X-Git-Url: https://git.auder.net/?p=vchess.git;a=blobdiff_plain;f=client%2Fsrc%2Fbase_rules.js;h=448604a46e27233ad8d2e3d73be438f8a5458f01;hp=fad1853a8ace34de286274ebb413220ebc6a5718;hb=d54f6261c9e30f4eabb402ad301dd5c5e40fb656;hpb=68e19a449db7a12e0a168e99cd750d985c983ba1 diff --git a/client/src/base_rules.js b/client/src/base_rules.js index fad1853a..448604a4 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; } @@ -73,6 +85,15 @@ 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"; @@ -116,12 +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]); @@ -131,9 +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; } @@ -181,9 +200,9 @@ 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) @@ -357,6 +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; @@ -365,7 +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]); @@ -373,7 +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 } @@ -421,7 +447,7 @@ 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] }; + 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)); @@ -593,21 +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 }) ] }); @@ -646,82 +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 ? @@ -750,15 +816,17 @@ export const ChessRules = class ChessRules { // 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) 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) @@ -778,7 +846,14 @@ export const ChessRules = class ChessRules { 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, 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; @@ -786,11 +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; } @@ -799,7 +874,6 @@ 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; } @@ -820,11 +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 @@ -988,7 +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)); } ///////////////// @@ -1010,7 +1084,7 @@ 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); @@ -1022,6 +1096,31 @@ export const ChessRules = class ChessRules { 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 postPlay(move) { const c = V.GetOppCol(this.turn); @@ -1032,33 +1131,14 @@ 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) { 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 (V.HasCastle) this.updateCastleFlags(move, piece); } preUndo() {} @@ -1073,7 +1153,7 @@ 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(); } @@ -1092,14 +1172,11 @@ export const ChessRules = class ChessRules { // 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"); } @@ -1129,7 +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; } @@ -1216,8 +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)]]; }