client/src/variants/Coronation.js

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