client/src/variants/Cannibal2.js

   1 import { Cannibal1Rules } from "@/variants/Cannibal1";
   2
   3 export class Cannibal2Rules extends Cannibal1Rules {
   4
   5   // Trim all non-capturing moves
   6   static KeepCaptures(moves) {
   7     return moves.filter(m => m.vanish.length == 2 && m.appear.length == 1);
   8   }
   9
  10   // Stop at the first capture found (if any)
  11   atLeastOneCapture() {
  12     const color = this.turn;
  13     const oppCol = V.GetOppCol(color);
  14     for (let i = 0; i < V.size.x; i++) {
  15       for (let j = 0; j < V.size.y; j++) {
  16         if (
  17           this.board[i][j] != V.EMPTY &&
  18           this.getColor(i, j) != oppCol &&
  19           this.filterValid(this.getPotentialMovesFrom([i, j])).some(m =>
  20             // Warning: discard castle moves
  21             m.vanish.length == 2 && m.appear.length == 1)
  22         ) {
  23           return true;
  24         }
  25       }
  26     }
  27     return false;
  28   }
  29
  30   addPawnMoves([x1, y1], [x2, y2], moves) {
  31     let finalPieces = [V.PAWN];
  32     const color = this.turn;
  33     const lastRank = (color == "w" ? 0 : V.size.x - 1);
  34     if (x2 == lastRank) {
  35       if (this.board[x2][y2] != V.EMPTY)
  36         // Cannibal rules: no choice if capture
  37         finalPieces = [this.getPiece(x2, y2)];
  38       else finalPieces = V.PawnSpecs.promotions;
  39     }
  40     let tr = null;
  41     for (let piece of finalPieces) {
  42       tr = (piece != V.PAWN ? { c: color, p: piece } : null);
  43       moves.push(this.getBasicMove([x1, y1], [x2, y2], tr));
  44     }
  45   }
  46
  47   getPossibleMovesFrom(sq) {
  48     let moves = this.filterValid(this.getPotentialMovesFrom(sq));
  49     const captureMoves = V.KeepCaptures(moves);
  50     if (captureMoves.length > 0) return captureMoves;
  51     if (this.atLeastOneCapture()) return [];
  52     return moves;
  53   }
  54
  55   getAllValidMoves() {
  56     const moves = super.getAllValidMoves();
  57     if (moves.some(m => m.vanish.length == 2 && m.appear.length == 1))
  58       return V.KeepCaptures(moves);
  59     return moves;
  60   }
  61
  62 };