK_PROMOTION", "QUEEN_PROMOTION",
"KNIGHT_PROMOTION_CAPTURE", "BISHOP_PROMOTION_CAPTURE",
"ROOK_PROMOTION_CAPTURE", "QUEEN_PROMOTION_CAPTURE",
}
func NewMove(originCoord Coord, dstCoord Coord, originSquare Square, dstSquare Square, moveKind MoveKind) Move {
moveOriginCoord := Move(originCoord) << MOVE_ORIGIN_COORD_SHIFT
moveDstCoord := Move(dstCoord) << MOVE_DST_COORD_SHIFT
moveOriginSquare := Move(originSquare) << MOVE_ORIGIN_SQUARE_SHIFT
moveDstSquare := Move(dstSquare) << MOVE_DST_SQUARE_SHIFT
return moveOriginCoord | moveDstCoord | moveOriginSquare | moveDstSquare | Move(moveKind)
}
func NewUndo(move Move, clearSquare Square, halfMove HalfMove, castleRights CastleRights, epCoord Coord) Undo {
undoClearSquare := Undo(clearSquare) << UNDO_CLEAR_SQUARE_SHIFT
undoHalfMove := Undo(halfMove) << UNDO_HALF_MOVE_SHIFT
undoCastleRights := Undo(castleRights) << UNDO_CASTLE_RIGHTS_SHIFT
undoEpCoord := Undo(epCoord) << UNDO_EP_COORD_SHIFT
return Undo(move) | undoClearSquare | undoHalfMove | undoCastleRights | undoEpCoord
}
type MoveUnpacked struct {
originCoord Coord
dstCoord Coord
originSquare Square
dstSquare Square
moveKind MoveKind
}
type UndoUnpacked struct {
clearSquare Square
halfMove HalfMove
castleRights CastleRights
epCoord Coord
}
func (m *Move) ToString() string {
var mu MoveUnpacked
m.Unpack(&mu)
mk := MOVE_KIND_MAP[mu.moveKind]
oc := COORD_MAP[mu.originCoord]
os := SQUARE_MAP[mu.originSquare]
dc := COORD_MAP[mu.dstCoord]
ds := SQUARE_MAP[mu.dstSquare]
s := fmt.Sprintf("Move{%v: %v(%v) -> %v(%v)}", mk, oc, os, dc, ds)
return s
}
func (u *Undo) ToString() string {
var mu MoveUnpacked
var uu UndoUnpacked
move := Move(*u & UNDO_MOVE_MASK)
u.Unpack(&mu, &uu)
cs := SQUARE_MAP[uu.clearSquare]
hm := uu.halfMove
cr := uu.castleRights
ec := COORD_MAP[uu.epCoord]
s := fmt.Sprintf("Undo{ClearSquare: %v | HalfMove: %v | CastleRights: %v | EP Coord: %v | %v}", cs, hm, cr, ec, move.ToString())
return s
}
func (m *Move) Unpack(mu *MoveUnpacked) {
mu.originCoord = Coord((*m & MOVE_ORIGIN_COORD_MASK) >> MOVE_ORIGIN_COORD_SHIFT)
mu.dstCoord = Coord((*m & MOVE_DST_COORD_MASK) >> MOVE_DST_COORD_SHIFT)
mu.originSquare = Square((*m & MOVE_ORIGIN_SQUARE_MASK) >> MOVE_ORIGIN_SQUARE_SHIFT)
mu.dstSquare = Square((*m & MOVE_DST_SQUARE_MASK) >> MOVE_DST_SQUARE_SHIFT)
mu.moveKind = MoveKind(*m & MOVE_KIND_MASK)
}
func (u *Undo) Unpack(mu *MoveUnpacked, uu *UndoUnpacked) {
move := Move(*u & UNDO_MOVE_MASK)
move.Unpack(mu)
uu.clearSquare = Square((*u & UNDO_CLEAR_SQUARE_MASK) >> UNDO_CLEAR_SQUARE_SHIFT)
uu.halfMove = HalfMove((*u & UNDO_HALF_MOVE_MASK) >> UNDO_HALF_MOVE_SHIFT)
uu.castleRights = CastleRights((*u & UNDO_CASTLE_RIGHTS_MASK) >> UNDO_CASTLE_RIGHTS_SHIFT)
uu.epCoord = Coord((*u & UNDO_EP_COORD_MASK) >> UNDO_EP_COORD_SHIFT)
}
func (b *Board) SetSquare(c Coord, sq Square) {
b.squares[c] = sq
b.HashSquare(sq, c)
b.bbAllPieces.SetBit(c)
switch sq {
case WHITE_PAWN:
b.bbWP.SetBit(c)
b.bbWhitePieces.SetBit(c)
case WHITE_KNIGHT:
b.bbWN.SetBit(c)
b.bbWhitePieces.SetBit(c)
case WHITE_BISHOP:
b.bbWB.SetBit(c)
b.bbWhitePieces.SetBit(c)
case WHITE_ROOK:
b.bbWR.SetBit(c)
b.bbWhitePieces.SetBit(c)
case WHITE_QUEEN:
b.bbWQ.SetBit(c)
b.bbWhitePieces.SetBit(c)
case WHITE_KING:
b.bbWK.SetBit(c)
b.bbWhitePieces.SetBit(c)
b.kingCoords[b.sideToMove] = c
b.bbWhitePieces.SetBit(c)
case BLACK_PAWN:
b.bbBP.SetBit(c)
b.bbBlackPieces.SetBit(c)
case BLACK_KNIGHT:
b.bbBN.SetBit(c)
b.bbBlackPieces.SetBit(c)
case BLACK_BISHOP:
b.bbBB.SetBit(c)
b.bbBlackPieces.SetBit(c)
case BLACK_ROOK:
b.bbBR.SetBit(c)
b.bbBlackPieces.SetBit(c)
case BLACK_QUEEN:
b.bbBQ.SetBit(c)
b.bbBlackPieces.SetBit(c)
case BLACK_KING:
b.bbBK.SetBit(c)
b.bbBlackPieces.SetBit(c)
b.kingCoords[b.sideToMove] = c
default:
panic(fmt.Errorf("set square(%v) error at coord %v", SQUARE_MAP[sq], COORD_MAP[c]))
}
}
func (b *Board) ClearSquare(c Coord, sq Square) {
if sq != b.squares[c] {
panic(fmt.Errorf("clearing square mismatch %v != %v at coord %v\n\n%v", SQUARE_MAP[sq], SQUARE_MAP[b.squares[c]], COORD_MAP[c], b.ToString()))
}
b.squares[c] = EMPTY
b.HashSquare(sq, c)
b.bbAllPieces.ClearBit(c)
switch sq {
case WHITE_PAWN:
b.bbWP.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case WHITE_KNIGHT:
b.bbWN.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case WHITE_BISHOP:
b.bbWB.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case WHITE_ROOK:
b.bbWR.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case WHITE_QUEEN:
b.bbWQ.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case WHITE_KING:
b.bbWK.ClearBit(c)
b.bbWhitePieces.ClearBit(c)
case BLACK_PAWN:
b.bbBP.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
case BLACK_KNIGHT:
b.bbBN.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
case BLACK_BISHOP:
b.bbBB.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
case BLACK_ROOK:
b.bbBR.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
case BLACK_QUEEN:
b.bbBQ.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
case BLACK_KING:
b.bbBK.ClearBit(c)
b.bbBlackPieces.ClearBit(c)
default:
panic(fmt.Errorf("clear square(%v) error at coord %v", SQUARE_MAP[sq], COORD_MAP[c]))
}
}
func (b *Board) UpdateCastleRights(c Coord) {
var castleBits CastleRights
switch c {
case A8:
castleBits = 14
case H8:
castleBits = 13
case E8:
castleBits = 12
case A1:
castleBits = 11
case H1:
castleBits = 7
case E1:
castleBits = 3
}
if castleBits > 0 {
b.HashCastling()
b.castleRights &= castleBits
b.HashCastling()
}
}
func (b *Board) MakeMove(m Move) error {
var mu MoveUnpacked
m.Unpack(&mu)
moveDstSetSquare := mu.originSquare
epCoord := A1
epCaptureSquare := EMPTY
epCaptureCoord := A1
castleRookSquare := EMPTY
castleRookClearCoord := A1
castleRookSetCoord := A1
switch mu.moveKind {
case DOUBLE_PAWN_PUSH:
if b.sideToMove == WHITE &&
(b.squares[int(mu.dstCoord)-SHIFT_HORIZONTAL] == BLACK_PAWN ||
b.squares[int(mu.dstCoord)+SHIFT_HORIZONTAL] == BLACK_PAWN) {
epCoord = mu.dstCoord - Coord(SHIFT_VERTICAL)
} else if b.sideToMove == BLACK &&
(b.squares[int(mu.dstCoord)-SHIFT_HORIZONTAL] == WHITE_PAWN ||
b.squares[int(mu.dstCoord)+SHIFT_HORIZONTAL] == WHITE_PAWN) {
epCoord = mu.dstCoord + Coord(SHIFT_VERTICAL)
}
case KING_CASTLE:
fallthrough
case QUEEN_CASTLE:
switch mu.dstCoord {
case G1:
castleRookSquare = WHITE_ROOK
castleRookClearCoord = H1
castleRookSetCoord = F1
case C1:
castleRookSquare = WHITE_ROOK
castleRookClearCoord = A1
castleRookSetCoord = D1
case G8:
castleRookSquare = BLACK_ROOK
castleRookClearCoord = H8
castleRookSetCoord = F8
case C8:
castleRookSquare = BLACK_ROOK
castleRookClearCoord = A8
castleRookSetCoord = D8
}
case EP_CAPTURE:
if b.sideToMove == WHITE {
epCaptureSquare = BLACK_PAWN
epCaptureCoord = mu.dstCoord - Coord(SHIFT_VERTICAL)
} else {
epCaptureSquare = WHITE_PAWN
epCaptureCoord = mu.dstCoord + Coord(SHIFT_VERTICAL)
}
case KNIGHT_PROMOTION_CAPTURE:
fallthrough
case KNIGHT_PROMOTION:
if b.sideToMove == WHITE {
moveDstSetSquare = WHITE_KNIGHT
} else {
moveDstSetSquare = BLACK_KNIGHT
}
case BISHOP_PROMOTION_CAPTURE:
fallthrough
case BISHOP_PROMOTION:
if b.sideToMove == WHITE {
moveDstSetSquare = WHITE_BISHOP
} else {
moveDstSetSquare = BLACK_BISHOP
}
case ROOK_PROMOTION_CAPTURE:
fallthrough
case ROOK_PROMOTION:
if b.sideToMove == WHITE {
moveDstSetSquare = WHITE_ROOK
} else {
moveDstSetSquare = BLACK_ROOK
}
case QUEEN_PROMOTION_CAPTURE:
fallthrough
case QUEEN_PROMOTION:
if b.sideToMove == WHITE {
moveDstSetSquare = WHITE_QUEEN
} else {
moveDstSetSquare = BLACK_QUEEN
}
}
// Update Undo (should happen before any state is modified)
u := NewUndo(m, moveDstSetSquare, b.halfMove, b.castleRights, b.epCoord)
b.undos[b.undoIndex] = u
b.undoIndex++
// Update board
b.ClearSquare(mu.originCoord, mu.originSquare)
if mu.dstSquare != EMPTY {
b.ClearSquare(mu.dstCoord, mu.dstSquare)
}
b.SetSquare(mu.dstCoord, moveDstSetSquare)
if castleRookSquare != EMPTY {
b.ClearSquare(castleRookClearCoord, castleRookSquare)
b.SetSquare(castleRookSetCoord, castleRookSquare)
}
if epCaptureSquare != EMPTY {
b.ClearSquare(epCaptureCoord, epCaptureSquare)
}
// Update CastleRights
if b.castleRights != 0 {
b.UpdateCastleRights(mu.originCoord)
b.UpdateCastleRights(mu.dstCoord)
}
// Update En Passant
if b.epCoord != A1 {
b.HashEnPassant()
b.epCoord = A1
}
if epCoord != A1 {
b.epCoord = epCoord
b.HashEnPassant()
}
// Update Move Clocks
if b.sideToMove == BLACK {
b.fullMove++
}
b.halfMove++
if mu.originSquare == WHITE_PAWN ||
mu.originSquare == BLACK_PAWN ||
mu.dstSquare != EMPTY {
b.halfMove = 0
}
// Move Legality Check
kingAttacked := b.CoordAttacked(b.kingCoords[b.sideToMove], b.sideToMove)
// Update Side
b.HashSide()
b.sideToMove ^= 1
if kingAttacked {
return fmt.Errorf("king is attacked")
}
return nil
}
func (b *Board) UndoMove() error {
if b.undoIndex <= 0 {
return fmt.Errorf("invalid undo index: %v", b.undoIndex)
}
epCaptureSquare := EMPTY
epCaptureCoord := A1
castleRookSquare := EMPTY
castleRookClearCoord := A1
castleRookSetCoord := A1
// Update Undo
b.undoIndex--
u := b.undos[b.undoIndex]
var mu MoveUnpacked
var uu UndoUnpacked
u.Unpack(&mu, &uu)
// Update Side
b.sideToMove ^= 1
b.HashSide()
switch mu.moveKind {
case KING_CASTLE:
fallthrough
case QUEEN_CASTLE:
switch mu.dstCoord {
case G1:
castleRookSquare = WHITE_ROOK
castleRookClearCoord = F1
castleRookSetCoord = H1
case C1:
castleRookSquare = WHITE_ROOK
castleRookClearCoord = D1
castleRookSetCoord = A1
case G8:
castleRookSquare = BLACK_ROOK
castleRookClearCoord = F8
castleRookSetCoord = H8
case C8:
castleRookSquare = BLACK_ROOK
castleRookClearCoord = D8
castleRookSetCoord = A8
}
case EP_CAPTURE:
if b.sideToMove == WHITE {
epCaptureCoord = uu.epCoord - Coord(SHIFT_VERTICAL)
epCaptureSquare = BLACK_PAWN
} else if b.sideToMove == BLACK {
epCaptureCoord = uu.epCoord + Coord(SHIFT_VERTICAL)
epCaptureSquare = WHITE_PAWN
}
}
// Update board
b.ClearSquare(mu.dstCoord, uu.clearSquare)
if mu.dstSquare != EMPTY {
b.SetSquare(mu.dstCoord, mu.dstSquare)
}
b.SetSquare(mu.originCoord, mu.originSquare)
if castleRookSquare != EMPTY {
b.ClearSquare(castleRookClearCoord, castleRookSquare)
b.SetSquare(castleRookSetCoord, castleRookSquare)
}
if epCaptureSquare != EMPTY {
b.SetSquare(epCaptureCoord, epCaptureSquare)
}
// Update CastleRights
b.HashCastling()
b.castleRights = uu.castleRights
b.HashCastling()
// Update En Passant
if b.epCoord != A1 {
b.HashEnPassant()
b.epCoord = A1
}
if uu.epCoord != A1 {
b.epCoord = uu.epCoord
b.HashEnPassant()
}
// Update Move Clocks
if b.sideToMove == BLACK {
b.fullMove--
}
b.halfMove = uu.halfMove
return nil
}