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
  63         const c = this.getColor(move.start.x,move.start.y);
  64         // Next condition to avoid conflicts with harmless castle moves
  65         if (c != this.getColor(move.end.x,move.end.y)
  66             && this.board[move.end.x][move.end.y] != VariantRules.EMPTY)
  67         {
  68             const oppCol = this.getOppCol(c);
  69             const oppFirstRank = (oppCol == "w" ? 7 : 0);
  70
  71             // Did we explode our king ? (TODO: remove move earlier)
  72             if (Math.abs(this.kingPos[c][0]-move.end.x) <= 1
  73                 && Math.abs(this.kingPos[c][1]-move.end.y) <= 1)
  74             {
  75                 this.kingPos[c] = [-1,-1];
  76                 this.castleFlags[c] = [false,false];
  77             }
  78
  79             // Did we explode opponent king ?
  80             if (Math.abs(this.kingPos[oppCol][0]-move.end.x) <= 1
  81                 && Math.abs(this.kingPos[oppCol][1]-move.end.y) <= 1)
  82             {
  83                 this.kingPos[oppCol] = [-1,-1];
  84                 this.castleFlags[oppCol] = [false,false];
  85             }
  86             else
  87             {
  88                 // Now check if opponent init rook(s) exploded
  89                 if (Math.abs(move.end.x-oppFirstRank) <= 1)
  90                 {
  91                     if (Math.abs(move.end.y-this.INIT_COL_ROOK[oppCol][0]) <= 1)
  92                         this.castleFlags[oppCol][0] = false;
  93                     if (Math.abs(move.end.y-this.INIT_COL_ROOK[oppCol][1]) <= 1)
  94                         this.castleFlags[oppCol][1] = false;
  95                 }
  96             }
  97         }
  98     }
  99
 100     unupdateVariables(move)
 101     {
 102         super.unupdateVariables(move);
 103         const c = this.getColor(move.start.x,move.start.y);
 104         const oppCol = this.getOppCol(c);
 105         if ([this.kingPos[c][0],this.kingPos[oppCol][0]].some(e => { return e < 0; }))
 106         {
 107             // There is a chance that last move blowed some king away..
 108             for (let psq of move.vanish)
 109             {
 110                 if (psq.p == 'k')
 111                     this.kingPos[psq.c==c ? c : oppCol] = [psq.x, psq.y];
 112             }
 113         }
 114     }
 115
 116     underCheck(move)
 117     {
 118         const c = this.turn;
 119         const oppCol = this.getOppCol(c);
 120         this.play(move);
 121         let res = undefined;
 122         // If our king disappeared, move is not valid
 123         if (this.kingPos[c][0] < 0)
 124             res = true;
 125         // If opponent king disappeared, move is valid
 126         else if (this.kingPos[oppCol][0] < 0)
 127             res = false;
 128         // Otherwise, if we remain under check, move is not valid
 129         else
 130             res = this.isAttacked(this.kingPos[c], [oppCol]);
 131         this.undo(move);
 132         return res;
 133     }
 134
 135     getCheckSquares(move)
 136     {
 137         const c = this.getOppCol(this.turn);
 138         // King might explode:
 139         const saveKingPos = JSON.parse(JSON.stringify(this.kingPos[c]));
 140         this.play(move);
 141         let res = [ ];
 142         if (this.kingPos[c][0] < 0)
 143             res = [saveKingPos];
 144         else if (this.isAttacked(this.kingPos[c], [this.getOppCol(c)]))
 145             res = [ JSON.parse(JSON.stringify(this.kingPos[c])) ]
 146         this.undo(move);
 147         return res;
 148     }
 149
 150     checkGameEnd()
 151     {
 152         const color = this.turn;
 153         const kp = this.kingPos[color];
 154         if (kp[0] < 0) //king disappeared
 155             return color == "w" ? "0-1" : "1-0";
 156         if (!this.isAttacked(kp, [this.getOppCol(color)]))
 157             return "1/2";
 158         // Checkmate
 159         return color == "w" ? "0-1" : "1-0";
 160     }
 161 }