variants/Coronation/class.js

   1 import ChessRules from "/base_rules.js";
   2
   3 export default class CoronationRules extends ChessRules {
   4
   5   get hasSelfCaptures() {
   6     return true;
   7   }
   8
   9   canSelfTake([x1, y1], [x2, y2]) {
  10     const c = this.getColor(x1, y1);
  11     if (
  12       this.board.some(row =>
  13         row.some(square =>
  14           square[0] == c && square[1] == 'q')
  15       )
  16     ) {
  17       // Already a queen on the board: no coronation
  18       return false;
  19     }
  20     const [p1, p2] = [this.getPiece(x1, y1), this.getPiece(x2, y2)];
  21     return ((p1 == 'r' && p2 == 'b') || (p1 == 'b' && p2 == 'r'));
  22   }
  23
  24   getPotentialMovesOf(piece, [x, y]) {
  25     const res = super.getPotentialMovesOf(piece, [x, y]);
  26     if (['r', 'b'].includes(piece)) {
  27       res.forEach(m => {
  28         if (
  29           m.vanish.length == 2 &&
  30           m.appear.length == 1 &&
  31           m.vanish[1].c == m.vanish[0].c
  32         ) {
  33           m.appear[0].p = 'q';
  34         }
  35       });
  36     }
  37     return res;
  38   }
  39
  40 };