client/src/variants/Atomic.js

   1 import { ChessRules, PiPo } from "@/base_rules";
   2
   3 export const VariantRules = class AtomicRules extends ChessRules {
   4   getEpSquare(moveOrSquare) {
   5     if (typeof moveOrSquare !== "object" || moveOrSquare.appear.length > 0)
   6       return super.getEpSquare(moveOrSquare);
   7     // Capturing move: no en-passant
   8     return undefined;
   9   }
  10
  11   getPotentialMovesFrom([x, y]) {
  12     let moves = super.getPotentialMovesFrom([x, y]);
  13
  14     // Handle explosions
  15     moves.forEach(m => {
  16       // NOTE: if vanish.length==2 and appear.length==2, this is castle
  17       if (m.vanish.length > 1 && m.appear.length <= 1) {
  18         // Explosion! (TODO?: drop moves which explode our king here)
  19         let steps = [
  20           [-1, -1],
  21           [-1, 0],
  22           [-1, 1],
  23           [0, -1],
  24           [0, 1],
  25           [1, -1],
  26           [1, 0],
  27           [1, 1]
  28         ];
  29         for (let step of steps) {
  30           let x = m.end.x + step[0];
  31           let y = m.end.y + step[1];
  32           if (
  33             V.OnBoard(x, y) &&
  34             this.board[x][y] != V.EMPTY &&
  35             this.getPiece(x, y) != V.PAWN
  36           ) {
  37             m.vanish.push(
  38               new PiPo({
  39                 p: this.getPiece(x, y),
  40                 c: this.getColor(x, y),
  41                 x: x,
  42                 y: y
  43               })
  44             );
  45           }
  46         }
  47         m.end = { x: m.appear[0].x, y: m.appear[0].y };
  48         m.appear.pop(); //Nothin appears in this case
  49       }
  50     });
  51
  52     return moves;
  53   }
  54
  55   getPotentialKingMoves([x, y]) {
  56     // King cannot capture:
  57     let moves = [];
  58     const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
  59     for (let step of steps) {
  60       const i = x + step[0];
  61       const j = y + step[1];
  62       if (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY)
  63         moves.push(this.getBasicMove([x, y], [i, j]));
  64     }
  65     return moves.concat(this.getCastleMoves([x, y]));
  66   }
  67
  68   isAttacked(sq, colors) {
  69     if (
  70       this.getPiece(sq[0], sq[1]) == V.KING &&
  71       this.isAttackedByKing(sq, colors)
  72     )
  73       return false; //king cannot take...
  74     return (
  75       this.isAttackedByPawn(sq, colors) ||
  76       this.isAttackedByRook(sq, colors) ||
  77       this.isAttackedByKnight(sq, colors) ||
  78       this.isAttackedByBishop(sq, colors) ||
  79       this.isAttackedByQueen(sq, colors)
  80     );
  81   }
  82
  83   updateVariables(move) {
  84     super.updateVariables(move);
  85     if (move.appear.length == 0) {
  86       // Capture
  87       const firstRank = { w: 7, b: 0 };
  88       for (let c of ["w", "b"]) {
  89         // Did we explode king of color c ? (TODO: remove move earlier)
  90         if (
  91           Math.abs(this.kingPos[c][0] - move.end.x) <= 1 &&
  92           Math.abs(this.kingPos[c][1] - move.end.y) <= 1
  93         ) {
  94           this.kingPos[c] = [-1, -1];
  95           this.castleFlags[c] = [false, false];
  96         } else {
  97           // Now check if init rook(s) exploded
  98           if (Math.abs(move.end.x - firstRank[c]) <= 1) {
  99             if (Math.abs(move.end.y - this.INIT_COL_ROOK[c][0]) <= 1)
 100               this.castleFlags[c][0] = false;
 101             if (Math.abs(move.end.y - this.INIT_COL_ROOK[c][1]) <= 1)
 102               this.castleFlags[c][1] = false;
 103           }
 104         }
 105       }
 106     }
 107   }
 108
 109   unupdateVariables(move) {
 110     super.unupdateVariables(move);
 111     const c = move.vanish[0].c;
 112     const oppCol = V.GetOppCol(c);
 113     if (
 114       [this.kingPos[c][0], this.kingPos[oppCol][0]].some(e => {
 115         return e < 0;
 116       })
 117     ) {
 118       // There is a chance that last move blowed some king away..
 119       for (let psq of move.vanish) {
 120         if (psq.p == "k")
 121           this.kingPos[psq.c == c ? c : oppCol] = [psq.x, psq.y];
 122       }
 123     }
 124   }
 125
 126   underCheck(color) {
 127     const oppCol = V.GetOppCol(color);
 128     let res = undefined;
 129     // If our king disappeared, move is not valid
 130     if (this.kingPos[color][0] < 0) res = true;
 131     // If opponent king disappeared, move is valid
 132     else if (this.kingPos[oppCol][0] < 0) res = false;
 133     // Otherwise, if we remain under check, move is not valid
 134     else res = this.isAttacked(this.kingPos[color], [oppCol]);
 135     return res;
 136   }
 137
 138   getCheckSquares(color) {
 139     let res = [];
 140     if (
 141       this.kingPos[color][0] >= 0 && //king might have exploded
 142       this.isAttacked(this.kingPos[color], [V.GetOppCol(color)])
 143     ) {
 144       res = [JSON.parse(JSON.stringify(this.kingPos[color]))];
 145     }
 146     return res;
 147   }
 148
 149   getCurrentScore() {
 150     const color = this.turn;
 151     const kp = this.kingPos[color];
 152     if (kp[0] < 0)
 153       // King disappeared
 154       return color == "w" ? "0-1" : "1-0";
 155     if (this.atLeastOneMove())
 156       return "*";
 157     if (!this.isAttacked(kp, [V.GetOppCol(color)])) return "1/2";
 158     return color == "w" ? "0-1" : "1-0"; //checkmate
 159   }
 160 };