variants/Balaklava/class.js

   1 import ChessRules from "/base_rules.js";
   2
   3 export default class BalaklavaRules extends ChessRules {
   4
   5   get pawnPromotions() {
   6     return ['r', 'm', 'b', 'q'];
   7   }
   8
   9   get hasEnpassant() {
  10     return false;
  11   }
  12
  13   pieces(color, x, y) {
  14     let res = super.pieces(color, x, y);
  15     const knightSpec = res['n'];
  16     delete res['n'];
  17     res['m'] = {
  18       "class": "mammoth",
  19       both: [
  20         {
  21           steps: [
  22             [-2, -2], [-2, 0], [-2, 2],
  23             [0, -2], [0, 2], [2, -2],
  24             [2, 0], [2, 2]
  25           ],
  26           range: 1
  27         }
  28       ]
  29     };
  30     ['p', 'r', 'b', 'm', 'q'].forEach(p => res[p].moves = knightSpec.moves);
  31     return res;
  32   }
  33
  34   genRandInitBaseFen() {
  35     const baseFen = super.genRandInitBaseFen();
  36     return {
  37       fen: baseFen.fen.replace(/n/g, 'm').replace(/N/g, 'M'),
  38       o: baseFen.o
  39     };
  40   }
  41
  42   pawnPostProcess(moves) {
  43     if (moves.length == 0)
  44       return [];
  45     const color = moves[0].vanish[0].c;
  46     const lastRank = (color == 'w' ? 0 : this.size.x - 1);
  47     const forward = (color == 'w' ? -1 : 1);
  48     const noKnightPromotions = moves.filter(m => {
  49       return (
  50         (m.end.x - m.start.x) * forward > 0 &&
  51         (
  52           m.end.x != lastRank ||
  53           (
  54             Math.abs(m.start.x - m.end.x) <= 1 &&
  55             Math.abs(m.start.y - m.end.y) <= 1
  56           )
  57         )
  58       );
  59     });
  60     return super.pawnPostProcess(noKnightPromotions);
  61   }
  62
  63 };