public/javascripts/variants/Alice.js

   1 class AliceRules extends ChessRules
   2 {
   3     static get ALICE_PIECES()
   4     {
   5         return {
   6             's': 'p',
   7             't': 'q',
   8             'u': 'r',
   9             'c': 'b',
  10             'o': 'n',
  11             'l': 'k',
  12         };
  13     }
  14     static get ALICE_CODES()
  15     {
  16         return {
  17             'p': 's',
  18             'q': 't',
  19             'r': 'u',
  20             'b': 'c',
  21             'n': 'o',
  22             'k': 'l',
  23         };
  24     }
  25
  26     static getPpath(b)
  27     {
  28         return (Object.keys(this.ALICE_PIECES).includes(b[1]) ? "Alice/" : "") + b;
  29     }
  30
  31     initVariables(fen)
  32     {
  33         super.initVariables(fen);
  34         const fenParts = fen.split(" ");
  35         const position = fenParts[0].split("/");
  36         if (this.kingPos["w"][0] < 0 || this.kingPos["b"][0] < 0)
  37         {
  38             // INIT_COL_XXX won't be used, so no need to set them for Alice kings
  39             for (let i=0; i<position.length; i++)
  40             {
  41                 let k = 0; //column index on board
  42                 for (let j=0; j<position[i].length; j++)
  43                 {
  44                     switch (position[i].charAt(j))
  45                     {
  46                         case 'l':
  47                             this.kingPos['b'] = [i,k];
  48                             break;
  49                         case 'L':
  50                             this.kingPos['w'] = [i,k];
  51                             break;
  52                         default:
  53                             let num = parseInt(position[i].charAt(j));
  54                             if (!isNaN(num))
  55                                 k += (num-1);
  56                     }
  57                     k++;
  58                 }
  59             }
  60         }
  61     }
  62
  63     // Build board of the given (mirror)side
  64     getSideBoard(mirrorSide)
  65     {
  66         const V = VariantRules;
  67         // Build corresponding board from complete board
  68         const [sizeX,sizeY] = V.size;
  69         let sideBoard = doubleArray(sizeX, sizeY, "");
  70         for (let i=0; i<sizeX; i++)
  71         {
  72             for (let j=0; j<sizeY; j++)
  73             {
  74                 const piece = this.getPiece(i,j);
  75                 if (mirrorSide==1 && Object.keys(V.ALICE_CODES).includes(piece))
  76                     sideBoard[i][j] = this.board[i][j];
  77                 else if (mirrorSide==2 && Object.keys(V.ALICE_PIECES).includes(piece))
  78                     sideBoard[i][j] = this.getColor(i,j) + V.ALICE_PIECES[piece];
  79             }
  80         }
  81         return sideBoard;
  82     }
  83
  84     // NOTE: castle & enPassant https://www.chessvariants.com/other.dir/alice.html
  85     // --> Should be OK as is.
  86     getPotentialMovesFrom([x,y], sideBoard)
  87     {
  88         const pieces = Object.keys(VariantRules.ALICE_CODES);
  89         const codes = Object.keys(VariantRules.ALICE_PIECES);
  90         const mirrorSide = (pieces.includes(this.getPiece(x,y)) ? 1 : 2);
  91
  92         // Search valid moves on sideBoard
  93         let saveBoard = this.board;
  94         this.board = sideBoard || this.getSideBoard(mirrorSide);
  95         let moves = super.getPotentialMovesFrom([x,y]);
  96         this.board = saveBoard;
  97
  98         // Finally filter impossible moves
  99         let res = moves.filter(m => {
 100             if (m.appear.length == 2) //castle
 101             {
 102                 // If appear[i] not in vanish array, then must be empty square on other board
 103                 m.appear.forEach(psq => {
 104                     if (this.board[psq.x][psq.y] != VariantRules.EMPTY &&
 105                         ![m.vanish[0].y,m.vanish[1].y].includes(psq.y))
 106                     {
 107                         return false;
 108                     }
 109                 });
 110             }
 111             else if (this.board[m.end.x][m.end.y] != VariantRules.EMPTY)
 112             {
 113                 // Attempt to capture
 114                 const piece = this.getPiece(m.end.x,m.end.y);
 115                 if ((mirrorSide==1 && codes.includes(piece))
 116                     || (mirrorSide==2 && pieces.includes(piece)))
 117                 {
 118                     return false;
 119                 }
 120             }
 121             // If the move is computed on board1, m.appear change for Alice pieces.
 122             if (mirrorSide==1)
 123             {
 124                 m.appear.forEach(psq => { //forEach: castling taken into account
 125                     psq.p = VariantRules.ALICE_CODES[psq.p]; //goto board2
 126                 });
 127             }
 128             else //move on board2: mark vanishing pieces as Alice
 129             {
 130                 m.vanish.forEach(psq => {
 131                     psq.p = VariantRules.ALICE_CODES[psq.p];
 132                 });
 133             }
 134             // Fix en-passant captures
 135             if (m.vanish[0].p == VariantRules.PAWN
 136                 && m.vanish.length == 2 && this.board[m.end.x][m.end.y] == VariantRules.EMPTY)
 137             {
 138                 m.vanish[1].c = this.getOppCol(this.getColor(x,y));
 139                 // In the special case of en-passant, if
 140                 //  - board1 takes board2 : vanish[1] --> Alice
 141                 //  - board2 takes board1 : vanish[1] --> normal
 142                 let van = m.vanish[1];
 143                 if (mirrorSide==1 && codes.includes(this.getPiece(van.x,van.y)))
 144                     van.p = VariantRules.ALICE_CODES[van.p];
 145                 else if (mirrorSide==2 && pieces.includes(this.getPiece(van.x,van.y)))
 146                     van.p = VariantRules.ALICE_PIECES[van.p];
 147             }
 148             return true;
 149         });
 150         return res;
 151     }
 152
 153     // NOTE: alternative implementation, recompute sideBoard's in this function
 154     filterValid(moves, sideBoard)
 155     {
 156         if (moves.length == 0)
 157             return [];
 158         const pieces = Object.keys(VariantRules.ALICE_CODES);
 159         return moves.filter(m => {
 160             // WARNING: for underCheck(), we need the sideBoard of the arrival world !
 161             const mirrorSide = (pieces.includes(this.getPiece(m.start.x,m.start.y)) ? 2 : 1);
 162             return !this.underCheck(m, !!sideBoard ? sideBoard[mirrorSide-1] : null);
 163         });
 164     }
 165
 166     getAllValidMoves()
 167     {
 168         const color = this.turn;
 169         const oppCol = this.getOppCol(color);
 170         var potentialMoves = [];
 171         let [sizeX,sizeY] = VariantRules.size;
 172         let sideBoard = [this.getSideBoard(1), this.getSideBoard(2)];
 173         for (var i=0; i<sizeX; i++)
 174         {
 175             for (var j=0; j<sizeY; j++)
 176             {
 177                 if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) == color)
 178                 {
 179                     const mirrorSide =
 180                         (Object.keys(VariantRules.ALICE_CODES).includes(this.getPiece(i,j)) ? 1 : 2);
 181                     Array.prototype.push.apply(potentialMoves,
 182                         this.getPotentialMovesFrom([i,j], sideBoard[mirrorSide-1]));
 183                 }
 184             }
 185         }
 186         return this.filterValid(potentialMoves, sideBoard);
 187     }
 188
 189     underCheck(move, sideBoard)
 190     {
 191         const color = this.turn;
 192         this.play(move);
 193         const pieces = Object.keys(VariantRules.ALICE_CODES);
 194         const kp = this.kingPos[color];
 195         const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
 196         let saveBoard = this.board;
 197         this.board = sideBoard || this.getSideBoard(mirrorSide);
 198         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
 199         this.board = saveBoard;
 200         this.undo(move);
 201         return res;
 202     }
 203
 204     getCheckSquares(move)
 205     {
 206         this.play(move);
 207         const color = this.turn; //opponent
 208         const pieces = Object.keys(VariantRules.ALICE_CODES);
 209         const kp = this.kingPos[color];
 210         const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
 211         let sideBoard = this.getSideBoard(mirrorSide);
 212         let saveBoard = this.board;
 213         this.board = sideBoard;
 214         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
 215             ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ]
 216             : [ ];
 217         this.board = saveBoard;
 218         this.undo(move);
 219         return res;
 220     }
 221
 222     updateVariables(move)
 223     {
 224         super.updateVariables(move); //standard king
 225         const piece = this.getPiece(move.start.x,move.start.y);
 226         const c = this.getColor(move.start.x,move.start.y);
 227         // "l" = Alice king
 228         if (piece == "l")
 229         {
 230             this.kingPos[c][0] = move.appear[0].x;
 231             this.kingPos[c][1] = move.appear[0].y;
 232             this.castleFlags[c] = [false,false];
 233         }
 234     }
 235
 236     unupdateVariables(move)
 237     {
 238         super.unupdateVariables(move);
 239         const c = this.getColor(move.start.x,move.start.y);
 240         if (this.getPiece(move.start.x,move.start.y) == "l")
 241             this.kingPos[c] = [move.start.x, move.start.y];
 242     }
 243
 244     checkGameEnd()
 245     {
 246         const pieces = Object.keys(VariantRules.ALICE_CODES);
 247         const color = this.turn;
 248         const kp = this.kingPos[color];
 249         const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
 250         let sideBoard = this.getSideBoard(mirrorSide);
 251         let saveBoard = this.board;
 252         this.board = sideBoard;
 253         let res = "*";
 254         if (!this.isAttacked(this.kingPos[color], this.getOppCol(color)))
 255             res = "1/2";
 256         else
 257             res = (color == "w" ? "0-1" : "1-0");
 258         this.board = saveBoard;
 259         return res;
 260     }
 261
 262     static get VALUES() {
 263         return {
 264             'p': 1,
 265             's': 1,
 266             'r': 5,
 267             'u': 5,
 268             'n': 3,
 269             'o': 3,
 270             'b': 3,
 271             'c': 3,
 272             'q': 9,
 273             't': 9,
 274             'k': 1000,
 275             'l': 1000
 276         };
 277     }
 278
 279     getNotation(move)
 280     {
 281         if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING)
 282         {
 283             if (move.end.y < move.start.y)
 284                 return "0-0-0";
 285             else
 286                 return "0-0";
 287         }
 288
 289         const finalSquare =
 290             String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
 291         const piece = this.getPiece(move.start.x, move.start.y);
 292
 293         const captureMark = (move.vanish.length > move.appear.length ? "x" : "");
 294         let pawnMark = "";
 295         if (["p","s"].includes(piece) && captureMark.length == 1)
 296             pawnMark = String.fromCharCode(97 + move.start.y); //start column
 297
 298         // Piece or pawn movement
 299         let notation = piece.toUpperCase() + pawnMark + captureMark + finalSquare;
 300         if (['s','p'].includes(piece) && !['s','p'].includes(move.appear[0].p))
 301         {
 302             // Promotion
 303             notation += "=" + move.appear[0].p.toUpperCase();
 304         }
 305         return notation;
 306     }
 307 }