client/src/variants/Twokings.js

   1 import { ChessRules } from "@/base_rules";
   2 import { CoregalRules } from "@/variants/Coregal";
   3
   4 export class TwokingsRules extends CoregalRules {
   5   static get PawnSpecs() {
   6     return Object.assign(
   7       {},
   8       ChessRules.PawnSpecs,
   9       { promotions: ChessRules.PawnSpecs.promotions.concat([V.KING]) }
  10     );
  11   }
  12
  13   static IsGoodPosition(position) {
  14     if (position.length == 0) return false;
  15     const rows = position.split("/");
  16     if (rows.length != V.size.x) return false;
  17     let kings = { "w": 0, "b": 0 };
  18     for (let row of rows) {
  19       let sumElts = 0;
  20       for (let i = 0; i < row.length; i++) {
  21         if (['K','k'].includes(row[i])) kings[row[i]]++;
  22         if (V.PIECES.includes(row[i].toLowerCase())) sumElts++;
  23         else {
  24           const num = parseInt(row[i]);
  25           if (isNaN(num)) return false;
  26           sumElts += num;
  27         }
  28       }
  29       if (sumElts != V.size.y) return false;
  30     }
  31     // Two kings (at least) per side should be present:
  32     if (Object.values(kings).some(v => v < 2)) return false;
  33     return true;
  34   }
  35
  36   // Not scanning king positions. In this variant, scan the board everytime.
  37   scanKings(fen) {}
  38
  39   getCheckSquares(color) {
  40     let squares = [];
  41     const oppCol = V.GetOppCol(color);
  42     for (let i=0; i<V.size.x; i++) {
  43       for (let j=0; j<V.size.y; j++) {
  44         if (
  45           this.getColor(i, j) == color &&
  46           this.getPiece(i, j) == V.KING &&
  47           this.isAttacked([i, j], oppCol)
  48         ) {
  49           squares.push([i, j]);
  50         }
  51       }
  52     }
  53     return squares;
  54   }
  55
  56   static GenRandInitFen(randomness) {
  57     const fen = CoregalRules.GenRandInitFen(randomness);
  58     return fen.replace("q", "k").replace("Q", "K");
  59   }
  60
  61   underCheck(color) {
  62     const oppCol = V.GetOppCol(color);
  63     for (let i=0; i<V.size.x; i++) {
  64       for (let j=0; j<V.size.y; j++) {
  65         if (
  66           this.getColor(i, j) == color &&
  67           this.getPiece(i, j) == V.KING &&
  68           this.isAttacked([i, j], oppCol)
  69         ) {
  70           return true;
  71         }
  72       }
  73     }
  74     return false;
  75   }
  76
  77   postPlay(move) {
  78     const piece = move.vanish[0].p;
  79     super.updateCastleFlags(move, piece, "twoKings");
  80   }
  81
  82   postUndo() {}
  83 };