client/src/variants/Atomic.js

   1 import { ChessRules, PiPo } from "@/base_rules";
   2
   3 export const VariantRules = class AtomicRules extends ChessRules {
   4   getPotentialMovesFrom([x, y]) {
   5     let moves = super.getPotentialMovesFrom([x, y]);
   6
   7     // Handle explosions
   8     moves.forEach(m => {
   9       // NOTE: if vanish.length==2 and appear.length==2, this is castle
  10       if (m.vanish.length > 1 && m.appear.length <= 1) {
  11         // Explosion! (TODO?: drop moves which explode our king here)
  12         let steps = [
  13           [-1, -1],
  14           [-1, 0],
  15           [-1, 1],
  16           [0, -1],
  17           [0, 1],
  18           [1, -1],
  19           [1, 0],
  20           [1, 1]
  21         ];
  22         for (let step of steps) {
  23           let x = m.end.x + step[0];
  24           let y = m.end.y + step[1];
  25           if (
  26             V.OnBoard(x, y) &&
  27             this.board[x][y] != V.EMPTY &&
  28             this.getPiece(x, y) != V.PAWN
  29           ) {
  30             m.vanish.push(
  31               new PiPo({
  32                 p: this.getPiece(x, y),
  33                 c: this.getColor(x, y),
  34                 x: x,
  35                 y: y
  36               })
  37             );
  38           }
  39         }
  40         m.end = { x: m.appear[0].x, y: m.appear[0].y };
  41         m.appear.pop(); //Nothin appears in this case
  42       }
  43     });
  44
  45     return moves;
  46   }
  47
  48   getPotentialKingMoves([x, y]) {
  49     // King cannot capture:
  50     let moves = [];
  51     const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
  52     for (let step of steps) {
  53       const i = x + step[0];
  54       const j = y + step[1];
  55       if (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY)
  56         moves.push(this.getBasicMove([x, y], [i, j]));
  57     }
  58     return moves.concat(this.getCastleMoves([x, y]));
  59   }
  60
  61   isAttacked(sq, colors) {
  62     if (
  63       this.getPiece(sq[0], sq[1]) == V.KING &&
  64       this.isAttackedByKing(sq, colors)
  65     )
  66       return false; //king cannot take...
  67     return (
  68       this.isAttackedByPawn(sq, colors) ||
  69       this.isAttackedByRook(sq, colors) ||
  70       this.isAttackedByKnight(sq, colors) ||
  71       this.isAttackedByBishop(sq, colors) ||
  72       this.isAttackedByQueen(sq, colors)
  73     );
  74   }
  75
  76   updateVariables(move) {
  77     super.updateVariables(move);
  78     if (move.appear.length == 0) {
  79       // Capture
  80       const firstRank = { w: 7, b: 0 };
  81       for (let c of ["w", "b"]) {
  82         // Did we explode king of color c ? (TODO: remove move earlier)
  83         if (
  84           Math.abs(this.kingPos[c][0] - move.end.x) <= 1 &&
  85           Math.abs(this.kingPos[c][1] - move.end.y) <= 1
  86         ) {
  87           this.kingPos[c] = [-1, -1];
  88           this.castleFlags[c] = [false, false];
  89         } else {
  90           // Now check if init rook(s) exploded
  91           if (Math.abs(move.end.x - firstRank[c]) <= 1) {
  92             if (Math.abs(move.end.y - this.INIT_COL_ROOK[c][0]) <= 1)
  93               this.castleFlags[c][0] = false;
  94             if (Math.abs(move.end.y - this.INIT_COL_ROOK[c][1]) <= 1)
  95               this.castleFlags[c][1] = false;
  96           }
  97         }
  98       }
  99     }
 100   }
 101
 102   unupdateVariables(move) {
 103     super.unupdateVariables(move);
 104     const c = move.vanish[0].c;
 105     const oppCol = V.GetOppCol(c);
 106     if (
 107       [this.kingPos[c][0], this.kingPos[oppCol][0]].some(e => {
 108         return e < 0;
 109       })
 110     ) {
 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(color) {
 132     let res = [];
 133     if (
 134       this.kingPos[color][0] >= 0 && //king might have exploded
 135       this.isAttacked(this.kingPos[color], [V.GetOppCol(color)])
 136     ) {
 137       res = [JSON.parse(JSON.stringify(this.kingPos[color]))];
 138     }
 139     return res;
 140   }
 141
 142   getCurrentScore() {
 143     const color = this.turn;
 144     const kp = this.kingPos[color];
 145     if (kp[0] < 0)
 146       // King disappeared
 147       return color == "w" ? "0-1" : "1-0";
 148     if (this.atLeastOneMove())
 149       return "*";
 150     if (!this.isAttacked(kp, [V.GetOppCol(color)])) return "1/2";
 151     return color == "w" ? "0-1" : "1-0"; //checkmate
 152   }
 153 };