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     getBoardOfPiece([x,y])
  64     {
  65         const V = VariantRules;
  66         // Build board where the piece is
  67         const mirrorSide = (Object.keys(V.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
  68         // Build corresponding board from complete board
  69         const [sizeX,sizeY] = V.size;
  70         let sideBoard = doubleArray(sizeX, sizeY, "");
  71         for (let i=0; i<sizeX; i++)
  72         {
  73             for (let j=0; j<sizeY; j++)
  74             {
  75                 const piece = this.getPiece(i,j);
  76                 if (mirrorSide==1 && Object.keys(V.ALICE_CODES).includes(piece))
  77                     sideBoard[i][j] = this.board[i][j];
  78                 else if (mirrorSide==2 && Object.keys(V.ALICE_PIECES).includes(piece))
  79                     sideBoard[i][j] = this.getColor(i,j) + V.ALICE_PIECES[piece];
  80             }
  81         }
  82         return sideBoard;
  83     }
  84
  85     // TODO: move board building one level up (findAllMoves()) to avoid re-building at every piece...
  86     // NOTE: castle & enPassant https://www.chessvariants.com/other.dir/alice.html
  87     // --> Should be OK as is.
  88     getPotentialMovesFrom([x,y])
  89     {
  90         let sideBoard = this.getBoardOfPiece([x,y]);
  91
  92         // Search valid moves on sideBoard
  93         let saveBoard = this.board;
  94         this.board = sideBoard;
  95         let moves = super.getPotentialMovesFrom([x,y]);
  96         this.board = saveBoard;
  97
  98         const pieces = Object.keys(VariantRules.ALICE_CODES);
  99         const codes = Object.keys(VariantRules.ALICE_PIECES);
 100
 101         // Finally filter impossible moves
 102         const mirrorSide = (pieces.includes(this.getPiece(x,y)) ? 1 : 2);
 103         return moves.filter(m => {
 104             if (m.appear.length == 2) //castle
 105             {
 106                 // If appear[i] not in vanish array, then must be empty square on other board
 107                 m.appear.forEach(psq => {
 108                     if (this.board[psq.x][psq.y] != VariantRules.EMPTY &&
 109                         ![m.vanish[0].y,m.vanish[1].y].includes(psq.y))
 110                     {
 111                         return false;
 112                     }
 113                 });
 114             }
 115             else if (this.board[m.end.x][m.end.y] != VariantRules.EMPTY)
 116             {
 117                 // Attempt to capture
 118                 const piece = this.getPiece(m.end.x,m.end.y);
 119                 if ((mirrorSide==1 && codes.includes(piece))
 120                     || (mirrorSide==2 && pieces.includes(piece)))
 121                 {
 122                     return false;
 123                 }
 124             }
 125             // If the move is computed on board1, m.appear change for Alice pieces.
 126             if (mirrorSide==1)
 127             {
 128                 m.appear.forEach(psq => { //forEach: castling taken into account
 129                     psq.p = VariantRules.ALICE_CODES[psq.p]; //goto board2
 130                 });
 131             }
 132             else //move on board2: mark vanishing pieces as Alice
 133             {
 134                 m.vanish.forEach(psq => {
 135                     psq.p = VariantRules.ALICE_CODES[psq.p];
 136                 });
 137             }
 138             // Fix en-passant captures
 139             if (m.vanish.length == 2 && this.board[m.end.x][m.end.y] == VariantRules.EMPTY)
 140             {
 141                 m.vanish[1].c = this.getOppCol(this.getColor(x,y));
 142                 // In the special case of en-passant, if
 143                 //  - board1 takes board2 : vanish[1] --> Alice
 144                 //  - board2 takes board1 : vanish[1] --> normal
 145                 let van = m.vanish[1];
 146                 if (mirrorSide==1 && codes.includes(this.getPiece(van.x,van.y)))
 147                     van.p = VariantRules.ALICE_CODES[van.p];
 148                 else if (mirrorSide==2 && pieces.includes(this.getPiece(van.x,van.y)))
 149                     van.p = VariantRules.ALICE_PIECES[van.p];
 150             }
 151             return true;
 152         });
 153     }
 154
 155     underCheck(move)
 156     {
 157         const color = this.turn;
 158         this.play(move);
 159         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 160         let saveBoard = this.board;
 161         this.board = sideBoard;
 162         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
 163         this.board = saveBoard;
 164         this.undo(move);
 165         return res;
 166     }
 167
 168     getCheckSquares(move)
 169     {
 170         this.play(move);
 171         const color = this.turn; //opponent
 172         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 173         let saveBoard = this.board;
 174         this.board = sideBoard;
 175         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
 176             ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ]
 177             : [ ];
 178         this.board = saveBoard;
 179         this.undo(move);
 180         return res;
 181     }
 182
 183     updateVariables(move)
 184     {
 185         super.updateVariables(move); //standard king
 186         const piece = this.getPiece(move.start.x,move.start.y);
 187         const c = this.getColor(move.start.x,move.start.y);
 188         // "l" = Alice king
 189         if (piece == "l")
 190         {
 191             this.kingPos[c][0] = move.appear[0].x;
 192             this.kingPos[c][1] = move.appear[0].y;
 193             this.castleFlags[c] = [false,false];
 194         }
 195     }
 196
 197     unupdateVariables(move)
 198     {
 199         super.unupdateVariables(move);
 200         const c = this.getColor(move.start.x,move.start.y);
 201         if (this.getPiece(move.start.x,move.start.y) == "l")
 202             this.kingPos[c] = [move.start.x, move.start.y];
 203     }
 204
 205     checkGameEnd()
 206     {
 207         const color = this.turn;
 208         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 209         let saveBoard = this.board;
 210         this.board = sideBoard;
 211         let res = "*";
 212         if (!this.isAttacked(this.kingPos[color], this.getOppCol(color)))
 213             res = "1/2";
 214         else
 215             res = (color == "w" ? "0-1" : "1-0");
 216         this.board = saveBoard;
 217         return res;
 218     }
 219
 220     static get VALUES() {
 221         return {
 222             'p': 1,
 223             's': 1,
 224             'r': 5,
 225             'u': 5,
 226             'n': 3,
 227             'o': 3,
 228             'b': 3,
 229             'c': 3,
 230             'q': 9,
 231             't': 9,
 232             'k': 1000,
 233             'l': 1000
 234         };
 235     }
 236
 237     getNotation(move)
 238     {
 239         if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING)
 240         {
 241             if (move.end.y < move.start.y)
 242                 return "0-0-0";
 243             else
 244                 return "0-0";
 245         }
 246
 247         const finalSquare =
 248             String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
 249         const piece = this.getPiece(move.start.x, move.start.y);
 250
 251         const captureMark = (move.vanish.length > move.appear.length ? "x" : "");
 252         let pawnMark = "";
 253         if (["p","s"].includes(piece) && captureMark.length == 1)
 254             pawnMark = String.fromCharCode(97 + move.start.y); //start column
 255
 256         // Piece or pawn movement
 257         let notation = piece.toUpperCase() + pawnMark + captureMark + finalSquare;
 258         if (['s','p'].includes(piece) && !['s','p'].includes(move.appear[0].p))
 259         {
 260             // Promotion
 261             notation += "=" + move.appear[0].p.toUpperCase();
 262         }
 263         return notation;
 264     }
 265 }