client/src/variants/Atomic.js

   1 import { ChessRules, PiPo } from "@/base_rules";
   2
   3 export class AtomicRules extends ChessRules {
   4
   5   getPotentialMovesFrom([x, y]) {
   6     let moves = super.getPotentialMovesFrom([x, y]);
   7
   8     // Handle explosions
   9     moves.forEach(m => {
  10       // NOTE: if vanish.length==2 and appear.length==2, this is castle
  11       if (m.vanish.length > 1 && m.appear.length <= 1) {
  12         // Explosion! (TODO?: drop moves which explode our king here)
  13         let steps = [
  14           [-1, -1],
  15           [-1, 0],
  16           [-1, 1],
  17           [0, -1],
  18           [0, 1],
  19           [1, -1],
  20           [1, 0],
  21           [1, 1]
  22         ];
  23         for (let step of steps) {
  24           let x = m.end.x + step[0];
  25           let y = m.end.y + step[1];
  26           if (
  27             V.OnBoard(x, y) &&
  28             this.board[x][y] != V.EMPTY &&
  29             this.getPiece(x, y) != V.PAWN
  30           ) {
  31             m.vanish.push(
  32               new PiPo({
  33                 p: this.getPiece(x, y),
  34                 c: this.getColor(x, y),
  35                 x: x,
  36                 y: y
  37               })
  38             );
  39           }
  40         }
  41         m.end = { x: m.appear[0].x, y: m.appear[0].y };
  42         m.appear.pop(); //Nothin appears in this case
  43       }
  44     });
  45
  46     return moves;
  47   }
  48
  49   getPotentialKingMoves([x, y]) {
  50     // King cannot capture:
  51     let moves = [];
  52     const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
  53     for (let step of steps) {
  54       const i = x + step[0];
  55       const j = y + step[1];
  56       if (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY)
  57         moves.push(this.getBasicMove([x, y], [i, j]));
  58     }
  59     return moves.concat(this.getCastleMoves([x, y]));
  60   }
  61
  62   isAttacked(sq, color) {
  63     if (
  64       this.getPiece(sq[0], sq[1]) == V.KING &&
  65       this.isAttackedByKing(sq, color)
  66     ) {
  67       // A king next to the enemy king is immune to attacks
  68       return false;
  69     }
  70     return (
  71       this.isAttackedByPawn(sq, color) ||
  72       this.isAttackedByRook(sq, color) ||
  73       this.isAttackedByKnight(sq, color) ||
  74       this.isAttackedByBishop(sq, color) ||
  75       this.isAttackedByQueen(sq, color)
  76       // No "attackedByKing": it cannot take
  77     );
  78   }
  79
  80   postPlay(move) {
  81     super.postPlay(move);
  82     if (move.appear.length == 0) {
  83       // Capture
  84       const firstRank = { w: 7, b: 0 };
  85       for (let c of ["w", "b"]) {
  86         // Did we explode king of color c ? (TODO: remove move earlier)
  87         if (
  88           Math.abs(this.kingPos[c][0] - move.end.x) <= 1 &&
  89           Math.abs(this.kingPos[c][1] - move.end.y) <= 1
  90         ) {
  91           this.kingPos[c] = [-1, -1];
  92           this.castleFlags[c] = [8, 8];
  93         } else {
  94           // Now check if init rook(s) exploded
  95           if (Math.abs(move.end.x - firstRank[c]) <= 1) {
  96             if (Math.abs(move.end.y - this.castleFlags[c][0]) <= 1)
  97               this.castleFlags[c][0] = 8;
  98             if (Math.abs(move.end.y - this.castleFlags[c][1]) <= 1)
  99               this.castleFlags[c][1] = 8;
 100           }
 101         }
 102       }
 103     }
 104   }
 105
 106   postUndo(move) {
 107     super.postUndo(move);
 108     const c = this.turn;
 109     const oppCol = V.GetOppCol(c);
 110     if ([this.kingPos[c][0], this.kingPos[oppCol][0]].some(e => e < 0)) {
 111       // There is a chance that last move blowed some king away..
 112       for (let psq of move.vanish) {
 113         if (psq.p == "k")
 114           this.kingPos[psq.c == c ? c : oppCol] = [psq.x, psq.y];
 115       }
 116     }
 117   }
 118
 119   underCheck(color) {
 120     const oppCol = V.GetOppCol(color);
 121     let res = undefined;
 122     // If our king disappeared, move is not valid
 123     if (this.kingPos[color][0] < 0) res = true;
 124     // If opponent king disappeared, move is valid
 125     else if (this.kingPos[oppCol][0] < 0) res = false;
 126     // Otherwise, if we remain under check, move is not valid
 127     else res = this.isAttacked(this.kingPos[color], oppCol);
 128     return res;
 129   }
 130
 131   getCheckSquares() {
 132     const color = this.turn;
 133     let res = [];
 134     if (
 135       this.kingPos[color][0] >= 0 && //king might have exploded
 136       this.isAttacked(this.kingPos[color], V.GetOppCol(color))
 137     ) {
 138       res = [JSON.parse(JSON.stringify(this.kingPos[color]))];
 139     }
 140     return res;
 141   }
 142
 143   getCurrentScore() {
 144     const color = this.turn;
 145     const kp = this.kingPos[color];
 146     if (kp[0] < 0)
 147       // King disappeared
 148       return color == "w" ? "0-1" : "1-0";
 149     if (this.atLeastOneMove()) return "*";
 150     if (!this.isAttacked(kp, V.GetOppCol(color))) return "1/2";
 151     return color == "w" ? "0-1" : "1-0"; //checkmate
 152   }
 153
 154 };