variants/Balaklava/class.js

   1 import ChessRules from "/base_rules.js";
   2 import {FenUtil} from "/utils/setupPieces.js";
   3
   4 export default class BalaklavaRules extends ChessRules {
   5
   6   get pawnPromotions() {
   7     return ['r', 'm', 'b', 'q'];
   8   }
   9
  10   get hasEnpassant() {
  11     return false;
  12   }
  13
  14   pieces(color, x, y) {
  15     let res = super.pieces(color, x, y);
  16     const knightSpecMoves = res['n'].both;
  17     delete res['n'];
  18     res['m'] = {
  19       "class": "mammoth",
  20       both: [
  21         {
  22           steps: [
  23             [-2, -2], [-2, 0], [-2, 2],
  24             [0, -2], [0, 2], [2, -2],
  25             [2, 0], [2, 2]
  26           ],
  27           range: 1
  28         }
  29       ]
  30     };
  31     ['p', 'r', 'b', 'm', 'q'].forEach(p => {
  32       if (!res[p].moves)
  33         res[p].moves = [];
  34       Array.prototype.push.apply(res[p].moves, knightSpecMoves);
  35     });
  36     return res;
  37   }
  38
  39   genRandInitBaseFen() {
  40     const s = FenUtil.setupPieces(
  41       ['r', 'm', 'b', 'q', 'k', 'b', 'm', 'r'],
  42       {
  43         randomness: this.options["randomness"],
  44         diffCol: ['b']
  45       }
  46     );
  47     return {
  48       fen: s.b.join("") + "/pppppppp/8/8/8/8/PPPPPPPP/" +
  49            s.w.join("").toUpperCase(),
  50       o: {flags: s.flags}
  51     };
  52   }
  53
  54   pawnPostProcess(moves) {
  55     if (moves.length == 0)
  56       return [];
  57     const color = moves[0].vanish[0].c;
  58     const lastRank = (color == 'w' ? 0 : this.size.x - 1);
  59     const forward = (color == 'w' ? -1 : 1);
  60     const noKnightPromotions = moves.filter(m => {
  61       return (
  62         (m.end.x - m.start.x) * forward > 0 &&
  63         (
  64           m.end.x != lastRank ||
  65           (
  66             Math.abs(m.start.x - m.end.x) <= 1 &&
  67             Math.abs(m.start.y - m.end.y) <= 1
  68           )
  69         )
  70       );
  71     });
  72     return super.pawnPostProcess(noKnightPromotions);
  73   }
  74
  75 };