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     getBoardOfPiece([x,y])
  32     {
  33         const V = VariantRules;
  34         // Build board where the piece is
  35         const mirrorSide = (Object.keys(V.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
  36         // Build corresponding board from complete board
  37         const [sizeX,sizeY] = V.size;
  38         let sideBoard = doubleArray(sizeX, sizeY, "");
  39         for (let i=0; i<sizeX; i++)
  40         {
  41             for (let j=0; j<sizeY; j++)
  42             {
  43                 const piece = this.getPiece(i,j);
  44                 if (mirrorSide==1 && Object.keys(V.ALICE_CODES).includes(piece))
  45                     sideBoard[i][j] = this.board[i][j];
  46                 else if (mirrorSide==2 && Object.keys(V.ALICE_PIECES).includes(piece))
  47                     sideBoard[i][j] = this.getColor(i,j) + V.ALICE_PIECES[piece];
  48             }
  49         }
  50         return sideBoard;
  51     }
  52
  53     // NOTE: castle & enPassant https://www.chessvariants.com/other.dir/alice.html
  54     // --> Should be OK as is.
  55     getPotentialMovesFrom([x,y])
  56     {
  57         let sideBoard = this.getBoardOfPiece([x,y]);
  58
  59         // Search valid moves on sideBoard
  60         let saveBoard = this.board;
  61         this.board = sideBoard;
  62         let moves = super.getPotentialMovesFrom([x,y]);
  63         this.board = saveBoard;
  64
  65         // Finally filter impossible moves
  66         const mirrorSide = (Object.keys(VariantRules.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
  67         return moves.filter(m => {
  68             if (m.appear.length == 2) //castle
  69             {
  70                 // If appear[i] not in vanish array, then must be empty square on other board
  71                 m.appear.forEach(psq => {
  72                     if (this.board[psq.x][psq.y] != VariantRules.EMPTY &&
  73                         ![m.vanish[0].y,m.vanish[1].y].includes(psq.y))
  74                     {
  75                         return false;
  76                     }
  77                 });
  78             }
  79             else if (this.board[m.end.x][m.end.y] != VariantRules.EMPTY)
  80             {
  81                 // Attempt to capture
  82                 const piece = this.getPiece(m.end.x,m.end.y);
  83                 if ((mirrorSide==1 && Object.keys(VariantRules.ALICE_PIECES).includes(piece))
  84                     || (mirrorSide==2 && Object.keys(VariantRules.ALICE_CODES).includes(piece)))
  85                 {
  86                     return false;
  87                 }
  88             }
  89             // If the move is computed on board1, m.appear change for Alice pieces.
  90             if (mirrorSide==1)
  91             {
  92                 m.appear.forEach(psq => { //forEach: castling taken into account
  93                     psq.p = VariantRules.ALICE_CODES[psq.p]; //goto board2
  94                 });
  95             }
  96             else //move on board2: mark vanishing piece as Alice
  97                 m.vanish[0].p = VariantRules.ALICE_CODES[m.vanish[0].p]
  98             return true;
  99         });
 100     }
 101
 102     underCheck(move)
 103     {
 104         const color = this.turn;
 105         this.play(move);
 106         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 107         let saveBoard = this.board;
 108         this.board = sideBoard;
 109         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
 110         this.board = saveBoard;
 111         this.undo(move);
 112         return res;
 113     }
 114
 115     getCheckSquares(move)
 116     {
 117         this.play(move);
 118         const color = this.turn; //opponent
 119         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 120         let saveBoard = this.board;
 121         this.board = sideBoard;
 122         let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
 123             ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ]
 124             : [ ];
 125         this.board = saveBoard;
 126         this.undo(move);
 127         return res;
 128     }
 129
 130     getNotation(move)
 131     {
 132         if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING)
 133         {
 134             if (move.end.y < move.start.y)
 135                 return "0-0-0";
 136             else
 137                 return "0-0";
 138         }
 139
 140         const finalSquare =
 141             String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
 142         const piece = this.getPiece(move.start.x, move.start.y);
 143
 144         // Piece or pawn movement
 145         let notation = piece.toUpperCase() +
 146             (move.vanish.length > move.appear.length ? "x" : "") + finalSquare;
 147         if (['s','p'].includes(piece) && !['s','p'].includes(move.appear[0].p))
 148         {
 149             // Promotion
 150             notation += "=" + move.appear[0].p.toUpperCase();
 151         }
 152         return notation;
 153     }
 154
 155     checkGameEnd()
 156     {
 157         const color = this.turn;
 158         let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
 159         let saveBoard = this.board;
 160         this.board = sideBoard;
 161         let res = "*";
 162         if (!this.isAttacked(this.kingPos[color], this.getOppCol(color)))
 163             res = "1/2";
 164         else
 165             res = (color == "w" ? "0-1" : "1-0");
 166         this.board = saveBoard;
 167         return res;
 168     }
 169 }