X-Git-Url: https://git.auder.net/?p=vchess.git;a=blobdiff_plain;f=client%2Fsrc%2Fbase_rules.js;h=448604a46e27233ad8d2e3d73be438f8a5458f01;hp=4c32fe69ea34454f7bec628b2afa53e5ca38e7c9;hb=d54f6261c9e30f4eabb402ad301dd5c5e40fb656;hpb=afbf3ca7151ef15a9e579b0f913683ab212396c4 diff --git a/client/src/base_rules.js b/client/src/base_rules.js index 4c32fe69..448604a4 100644 --- a/client/src/base_rules.js +++ b/client/src/base_rules.js @@ -37,7 +37,24 @@ export const ChessRules = class ChessRules { return true; } - // Some variants don't have en-passant + // Or castle + static get HasCastle() { + return V.HasFlags; + } + + // Pawns specifications + static get PawnSpecs() { + return { + directions: { 'w': -1, 'b': 1 }, + twoSquares: true, + 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; } @@ -68,6 +85,20 @@ export const ChessRules = class ChessRules { return V.CanFlip; } + // Some variants require turn indicator + // (generally when analysis or flip is diabled) + static get ShowTurn() { + return !V.CanAnalyze || V.ShowMoves != "all" || !V.CanFlip; + } + get showTurn() { + return V.ShowTurn; + } + + 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]; @@ -78,7 +109,7 @@ export const ChessRules = class ChessRules { 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 @@ -106,12 +137,11 @@ export const ChessRules = class ChessRules { 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]); @@ -121,9 +151,8 @@ export const ChessRules = class ChessRules { } 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; } @@ -134,7 +163,8 @@ export const ChessRules = class ChessRules { // 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) { @@ -170,9 +200,14 @@ export const ChessRules = class ChessRules { 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); } // Aggregates flags into one object @@ -227,9 +262,11 @@ export const ChessRules = class ChessRules { // 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! + : [] + ); } ///////////// @@ -239,13 +276,15 @@ export const ChessRules = class ChessRules { 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; } @@ -289,13 +328,14 @@ export const ChessRules = class ChessRules { 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 + " -" ); } @@ -336,6 +376,13 @@ export const ChessRules = class ChessRules { // 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; @@ -344,7 +391,7 @@ export const ChessRules = class ChessRules { else { if (emptyCount > 0) { // Add empty squares in-between - position += emptyCount; + position += format(emptyCount); emptyCount = 0; } position += V.board2fen(this.board[i][j]); @@ -352,7 +399,7 @@ export const ChessRules = class ChessRules { } if (emptyCount > 0) { // "Flush remainder" - position += emptyCount; + position += format(emptyCount); } if (i < V.size.x - 1) position += "/"; //separate rows } @@ -366,10 +413,9 @@ export const ChessRules = class ChessRules { // 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; } @@ -401,9 +447,11 @@ export const ChessRules = class ChessRules { // 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] }; - for (let i = 0; i < 4; i++) - this.castleFlags[i < 2 ? "w" : "b"][i % 2] = fenflags.charAt(i) == "1"; + 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)); + } } ////////////////// @@ -422,10 +470,9 @@ export const ChessRules = class ChessRules { 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 }; @@ -441,18 +488,6 @@ export const ChessRules = class ChessRules { this.kingPos["w"] = [i, k]; this.INIT_COL_KING["w"] = k; break; - case "r": - if (i == startRow['b']) { - 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 (i == startRow['w']) { - 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; @@ -475,8 +510,8 @@ export const ChessRules = class ChessRules { : undefined; this.epSquares = [epSq]; } - // Search for king and rooks positions: - this.scanKingsRooks(fen); + // Search for kings positions: + this.scanKings(fen); } ///////////////////// @@ -584,21 +619,23 @@ export const ChessRules = class ChessRules { // 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.getPiece(sx, sy); 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 }) ] }); @@ -637,82 +674,120 @@ export const ChessRules = class ChessRules { 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, + // Captured piece is usually a pawn, but next line seems harmless + p: this.getPiece(x, epSquare.y), + 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; + 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]) { + getPotentialPawnMoves([x, y], promotions) { const color = this.turn; - let moves = []; 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 startRank = (color == "w" ? sizeX - 2 : 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 + 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 + ) { + // Two squares jump + moves.push(this.getBasicMove([x, y], [x + 2 * 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 && + 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 ? @@ -746,10 +821,12 @@ export const ChessRules = class ChessRules { 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]) { + // "castleInCheck" arg to let some variants castle under check + getCastleMoves([x, y], castleInCheck) { 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) @@ -768,8 +845,15 @@ export const ChessRules = class ChessRules { castleSide < 2; castleSide++ //large, then small ) { - if (!this.castleFlags[c][castleSide]) continue; - // If this code is reached, rooks and king are on initial position + 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 + 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) + continue; // Nothing on the path of the king ? (and no checks) const finDist = finalSquares[castleSide][0] - y; @@ -777,11 +861,11 @@ export const ChessRules = class ChessRules { i = y; do { if ( - this.isAttacked([x, i], [oppCol]) || + (!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)))) + ![V.KING, castlingPiece].includes(this.getPiece(x, i)))) ) { continue castlingCheck; } @@ -790,10 +874,9 @@ export const ChessRules = class ChessRules { // 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) { + 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++) { @@ -811,11 +894,11 @@ export const ChessRules = class ChessRules { 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][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 }) + new PiPo({ x: x, y: rookPos, p: castlingPiece, c: c }) ], end: Math.abs(y - rookPos) <= 2 @@ -884,21 +967,21 @@ export const ChessRules = class ChessRules { 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]; @@ -908,8 +991,8 @@ export const ChessRules = class ChessRules { } 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; } @@ -917,62 +1000,60 @@ export const ChessRules = class ChessRules { 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" @@ -981,7 +1062,7 @@ export const ChessRules = class ChessRules { // 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)); } ///////////////// @@ -998,106 +1079,106 @@ export const ChessRules = class ChessRules { 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.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) + 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); + } + + updateCastleFlags(move, piece) { + 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 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 - 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]; return; } - if (V.HasFlags) { - // 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) - ) { - const flagIdx = (move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1); - this.castleFlags[c][flagIdx] = false; - } else if ( - move.end.x == oppFirstRank && //we took opponent rook? - this.INIT_COL_ROOK[oppCol].includes(move.end.y) - ) { - const flagIdx = (move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1); - this.castleFlags[oppCol][flagIdx] = false; - } - } + if (V.HasCastle) this.updateCastleFlags(move, piece); } - // 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.getFen() + JSON.stringify(this.kingPos); // 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 // 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 (color == "w" ? "0-1" : "1-0"); } /////////////// @@ -1125,7 +1206,7 @@ export const ChessRules = class ChessRules { return V.INFINITY; } - // Search depth: 2 for high branching factor, 4 for small (Loser chess, eg.) + // Search depth: 1,2 for high branching factor, 4 for small (Loser chess, eg.) static get SEARCH_DEPTH() { return 3; } @@ -1212,8 +1293,8 @@ export const ChessRules = class ChessRules { } 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)]]; }