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         // Finally filter impossible moves
  99         const mirrorSide = (Object.keys(VariantRules.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
 100         return moves.filter(m => {
 101             if (m.appear.length == 2) //castle
 102             {
 103                 // If appear[i] not in vanish array, then must be empty square on other board
 104                 m.appear.forEach(psq => {
 105                     if (this.board[psq.x][psq.y] != VariantRules.EMPTY &&
 106                         ![m.vanish[0].y,m.vanish[1].y].includes(psq.y))
 107                     {
 108                         return false;
 109                     }
 110                 });
 111             }
 112             else if (this.board[m.end.x][m.end.y] != VariantRules.EMPTY)
 113             {
 114                 // Attempt to capture
 115                 const piece = this.getPiece(m.end.x,m.end.y);
 116                 if ((mirrorSide==1 && Object.keys(VariantRules.ALICE_PIECES).includes(piece))
 117                     || (mirrorSide==2 && Object.keys(VariantRules.ALICE_CODES).includes(piece)))
 118                 {
 119                     return false;
 120                 }
 121             }
 122             // If the move is computed on board1, m.appear change for Alice pieces.
 123             if (mirrorSide==1)
 124             {
 125                 m.appear.forEach(psq => { //forEach: castling taken into account
 126                     psq.p = VariantRules.ALICE_CODES[psq.p]; //goto board2
 127                 });
 128             }
 129             else //move on board2: mark vanishing pieces as Alice
 130             {
 131                 m.vanish.forEach(psq => {
 132                     psq.p = VariantRules.ALICE_CODES[psq.p];
 133                 });
 134             }
 135             // Fix en-passant captures
 136             if (m.vanish.length == 2 && this.board[m.end.x][m.end.y] == VariantRules.EMPTY)
 137                 m.vanish[1].c = this.getOppCol(this.getColor(x,y));
 138             return true;
 139         });
 140     }
 141
 142     underCheck(move)
 143     {
 144         const color = this.turn;
 145         this.play(move);
 146         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 147         let saveBoard = this.board;
 148         this.board = sideBoard;
 149         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
 150         this.board = saveBoard;
 151         this.undo(move);
 152         return res;
 153     }
 154
 155     getCheckSquares(move)
 156     {
 157         this.play(move);
 158         const color = this.turn; //opponent
 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             ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ]
 164             : [ ];
 165         this.board = saveBoard;
 166         this.undo(move);
 167         return res;
 168     }
 169
 170     updateVariables(move)
 171     {
 172         super.updateVariables(move); //standard king
 173         const piece = this.getPiece(move.start.x,move.start.y);
 174         const c = this.getColor(move.start.x,move.start.y);
 175         // "l" = Alice king
 176         if (piece == "l")
 177         {
 178             this.kingPos[c][0] = move.appear[0].x;
 179             this.kingPos[c][1] = move.appear[0].y;
 180             this.castleFlags[c] = [false,false];
 181         }
 182     }
 183
 184     unupdateVariables(move)
 185     {
 186         super.unupdateVariables(move);
 187         const c = this.getColor(move.start.x,move.start.y);
 188         if (this.getPiece(move.start.x,move.start.y) == "l")
 189             this.kingPos[c] = [move.start.x, move.start.y];
 190     }
 191
 192     getNotation(move)
 193     {
 194         if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING)
 195         {
 196             if (move.end.y < move.start.y)
 197                 return "0-0-0";
 198             else
 199                 return "0-0";
 200         }
 201
 202         const finalSquare =
 203             String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
 204         const piece = this.getPiece(move.start.x, move.start.y);
 205
 206         // Piece or pawn movement
 207         let notation = piece.toUpperCase() +
 208             (move.vanish.length > move.appear.length ? "x" : "") + finalSquare;
 209         if (['s','p'].includes(piece) && !['s','p'].includes(move.appear[0].p))
 210         {
 211             // Promotion
 212             notation += "=" + move.appear[0].p.toUpperCase();
 213         }
 214         return notation;
 215     }
 216
 217     checkGameEnd()
 218     {
 219         const color = this.turn;
 220         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 221         let saveBoard = this.board;
 222         this.board = sideBoard;
 223         let res = "*";
 224         if (!this.isAttacked(this.kingPos[color], this.getOppCol(color)))
 225             res = "1/2";
 226         else
 227             res = (color == "w" ? "0-1" : "1-0");
 228         this.board = saveBoard;
 229         return res;
 230     }
 231
 232     static get VALUES() {
 233         return {
 234             'p': 1,
 235             's': 1,
 236             'r': 5,
 237             'u': 5,
 238             'n': 3,
 239             'o': 3,
 240             'b': 3,
 241             'c': 3,
 242             'q': 9,
 243             't': 9,
 244             'k': 1000,
 245             'l': 1000
 246         };
 247     }
 248 }