client/src/variants/Losers.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 export class LosersRules extends ChessRules {
   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     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) == color &&
  19           this.getPotentialMovesFrom([i, j]).some(m => {
  20             return (
  21               // Warning: discard castle moves
  22               m.vanish.length == 2 && m.appear.length == 1 &&
  23               this.filterValid([m]).length == 1
  24             );
  25           })
  26         ) {
  27           return true;
  28         }
  29       }
  30     }
  31     return false;
  32   }
  33
  34   getPossibleMovesFrom(sq) {
  35     let moves = this.filterValid(this.getPotentialMovesFrom(sq));
  36     const captureMoves = V.KeepCaptures(moves);
  37
  38 console.log(this.atLeastOneCapture());
  39
  40     if (captureMoves.length > 0) return captureMoves;
  41     if (this.atLeastOneCapture()) return [];
  42     return moves;
  43   }
  44
  45   getAllValidMoves() {
  46     const moves = super.getAllValidMoves();
  47     if (moves.some(m => m.vanish.length == 2 && m.appear.length == 1))
  48       return V.KeepCaptures(moves);
  49     return moves;
  50   }
  51
  52   getCurrentScore() {
  53     // If only my king remains, I win
  54     const color = this.turn;
  55     let onlyKing = true;
  56     outerLoop: for (let i=0; i<V.size.x; i++) {
  57       for (let j=0; j<V.size.y; j++) {
  58         if (
  59           this.board[i][j] != V.EMPTY &&
  60           this.getColor(i,j) == color &&
  61           this.getPiece(i,j) != V.KING
  62         ) {
  63           onlyKing = false;
  64           break outerLoop;
  65         }
  66       }
  67     }
  68     if (onlyKing) return color == "w" ? "1-0" : "0-1";
  69     if (this.atLeastOneMove()) return "*";
  70     // No valid move: the side who cannot move (or is checkmated) wins
  71     return this.turn == "w" ? "1-0" : "0-1";
  72   }
  73
  74   evalPosition() {
  75     // Less material is better (more subtle in fact but...)
  76     return -super.evalPosition();
  77   }
  78 };