return true;
}
+ // Or castle
+ static get HasCastle() {
+ return V.HasFlags;
+ }
+
// Some variants don't have en-passant
static get HasEnpassant() {
return true;
return V.CanFlip;
}
+ static get IMAGE_EXTENSION() {
+ // All pieces should be in the SVG format
+ return ".svg";
+ }
+
// Turn "wb" into "B" (for FEN)
static board2fen(b) {
return b[0] == "w" ? b[1].toUpperCase() : b[1];
return f.charCodeAt() <= 90 ? "w" + f.toLowerCase() : "b" + f;
}
- // Check if FEN describe a board situation correctly
+ // Check if FEN describes a board situation correctly
static IsGoodFen(fen) {
const fenParsed = V.ParseFen(fen);
// 1) Check position
// For FEN checking
static IsGoodFlags(flags) {
- return !!flags.match(/^[01]{4,4}$/);
+ // NOTE: a little too permissive to work with more variants
+ return !!flags.match(/^[a-z]{4,4}$/);
}
static IsGoodEnpassant(enpassant) {
return b; //usual pieces in pieces/ folder
}
+ // Path to promotion pieces (usually the same)
+ getPPpath(b) {
+ return this.getPpath(b);
+ }
+
// Aggregates flags into one object
aggregateFlags() {
return this.castleFlags;
const move = moveOrSquare;
const s = move.start,
e = move.end;
- // NOTE: next conditions are first for Atomic, and last for Checkered
if (
- move.appear.length > 0 &&
Math.abs(s.x - e.x) == 2 &&
s.y == e.y &&
- move.appear[0].p == V.PAWN &&
- ["w", "b"].includes(move.appear[0].c)
+ move.appear[0].p == V.PAWN
) {
return {
x: (s.x + e.x) / 2,
// On which squares is color under check ? (for interface)
getCheckSquares(color) {
- return this.isAttacked(this.kingPos[color], [V.GetOppCol(color)])
- ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
- : [];
+ return (
+ this.underCheck(color)
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
+ : []
+ );
}
/////////////
static GenRandInitFen(randomness) {
if (randomness == 0)
// Deterministic:
- return "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0 1111 -";
+ return "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0 ahah -";
let pieces = { w: new Array(8), b: new Array(8) };
+ let flags = "";
// Shuffle pieces on first (and last rank if randomness == 2)
for (let c of ["w", "b"]) {
if (c == 'b' && randomness == 1) {
pieces['b'] = pieces['w'];
+ flags += flags;
break;
}
pieces[c][bishop2Pos] = "b";
pieces[c][knight2Pos] = "n";
pieces[c][rook2Pos] = "r";
+ flags += V.CoordToColumn(rook1Pos) + V.CoordToColumn(rook2Pos);
}
// Add turn + flags + enpassant
return (
pieces["b"].join("") +
"/pppppppp/8/8/8/8/PPPPPPPP/" +
pieces["w"].join("").toUpperCase() +
- " w 0 1111 -"
+ " w 0 " + flags + " -"
);
}
// Return current fen (game state)
getFen() {
return (
- this.getBaseFen() +
- " " +
- this.getTurnFen() +
- " " +
+ this.getBaseFen() + " " +
+ this.getTurnFen() + " " +
this.movesCount +
(V.HasFlags ? " " + this.getFlagsFen() : "") +
(V.HasEnpassant ? " " + this.getEnpassantFen() : "")
);
}
+ getFenForRepeat() {
+ // Omit movesCount, only variable allowed to differ
+ return (
+ this.getBaseFen() + "_" +
+ this.getTurnFen() +
+ (V.HasFlags ? "_" + this.getFlagsFen() : "") +
+ (V.HasEnpassant ? "_" + this.getEnpassantFen() : "")
+ );
+ }
+
// Position part of the FEN string
getBaseFen() {
let position = "";
// Flags part of the FEN string
getFlagsFen() {
let flags = "";
- // Add castling flags
- for (let i of ["w", "b"]) {
- for (let j = 0; j < 2; j++) flags += this.castleFlags[i][j] ? "1" : "0";
- }
+ // Castling flags
+ for (let c of ["w", "b"])
+ flags += this.castleFlags[c].map(V.CoordToColumn).join("");
return flags;
}
setFlags(fenflags) {
// white a-castle, h-castle, black a-castle, h-castle
this.castleFlags = { w: [true, true], b: [true, true] };
- for (let i = 0; i < 4; i++)
- this.castleFlags[i < 2 ? "w" : "b"][i % 2] = fenflags.charAt(i) == "1";
+ for (let i = 0; i < 4; i++) {
+ this.castleFlags[i < 2 ? "w" : "b"][i % 2] =
+ V.ColumnToCoord(fenflags.charAt(i));
+ }
}
//////////////////
this.setOtherVariables(fen);
}
- // Scan board for kings and rooks positions
- scanKingsRooks(fen) {
+ // Scan board for kings positions
+ scanKings(fen) {
this.INIT_COL_KING = { w: -1, b: -1 };
- this.INIT_COL_ROOK = { w: [-1, -1], b: [-1, -1] };
this.kingPos = { w: [-1, -1], b: [-1, -1] }; //squares of white and black king
const fenRows = V.ParseFen(fen).position.split("/");
+ const startRow = { 'w': V.size.x - 1, 'b': 0 };
for (let i = 0; i < fenRows.length; i++) {
let k = 0; //column index on board
for (let j = 0; j < fenRows[i].length; j++) {
this.kingPos["w"] = [i, k];
this.INIT_COL_KING["w"] = k;
break;
- case "r":
- if (this.INIT_COL_ROOK["b"][0] < 0) this.INIT_COL_ROOK["b"][0] = k;
- else this.INIT_COL_ROOK["b"][1] = k;
- break;
- case "R":
- if (this.INIT_COL_ROOK["w"][0] < 0) this.INIT_COL_ROOK["w"][0] = k;
- else this.INIT_COL_ROOK["w"][1] = k;
- break;
default: {
const num = parseInt(fenRows[i].charAt(j));
if (!isNaN(num)) k += num - 1;
: undefined;
this.epSquares = [epSq];
}
- // Search for king and rooks positions:
- this.scanKingsRooks(fen);
+ // Search for kings positions:
+ this.scanKings(fen);
}
/////////////////////
const firstRank = color == "w" ? sizeX - 1 : 0;
const startRank = color == "w" ? sizeX - 2 : 1;
const lastRank = color == "w" ? 0 : sizeX - 1;
- const pawnColor = this.getColor(x, y); //can be different for checkered
// NOTE: next condition is generally true (no pawn on last rank)
if (x + shiftX >= 0 && x + shiftX < sizeX) {
for (let piece of finalPieces) {
moves.push(
this.getBasicMove([x, y], [x + shiftX, y], {
- c: pawnColor,
+ c: color,
p: piece
})
);
for (let piece of finalPieces) {
moves.push(
this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
- c: pawnColor,
+ c: color,
p: piece
})
);
V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
"oneStep"
);
- return moves.concat(this.getCastleMoves(sq));
+ if (V.HasCastle) moves = moves.concat(this.getCastleMoves(sq));
+ return moves;
}
getCastleMoves([x, y]) {
castleSide < 2;
castleSide++ //large, then small
) {
- if (!this.castleFlags[c][castleSide]) continue;
+ if (this.castleFlags[c][castleSide] >= V.size.y) continue;
// If this code is reached, rooks and king are on initial position
// Nothing on the path of the king ? (and no checks)
i = y;
do {
if (
- this.isAttacked([x, i], [oppCol]) ||
+ 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 ||
// Nothing on the path to the rook?
step = castleSide == 0 ? -1 : 1;
- for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step) {
+ const rookPos = this.castleFlags[c][castleSide];
+ for (i = y + step; i != rookPos; i += step) {
if (this.board[x][i] != V.EMPTY) continue castlingCheck;
}
- const rookPos = this.INIT_COL_ROOK[c][castleSide];
// Nothing on final squares, except maybe king and castling rook?
for (i = 0; i < 2; i++) {
return false;
}
- // Check if pieces of color in 'colors' are attacking (king) on square x,y
- isAttacked(sq, colors) {
+ // Check if pieces of given color are attacking (king) on square x,y
+ isAttacked(sq, color) {
return (
- this.isAttackedByPawn(sq, colors) ||
- this.isAttackedByRook(sq, colors) ||
- this.isAttackedByKnight(sq, colors) ||
- this.isAttackedByBishop(sq, colors) ||
- this.isAttackedByQueen(sq, colors) ||
- this.isAttackedByKing(sq, colors)
+ this.isAttackedByPawn(sq, color) ||
+ this.isAttackedByRook(sq, color) ||
+ this.isAttackedByKnight(sq, color) ||
+ this.isAttackedByBishop(sq, color) ||
+ this.isAttackedByQueen(sq, color) ||
+ this.isAttackedByKing(sq, color)
);
}
// Generic method for non-pawn pieces ("sliding or jumping"):
- // is x,y attacked by a piece of color in array 'colors' ?
- isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
+ // is x,y attacked by a piece of given color ?
+ isAttackedBySlideNJump([x, y], color, piece, steps, oneStep) {
for (let step of steps) {
let rx = x + step[0],
ry = y + step[1];
}
if (
V.OnBoard(rx, ry) &&
- this.getPiece(rx, ry) === piece &&
- colors.includes(this.getColor(rx, ry))
+ this.getPiece(rx, ry) == piece &&
+ this.getColor(rx, ry) == color
) {
return true;
}
return false;
}
- // Is square x,y attacked by 'colors' pawns ?
- isAttackedByPawn([x, y], colors) {
- for (let c of colors) {
- const pawnShift = c == "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) == c
- ) {
- return true;
- }
+ // Is square x,y attacked by 'color' pawns ?
+ isAttackedByPawn([x, y], 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;
}
- // Is square x,y attacked by 'colors' rooks ?
- isAttackedByRook(sq, colors) {
- return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
+ // Is square x,y attacked by 'color' rooks ?
+ isAttackedByRook(sq, color) {
+ return this.isAttackedBySlideNJump(sq, color, V.ROOK, V.steps[V.ROOK]);
}
- // Is square x,y attacked by 'colors' knights ?
- isAttackedByKnight(sq, colors) {
+ // Is square x,y attacked by 'color' knights ?
+ isAttackedByKnight(sq, color) {
return this.isAttackedBySlideNJump(
sq,
- colors,
+ color,
V.KNIGHT,
V.steps[V.KNIGHT],
"oneStep"
);
}
- // Is square x,y attacked by 'colors' bishops ?
- isAttackedByBishop(sq, colors) {
- return this.isAttackedBySlideNJump(sq, colors, V.BISHOP, V.steps[V.BISHOP]);
+ // Is square x,y attacked by 'color' bishops ?
+ isAttackedByBishop(sq, color) {
+ return this.isAttackedBySlideNJump(sq, color, V.BISHOP, V.steps[V.BISHOP]);
}
- // Is square x,y attacked by 'colors' queens ?
- isAttackedByQueen(sq, colors) {
+ // Is square x,y attacked by 'color' queens ?
+ isAttackedByQueen(sq, color) {
return this.isAttackedBySlideNJump(
sq,
- colors,
+ color,
V.QUEEN,
V.steps[V.ROOK].concat(V.steps[V.BISHOP])
);
}
- // Is square x,y attacked by 'colors' king(s) ?
- isAttackedByKing(sq, colors) {
+ // Is square x,y attacked by 'color' king(s) ?
+ isAttackedByKing(sq, color) {
return this.isAttackedBySlideNJump(
sq,
- colors,
+ color,
V.KING,
V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
"oneStep"
for (let psq of move.vanish) board[psq.x][psq.y] = psq.c + psq.p;
}
+ prePlay() {}
+
+ play(move) {
+ // DEBUG:
+// if (!this.states) this.states = [];
+// const stateFen = this.getBaseFen() + this.getTurnFen();// + this.getFlagsFen();
+// this.states.push(stateFen);
+
+ this.prePlay(move);
+ if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
+ if (V.HasEnpassant) this.epSquares.push(this.getEpSquare(move));
+ V.PlayOnBoard(this.board, move);
+ this.turn = V.GetOppCol(this.turn);
+ this.movesCount++;
+ this.postPlay(move);
+ }
+
// After move is played, update variables + flags
- updateVariables(move) {
+ postPlay(move) {
+ const c = V.GetOppCol(this.turn);
let piece = undefined;
- // TODO: update variables before move is played, and just use this.turn ?
- // (doesn't work in general, think MarseilleChess)
- let c = undefined;
- if (move.vanish.length >= 1) {
+ if (move.vanish.length >= 1)
// Usual case, something is moved
piece = move.vanish[0].p;
- c = move.vanish[0].c;
- } else {
+ else
// Crazyhouse-like variants
piece = move.appear[0].p;
- c = move.appear[0].c;
- }
- if (!['w','b'].includes(c)) {
- // Checkered, for example
- c = V.GetOppCol(this.turn);
- }
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.HasFlags) this.castleFlags[c] = [false, false];
+ if (V.HasCastle) this.castleFlags[c] = [V.size.y, V.size.y];
return;
}
- if (V.HasFlags) {
+ 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.INIT_COL_ROOK[c].includes(move.start.y)
+ this.castleFlags[c].includes(move.start.y)
) {
- const flagIdx = move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1;
- this.castleFlags[c][flagIdx] = false;
+ 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.INIT_COL_ROOK[oppCol].includes(move.end.y)
+ this.castleFlags[oppCol].includes(move.end.y)
) {
- const flagIdx = move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1;
- this.castleFlags[oppCol][flagIdx] = false;
+ const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 1);
+ this.castleFlags[oppCol][flagIdx] = V.size.y;
}
}
}
- // After move is undo-ed *and flags resetted*, un-update other variables
- // TODO: more symmetry, by storing flags increment in move (?!)
- unupdateVariables(move) {
- // (Potentially) Reset king position
- const c = this.getColor(move.start.x, move.start.y);
- if (this.getPiece(move.start.x, move.start.y) == V.KING)
- this.kingPos[c] = [move.start.x, move.start.y];
- }
-
- play(move) {
- // DEBUG:
-// if (!this.states) this.states = [];
-// const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
-// this.states.push(stateFen);
-
- if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
- if (V.HasEnpassant) this.epSquares.push(this.getEpSquare(move));
- V.PlayOnBoard(this.board, move);
- this.turn = V.GetOppCol(this.turn);
- this.movesCount++;
- this.updateVariables(move);
- }
+ preUndo() {}
undo(move) {
+ this.preUndo(move);
if (V.HasEnpassant) this.epSquares.pop();
if (V.HasFlags) this.disaggregateFlags(JSON.parse(move.flags));
V.UndoOnBoard(this.board, move);
this.turn = V.GetOppCol(this.turn);
this.movesCount--;
- this.unupdateVariables(move);
+ this.postUndo(move);
// DEBUG:
-// const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
+// const stateFen = this.getBaseFen() + this.getTurnFen();// + this.getFlagsFen();
// if (stateFen != this.states[this.states.length-1]) debugger;
// this.states.pop();
}
+ // After move is undo-ed *and flags resetted*, un-update other variables
+ // TODO: more symmetry, by storing flags increment in move (?!)
+ postUndo(move) {
+ // (Potentially) Reset king position
+ const c = this.getColor(move.start.x, move.start.y);
+ if (this.getPiece(move.start.x, move.start.y) == V.KING)
+ this.kingPos[c] = [move.start.x, move.start.y];
+ }
+
///////////////
// END OF GAME
// Game over
const color = this.turn;
// No valid move: stalemate or checkmate?
- if (!this.isAttacked(this.kingPos[color], [V.GetOppCol(color)]))
+ if (!this.isAttacked(this.kingPos[color], V.GetOppCol(color)))
return "1/2";
// OK, checkmate
- return color == "w" ? "0-1" : "1-0";
+ return (color == "w" ? "0-1" : "1-0");
}
///////////////
getComputerMove() {
const maxeval = V.INFINITY;
const color = this.turn;
- // Some variants may show a bigger moves list to the human (Switching),
- // thus the argument "computer" below (which is generally ignored)
let moves1 = this.getAllValidMoves();
if (moves1.length == 0)
// TODO: this situation should not happen
return null;
- // Rank moves using a min-max at depth 2
+ // Rank moves using a min-max at depth 2 (if search_depth >= 2!)
for (let i = 0; i < moves1.length; i++) {
- // Initial self evaluation is very low: "I'm checkmated"
- moves1[i].eval = (color == "w" ? -1 : 1) * maxeval;
this.play(moves1[i]);
const score1 = this.getCurrentScore();
- let eval2 = undefined;
- if (score1 == "*") {
- // Initial enemy evaluation is very low too, for him
- eval2 = (color == "w" ? 1 : -1) * maxeval;
- // Second half-move:
- let moves2 = this.getAllValidMoves();
- for (let j = 0; j < moves2.length; j++) {
- this.play(moves2[j]);
- const score2 = this.getCurrentScore();
- let evalPos = 0; //1/2 value
- switch (score2) {
- case "*":
- evalPos = this.evalPosition();
- break;
- case "1-0":
- evalPos = maxeval;
- break;
- case "0-1":
- evalPos = -maxeval;
- break;
- }
- if (
- (color == "w" && evalPos < eval2) ||
- (color == "b" && evalPos > eval2)
- ) {
- eval2 = evalPos;
- }
- this.undo(moves2[j]);
+ if (score1 != "*") {
+ moves1[i].eval =
+ score1 == "1/2"
+ ? 0
+ : (score1 == "1-0" ? 1 : -1) * maxeval;
+ }
+ if (V.SEARCH_DEPTH == 1 || score1 != "*") {
+ if (!moves1[i].eval) moves1[i].eval = this.evalPosition();
+ this.undo(moves1[i]);
+ continue;
+ }
+ // Initial self evaluation is very low: "I'm checkmated"
+ moves1[i].eval = (color == "w" ? -1 : 1) * maxeval;
+ // Initial enemy evaluation is very low too, for him
+ let eval2 = (color == "w" ? 1 : -1) * maxeval;
+ // Second half-move:
+ let moves2 = this.getAllValidMoves();
+ for (let j = 0; j < moves2.length; j++) {
+ this.play(moves2[j]);
+ const score2 = this.getCurrentScore();
+ let evalPos = 0; //1/2 value
+ switch (score2) {
+ case "*":
+ evalPos = this.evalPosition();
+ break;
+ case "1-0":
+ evalPos = maxeval;
+ break;
+ case "0-1":
+ evalPos = -maxeval;
+ break;
}
- } else eval2 = score1 == "1/2" ? 0 : (score1 == "1-0" ? 1 : -1) * maxeval;
+ if (
+ (color == "w" && evalPos < eval2) ||
+ (color == "b" && evalPos > eval2)
+ ) {
+ eval2 = evalPos;
+ }
+ this.undo(moves2[j]);
+ }
if (
(color == "w" && eval2 > moves1[i].eval) ||
(color == "b" && eval2 < moves1[i].eval)
});
// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
- let candidates = [0]; //indices of candidates moves
- for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
- candidates.push(j);
- let currentBest = moves1[candidates[randInt(candidates.length)]];
-
// Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...)
if (V.SEARCH_DEPTH >= 3 && Math.abs(moves1[0].eval) < V.THRESHOLD_MATE) {
- // From here, depth >= 3: may take a while, so we control time
- const timeStart = Date.now();
for (let i = 0; i < moves1.length; i++) {
- if (Date.now() - timeStart >= 5000)
- //more than 5 seconds
- return currentBest; //depth 2 at least
this.play(moves1[i]);
// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
moves1[i].eval =
moves1.sort((a, b) => {
return (color == "w" ? 1 : -1) * (b.eval - a.eval);
});
- } else return currentBest;
-// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
+ }
- candidates = [0];
+ let candidates = [0];
for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
candidates.push(j);
return moves1[candidates[randInt(candidates.length)]];