variants/Coregal/Coregal.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt, sample } from "@/utils/alea";
   4
   5 export class CoregalRules extends ChessRules {
   6
   7 // TODO: special symbol (l) for royal queen...
   8
   9   getPPpath(m) {
  10     if (
  11       m.vanish.length == 2 &&
  12       m.appear.length == 2 &&
  13       m.vanish[0].p == V.QUEEN
  14     ) {
  15       // Large castle: show castle symbol
  16       return "Coregal/castle";
  17     }
  18     return super.getPPpath(m);
  19   }
  20
  21   genRandInitBaseFen() {
  22     const s = FenUtil.setupPieces(
  23       ['r', 'n', 'b', 'l', 'k', 'b', 'n', 'r'],
  24       {
  25         randomness: this.options["randomness"],
  26         between: [{p1: 'k', p2: 'r'}, {p1: 'l', p2: 'r'}],
  27         diffCol: ['b'],
  28         flags: ['r', 'k', 'l']
  29       }
  30     );
  31     return {
  32       fen: s.b.join("") + "/pppppppp/8/8/8/8/PPPPPPPP/" +
  33            s.w.join("").toUpperCase(),
  34       o: {flags: s.flags}
  35     };
  36   }
  37
  38   pieces() {
  39     let res = super.pieces();
  40     res['l'] = {...};
  41     return res;
  42   }
  43
  44   setFlags(fenflags) {
  45     // white pieces positions, then black pieces positions
  46     this.castleFlags = { w: [...Array(4)], b: [...Array(4)] };
  47     for (let i = 0; i < 8; i++) {
  48       this.castleFlags[i < 4 ? "w" : "b"][i % 4] =
  49         parseInt(fenflags.charAt(i), 10);
  50     }
  51   }
  52
  53   getPotentialQueenMoves([x, y]) {
  54     let moves = super.getPotentialQueenMoves([x, y]);
  55     const c = this.getColor(x, y);
  56     if (this.castleFlags[c].slice(1, 3).includes(y))
  57       moves = moves.concat(this.getCastleMoves([x, y]));
  58     return moves;
  59   }
  60
  61   getPotentialKingMoves([x, y]) {
  62     let moves = this.getSlideNJumpMoves(
  63       [x, y], V.steps[V.ROOK].concat(V.steps[V.BISHOP]), 1);
  64     const c = this.getColor(x, y);
  65     if (this.castleFlags[c].slice(1, 3).includes(y))
  66       moves = moves.concat(this.getCastleMoves([x, y]));
  67     return moves;
  68   }
  69
  70   getCastleMoves([x, y]) {
  71     // Relative position of the selected piece: left or right ?
  72     // If left: small castle left, large castle right.
  73     // If right: usual situation.
  74     const c = this.getColor(x, y);
  75     const relPos = (this.castleFlags[c][1] == y ? "left" : "right");
  76
  77     const finalSquares = [
  78       relPos == "left" ? [1, 2] : [2, 3],
  79       relPos == "right" ? [6, 5] : [5, 4]
  80     ];
  81     const saveFlags = JSON.stringify(this.castleFlags[c]);
  82     // Alter flags to follow base_rules semantic
  83     this.castleFlags[c] = [0, 3].map(i => this.castleFlags[c][i]);
  84     const moves = super.getCastleMoves([x, y], finalSquares);
  85     this.castleFlags[c] = JSON.parse(saveFlags);
  86     return moves;
  87   }
  88
  89   // "twoKings" arg for the similar Twokings variant.
  90   updateCastleFlags(move, piece, twoKings) {
  91     const c = V.GetOppCol(this.turn);
  92     const firstRank = (c == "w" ? V.size.x - 1 : 0);
  93     // Update castling flags if castling pieces moved or were captured
  94     const oppCol = V.GetOppCol(c);
  95     const oppFirstRank = V.size.x - 1 - firstRank;
  96     if (move.start.x == firstRank) {
  97       if (piece == V.KING || (!twoKings && piece == V.QUEEN)) {
  98         if (this.castleFlags[c][1] == move.start.y)
  99           this.castleFlags[c][1] = 8;
 100         else if (this.castleFlags[c][2] == move.start.y)
 101           this.castleFlags[c][2] = 8;
 102         // Else: the flag is already turned off
 103       }
 104     }
 105     else if (
 106       move.start.x == firstRank && //our rook moves?
 107       [this.castleFlags[c][0], this.castleFlags[c][3]].includes(move.start.y)
 108     ) {
 109       const flagIdx = (move.start.y == this.castleFlags[c][0] ? 0 : 3);
 110       this.castleFlags[c][flagIdx] = 8;
 111     } else if (
 112       move.end.x == oppFirstRank && //we took opponent rook?
 113       [this.castleFlags[oppCol][0], this.castleFlags[oppCol][3]]
 114         .includes(move.end.y)
 115     ) {
 116       const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 3);
 117       this.castleFlags[oppCol][flagIdx] = 8;
 118     }
 119   }
 120
 121 };