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 knightSpec = res['n'];
  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 => res[p].moves = knightSpec.moves);
  32     return res;
  33   }
  34
  35   genRandInitBaseFen() {
  36     const s = FenUtil.setupPieces(
  37       ['r', 'm', 'b', 'q', 'k', 'b', 'm', 'r'], {diffCol: ['b']});
  38     return {
  39       fen: s.b.join("") + "/pppppppp/8/8/8/8/PPPPPPPP/" +
  40            s.w.join("").toUpperCase(),
  41       o: {}
  42     };
  43   }
  44
  45   pawnPostProcess(moves) {
  46     if (moves.length == 0)
  47       return [];
  48     const color = moves[0].vanish[0].c;
  49     const lastRank = (color == 'w' ? 0 : this.size.x - 1);
  50     const forward = (color == 'w' ? -1 : 1);
  51     const noKnightPromotions = moves.filter(m => {
  52       return (
  53         (m.end.x - m.start.x) * forward > 0 &&
  54         (
  55           m.end.x != lastRank ||
  56           (
  57             Math.abs(m.start.x - m.end.x) <= 1 &&
  58             Math.abs(m.start.y - m.end.y) <= 1
  59           )
  60         )
  61       );
  62     });
  63     return super.pawnPostProcess(noKnightPromotions);
  64   }
  65
  66 };