w: ['b', 'q'],
x: ['b', 'k'],
y: ['q', 'q'],
- z: ['q', 'k']
+ z: ['q', 'k'],
+ '@': ['k', 'k']
};
}
+ static fen2board(f) {
+ // Arobase is character 64
+ return f.charCodeAt() <= 90 ? "w" + f.toLowerCase() : "b" + f;
+ }
+
static IsGoodPosition(position) {
if (position.length == 0) return false;
const rows = position.split("/");
if (rows.length != V.size.x) return false;
- let kingSymb = ['k', 'g', 'm', 'u', 'x'];
+ let kingSymb = ['k', 'g', 'm', 'u', 'x', 'z', '@'];
let kings = { 'k': 0, 'K': 0 };
for (let row of rows) {
let sumElts = 0;
for (let i = 0; i < row.length; i++) {
- const lowR = row[i].toLowerCase
- if (!!(row[i].toLowerCase().match(/[a-z]/))) {
+ if (!!(row[i].toLowerCase().match(/[a-z@]/))) {
sumElts++;
if (kingSymb.includes(row[i])) kings['k']++;
- else if (kingSymb.some(s => row[i] == s.toUpperCase())) kings['K']++;
+ // Not "else if", if two kings dancing together
+ if (kingSymb.some(s => row[i] == s.toUpperCase())) kings['K']++;
}
else {
const num = parseInt(row[i], 10);
this.kingPos = { w: [-1, -1], b: [-1, -1] };
const fenRows = V.ParseFen(fen).position.split("/");
const startRow = { 'w': V.size.x - 1, 'b': 0 };
- const kingSymb = ['k', 'g', 'm', 'u', 'x'];
+ const kingSymb = ['k', 'g', 'm', 'u', 'x', 'z', '@'];
for (let i = 0; i < fenRows.length; i++) {
let k = 0;
for (let j = 0; j < fenRows[i].length; j++) {
const c = fenRows[i].charAt(j);
- if (kingSymb.includes(c))
- this.kingPos["b"] = [i, k];
- else if (kingSymb.some(s => c == s.toUpperCase()))
- this.kingPos["w"] = [i, k];
+ if (!!(c.toLowerCase().match(/[a-z@]/))) {
+ if (kingSymb.includes(c))
+ this.kingPos["b"] = [i, k];
+ // Not "else if", in case of two kings dancing together
+ if (kingSymb.some(s => c == s.toUpperCase()))
+ this.kingPos["w"] = [i, k];
+ }
else {
const num = parseInt(fenRows[i].charAt(j), 10);
if (!isNaN(num)) k += num - 1;
end: ChessRules.SquareToCoords(umove.substr(2))
});
}
+ // Local stack of positions to avoid redundant moves:
+ this.repetitions = [];
}
static IsGoodFen(fen) {
return true;
}
+ static IsGoodFlags(flags) {
+ // 4 for castle + 16 for pawns
+ return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
+ }
+
+ setFlags(fenflags) {
+ super.setFlags(fenflags); //castleFlags
+ this.pawnFlags = {
+ w: [...Array(8)], //pawns can move 2 squares?
+ b: [...Array(8)]
+ };
+ const flags = fenflags.substr(4); //skip first 4 letters, for castle
+ for (let c of ["w", "b"]) {
+ for (let i = 0; i < 8; i++)
+ this.pawnFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
+ }
+ }
+
+ aggregateFlags() {
+ return [this.castleFlags, this.pawnFlags];
+ }
+
+ disaggregateFlags(flags) {
+ this.castleFlags = flags[0];
+ this.pawnFlags = flags[1];
+ }
+
getUmove(move) {
if (
move.vanish.length == 1 &&
- !(ChessRules.PIECES.includes(move.appear[0].p))
+ !(ChessRules.PIECES.includes(move.appear[0].p)) &&
+ move.appear[0].p == move.vanish[0].p //not a promotion
) {
// An union moving
return { start: move.start, end: move.end };
);
}
- static GenRandInitFen(randomness) {
- // Add empty umove
- return ChessRules.GenRandInitFen(randomness) + " -";
+ static GenRandInitFen(options) {
+ // Add 16 pawns flags + empty umove:
+ return ChessRules.GenRandInitFen(options)
+ .slice(0, -2) + "1111111111111111 - -";
+ }
+
+ getFlagsFen() {
+ let fen = super.getFlagsFen();
+ // Add pawns flags
+ for (let c of ["w", "b"])
+ for (let i = 0; i < 8; i++) fen += (this.pawnFlags[c][i] ? "1" : "0");
+ return fen;
}
getUmoveFen() {
p: cp.p
})
];
- mv.released = up[c];
+ // In move.end, to be sent to the server
+ mv.end.released = up[c];
return mv;
}
this.board[x][y] = this.turn + piece;
}
let baseMoves = [];
- switch (piece || this.getPiece(x, y)) {
- case V.PAWN:
- baseMoves = this.getPotentialPawnMoves([x, y]);
+ const c = this.turn;
+ switch (piece) {
+ case V.PAWN: {
+ const firstRank = (c == 'w' ? 7 : 0);
+ baseMoves = this.getPotentialPawnMoves([x, y]).filter(m => {
+ // Skip forbidden 2-squares jumps (except from first rank)
+ // Also skip unions capturing en-passant (not allowed).
+ return (
+ (
+ m.start.x == firstRank ||
+ Math.abs(m.end.x - m.start.x) == 1 ||
+ this.pawnFlags[c][m.start.y]
+ )
+ &&
+ (
+ this.board[x][y].charAt(1) == V.PAWN ||
+ m.start.y == m.end.y
+ )
+ );
+ });
break;
+ }
case V.ROOK:
baseMoves = this.getPotentialRookMoves([x, y]);
break;
// When a pawn in an union reaches final rank with a non-standard
// promotion move: apply promotion anyway
let moves = [];
- const c = this.turn;
const oppCol = V.GetOppCol(c);
const oppLastRank = (c == 'w' ? 7 : 0);
baseMoves.forEach(m => {
return;
// Fix en-passant capture: union type, maybe released piece too
const cs = [m.end.x + (c == 'w' ? 1 : -1), m.end.y];
- const color = this.board[cs[0]][cs[1]].charAt(0);
const code = this.board[cs[0]][cs[1]].charAt(1);
if (code == V.PAWN) {
// Simple en-passant capture (usual: just form union)
m.appear[0].p = 'a';
}
else {
- // An union pawn + something juste moved two squares
+ // An union pawn + something just moved two squares
+ const color = this.board[cs[0]][cs[1]].charAt(0);
const up = this.getUnionPieces(color, code);
- m.released = up[c];
+ m.end.released = up[c];
let args = [V.PAWN, up[oppCol]];
if (c == 'b') args = args.reverse();
const cp = this.getUnionCode(args[0], args[1]);
return moves;
}
- getPotentialKingMoves(sq) {
- let moves = this.getSlideNJumpMoves(
- sq,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
- "oneStep"
- );
- const c = this.turn;
- const oppCol = V.GetOppCol(c);
- if (
- !this.isAttacked(this.kingPos[c], oppCol) &&
- this.castleFlags[c].some(v => v < V.size.y)
- ) {
- moves = moves.concat(super.getCastleMoves(sq, null, true));
- }
- return moves;
- }
-
getEpSquare(moveOrSquare) {
if (typeof moveOrSquare === "string") {
const square = moveOrSquare;
const move = moveOrSquare;
const s = move.start,
e = move.end;
- const oppCol = V.GetOppCol(this.turn);
if (
s.y == e.y &&
Math.abs(s.x - e.x) == 2 &&
- this.getPiece(s.x, s.y, oppCol) == V.PAWN
+ this.getPiece(s.x, s.y, this.turn) == V.PAWN
) {
return {
x: (s.x + e.x) / 2,
!!m1 &&
!(ChessRules.PIECES.includes(m2.appear[0].p)) &&
m2.vanish.length == 1 &&
+ !m2.end.released &&
m1.start.x == m2.end.x &&
m1.end.x == m2.start.x &&
m1.start.y == m2.end.y &&
);
}
- // Do not consider checks for now (TODO)
- underCheck() {
+ getCastleMoves([x, y]) {
+ const c = this.getColor(x, y);
+ const oppCol = V.GetOppCol(c);
+ let moves = [];
+ const finalSquares = [ [2, 3], [6, 5] ];
+ castlingCheck: for (let castleSide = 0; castleSide < 2; castleSide++) {
+ if (this.castleFlags[c][castleSide] >= 8) continue;
+ const rookPos = this.castleFlags[c][castleSide];
+ const castlingColor = this.board[x][rookPos].charAt(0);
+ const castlingPiece = this.board[x][rookPos].charAt(1);
+
+ // Nothing on the path of the king ?
+ const finDist = finalSquares[castleSide][0] - y;
+ let step = finDist / Math.max(1, Math.abs(finDist));
+ let i = y;
+ let kingSquares = [y];
+ do {
+ if (
+ (
+ this.board[x][i] != V.EMPTY &&
+ (this.getColor(x, i) != c || ![y, rookPos].includes(i))
+ )
+ ) {
+ continue castlingCheck;
+ }
+ i += step;
+ kingSquares.push(i);
+ } while (i != finalSquares[castleSide][0]);
+ // No checks on the path of the king ?
+ if (this.isAttacked(kingSquares, oppCol)) continue castlingCheck;
+
+ // Nothing on the path to the rook?
+ step = castleSide == 0 ? -1 : 1;
+ for (i = y + step; i != rookPos; i += step) {
+ if (this.board[x][i] != V.EMPTY) continue castlingCheck;
+ }
+
+ // Nothing on final squares, except maybe king and castling rook?
+ for (i = 0; i < 2; i++) {
+ if (
+ finalSquares[castleSide][i] != rookPos &&
+ this.board[x][finalSquares[castleSide][i]] != V.EMPTY &&
+ (
+ finalSquares[castleSide][i] != y ||
+ this.getColor(x, finalSquares[castleSide][i]) != c
+ )
+ ) {
+ continue castlingCheck;
+ }
+ }
+
+ moves.push(
+ new Move({
+ appear: [
+ new PiPo({
+ x: x,
+ y: finalSquares[castleSide][0],
+ p: V.KING,
+ c: c
+ }),
+ new PiPo({
+ x: x,
+ y: finalSquares[castleSide][1],
+ p: castlingPiece,
+ c: castlingColor
+ })
+ ],
+ vanish: [
+ // King might be initially disguised (Titan...)
+ new PiPo({ x: x, y: y, p: V.KING, c: c }),
+ new PiPo({ x: x, y: rookPos, p: castlingPiece, c: castlingColor })
+ ],
+ end:
+ Math.abs(y - rookPos) <= 2
+ ? { x: x, y: rookPos }
+ : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) }
+ })
+ );
+ }
+
+ return moves;
+ }
+
+ getEnpassantCaptures(sq, shiftX) {
+ // HACK: when artificially change turn, do not consider en-passant
+ const mcMod2 = this.movesCount % 2;
+ const c = this.turn;
+ if ((c == 'w' && mcMod2 == 1) || (c == 'b' && mcMod2 == 0)) return [];
+ return super.getEnpassantCaptures(sq, shiftX);
+ }
+
+ isAttacked_aux(files, color, positions, fromSquare, released) {
+ // "positions" = array of FENs to detect infinite loops. Example:
+ // r1q1k2r/p1Pb1ppp/5n2/1f1p4/AV5P/P1eDP3/3B1PP1/R3K1NR,
+ // Bxd2 Bxc3 Bxb4 Bxc3 Bxb4 etc.
+ const newPos = {
+ fen: super.getBaseFen(),
+ piece: released,
+ from: fromSquare
+ };
+ if (
+ positions.some(p => {
+ return (
+ p.piece == newPos.piece &&
+ p.fen == newPos.fen &&
+ p.from == newPos.from
+ );
+ })
+ ) {
+ // Start of an infinite loop: exit
+ return false;
+ }
+ positions.push(newPos);
+ const rank = (color == 'w' ? 0 : 7);
+ const moves = this.getPotentialMovesFrom(fromSquare);
+ if (moves.some(m => m.end.x == rank && files.includes(m.end.y)))
+ // Found an attack!
+ return true;
+ for (let m of moves) {
+ if (!!m.end.released) {
+ // Turn won't change since !!m.released
+ this.play(m);
+ const res = this.isAttacked_aux(
+ files, color, positions, [m.end.x, m.end.y], m.end.released);
+ this.undo(m);
+ if (res) return true;
+ }
+ }
+ return false;
+ }
+
+ isAttacked(files, color) {
+ const rank = (color == 'w' ? 0 : 7);
+ // Since it's too difficult (impossible?) to search from the square itself,
+ // let's adopt a suboptimal but working strategy: find all attacks.
+ const c = this.turn;
+ // Artificial turn change is required:
+ this.turn = color;
+ let res = false;
+ outerLoop: for (let i=0; i<8; i++) {
+ for (let j=0; j<8; j++) {
+ // Attacks must start from a normal piece, not an union.
+ // Therefore, the following test is correct.
+ if (
+ this.board[i][j] != V.EMPTY &&
+ // Do not start with king (irrelevant, and lead to infinite calls)
+ [V.PAWN, V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN].includes(
+ this.board[i][j].charAt(1)) &&
+ this.board[i][j].charAt(0) == color
+ ) {
+ // Try from here.
+ const moves = this.getPotentialMovesFrom([i, j]);
+ if (moves.some(m => m.end.x == rank && files.includes(m.end.y))) {
+ res = true;
+ break outerLoop;
+ }
+ for (let m of moves) {
+ if (!!m.end.released) {
+ // Turn won't change since !!m.released
+ this.play(m);
+ let positions = [];
+ res = this.isAttacked_aux(
+ files, color, positions, [m.end.x, m.end.y], m.end.released);
+ this.undo(m);
+ if (res) break outerLoop;
+ }
+ }
+ }
+ }
+ }
+ this.turn = c;
+ return res;
+ }
+
+ isAttackedBySlideNJump([x, y], color, piece, steps, oneStep) {
+ for (let step of steps) {
+ let rx = x + step[0],
+ ry = y + step[1];
+ while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
+ rx += step[0];
+ ry += step[1];
+ }
+ if (
+ V.OnBoard(rx, ry) &&
+ this.board[rx][ry] != V.EMPTY &&
+ this.getPiece(rx, ry) == piece &&
+ this.getColor(rx, ry) == color &&
+ this.canTake([rx, ry], [x, y]) //TODO: necessary line?
+ //If not, generic method is OK
+ ) {
+ return true;
+ }
+ }
return false;
}
+
+ // Do not consider checks, except to forbid castling
getCheckSquares() {
return [];
}
+
filterValid(moves) {
if (moves.length == 0) return [];
const L = this.umoves.length; //at least 1: init from FEN
- return moves.filter(m => !this.oppositeMoves(this.umoves[L - 1], m));
+ return moves.filter(m => {
+ if (this.oppositeMoves(this.umoves[L - 1], m)) return false;
+ if (!m.end.released) return true;
+ // Check for repetitions:
+ V.PlayOnBoard(this.board, m);
+ const newState = {
+ piece: m.end.released,
+ square: { x: m.end.x, y: m.end.y },
+ position: this.getBaseFen()
+ };
+ const repet =
+ this.repetitions.some(r => {
+ return (
+ r.piece == newState.piece &&
+ (
+ r.square.x == newState.square.x &&
+ r.square.y == newState.square.y
+ ) &&
+ r.position == newState.position
+ );
+ });
+ V.UndoOnBoard(this.board, m);
+ return !repet;
+ });
+ }
+
+ updateCastleFlags(move, piece) {
+ const c = this.turn;
+ const firstRank = (c == "w" ? 7 : 0);
+ if (piece == V.KING && move.appear.length > 0)
+ this.castleFlags[c] = [V.size.y, V.size.y];
+ else if (
+ move.start.x == firstRank &&
+ this.castleFlags[c].includes(move.start.y)
+ ) {
+ const flagIdx = (move.start.y == this.castleFlags[c][0] ? 0 : 1);
+ this.castleFlags[c][flagIdx] = V.size.y;
+ }
+ else if (
+ move.end.x == firstRank &&
+ this.castleFlags[c].includes(move.end.y)
+ ) {
+ // Move to our rook: necessary normal piece, to union, releasing
+ // (or the rook was moved before!)
+ const flagIdx = (move.end.y == this.castleFlags[c][0] ? 0 : 1);
+ this.castleFlags[c][flagIdx] = V.size.y;
+ }
+ }
+
+ prePlay(move) {
+ // Easier before move is played in this case (flags are saved)
+ const c = this.turn;
+ const L = this.lastMoveEnd.length;
+ const lm = this.lastMoveEnd[L-1];
+ // NOTE: lm.p != V.KING, always.
+ const piece =
+ !!lm
+ ? lm.p
+ : this.getPiece(move.vanish[0].x, move.vanish[0].y);
+ if (piece == V.KING)
+ this.kingPos[c] = [move.appear[0].x, move.appear[0].y];
+ this.updateCastleFlags(move, piece);
+ const pawnFirstRank = (c == 'w' ? 6 : 1);
+ if (
+ move.start.x == pawnFirstRank &&
+ piece == V.PAWN &&
+ Math.abs(move.end.x - move.start.x) == 2
+ ) {
+ // This move turns off a 2-squares pawn flag
+ this.pawnFlags[c][move.start.y] = false;
+ }
}
play(move) {
+ move.flags = JSON.stringify(this.aggregateFlags());
+ this.prePlay(move);
this.epSquares.push(this.getEpSquare(move));
// Check if the move is the last of the turn: all cases except releases
- if (!move.released) {
+ if (!move.end.released) {
// No more union releases available
this.turn = V.GetOppCol(this.turn);
this.movesCount++;
this.lastMoveEnd.push(null);
}
- else this.lastMoveEnd.push(Object.assign({ p: move.released }, move.end));
+ else {
+ this.lastMoveEnd.push({
+ p: move.end.released,
+ x: move.end.x,
+ y: move.end.y
+ });
+ }
V.PlayOnBoard(this.board, move);
this.umoves.push(this.getUmove(move));
- this.postPlay(move);
- }
-
- postPlay(move) {
- if (move.vanish.length == 0)
- // A piece released just moved. Cannot be the king.
- return;
- const c = move.vanish[0].c;
- const piece = move.vanish[0].p;
- if (piece == V.KING)
- this.kingPos[c] = [move.appear[0].x, move.appear[0].y];
- this.updateCastleFlags(move, piece);
+ if (!move.end.released) this.repetitions = [];
+ else {
+ this.repetitions.push(
+ {
+ piece: move.end.released,
+ square: { x: move.end.x, y: move.end.y },
+ position: this.getBaseFen()
+ }
+ );
+ }
}
undo(move) {
this.epSquares.pop();
+ this.disaggregateFlags(JSON.parse(move.flags));
V.UndoOnBoard(this.board, move);
this.lastMoveEnd.pop();
- if (!move.released) {
+ if (!move.end.released) {
this.turn = V.GetOppCol(this.turn);
this.movesCount--;
}
this.umoves.pop();
+ if (!!move.end.released) this.repetitions.pop();
this.postUndo(move);
}
mv = moves[randInt(moves.length)];
mvArray.push(mv);
this.play(mv);
- if (!!mv.released)
+ if (!!mv.end.released)
// A piece was just released from an union
moves = this.getPotentialMovesFrom([mv.end.x, mv.end.y]);
else break;
}
for (let i = mvArray.length - 1; i >= 0; i--) this.undo(mvArray[i]);
- if (!mv.released) return (mvArray.length > 1 ? mvArray : mvArray[0]);
+ if (!mv.end.released) return (mvArray.length > 1 ? mvArray : mvArray[0]);
}
+ return null; //never reached
}
// NOTE: evalPosition() is wrong, but unused since bot plays at random
// Add potential promotion indications:
const firstLastRank = (c == 'w' ? [7, 0] : [0, 7]);
if (move.end.x == firstLastRank[1] && piece == V.PAWN) {
- const up = this.getUnionPieces(move.appear[0].c, move.appear[0].p);
- notation += "=" + up[c].toUpperCase();
+ notation += "=";
+ if (ChessRules.PIECES.includes(move.appear[0].p))
+ notation += move.appear[0].p.toUpperCase();
+ else {
+ const up = this.getUnionPieces(move.appear[0].c, move.appear[0].p);
+ notation += up[c].toUpperCase();
+ }
}
else if (
move.end.x == firstLastRank[0] &&
projects / vchess.git / blobdiff