}
};
-// NOTE: x coords = top to bottom; y = left to right (from white player perspective)
+// NOTE: x coords = top to bottom; y = left to right
+// (from white player perspective)
export const ChessRules = class ChessRules {
+
//////////////
// MISC UTILS
return V.HasFlags;
}
- // Some variants don't have en-passant
+ // Pawns specifications
+ static get PawnSpecs() {
+ return {
+ directions: { 'w': -1, 'b': 1 },
+ initShift: { w: 1, b: 1 },
+ twoSquares: true,
+ threeSquares: false,
+ promotions: [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN],
+ canCapture: true,
+ captureBackward: false,
+ bidirectional: false
+ };
+ }
+
+ // En-passant captures need a stack of squares:
static get HasEnpassant() {
return true;
}
return V.ShowMoves;
}
+ // Sometimes moves must remain hidden until game ends
+ static get SomeHiddenMoves() {
+ return false;
+ }
+ get someHiddenMoves() {
+ return V.SomeHiddenMoves;
+ }
+
+ // Generally true, unless the variant includes random effects
+ static get CorrConfirm() {
+ return true;
+ }
+
+ // Used for Monochrome variant (TODO: harmonize: !canFlip ==> showFirstTurn)
+ get showFirstTurn() {
+ return false;
+ }
+
// Some variants always show the same orientation
static get CanFlip() {
return true;
return V.CanFlip;
}
+ // For (generally old) variants without checkered board
+ static get Monochrome() {
+ return false;
+ }
+
+ // Some games are drawn unusually (bottom right corner is black)
+ static get DarkBottomRight() {
+ return false;
+ }
+
+ // Some variants require lines drawing
+ static get Lines() {
+ if (V.Monochrome) {
+ let lines = [];
+ // Draw all inter-squares lines
+ for (let i = 0; i <= V.size.x; i++)
+ lines.push([[i, 0], [i, V.size.y]]);
+ for (let j = 0; j <= V.size.y; j++)
+ lines.push([[0, j], [V.size.x, j]]);
+ return lines;
+ }
+ return null;
+ }
+
+ // In some variants, the player who repeat a position loses
+ static get LoseOnRepetition() {
+ return false;
+ }
+
+ // Some variants use click infos:
+ doClick() {
+ return null;
+ }
+
+ // Some variants may need to highlight squares on hover (Hamilton, Weiqi...)
+ hoverHighlight() {
+ return false;
+ }
+
static get IMAGE_EXTENSION() {
// All pieces should be in the SVG format
return ".svg";
// 2) Check turn
if (!fenParsed.turn || !V.IsGoodTurn(fenParsed.turn)) return false;
// 3) Check moves count
- if (!fenParsed.movesCount || !(parseInt(fenParsed.movesCount) >= 0))
+ if (!fenParsed.movesCount || !(parseInt(fenParsed.movesCount, 10) >= 0))
return false;
// 4) Check flags
if (V.HasFlags && (!fenParsed.flags || !V.IsGoodFlags(fenParsed.flags)))
if (position.length == 0) return false;
const rows = position.split("/");
if (rows.length != V.size.x) return false;
- let kings = {};
+ let kings = { "k": 0, "K": 0 };
for (let row of rows) {
let sumElts = 0;
for (let i = 0; i < row.length; i++) {
- if (['K','k'].includes(row[i]))
- kings[row[i]] = true;
+ if (['K','k'].includes(row[i])) kings[row[i]]++;
if (V.PIECES.includes(row[i].toLowerCase())) sumElts++;
else {
- const num = parseInt(row[i]);
- if (isNaN(num)) return false;
+ const num = parseInt(row[i], 10);
+ if (isNaN(num) || num <= 0) return false;
sumElts += num;
}
}
if (sumElts != V.size.y) return false;
}
- // Both kings should be on board:
- if (Object.keys(kings).length != 2)
- return false;
+ // Both kings should be on board. Exactly one per color.
+ if (Object.values(kings).some(v => v != 1)) return false;
return true;
}
return !!flags.match(/^[a-z]{4,4}$/);
}
+ // NOTE: not with regexp to adapt to different board sizes. (TODO?)
static IsGoodEnpassant(enpassant) {
if (enpassant != "-") {
const ep = V.SquareToCoords(enpassant);
return {
// NOTE: column is always one char => max 26 columns
// row is counted from black side => subtraction
- x: V.size.x - parseInt(sq.substr(1)),
+ x: V.size.x - parseInt(sq.substr(1), 10),
y: sq[0].charCodeAt() - 97
};
}
return V.CoordToColumn(coords.y) + (V.size.x - coords.x);
}
- // Path to pieces
+ // Path to pieces (standard ones in pieces/ folder)
getPpath(b) {
- return b; //usual pieces in pieces/ folder
+ return b;
}
// Path to promotion pieces (usually the same)
- getPPpath(b) {
- return this.getPpath(b);
+ getPPpath(m) {
+ return this.getPpath(m.appear[0].c + m.appear[0].p);
}
// Aggregates flags into one object
const s = move.start,
e = move.end;
if (
- Math.abs(s.x - e.x) == 2 &&
s.y == e.y &&
- move.appear[0].p == V.PAWN
+ Math.abs(s.x - e.x) == 2 &&
+ // Next conditions for variants like Atomic or Rifle, Recycle...
+ (move.appear.length > 0 && move.appear[0].p == V.PAWN) &&
+ (move.vanish.length > 0 && move.vanish[0].p == V.PAWN)
) {
return {
x: (s.x + e.x) / 2,
}
// On which squares is color under check ? (for interface)
- getCheckSquares(color) {
+ getCheckSquares() {
+ const color = this.turn;
return (
this.underCheck(color)
- ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
+ // kingPos must be duplicated, because it may change:
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))]
: []
);
}
// Position part of the FEN string
getBaseFen() {
+ const format = (count) => {
+ // if more than 9 consecutive free spaces, break the integer,
+ // otherwise FEN parsing will fail.
+ if (count <= 9) return count;
+ // Currently only boards of size up to 11 or 12:
+ return "9" + (count - 9);
+ };
let position = "";
for (let i = 0; i < V.size.x; i++) {
let emptyCount = 0;
else {
if (emptyCount > 0) {
// Add empty squares in-between
- position += emptyCount;
+ position += format(emptyCount);
emptyCount = 0;
}
position += V.board2fen(this.board[i][j]);
}
if (emptyCount > 0) {
// "Flush remainder"
- position += emptyCount;
+ position += format(emptyCount);
}
if (i < V.size.x - 1) position += "/"; //separate rows
}
let j = 0;
for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++) {
const character = rows[i][indexInRow];
- const num = parseInt(character);
+ const num = parseInt(character, 10);
// If num is a number, just shift j:
if (!isNaN(num)) j += num;
// Else: something at position i,j
// Extract (relevant) flags from fen
setFlags(fenflags) {
// white a-castle, h-castle, black a-castle, h-castle
- this.castleFlags = { w: [true, true], b: [true, true] };
+ this.castleFlags = { w: [-1, -1], b: [-1, -1] };
for (let i = 0; i < 4; i++) {
this.castleFlags[i < 2 ? "w" : "b"][i % 2] =
V.ColumnToCoord(fenflags.charAt(i));
return;
const fenParsed = V.ParseFen(fen);
this.board = V.GetBoard(fenParsed.position);
- this.turn = fenParsed.turn[0]; //[0] to work with MarseilleRules
- this.movesCount = parseInt(fenParsed.movesCount);
+ this.turn = fenParsed.turn;
+ this.movesCount = parseInt(fenParsed.movesCount, 10);
this.setOtherVariables(fen);
}
// Scan board for kings positions
scanKings(fen) {
- this.INIT_COL_KING = { w: -1, b: -1 };
- this.kingPos = { w: [-1, -1], b: [-1, -1] }; //squares of white and black king
+ // Squares of white and black king:
+ this.kingPos = { w: [-1, -1], b: [-1, -1] };
const fenRows = V.ParseFen(fen).position.split("/");
const startRow = { 'w': V.size.x - 1, 'b': 0 };
for (let i = 0; i < fenRows.length; i++) {
switch (fenRows[i].charAt(j)) {
case "k":
this.kingPos["b"] = [i, k];
- this.INIT_COL_KING["b"] = k;
break;
case "K":
this.kingPos["w"] = [i, k];
- this.INIT_COL_KING["w"] = k;
break;
default: {
- const num = parseInt(fenRows[i].charAt(j));
+ const num = parseInt(fenRows[i].charAt(j), 10);
if (!isNaN(num)) k += num - 1;
}
}
// MOVES GENERATION
// All possible moves from selected square
- getPotentialMovesFrom([x, y]) {
- switch (this.getPiece(x, y)) {
- case V.PAWN:
- return this.getPotentialPawnMoves([x, y]);
- case V.ROOK:
- return this.getPotentialRookMoves([x, y]);
- case V.KNIGHT:
- return this.getPotentialKnightMoves([x, y]);
- case V.BISHOP:
- return this.getPotentialBishopMoves([x, y]);
- case V.QUEEN:
- return this.getPotentialQueenMoves([x, y]);
- case V.KING:
- return this.getPotentialKingMoves([x, y]);
+ getPotentialMovesFrom(sq) {
+ switch (this.getPiece(sq[0], sq[1])) {
+ case V.PAWN: return this.getPotentialPawnMoves(sq);
+ case V.ROOK: return this.getPotentialRookMoves(sq);
+ case V.KNIGHT: return this.getPotentialKnightMoves(sq);
+ case V.BISHOP: return this.getPotentialBishopMoves(sq);
+ case V.QUEEN: return this.getPotentialQueenMoves(sq);
+ case V.KING: return this.getPotentialKingMoves(sq);
}
return []; //never reached
}
// Build a regular move from its initial and destination squares.
// tr: transformation
getBasicMove([sx, sy], [ex, ey], tr) {
+ const initColor = this.getColor(sx, sy);
+ const initPiece = this.board[sx][sy].charAt(1);
let mv = new Move({
appear: [
new PiPo({
x: ex,
y: ey,
- c: tr ? tr.c : this.getColor(sx, sy),
- p: tr ? tr.p : this.getPiece(sx, sy)
+ c: !!tr ? tr.c : initColor,
+ p: !!tr ? tr.p : initPiece
})
],
vanish: [
new PiPo({
x: sx,
y: sy,
- c: this.getColor(sx, sy),
- p: this.getPiece(sx, sy)
+ c: initColor,
+ p: initPiece
})
]
});
x: ex,
y: ey,
c: this.getColor(ex, ey),
- p: this.getPiece(ex, ey)
+ p: this.board[ex][ey].charAt(1)
})
);
}
return moves;
}
+ // Special case of en-passant captures: treated separately
+ getEnpassantCaptures([x, y], shiftX) {
+ const Lep = this.epSquares.length;
+ const epSquare = this.epSquares[Lep - 1]; //always at least one element
+ let enpassantMove = null;
+ if (
+ !!epSquare &&
+ epSquare.x == x + shiftX &&
+ Math.abs(epSquare.y - y) == 1
+ ) {
+ enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
+ enpassantMove.vanish.push({
+ x: x,
+ y: epSquare.y,
+ p: this.board[x][epSquare.y].charAt(1),
+ c: this.getColor(x, epSquare.y)
+ });
+ }
+ return !!enpassantMove ? [enpassantMove] : [];
+ }
+
+ // Consider all potential promotions:
+ addPawnMoves([x1, y1], [x2, y2], moves, promotions) {
+ let finalPieces = [V.PAWN];
+ const color = this.turn; //this.getColor(x1, y1);
+ const lastRank = (color == "w" ? 0 : V.size.x - 1);
+ if (x2 == lastRank) {
+ // promotions arg: special override for Hiddenqueen variant
+ if (!!promotions) finalPieces = promotions;
+ else if (!!V.PawnSpecs.promotions) finalPieces = V.PawnSpecs.promotions;
+ }
+ let tr = null;
+ for (let piece of finalPieces) {
+ tr = (piece != V.PAWN ? { c: color, p: piece } : null);
+ moves.push(this.getBasicMove([x1, y1], [x2, y2], tr));
+ }
+ }
+
// What are the pawn moves from square x,y ?
- getPotentialPawnMoves([x, y]) {
- const color = this.turn;
- let moves = [];
+ getPotentialPawnMoves([x, y], promotions) {
+ const color = this.turn; //this.getColor(x, y);
const [sizeX, sizeY] = [V.size.x, V.size.y];
- const shiftX = color == "w" ? -1 : 1;
- const firstRank = color == "w" ? sizeX - 1 : 0;
- const startRank = color == "w" ? sizeX - 2 : 1;
- const lastRank = color == "w" ? 0 : sizeX - 1;
-
- // NOTE: next condition is generally true (no pawn on last rank)
- if (x + shiftX >= 0 && x + shiftX < sizeX) {
- const finalPieces =
- x + shiftX == lastRank
- ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
- : [V.PAWN];
- if (this.board[x + shiftX][y] == V.EMPTY) {
- // One square forward
- for (let piece of finalPieces) {
- moves.push(
- this.getBasicMove([x, y], [x + shiftX, y], {
- c: color,
- p: piece
- })
- );
- }
- // Next condition because pawns on 1st rank can generally jump
- if (
- [startRank, firstRank].includes(x) &&
- this.board[x + 2 * shiftX][y] == V.EMPTY
- ) {
- // Two squares jump
- moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
+ const pawnShiftX = V.PawnSpecs.directions[color];
+ const firstRank = (color == "w" ? sizeX - 1 : 0);
+ const forward = (color == 'w' ? -1 : 1);
+
+ // Pawn movements in shiftX direction:
+ const getPawnMoves = (shiftX) => {
+ let moves = [];
+ // NOTE: next condition is generally true (no pawn on last rank)
+ if (x + shiftX >= 0 && x + shiftX < sizeX) {
+ if (this.board[x + shiftX][y] == V.EMPTY) {
+ // One square forward (or backward)
+ this.addPawnMoves([x, y], [x + shiftX, y], moves, promotions);
+ // Next condition because pawns on 1st rank can generally jump
+ if (
+ V.PawnSpecs.twoSquares &&
+ (
+ (color == 'w' && x >= V.size.x - 1 - V.PawnSpecs.initShift['w'])
+ ||
+ (color == 'b' && x <= V.PawnSpecs.initShift['b'])
+ )
+ ) {
+ if (
+ shiftX == forward &&
+ this.board[x + 2 * shiftX][y] == V.EMPTY
+ ) {
+ // Two squares jump
+ moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
+ if (
+ V.PawnSpecs.threeSquares &&
+ this.board[x + 3 * shiftX][y] == V.EMPTY
+ ) {
+ // Three squares jump
+ moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
+ }
+ }
+ }
}
- }
- // Captures
- for (let shiftY of [-1, 1]) {
- if (
- y + shiftY >= 0 &&
- y + shiftY < sizeY &&
- this.board[x + shiftX][y + shiftY] != V.EMPTY &&
- this.canTake([x, y], [x + shiftX, y + shiftY])
- ) {
- for (let piece of finalPieces) {
- moves.push(
- this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
- c: color,
- p: piece
- })
- );
+ // Captures
+ if (V.PawnSpecs.canCapture) {
+ for (let shiftY of [-1, 1]) {
+ if (y + shiftY >= 0 && y + shiftY < sizeY) {
+ if (
+ this.board[x + shiftX][y + shiftY] != V.EMPTY &&
+ this.canTake([x, y], [x + shiftX, y + shiftY])
+ ) {
+ this.addPawnMoves(
+ [x, y], [x + shiftX, y + shiftY],
+ moves, promotions
+ );
+ }
+ if (
+ V.PawnSpecs.captureBackward && shiftX == forward &&
+ x - shiftX >= 0 && x - shiftX < V.size.x &&
+ this.board[x - shiftX][y + shiftY] != V.EMPTY &&
+ this.canTake([x, y], [x - shiftX, y + shiftY])
+ ) {
+ this.addPawnMoves(
+ [x, y], [x - shiftX, y + shiftY],
+ moves, promotions
+ );
+ }
+ }
}
}
}
+ return moves;
}
+ let pMoves = getPawnMoves(pawnShiftX);
+ if (V.PawnSpecs.bidirectional)
+ pMoves = pMoves.concat(getPawnMoves(-pawnShiftX));
+
if (V.HasEnpassant) {
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep - 1]; //always at least one element
- if (
- !!epSquare &&
- epSquare.x == x + shiftX &&
- Math.abs(epSquare.y - y) == 1
- ) {
- let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
- enpassantMove.vanish.push({
- x: x,
- y: epSquare.y,
- p: "p",
- c: this.getColor(x, epSquare.y)
- });
- moves.push(enpassantMove);
- }
+ // NOTE: backward en-passant captures are not considered
+ // because no rules define them (for now).
+ Array.prototype.push.apply(
+ pMoves,
+ this.getEnpassantCaptures([x, y], pawnShiftX)
+ );
}
- return moves;
+ return pMoves;
}
// What are the rook moves from square x,y ?
// What are the king moves from square x,y ?
getPotentialKingMoves(sq) {
// Initialize with normal moves
- const moves = this.getSlideNJumpMoves(
+ let moves = this.getSlideNJumpMoves(
sq,
V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
"oneStep"
);
- return moves.concat(this.getCastleMoves(sq));
+ if (V.HasCastle && this.castleFlags[this.turn].some(v => v < V.size.y))
+ moves = moves.concat(this.getCastleMoves(sq));
+ return moves;
}
- getCastleMoves([x, y]) {
+ // "castleInCheck" arg to let some variants castle under check
+ getCastleMoves([x, y], finalSquares, castleInCheck, castleWith) {
const c = this.getColor(x, y);
- if (x != (c == "w" ? V.size.x - 1 : 0) || y != this.INIT_COL_KING[c])
- return []; //x isn't first rank, or king has moved (shortcut)
// Castling ?
const oppCol = V.GetOppCol(c);
let moves = [];
let i = 0;
// King, then rook:
- const finalSquares = [
- [2, 3],
- [V.size.y - 2, V.size.y - 3]
- ];
+ finalSquares = finalSquares || [ [2, 3], [V.size.y - 2, V.size.y - 3] ];
+ const castlingKing = this.board[x][y].charAt(1);
castlingCheck: for (
let castleSide = 0;
castleSide < 2;
castleSide++ //large, then small
) {
if (this.castleFlags[c][castleSide] >= V.size.y) continue;
- // If this code is reached, rooks and king are on initial position
+ // If this code is reached, rook and king are on initial position
+
+ // NOTE: in some variants this is not a rook
+ const rookPos = this.castleFlags[c][castleSide];
+ const castlingPiece = this.board[x][rookPos].charAt(1);
+ if (
+ this.board[x][rookPos] == V.EMPTY ||
+ this.getColor(x, rookPos) != c ||
+ (!!castleWith && !castleWith.includes(castlingPiece))
+ ) {
+ // Rook is not here, or changed color (see Benedict)
+ continue;
+ }
// Nothing on the path of the king ? (and no checks)
const finDist = finalSquares[castleSide][0] - y;
i = y;
do {
if (
- this.isAttacked([x, i], oppCol) ||
- (this.board[x][i] != V.EMPTY &&
+ (!castleInCheck && this.isAttacked([x, i], oppCol)) ||
+ (
+ this.board[x][i] != V.EMPTY &&
// NOTE: next check is enough, because of chessboard constraints
- (this.getColor(x, i) != c ||
- ![V.KING, V.ROOK].includes(this.getPiece(x, i))))
+ (this.getColor(x, i) != c || ![y, rookPos].includes(i))
+ )
) {
continue castlingCheck;
}
// Nothing on the path to the rook?
step = castleSide == 0 ? -1 : 1;
- const rookPos = this.castleFlags[c][castleSide];
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 &&
- this.getPiece(x, finalSquares[castleSide][i]) != V.KING &&
- finalSquares[castleSide][i] != rookPos
+ (
+ 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: V.ROOK, c: c })
+ new PiPo({
+ x: x,
+ y: finalSquares[castleSide][0],
+ p: castlingKing,
+ c: c
+ }),
+ new PiPo({
+ x: x,
+ y: finalSquares[castleSide][1],
+ p: castlingPiece,
+ c: c
+ })
],
vanish: [
- new PiPo({ x: x, y: y, p: V.KING, c: c }),
- new PiPo({ x: x, y: rookPos, p: V.ROOK, c: c })
+ // King might be initially disguised (Titan...)
+ new PiPo({ x: x, y: y, p: castlingKing, c: c }),
+ new PiPo({ x: x, y: rookPos, p: castlingPiece, c: c })
],
end:
Math.abs(y - rookPos) <= 2
});
}
- // Search for all valid moves considering current turn
- // (for engine and game end)
- getAllValidMoves() {
+ getAllPotentialMoves() {
const color = this.turn;
let potentialMoves = [];
for (let i = 0; i < V.size.x; i++) {
for (let j = 0; j < V.size.y; j++) {
- if (this.getColor(i, j) == color) {
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) {
Array.prototype.push.apply(
potentialMoves,
this.getPotentialMovesFrom([i, j])
}
}
}
- return this.filterValid(potentialMoves);
+ return potentialMoves;
+ }
+
+ // Search for all valid moves considering current turn
+ // (for engine and game end)
+ getAllValidMoves() {
+ return this.filterValid(this.getAllPotentialMoves());
}
// Stop at the first move found
+ // TODO: not really, it explores all moves from a square (one is enough).
atLeastOneMove() {
const color = this.turn;
for (let i = 0; i < V.size.x; i++) {
for (let j = 0; j < V.size.y; j++) {
- if (this.getColor(i, j) == color) {
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) {
const moves = this.getPotentialMovesFrom([i, j]);
if (moves.length > 0) {
- for (let k = 0; k < moves.length; k++) {
+ for (let k = 0; k < moves.length; k++)
if (this.filterValid([moves[k]]).length > 0) return true;
- }
}
}
}
}
// Is square x,y attacked by 'color' pawns ?
- isAttackedByPawn([x, y], color) {
+ isAttackedByPawn(sq, color) {
const pawnShift = (color == "w" ? 1 : -1);
- if (x + pawnShift >= 0 && x + pawnShift < V.size.x) {
- for (let i of [-1, 1]) {
- if (
- y + i >= 0 &&
- y + i < V.size.y &&
- this.getPiece(x + pawnShift, y + i) == V.PAWN &&
- this.getColor(x + pawnShift, y + i) == color
- ) {
- return true;
- }
- }
- }
- return false;
+ return this.isAttackedBySlideNJump(
+ sq,
+ color,
+ V.PAWN,
+ [[pawnShift, 1], [pawnShift, -1]],
+ "oneStep"
+ );
}
// Is square x,y attacked by 'color' rooks ?
// Is color under check after his move ?
underCheck(color) {
- return this.isAttacked(this.kingPos[color], [V.GetOppCol(color)]);
+ return this.isAttacked(this.kingPos[color], V.GetOppCol(color));
}
/////////////////
play(move) {
// DEBUG:
// if (!this.states) this.states = [];
-// const stateFen = this.getBaseFen() + this.getTurnFen();// + this.getFlagsFen();
+// const stateFen = this.getFen() + JSON.stringify(this.kingPos);
// this.states.push(stateFen);
this.prePlay(move);
- if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
+ // Save flags (for undo)
+ if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags());
if (V.HasEnpassant) this.epSquares.push(this.getEpSquare(move));
V.PlayOnBoard(this.board, move);
this.turn = V.GetOppCol(this.turn);
this.postPlay(move);
}
+ updateCastleFlags(move, piece, color) {
+ const c = color || V.GetOppCol(this.turn);
+ const firstRank = (c == "w" ? V.size.x - 1 : 0);
+ // Update castling flags if rooks are moved
+ const oppCol = this.turn;
+ const oppFirstRank = V.size.x - 1 - firstRank;
+ if (piece == V.KING && move.appear.length > 0)
+ this.castleFlags[c] = [V.size.y, V.size.y];
+ else if (
+ move.start.x == firstRank && //our rook moves?
+ 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;
+ }
+ // NOTE: not "else if" because a rook could take an opposing rook
+ if (
+ move.end.x == oppFirstRank && //we took opponent rook?
+ this.castleFlags[oppCol].includes(move.end.y)
+ ) {
+ const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 1);
+ this.castleFlags[oppCol][flagIdx] = V.size.y;
+ }
+ }
+
// After move is played, update variables + flags
postPlay(move) {
const c = V.GetOppCol(this.turn);
else
// Crazyhouse-like variants
piece = move.appear[0].p;
- const firstRank = c == "w" ? V.size.x - 1 : 0;
// Update king position + flags
- if (piece == V.KING && move.appear.length > 0) {
- this.kingPos[c][0] = move.appear[0].x;
- this.kingPos[c][1] = move.appear[0].y;
- if (V.HasCastle) this.castleFlags[c] = [V.size.y, V.size.y];
- return;
- }
- if (V.HasCastle) {
- // Update castling flags if rooks are moved
- const oppCol = V.GetOppCol(c);
- const oppFirstRank = V.size.x - 1 - firstRank;
- if (
- move.start.x == firstRank && //our rook moves?
- 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 == oppFirstRank && //we took opponent rook?
- this.castleFlags[oppCol].includes(move.end.y)
- ) {
- const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 1);
- this.castleFlags[oppCol][flagIdx] = V.size.y;
- }
- }
+ if (piece == V.KING && move.appear.length > 0)
+ this.kingPos[c] = [move.appear[0].x, move.appear[0].y];
+ if (V.HasCastle) this.updateCastleFlags(move, piece);
}
preUndo() {}
this.postUndo(move);
// DEBUG:
-// const stateFen = this.getBaseFen() + this.getTurnFen();// + this.getFlagsFen();
+// const stateFen = this.getFen() + JSON.stringify(this.kingPos);
// if (stateFen != this.states[this.states.length-1]) debugger;
// this.states.pop();
}
// What is the score ? (Interesting if game is over)
getCurrentScore() {
- if (this.atLeastOneMove())
- return "*";
-
+ if (this.atLeastOneMove()) return "*";
// Game over
const color = this.turn;
// No valid move: stalemate or checkmate?
- if (!this.isAttacked(this.kingPos[color], V.GetOppCol(color)))
- return "1/2";
+ if (!this.underCheck(color)) return "1/2";
// OK, checkmate
return (color == "w" ? "0-1" : "1-0");
}
return V.INFINITY;
}
- // Search depth: 2 for high branching factor, 4 for small (Loser chess, eg.)
+ // Search depth: 1,2 for e.g. higher branching factor, 4 for smaller
static get SEARCH_DEPTH() {
return 3;
}
- getComputerMove() {
+ // 'movesList' arg for some variants to provide a custom list
+ getComputerMove(movesList) {
const maxeval = V.INFINITY;
const color = this.turn;
- let moves1 = this.getAllValidMoves();
+ let moves1 = movesList || this.getAllValidMoves();
if (moves1.length == 0)
// TODO: this situation should not happen
}
let candidates = [0];
- for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
- candidates.push(j);
+ for (let i = 1; i < moves1.length && moves1[i].eval == moves1[0].eval; i++)
+ candidates.push(i);
return moves1[candidates[randInt(candidates.length)]];
}
finalSquare
);
}
+
+ static GetUnambiguousNotation(move) {
+ // Machine-readable format with all the informations about the move
+ return (
+ (!!move.start && V.OnBoard(move.start.x, move.start.y)
+ ? V.CoordsToSquare(move.start)
+ : "-"
+ ) + "." +
+ (!!move.end && V.OnBoard(move.end.x, move.end.y)
+ ? V.CoordsToSquare(move.end)
+ : "-"
+ ) + " " +
+ (!!move.appear && move.appear.length > 0
+ ? move.appear.map(a =>
+ a.c + a.p + V.CoordsToSquare({ x: a.x, y: a.y })).join(".")
+ : "-"
+ ) + "/" +
+ (!!move.vanish && move.vanish.length > 0
+ ? move.vanish.map(a =>
+ a.c + a.p + V.CoordsToSquare({ x: a.x, y: a.y })).join(".")
+ : "-"
+ )
+ );
+ }
+
};
projects / vchess.git / blobdiff