/**** * Plugins ****/ var tween = LK.import("@upit/tween.v1"); /**** * Classes ****/ // --- ChessBoard Class --- var ChessBoard = Container.expand(function () { var self = Container.call(this); // 8x8 array of ChessPiece or null self.squares = []; for (var y = 0; y < 8; y++) { self.squares[y] = []; for (var x = 0; x < 8; x++) { self.squares[y][x] = null; } } // Draw board squares self.squareNodes = []; for (var y = 0; y < 8; y++) { self.squareNodes[y] = []; for (var x = 0; x < 8; x++) { var isLight = (x + y) % 2 === 0; // Use classic chessboard colors: light = #f0d9b5, dark = #b58863 var color = isLight ? 0xf0d9b5 : 0xb58863; var assetId = 'board_' + (isLight ? 'light' : 'dark'); var node = LK.getAsset(assetId, { anchorX: 0, anchorY: 0, x: boardOriginX + x * squareSize, y: boardOriginY + y * squareSize, width: squareSize, height: squareSize, color: color, shape: 'box' }); self.addChild(node); self.squareNodes[y][x] = node; } } // Highlight squares (for moves) self.highlightNodes = []; for (var i = 0; i < 64; i++) { var highlightId = 'highlight_' + i; // Use a circle (ellipse) and center it in the square var node = LK.getAsset('centerCircle', { anchorX: 0.5, anchorY: 0.5, width: Math.floor(squareSize * 0.45), height: Math.floor(squareSize * 0.45), x: -1000, y: -1000 }); // Hide initially node.alpha = 0.25; self.addChild(node); self.highlightNodes[i] = node; } // Place pieces in starting position self.reset = function () { // Remove all pieces for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { if (self.squares[y][x]) { self.squares[y][x].destroy(); self.squares[y][x] = null; } } } // Place pawns for (var x = 0; x < 8; x++) { var wp = new ChessPiece(); wp.init('pawn', 'white', x, 6); wp.moveTo(x, 6, false); self.addChild(wp); self.squares[6][x] = wp; var bp = new ChessPiece(); bp.init('pawn', 'black', x, 1); bp.moveTo(x, 1, false); self.addChild(bp); self.squares[1][x] = bp; } // Place other pieces var order = ['rook', 'knight', 'bishop', 'queen', 'king', 'bishop', 'knight', 'rook']; for (var x = 0; x < 8; x++) { var w = new ChessPiece(); w.init(order[x], 'white', x, 7); w.moveTo(x, 7, false); self.addChild(w); self.squares[7][x] = w; var b = new ChessPiece(); b.init(order[x], 'black', x, 0); b.moveTo(x, 0, false); self.addChild(b); self.squares[0][x] = b; } }; // Remove all highlights self.clearHighlights = function () { for (var i = 0; i < 64; i++) { self.highlightNodes[i].x = -1000; self.highlightNodes[i].y = -1000; } }; // Highlight given squares (array of {x, y}) self.showHighlights = function (squares) { self.clearHighlights(); for (var i = 0; i < squares.length; i++) { var idx = squares[i].y * 8 + squares[i].x; var node = self.highlightNodes[idx]; // Center the highlight circle in the square node.x = boardOriginX + squares[i].x * squareSize + squareSize / 2; node.y = boardOriginY + squares[i].y * squareSize + squareSize / 2; } }; // Get piece at board position self.getPiece = function (x, y) { if (x < 0 || x > 7 || y < 0 || y > 7) return null; return self.squares[y][x]; }; // Set piece at board position self.setPiece = function (x, y, piece) { self.squares[y][x] = piece; }; // Remove piece at board position self.removePiece = function (x, y) { var p = self.squares[y][x]; if (p) { p.destroy(); self.squares[y][x] = null; } }; return self; }); // --- ChessPiece Class --- var ChessPiece = Container.expand(function () { var self = Container.call(this); // Properties self.type = null; // 'pawn', 'rook', 'knight', 'bishop', 'queen', 'king' self.color = null; // 'white' or 'black' self.boardX = 0; // 0-7 self.boardY = 0; // 0-7 self.hasMoved = false; // For castling/en passant self.promoted = false; // For pawn promotion // Asset self.pieceAsset = null; // Set piece type and color, and create asset self.init = function (type, color, boardX, boardY) { self.type = type; self.color = color; self.boardX = boardX; self.boardY = boardY; self.hasMoved = false; self.promoted = false; // Remove old asset if any if (self.pieceAsset) { self.removeChild(self.pieceAsset); } // Use classic piece colors: white = #fff, black = #222 var colorMap = { 'white': { 'pawn': 0xffffff, 'rook': 0xffffff, 'knight': 0xffffff, 'bishop': 0xffffff, 'queen': 0xffffff, 'king': 0xffffff }, 'black': { 'pawn': 0x222222, 'rook': 0x222222, 'knight': 0x222222, 'bishop': 0x222222, 'queen': 0x222222, 'king': 0x222222 } }; var shape = self.type === 'pawn' || self.type === 'bishop' ? 'ellipse' : 'box'; var assetId = self.color + '_' + self.type; var assetColor = colorMap[self.color][self.type]; var size = self.type === 'king' ? Math.floor(pieceSize * 1.25) : pieceSize; self.pieceAsset = self.attachAsset(assetId, { anchorX: 0.5, anchorY: 0.5, width: size, height: size, color: assetColor, shape: shape }); // Add a crown for promoted pawns if (self.promoted && self.type === 'queen') { // Overlay a small yellow ellipse as a "crown" var crown = LK.getAsset('crown_' + self.color, { anchorX: 0.5, anchorY: 0.5, y: -size * 0.3 }); self.addChild(crown); } }; // Move piece to board position (with optional animation) self.moveTo = function (bx, by, animate) { self.boardX = bx; self.boardY = by; var targetX = boardOriginX + bx * squareSize + squareSize / 2; var targetY = boardOriginY + by * squareSize + squareSize / 2; if (animate) { tween(self, { x: targetX, y: targetY }, { duration: 180, easing: tween.cubicOut }); } else { self.x = targetX; self.y = targetY; } }; return self; }); /**** * Initialize Game ****/ var game = new LK.Game({ backgroundColor: 0x222222 }); /**** * Game Code ****/ // --- Board and Piece Sizes --- // We need tween for piece movement animations // Board squares // White pieces // Black pieces // Crown for promoted pawn (queen) var boardSize = Math.min(2048, 2048); // Square board, fit width var squareSize = Math.floor(boardSize / 8); var pieceSize = Math.floor(squareSize * 0.8); var boardOriginX = Math.floor((2048 - squareSize * 8) / 2); var boardOriginY = Math.floor((2732 - squareSize * 8) / 2); // --- Game State --- var board = new ChessBoard(); game.addChild(board); board.reset(); var currentTurn = 'white'; // 'white' or 'black' var selectedPiece = null; var legalMoves = []; // Array of {x, y, special} var lastMove = null; // {from: {x,y}, to: {x,y}, piece, captured, special} var enPassantTarget = null; // {x, y} or null var halfmoveClock = 0; // For 50-move rule var fullmoveNumber = 1; var gameEnded = false; // --- GUI: Turn Display --- var turnText = new Text2('White to move', { size: 90, fill: "#fff" }); turnText.anchor.set(0.5, 0); LK.gui.top.addChild(turnText); // --- GUI: Timers --- // Each player starts with 10 minutes (600 seconds) var whiteTime = 600; var blackTime = 600; var whiteTimerText = new Text2('10:00', { size: 90, fill: "#fff" }); // Place white timer near bottom left, above white's side, but not in the bottom left 100x100 reserved area whiteTimerText.anchor.set(0, 1); // left aligned, bottom whiteTimerText.x = 320; // moved even further right whiteTimerText.y = LK.gui.height - 40; LK.gui.bottomLeft.addChild(whiteTimerText); var blackTimerText = new Text2('10:00', { size: 90, fill: "#fff" }); // Place black timer near top right, above black's side, but not in the top right 100x100 reserved area blackTimerText.anchor.set(1, 0); // right aligned, top blackTimerText.x = LK.gui.width - 40; // moved even further right (inward) blackTimerText.y = 0; LK.gui.topRight.addChild(blackTimerText); // Timer state var whiteTimerInterval = null; var blackTimerInterval = null; // Helper to format seconds as MM:SS function formatTime(secs) { var m = Math.floor(secs / 60); var s = Math.floor(secs % 60); return (m < 10 ? "0" : "") + m + ":" + (s < 10 ? "0" : "") + s; } // Start/stop timer helpers function startWhiteTimer() { if (whiteTimerInterval) LK.clearInterval(whiteTimerInterval); whiteTimerInterval = LK.setInterval(function () { if (gameEnded) return; whiteTime--; if (whiteTime < 0) whiteTime = 0; whiteTimerText.setText(formatTime(whiteTime)); if (whiteTime === 0) { gameEnded = true; LK.effects.flashScreen(0xff0000, 800); LK.showYouWin('Black wins on time!'); stopAllTimers(); } }, 1000); } function startBlackTimer() { if (blackTimerInterval) LK.clearInterval(blackTimerInterval); blackTimerInterval = LK.setInterval(function () { if (gameEnded) return; blackTime--; if (blackTime < 0) blackTime = 0; blackTimerText.setText(formatTime(blackTime)); if (blackTime === 0) { gameEnded = true; LK.effects.flashScreen(0xff0000, 800); LK.showYouWin('White wins on time!'); stopAllTimers(); } }, 1000); } function stopWhiteTimer() { if (whiteTimerInterval) { LK.clearInterval(whiteTimerInterval); whiteTimerInterval = null; } } function stopBlackTimer() { if (blackTimerInterval) { LK.clearInterval(blackTimerInterval); blackTimerInterval = null; } } function stopAllTimers() { stopWhiteTimer(); stopBlackTimer(); } // Start white's timer at game start startWhiteTimer(); whiteTimerText.setText(formatTime(whiteTime)); blackTimerText.setText(formatTime(blackTime)); // --- GUI: Promotion Popup --- var promotionPopup = null; // --- Helper Functions --- // Convert screen (x, y) to board (bx, by) function screenToBoard(x, y) { var bx = Math.floor((x - boardOriginX) / squareSize); var by = Math.floor((y - boardOriginY) / squareSize); if (bx < 0 || bx > 7 || by < 0 || by > 7) return null; return { x: bx, y: by }; } // Convert board (bx, by) to screen (x, y) (center of square) function boardToScreen(bx, by) { return { x: boardOriginX + bx * squareSize + squareSize / 2, y: boardOriginY + by * squareSize + squareSize / 2 }; } // Is (x, y) on the board? function isOnBoard(x, y) { return x >= 0 && x < 8 && y >= 0 && y < 8; } // Get all legal moves for a piece at (x, y) function getLegalMoves(piece, x, y, ignoreCheck) { var moves = []; if (!piece) return moves; var color = piece.color; var opp = color === 'white' ? 'black' : 'white'; // Directions for sliding pieces var dirs = { 'rook': [[1, 0], [-1, 0], [0, 1], [0, -1]], 'bishop': [[1, 1], [1, -1], [-1, 1], [-1, -1]], 'queen': [[1, 0], [-1, 0], [0, 1], [0, -1], [1, 1], [1, -1], [-1, 1], [-1, -1]] }; // Pawn moves if (piece.type === 'pawn') { var dir = color === 'white' ? -1 : 1; // Forward if (isOnBoard(x, y + dir) && !board.getPiece(x, y + dir)) { moves.push({ x: x, y: y + dir }); // Double move from start if (!piece.hasMoved && isOnBoard(x, y + 2 * dir) && !board.getPiece(x, y + 2 * dir)) { moves.push({ x: x, y: y + 2 * dir, special: 'double' }); } } // Captures for (var dx = -1; dx <= 1; dx += 2) { var tx = x + dx, ty = y + dir; if (isOnBoard(tx, ty)) { var target = board.getPiece(tx, ty); if (target && target.color === opp) { moves.push({ x: tx, y: ty }); } } } // En passant if (enPassantTarget) { if (Math.abs(enPassantTarget.x - x) === 1 && enPassantTarget.y === y + dir) { moves.push({ x: enPassantTarget.x, y: enPassantTarget.y, special: 'enpassant' }); } } } // Knight moves else if (piece.type === 'knight') { var knightDeltas = [[1, 2], [2, 1], [-1, 2], [-2, 1], [1, -2], [2, -1], [-1, -2], [-2, -1]]; for (var i = 0; i < knightDeltas.length; i++) { var dx = knightDeltas[i][0], dy = knightDeltas[i][1]; var tx = x + dx, ty = y + dy; if (isOnBoard(tx, ty)) { var target = board.getPiece(tx, ty); if (!target || target.color === opp) { moves.push({ x: tx, y: ty }); } } } } // King moves (including castling) else if (piece.type === 'king') { // Prevent infinite recursion: when ignoreCheck is true, do NOT generate king moves if (ignoreCheck) { // Do not generate king moves when ignoreCheck is true (used for attack detection) // This prevents infinite recursion between isInCheck and getLegalMoves } else { // Find the other king's position var otherKingPos = null; for (var yy = 0; yy < 8; yy++) { for (var xx = 0; xx < 8; xx++) { var p = board.getPiece(xx, yy); if (p && p.type === 'king' && p.color !== color) { otherKingPos = { x: xx, y: yy }; break; } } if (otherKingPos) break; } for (var dx = -1; dx <= 1; dx++) { for (var dy = -1; dy <= 1; dy++) { if (dx === 0 && dy === 0) continue; var tx = x + dx, ty = y + dy; if (isOnBoard(tx, ty)) { // Prevent moving within 3 squares horizontally or vertically of the other king var allow = true; if (otherKingPos) { if (Math.abs(tx - otherKingPos.x) <= 3 && ty === otherKingPos.y) allow = false; if (Math.abs(ty - otherKingPos.y) <= 3 && tx === otherKingPos.x) allow = false; if (tx === otherKingPos.x && ty === otherKingPos.y) allow = false; } var target = board.getPiece(tx, ty); if ((!target || target.color === opp) && allow) { moves.push({ x: tx, y: ty }); } } } } // Castling if (!piece.hasMoved && !isInCheck(color)) { // Kingside if (canCastle(color, 'kingside')) { // Check that castling does not violate the king distance rule var castleTx = x + 2; var castleTy = y; var allowCastle = true; if (otherKingPos) { if (Math.abs(castleTx - otherKingPos.x) <= 3 && castleTy === otherKingPos.y) allowCastle = false; if (Math.abs(castleTy - otherKingPos.y) <= 3 && castleTx === otherKingPos.x) allowCastle = false; if (castleTx === otherKingPos.x && castleTy === otherKingPos.y) allowCastle = false; } if (allowCastle) { moves.push({ x: castleTx, y: castleTy, special: 'castle_kingside' }); } } // Queenside if (canCastle(color, 'queenside')) { var castleTx = x - 2; var castleTy = y; var allowCastle = true; if (otherKingPos) { if (Math.abs(castleTx - otherKingPos.x) <= 3 && castleTy === otherKingPos.y) allowCastle = false; if (Math.abs(castleTy - otherKingPos.y) <= 3 && castleTx === otherKingPos.x) allowCastle = false; if (castleTx === otherKingPos.x && castleTy === otherKingPos.y) allowCastle = false; } if (allowCastle) { moves.push({ x: castleTx, y: castleTy, special: 'castle_queenside' }); } } } } } // Sliding pieces else if (piece.type === 'rook' || piece.type === 'bishop' || piece.type === 'queen') { var directions = dirs[piece.type]; for (var d = 0; d < directions.length; d++) { var dx = directions[d][0], dy = directions[d][1]; var tx = x + dx, ty = y + dy; while (isOnBoard(tx, ty)) { var target = board.getPiece(tx, ty); if (!target) { moves.push({ x: tx, y: ty }); } else { if (target.color === opp) { moves.push({ x: tx, y: ty }); } break; } tx += dx; ty += dy; } } } // Remove moves that leave king in check (unless ignoreCheck) if (!ignoreCheck) { var filtered = []; for (var i = 0; i < moves.length; i++) { var m = moves[i]; if (!wouldLeaveKingInCheck(piece, x, y, m.x, m.y, m.special)) { filtered.push(m); } } return filtered; } return moves; } // Would moving piece at (x, y) to (tx, ty) leave own king in check? function wouldLeaveKingInCheck(piece, x, y, tx, ty, special) { // Simulate move var origPiece = board.getPiece(tx, ty); var origEnPassant = enPassantTarget; var origHasMoved = piece.hasMoved; var origFrom = board.squares[y][x]; var origTo = board.squares[ty][tx]; // Remove captured piece if (special === 'enpassant') { var dir = piece.color === 'white' ? -1 : 1; var capY = ty - dir; var capPiece = board.getPiece(tx, capY); board.squares[capY][tx] = null; } board.squares[y][x] = null; board.squares[ty][tx] = piece; // For castling, move rook as well var rookMoved = null, rookFrom = null, rookTo = null; if (special === 'castle_kingside') { var row = piece.color === 'white' ? 7 : 0; rookFrom = board.getPiece(7, row); rookTo = board.getPiece(5, row); board.squares[row][7] = null; board.squares[row][5] = rookFrom; } if (special === 'castle_queenside') { var row = piece.color === 'white' ? 7 : 0; rookFrom = board.getPiece(0, row); rookTo = board.getPiece(3, row); board.squares[row][0] = null; board.squares[row][3] = rookFrom; } var inCheck = isInCheck(piece.color); // Undo move board.squares[y][x] = origFrom; board.squares[ty][tx] = origTo; if (special === 'enpassant') { var dir = piece.color === 'white' ? -1 : 1; var capY = ty - dir; board.squares[capY][tx] = origPiece; } if (special === 'castle_kingside') { var row = piece.color === 'white' ? 7 : 0; board.squares[row][7] = rookFrom; board.squares[row][5] = null; } if (special === 'castle_queenside') { var row = piece.color === 'white' ? 7 : 0; board.squares[row][0] = rookFrom; board.squares[row][3] = null; } piece.hasMoved = origHasMoved; enPassantTarget = origEnPassant; return inCheck; } // Is color's king in check? function isInCheck(color) { var kingPos = findKing(color); if (!kingPos) return false; var opp = color === 'white' ? 'black' : 'white'; for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p && p.color === opp) { var moves = getLegalMoves(p, x, y, true); for (var i = 0; i < moves.length; i++) { if (moves[i].x === kingPos.x && moves[i].y === kingPos.y) { return true; } } } } } return false; } // Find king of color function findKing(color) { for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p && p.type === 'king' && p.color === color) { return { x: x, y: y }; } } } return null; } // Can color castle on side ('kingside' or 'queenside')? function canCastle(color, side) { var row = color === 'white' ? 7 : 0; var king = board.getPiece(4, row); if (!king || king.hasMoved) return false; if (side === 'kingside') { var rook = board.getPiece(7, row); if (!rook || rook.type !== 'rook' || rook.hasMoved) return false; // Squares between must be empty if (board.getPiece(5, row) || board.getPiece(6, row)) return false; // Squares king passes through must not be attacked if (isAttacked(5, row, color) || isAttacked(6, row, color)) return false; return true; } if (side === 'queenside') { var rook = board.getPiece(0, row); if (!rook || rook.type !== 'rook' || rook.hasMoved) return false; if (board.getPiece(1, row) || board.getPiece(2, row) || board.getPiece(3, row)) return false; if (isAttacked(2, row, color) || isAttacked(3, row, color)) return false; return true; } return false; } // Is square (x, y) attacked by opponent of color? function isAttacked(x, y, color) { var opp = color === 'white' ? 'black' : 'white'; for (var yy = 0; yy < 8; yy++) { for (var xx = 0; xx < 8; xx++) { var p = board.getPiece(xx, yy); if (p && p.color === opp) { var moves = getLegalMoves(p, xx, yy, true); for (var i = 0; i < moves.length; i++) { if (moves[i].x === x && moves[i].y === y) { return true; } } } } } return false; } // Get all legal moves for color function getAllLegalMoves(color) { var moves = []; for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p && p.color === color) { var pieceMoves = getLegalMoves(p, x, y, false); for (var i = 0; i < pieceMoves.length; i++) { moves.push({ from: { x: x, y: y }, to: { x: pieceMoves[i].x, y: pieceMoves[i].y }, special: pieceMoves[i].special }); } } } } return moves; } // Is the game over? Returns {over: true/false, result: 'checkmate'/'stalemate'/'draw', winner: 'white'/'black'/null} function checkGameEnd() { var moves = getAllLegalMoves(currentTurn); if (moves.length === 0) { if (isInCheck(currentTurn)) { return { over: true, result: 'checkmate', winner: currentTurn === 'white' ? 'black' : 'white' }; } else { return { over: true, result: 'stalemate', winner: null }; } } // 50-move rule if (halfmoveClock >= 100) { return { over: true, result: 'draw', winner: null }; } // Insufficient material (only kings) var onlyKings = true; for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p && p.type !== 'king') onlyKings = false; } } if (onlyKings) { return { over: true, result: 'draw', winner: null }; } return { over: false }; } // --- Promotion Popup --- function showPromotionPopup(piece, toX, toY, onSelect) { if (promotionPopup) { promotionPopup.destroy(); promotionPopup = null; } promotionPopup = new Container(); var popupW = squareSize * 4; var popupH = squareSize * 1.2; var popupX = boardOriginX + (toX - 1) * squareSize; var popupY = boardOriginY + toY * squareSize - popupH / 2; var bg = LK.getAsset('promotion_bg', { anchorX: 0, anchorY: 0, x: 0, y: 0 }); bg.alpha = 0.95; promotionPopup.addChild(bg); var types = ['queen', 'rook', 'bishop', 'knight']; for (var i = 0; i < types.length; i++) { var t = types[i]; var tempPiece = new ChessPiece(); tempPiece.init(t, piece.color, 0, 0); tempPiece.x = squareSize * (i + 0.5); tempPiece.y = popupH / 2; tempPiece.pieceAsset.width = pieceSize * 0.9; tempPiece.pieceAsset.height = pieceSize * 0.9; (function (type) { tempPiece.down = function (x, y, obj) { if (promotionPopup) { onSelect(type); promotionPopup.destroy(); promotionPopup = null; } }; })(t); promotionPopup.addChild(tempPiece); } promotionPopup.x = popupX; promotionPopup.y = popupY; game.addChild(promotionPopup); } // --- Tap-to-select and tap-to-move --- // No dragging variables needed // --- Event Handlers --- // Handle touch/mouse down (tap) game.down = function (x, y, obj) { if (gameEnded) return; if (promotionPopup) return; // Block input during promotion var pos = screenToBoard(x, y); if (!pos) return; var p = board.getPiece(pos.x, pos.y); // If a piece is already selected and the tap is on a legal move, move there if (selectedPiece && legalMoves.length > 0) { for (var i = 0; i < legalMoves.length; i++) { var m = legalMoves[i]; if (m.x === pos.x && m.y === pos.y) { // Move piece doMove(selectedPiece, selectedPiece.boardX, selectedPiece.boardY, m.x, m.y, m.special); board.clearHighlights(); selectedPiece = null; legalMoves = []; return; } } } // If tap is on a piece of current turn, select it and show moves if (p && p.color === currentTurn) { selectedPiece = p; legalMoves = getLegalMoves(p, pos.x, pos.y, false); board.showHighlights(legalMoves); return; } // If tap is on empty square or not a legal move, clear selection board.clearHighlights(); selectedPiece = null; legalMoves = []; }; // No dragging, so move and up handlers are not needed game.move = function (x, y, obj) {}; game.up = function (x, y, obj) {}; // --- Move Execution --- function doMove(piece, fromX, fromY, toX, toY, special) { var opp = piece.color === 'white' ? 'black' : 'white'; var captured = null; var isPawnMove = piece.type === 'pawn'; var isCapture = false; // Handle en passant if (special === 'enpassant') { var dir = piece.color === 'white' ? -1 : 1; var capY = toY - dir; captured = board.getPiece(toX, capY); board.removePiece(toX, capY); isCapture = true; } // Handle castling if (special === 'castle_kingside') { var row = piece.color === 'white' ? 7 : 0; var rook = board.getPiece(7, row); board.setPiece(5, row, rook); board.setPiece(7, row, null); rook.moveTo(5, row, true); rook.hasMoved = true; } if (special === 'castle_queenside') { var row = piece.color === 'white' ? 7 : 0; var rook = board.getPiece(0, row); board.setPiece(3, row, rook); board.setPiece(0, row, null); rook.moveTo(3, row, true); rook.hasMoved = true; } // Remove captured piece var target = board.getPiece(toX, toY); if (target && target.color !== piece.color) { captured = target; board.removePiece(toX, toY); isCapture = true; } // Move piece board.setPiece(fromX, fromY, null); board.setPiece(toX, toY, piece); piece.moveTo(toX, toY, true); piece.hasMoved = true; // Play move sound LK.getSound('tas').play(); // Pawn promotion if (piece.type === 'pawn' && (toY === 0 || toY === 7)) { showPromotionPopup(piece, toX, toY, function (newType) { piece.type = newType; piece.promoted = newType === 'queen'; piece.init(newType, piece.color, toX, toY); endTurn(piece, fromX, fromY, toX, toY, special, captured, isPawnMove, isCapture); }); return; } endTurn(piece, fromX, fromY, toX, toY, special, captured, isPawnMove, isCapture); } function endTurn(piece, fromX, fromY, toX, toY, special, captured, isPawnMove, isCapture) { // Update en passant if (piece.type === 'pawn' && Math.abs(toY - fromY) === 2) { enPassantTarget = { x: toX, y: (fromY + toY) / 2 }; } else { enPassantTarget = null; } // Update halfmove clock if (isPawnMove || isCapture) { halfmoveClock = 0; } else { halfmoveClock++; } // Update fullmove number if (currentTurn === 'black') { fullmoveNumber++; } // Save last move lastMove = { from: { x: fromX, y: fromY }, to: { x: toX, y: toY }, piece: piece, captured: captured, special: special }; // Switch turn if (currentTurn === 'white') { stopWhiteTimer(); startBlackTimer(); currentTurn = 'black'; } else { stopBlackTimer(); startWhiteTimer(); currentTurn = 'white'; } turnText.setText((currentTurn === 'white' ? 'White' : 'Black') + ' to move'); // Check for game end var end = checkGameEnd(); if (end.over) { gameEnded = true; stopAllTimers(); if (end.result === 'checkmate') { LK.effects.flashScreen(0x00ff00, 800); if (end.winner === 'white') { LK.showYouWin('White wins by checkmate!'); } else if (end.winner === 'black') { LK.showYouWin('Black wins by checkmate!'); } } else if (end.result === 'stalemate') { LK.effects.flashScreen(0xffff00, 800); LK.showYouWin('Draw by stalemate'); } else if (end.result === 'draw') { LK.effects.flashScreen(0xffff00, 800); LK.showYouWin('Draw'); } return; } // --- AI Move for Black --- if (currentTurn === 'black' && !gameEnded) { // --- AI: If an important piece is threatened, try to move it away --- // Define important pieces var importantTypes = { queen: true, rook: true, bishop: true, knight: true }; // Find all black important pieces that are threatened var threatenedPieces = []; for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p && p.color === 'black' && importantTypes[p.type]) { if (isAttacked(x, y, 'black')) { threatenedPieces.push({ piece: p, x: x, y: y }); } } } } // If any important piece is threatened, try to move it to safety var aiMoves = getAllLegalMoves('black'); if (threatenedPieces.length > 0) { // Try to find a move that moves a threatened important piece to a safe square var safeMoves = []; for (var i = 0; i < threatenedPieces.length; i++) { var tp = threatenedPieces[i]; var moves = getLegalMoves(tp.piece, tp.x, tp.y, false); for (var j = 0; j < moves.length; j++) { var m = moves[j]; // Simulate the move var origX = tp.piece.boardX, origY = tp.piece.boardY; var origTo = board.getPiece(m.x, m.y); board.squares[tp.y][tp.x] = null; board.squares[m.y][m.x] = tp.piece; tp.piece.boardX = m.x; tp.piece.boardY = m.y; var stillAttacked = isAttacked(m.x, m.y, 'black'); // Undo board.squares[tp.y][tp.x] = tp.piece; board.squares[m.y][m.x] = origTo; tp.piece.boardX = origX; tp.piece.boardY = origY; if (!stillAttacked) { // Find the corresponding move in aiMoves for (var k = 0; k < aiMoves.length; k++) { var am = aiMoves[k]; if (am.from.x === tp.x && am.from.y === tp.y && am.to.x === m.x && am.to.y === m.y) { safeMoves.push(am); } } } } } // If there are safe moves, pick one randomly and play it if (safeMoves.length > 0) { var chosen = safeMoves[Math.floor(Math.random() * safeMoves.length)]; var piece = board.getPiece(chosen.from.x, chosen.from.y); var delay = 400; if (chosen.special === 'castle_kingside' || chosen.special === 'castle_queenside') delay = 900;else if (piece && piece.type === 'pawn' && (chosen.to.y === 0 || chosen.to.y === 7)) delay = 900;else if (board.getPiece(chosen.to.x, chosen.to.y)) delay = 700;else delay = 350; LK.setTimeout(function () { if (piece) { doMove(piece, chosen.from.x, chosen.from.y, chosen.to.x, chosen.to.y, chosen.special); } }, delay); return; } // If no safe move, fallback to normal AI below } // --- AI tries to mimic player's last move style --- // We'll try to find a move for black that is similar in type to the player's last move. // If not possible, fallback to best move as before. // Helper: get move type string var getMoveType = function getMoveType(move) { if (!move) return ''; if (move.special === 'castle_kingside' || move.special === 'castle_queenside') return 'castle'; if (move.special === 'enpassant') return 'enpassant'; if (move.piece && move.piece.type === 'pawn' && (move.to.y === 0 || move.to.y === 7)) return 'promotion'; if (move.captured) return 'capture'; if (move.piece && move.piece.type === 'pawn') return 'pawn'; if (move.piece && move.piece.type === 'knight') return 'knight'; if (move.piece && move.piece.type === 'bishop') return 'bishop'; if (move.piece && move.piece.type === 'rook') return 'rook'; if (move.piece && move.piece.type === 'queen') return 'queen'; if (move.piece && move.piece.type === 'king') return 'king'; return ''; }; // Helper: get move distance (for delay) var getMoveDistance = function getMoveDistance(move) { if (!move) return 1; var dx = Math.abs(move.from.x - move.to.x); var dy = Math.abs(move.from.y - move.to.y); return Math.max(dx, dy); }; // Get all legal moves for black // aiMoves already defined above if (aiMoves.length > 0) { // Use a simple minimax (depth 2) with material evaluation var evaluateBoard = function evaluateBoard() { var values = { pawn: 1, knight: 3, bishop: 3, rook: 5, queen: 9, king: 0 }; var score = 0; for (var y = 0; y < 8; y++) { for (var x = 0; x < 8; x++) { var p = board.getPiece(x, y); if (p) { var val = values[p.type] || 0; score += p.color === 'white' ? val : -val; } } } return score; }; var simulateMove = function simulateMove(move) { var piece = board.getPiece(move.from.x, move.from.y); var target = board.getPiece(move.to.x, move.to.y); var fromX = move.from.x, fromY = move.from.y, toX = move.to.x, toY = move.to.y; var special = move.special; var origHasMoved = piece.hasMoved; var origEnPassant = enPassantTarget; var captured = null; // Handle en passant if (special === 'enpassant') { var dir = piece.color === 'white' ? -1 : 1; var capY = toY - dir; captured = board.getPiece(toX, capY); board.squares[capY][toX] = null; } // Handle castling var rook = null, rookFrom = null, rookTo = null; if (special === 'castle_kingside') { var row = piece.color === 'white' ? 7 : 0; rook = board.getPiece(7, row); board.squares[row][5] = rook; board.squares[row][7] = null; } if (special === 'castle_queenside') { var row = piece.color === 'white' ? 7 : 0; rook = board.getPiece(0, row); board.squares[row][3] = rook; board.squares[row][0] = null; } // Remove captured piece if (target && target.color !== piece.color) { board.squares[toY][toX] = null; } // Move piece board.squares[fromY][fromX] = null; board.squares[toY][toX] = piece; piece.hasMoved = true; // Pawn promotion (always promote to queen for AI) var promoted = false; var oldType = piece.type; if (piece.type === 'pawn' && (toY === 0 || toY === 7)) { piece.type = 'queen'; promoted = true; } return function undo() { if (promoted) piece.type = oldType; // Undo move board.squares[fromY][fromX] = piece; board.squares[toY][toX] = target; piece.hasMoved = origHasMoved; // Undo en passant if (special === 'enpassant') { var dir = piece.color === 'white' ? -1 : 1; var capY = toY - dir; board.squares[capY][toX] = captured; } // Undo castling if (special === 'castle_kingside') { var row = piece.color === 'white' ? 7 : 0; board.squares[row][7] = board.squares[row][5]; board.squares[row][5] = null; } if (special === 'castle_queenside') { var row = piece.color === 'white' ? 7 : 0; board.squares[row][0] = board.squares[row][3]; board.squares[row][3] = null; } enPassantTarget = origEnPassant; }; }; // Try to mimic player's last move var mimicMove = null; var mimicType = getMoveType(lastMove); var mimicPieceType = lastMove && lastMove.piece ? lastMove.piece.type : null; var mimicCapture = lastMove && lastMove.captured ? true : false; var mimicSpecial = lastMove ? lastMove.special : null; // Find all black moves that match the last move's type var mimicCandidates = []; for (var i = 0; i < aiMoves.length; i++) { var move = aiMoves[i]; var piece = board.getPiece(move.from.x, move.from.y); if (!piece) continue; // Try to match special moves if (mimicSpecial && move.special === mimicSpecial) { mimicCandidates.push(move); continue; } // Try to match captures if (mimicCapture) { var target = board.getPiece(move.to.x, move.to.y); if (target && target.color === 'white') { mimicCandidates.push(move); continue; } } // Try to match piece type if (mimicPieceType && piece.type === mimicPieceType) { mimicCandidates.push(move); continue; } // Try to match move type if (getMoveType({ piece: piece, to: move.to, special: move.special, captured: board.getPiece(move.to.x, move.to.y) }) === mimicType) { mimicCandidates.push(move); continue; } } // If we have mimic candidates, pick the best among them using minimax var candidateMoves = mimicCandidates.length > 0 ? mimicCandidates : aiMoves; // Minimax, depth 2 (AI: black, Player: white) var bestScore = null; var bestMoves = []; for (var i = 0; i < candidateMoves.length; i++) { var move = candidateMoves[i]; var undo = simulateMove(move); // After black's move, get all white replies var whiteMoves = getAllLegalMoves('white'); var worstScore = null; if (whiteMoves.length === 0) { // If white has no moves, checkmate or stalemate if (isInCheck('white')) { // Black wins worstScore = -9999; } else { // Draw worstScore = 0; } } else { for (var j = 0; j < whiteMoves.length; j++) { var wmove = whiteMoves[j]; var wundo = simulateMove(wmove); var score = evaluateBoard(); if (worstScore === null || score > worstScore) { worstScore = score; } wundo(); } } undo(); // AI wants to minimize the score (since black is negative) if (bestScore === null || worstScore < bestScore) { bestScore = worstScore; bestMoves = [move]; } else if (worstScore === bestScore) { bestMoves.push(move); } } // Pick randomly among best moves var chosen = bestMoves[Math.floor(Math.random() * bestMoves.length)]; var piece = board.getPiece(chosen.from.x, chosen.from.y); // Add a delay based on move complexity (longer for captures, promotions, castling, or long moves) var delay = 400; if (chosen.special === 'castle_kingside' || chosen.special === 'castle_queenside') delay = 900;else if (piece && piece.type === 'pawn' && (chosen.to.y === 0 || chosen.to.y === 7)) delay = 900;else if (board.getPiece(chosen.to.x, chosen.to.y)) delay = 700;else delay = 350 + 80 * getMoveDistance(chosen); LK.setTimeout(function () { if (piece) { doMove(piece, chosen.from.x, chosen.from.y, chosen.to.x, chosen.to.y, chosen.special); } }, delay); } } } // --- Game Update --- game.update = function () { // No per-frame logic needed for chess }; // --- Reset on Game Over --- LK.on('gameover', function () { // Reset everything board.reset(); currentTurn = 'white'; selectedPiece = null; legalMoves = []; lastMove = null; enPassantTarget = null; halfmoveClock = 0; fullmoveNumber = 1; gameEnded = false; turnText.setText('White to move'); if (promotionPopup) { promotionPopup.destroy(); promotionPopup = null; } // Reset timers stopAllTimers(); whiteTime = 600; blackTime = 600; whiteTimerText.setText(formatTime(whiteTime)); blackTimerText.setText(formatTime(blackTime)); startWhiteTimer(); });