client/src/variants/Atomic.js

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