}
};
-// 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
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,
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 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;
+ }
+
+ // 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";
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);
}
// 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]))]
: []
);
}
return;
const fenParsed = V.ParseFen(fen);
this.board = V.GetBoard(fenParsed.position);
- this.turn = fenParsed.turn[0]; //[0] to work with MarseilleRules
+ this.turn = fenParsed.turn;
this.movesCount = parseInt(fenParsed.movesCount);
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++) {
// Consider all potential promotions:
addPawnMoves([x1, y1], [x2, y2], moves, promotions) {
let finalPieces = [V.PAWN];
- const color = this.turn;
+ 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;
+ else if (!!V.PawnSpecs.promotions) finalPieces = V.PawnSpecs.promotions;
}
let tr = null;
for (let piece of finalPieces) {
// What are the pawn moves from square x,y ?
getPotentialPawnMoves([x, y], promotions) {
- const color = this.turn;
+ const color = this.turn; //this.getColor(x, y);
const [sizeX, sizeY] = [V.size.x, V.size.y];
const pawnShiftX = V.PawnSpecs.directions[color];
const firstRank = (color == "w" ? sizeX - 1 : 0);
- const startRank = (color == "w" ? sizeX - 2 : 1);
+ const forward = (color == 'w' ? -1 : 1);
// Pawn movements in shiftX direction:
const getPawnMoves = (shiftX) => {
// 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
+ // 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 &&
- [startRank, firstRank].includes(x) &&
- this.board[x + 2 * shiftX][y] == V.EMPTY
+ (
+ (color == 'w' && x >= V.size.x - 1 - V.PawnSpecs.initShift['w'])
+ ||
+ (color == 'b' && x <= V.PawnSpecs.initShift['b'])
+ )
) {
- // Two squares jump
- moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
+ 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
if (V.PawnSpecs.canCapture) {
for (let shiftY of [-1, 1]) {
- if (
- y + shiftY >= 0 &&
- y + shiftY < sizeY
- ) {
+ if (y + shiftY >= 0 && y + shiftY < sizeY) {
if (
this.board[x + shiftX][y + shiftY] != V.EMPTY &&
this.canTake([x, y], [x + shiftX, y + shiftY])
);
}
if (
- V.PawnSpecs.captureBackward &&
+ 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],
+ [x, y], [x - shiftX, y + shiftY],
moves, promotions
);
}
if (this.castleFlags[c][castleSide] >= V.size.y) continue;
// If this code is reached, rook and king are on initial position
- // NOTE: in some variants this is not a rook, but let's keep variable name
+ // NOTE: in some variants this is not a rook
const rookPos = this.castleFlags[c][castleSide];
- const castlingPiece = this.getPiece(x, rookPos);
- if (this.getColor(x, rookPos) != c)
- // Rook is here but changed color (see Benedict)
+ if (this.board[x][rookPos] == V.EMPTY || this.getColor(x, rookPos) != c)
+ // Rook is not here, or changed color (see Benedict)
continue;
// Nothing on the path of the king ? (and no checks)
+ const castlingPiece = this.getPiece(x, rookPos);
const finDist = finalSquares[castleSide][0] - y;
let step = finDist / Math.max(1, Math.abs(finDist));
i = y;
do {
if (
- (!castleInCheck && this.isAttacked([x, i], oppCol)) ||
+ // NOTE: "castling" arg is used by some variants (Monster),
+ // where "isAttacked" is overloaded in an infinite-recursive way.
+ // TODO: not used anymore (Monster + Doublemove2 are simplified).
+ (!castleInCheck && this.isAttacked([x, i], oppCol, "castling")) ||
(this.board[x][i] != V.EMPTY &&
// NOTE: next check is enough, because of chessboard constraints
(this.getColor(x, i) != c ||
// 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
+ (
+ this.getPiece(x, finalSquares[castleSide][i]) != V.KING ||
+ 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: c })
+ new PiPo({
+ x: x,
+ y: finalSquares[castleSide][0],
+ p: V.KING,
+ 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 }),
});
}
- // 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 ?
// 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);
const c = V.GetOppCol(this.turn);
const firstRank = (c == "w" ? V.size.x - 1 : 0);
// Update castling flags if rooks are moved
- const oppCol = V.GetOppCol(c);
+ 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];
piece = move.appear[0].p;
// 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;
- return;
- }
+ 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);
}
return V.INFINITY;
}
- // Search depth: 1,2 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
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(".")
+ : "-"
+ )
+ );
+ }
};