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