public/javascripts/variants/Atomic.js

   1 class AtomicRules extends ChessRules
   2 {
   3     getPotentialMovesFrom([x,y])
   4     {
   5         let moves = super.getPotentialMovesFrom([x,y]);
   6
   7         // Handle explosions
   8         moves.forEach(m => {
   9             if (m.vanish.length > 1 && m.appear.length <= 1) //avoid castles
  10             {
  11                 // Explosion! TODO: drop moves which explode our king here
  12                 let steps = [ [-1,-1],[-1,0],[-1,1],[0,-1],[0,1],[1,-1],[1,0],[1,1] ];
  13                 for (let step of steps)
  14                 {
  15                     let x = m.end.x + step[0];
  16                     let y = m.end.y + step[1];
  17                     if (x>=0 && x<8 && y>=0 && y<8 && this.board[x][y] != VariantRules.EMPTY
  18                         && this.getPiece(x,y) != VariantRules.PAWN)
  19                     {
  20                         m.vanish.push(new PiPo({p:this.getPiece(x,y),c:this.getColor(x,y),x:x,y:y}));
  21                     }
  22                 }
  23                 m.end = {x:m.appear[0].x, y:m.appear[0].y};
  24                 m.appear.pop(); //Nothin appears in this case
  25             }
  26         });
  27
  28         return moves;
  29     }
  30
  31     getPotentialKingMoves([x,y])
  32     {
  33         const V = VariantRules;
  34         // King cannot capture:
  35         let moves = [];
  36         let [sizeX,sizeY] = V.size;
  37         const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
  38         for (let step of steps)
  39         {
  40             var i = x + step[0];
  41             var j = y + step[1];
  42             if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] == VariantRules.EMPTY)
  43                 moves.push(this.getBasicMove([x,y], [i,j]));
  44         }
  45         return moves.concat(this.getCastleMoves([x,y]));
  46     }
  47
  48     isAttacked(sq, colors)
  49     {
  50         if (this.getPiece(sq[0],sq[1]) == VariantRules.KING && this.isAttackedByKing(sq, colors))
  51             return false; //king cannot take...
  52         return (this.isAttackedByPawn(sq, colors)
  53             || this.isAttackedByRook(sq, colors)
  54             || this.isAttackedByKnight(sq, colors)
  55             || this.isAttackedByBishop(sq, colors)
  56             || this.isAttackedByQueen(sq, colors));
  57     }
  58
  59     updateVariables(move)
  60     {
  61         super.updateVariables(move);
  62         const color = this.getColor(move.start.x,move.start.y);
  63         // Next condition to avoid conflicts with harmless castle moves
  64         if (color != this.getColor(move.end.x,move.end.y)
  65             && this.board[move.end.x][move.end.y] != VariantRules.EMPTY)
  66         {
  67             const firstRank = {"w": 7, "b": 0};
  68             for (let c of ["w","b"])
  69             {
  70                 // Did we explode king of color c ? (TODO: remove move earlier)
  71                 if (Math.abs(this.kingPos[c][0]-move.end.x) <= 1
  72                     && Math.abs(this.kingPos[c][1]-move.end.y) <= 1)
  73                 {
  74                     this.kingPos[c] = [-1,-1];
  75                     this.castleFlags[c] = [false,false];
  76                 }
  77                 else
  78                 {
  79                     // Now check if init rook(s) exploded
  80                     if (Math.abs(move.end.x-firstRank[c]) <= 1)
  81                     {
  82                         if (Math.abs(move.end.y-this.INIT_COL_ROOK[c][0]) <= 1)
  83                             this.castleFlags[c][0] = false;
  84                         if (Math.abs(move.end.y-this.INIT_COL_ROOK[c][1]) <= 1)
  85                             this.castleFlags[c][1] = false;
  86                     }
  87                 }
  88             }
  89         }
  90     }
  91
  92     unupdateVariables(move)
  93     {
  94         super.unupdateVariables(move);
  95         const c = this.getColor(move.start.x,move.start.y);
  96         const oppCol = this.getOppCol(c);
  97         if ([this.kingPos[c][0],this.kingPos[oppCol][0]].some(e => { return e < 0; }))
  98         {
  99             // There is a chance that last move blowed some king away..
 100             for (let psq of move.vanish)
 101             {
 102                 if (psq.p == 'k')
 103                     this.kingPos[psq.c==c ? c : oppCol] = [psq.x, psq.y];
 104             }
 105         }
 106     }
 107
 108     underCheck(move)
 109     {
 110         const c = this.turn;
 111         const oppCol = this.getOppCol(c);
 112         this.play(move);
 113         let res = undefined;
 114         // If our king disappeared, move is not valid
 115         if (this.kingPos[c][0] < 0)
 116             res = true;
 117         // If opponent king disappeared, move is valid
 118         else if (this.kingPos[oppCol][0] < 0)
 119             res = false;
 120         // Otherwise, if we remain under check, move is not valid
 121         else
 122             res = this.isAttacked(this.kingPos[c], [oppCol]);
 123         this.undo(move);
 124         return res;
 125     }
 126
 127     getCheckSquares(move)
 128     {
 129         const c = this.getOppCol(this.turn);
 130         // King might explode:
 131         const saveKingPos = JSON.parse(JSON.stringify(this.kingPos[c]));
 132         this.play(move);
 133         let res = [ ];
 134         if (this.kingPos[c][0] < 0)
 135             res = [saveKingPos];
 136         else if (this.isAttacked(this.kingPos[c], [this.getOppCol(c)]))
 137             res = [ JSON.parse(JSON.stringify(this.kingPos[c])) ]
 138         this.undo(move);
 139         return res;
 140     }
 141
 142     checkGameEnd()
 143     {
 144         const color = this.turn;
 145         const kp = this.kingPos[color];
 146         if (kp[0] < 0) //king disappeared
 147             return color == "w" ? "0-1" : "1-0";
 148         if (!this.isAttacked(kp, [this.getOppCol(color)]))
 149             return "1/2";
 150         // Checkmate
 151         return color == "w" ? "0-1" : "1-0";
 152     }
 153 }