client/src/variants/Cannibal2.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2 import { Cannibal1Rules } from "@/variants/Cannibal1";
   3
   4 export class Cannibal2Rules extends Cannibal1Rules {
   5
   6   // Trim all non-capturing moves
   7   static KeepCaptures(moves) {
   8     return moves.filter(m => m.vanish.length == 2 && m.appear.length == 1);
   9   }
  10
  11   // Stop at the first capture found (if any)
  12   atLeastOneCapture() {
  13     const color = this.turn;
  14     const oppCol = V.GetOppCol(color);
  15     for (let i = 0; i < V.size.x; i++) {
  16       for (let j = 0; j < V.size.y; j++) {
  17         if (
  18           this.board[i][j] != V.EMPTY &&
  19           this.getColor(i, j) != oppCol &&
  20           this.filterValid(this.getPotentialMovesFrom([i, j])).some(m =>
  21             // Warning: discard castle moves
  22             m.vanish.length == 2 && m.appear.length == 1)
  23         ) {
  24           return true;
  25         }
  26       }
  27     }
  28     return false;
  29   }
  30
  31   addPawnMoves([x1, y1], [x2, y2], moves) {
  32     let finalPieces = [V.PAWN];
  33     const color = this.turn;
  34     const lastRank = (color == "w" ? 0 : V.size.x - 1);
  35     if (x2 == lastRank) {
  36       if (this.board[x2][y2] != V.EMPTY)
  37         // Cannibal rules: no choice if capture
  38         finalPieces = [this.getPiece(x2, y2)];
  39       else finalPieces = V.PawnSpecs.promotions;
  40     }
  41     let tr = null;
  42     for (let piece of finalPieces) {
  43       tr = (piece != V.PAWN ? { c: color, p: piece } : null);
  44       moves.push(this.getBasicMove([x1, y1], [x2, y2], tr));
  45     }
  46   }
  47
  48   getPossibleMovesFrom(sq) {
  49     let moves = this.filterValid(this.getPotentialMovesFrom(sq));
  50     const captureMoves = V.KeepCaptures(moves);
  51     if (captureMoves.length > 0) return captureMoves;
  52     if (this.atLeastOneCapture()) return [];
  53     return moves;
  54   }
  55
  56   getAllValidMoves() {
  57     const moves = super.getAllValidMoves();
  58     if (moves.some(m => m.vanish.length == 2 && m.appear.length == 1))
  59       return V.KeepCaptures(moves);
  60     return moves;
  61   }
  62
  63 };