X-Git-Url: https://git.auder.net/?p=vchess.git;a=blobdiff_plain;f=client%2Fsrc%2Fbase_rules.js;h=267b2335d8da4ac163b0970edf6a1b5235fd0846;hp=29b3af60525973b19661f03f9d4c1d1f61ece765;hb=a68362420a3a92099dfaacea10f6cbd579161183;hpb=c583ef1c1dfd19aee88b22c2175202fbdf4dc1c0 diff --git a/client/src/base_rules.js b/client/src/base_rules.js index 29b3af60..267b2335 100644 --- a/client/src/base_rules.js +++ b/client/src/base_rules.js @@ -42,7 +42,19 @@ export const ChessRules = class ChessRules { return V.HasFlags; } - // Some variants don't have en-passant + // 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; } @@ -593,21 +605,23 @@ 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 }) ] }); @@ -646,82 +660,119 @@ 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, + p: "p", + 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 ? @@ -759,7 +810,8 @@ export const ChessRules = class ChessRules { 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) @@ -781,17 +833,24 @@ export const ChessRules = class ChessRules { if (this.castleFlags[c][castleSide] >= V.size.y) continue; // If this code is reached, rooks 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; let step = finDist / Math.max(1, Math.abs(finDist)); 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; } @@ -800,7 +859,6 @@ export const ChessRules = class ChessRules { // 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; } @@ -821,11 +879,11 @@ 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 @@ -989,7 +1047,7 @@ 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)); } ///////////////// @@ -1011,7 +1069,7 @@ export const ChessRules = class ChessRules { 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); @@ -1023,6 +1081,27 @@ export const ChessRules = class ChessRules { this.postPlay(move); } + updateCastleFlags(move) { + 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 ( + 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; + } + } + // After move is played, update variables + flags postPlay(move) { const c = V.GetOppCol(this.turn); @@ -1033,7 +1112,6 @@ export const ChessRules = class ChessRules { 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) { @@ -1042,24 +1120,7 @@ export const ChessRules = class ChessRules { 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 (V.HasCastle) this.updateCastleFlags(move); } preUndo() {} @@ -1074,7 +1135,7 @@ export const ChessRules = class ChessRules { 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(); }