client/src/variants/Coronation.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2
   3 export class CoronationRules extends ChessRules {
   4
   5   getPotentialMovesFrom([x, y]) {
   6     let moves = super.getPotentialMovesFrom([x, y]);
   7     // If no queen on board, allow rook+bishop fusions:
   8     const color = this.turn;
   9     const piece = this.getPiece(x, y);
  10     if (
  11       [V.ROOK, V.BISHOP].includes(piece) &&
  12       this.board.every(b => b.every(cell =>
  13         (cell == V.EMPTY || cell[0] != color || cell[1] != V.QUEEN)
  14       ))
  15     ) {
  16       const fusionWith = [V.ROOK, V.BISHOP][1 - "rb".indexOf(piece)];
  17       // Can I "self-capture" fusionWith ?
  18       for (let step of V.steps[piece]) {
  19         let [i, j] = [x + step[0], y + step[1]];
  20         while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
  21           i += step[0];
  22           j += step[1];
  23         }
  24         if (
  25           V.OnBoard(i, j) &&
  26           this.getColor(i, j) == color &&
  27           this.getPiece(i, j) == fusionWith
  28         ) {
  29           moves.push(
  30             new Move({
  31               appear: [new PiPo({ x: i, y: j, p: V.QUEEN, c: color })],
  32               vanish: [
  33                 new PiPo({ x: x, y: y, p: piece, c: color }),
  34                 new PiPo({ x: i, y: j, p: fusionWith, c: color })
  35               ]
  36             })
  37           );
  38         }
  39       }
  40     }
  41     return moves;
  42   }
  43
  44   getNotation(move) {
  45     let notation = super.getNotation(move);
  46     if (move.appear[0].p == V.QUEEN && move.vanish[0].p != V.QUEEN)
  47       // Coronation
  48       notation += "=Q";
  49     return notation;
  50   }
  51
  52 };