client/src/variants/Arena.js

   1 import { ChessRules } from "@/base_rules";
   2
   3 export class ArenaRules extends ChessRules {
   4   static get HasFlags() {
   5     return false;
   6   }
   7
   8   static get PawnSpecs() {
   9     return Object.assign(
  10       {},
  11       ChessRules.PawnSpecs,
  12       { captureBackward: true }
  13     );
  14   }
  15
  16   static GenRandInitFen(randomness) {
  17     return ChessRules.GenRandInitFen(randomness).slice(0, -6) + "-";
  18   }
  19
  20   static InArena(x) {
  21     return Math.abs(3.5 - x) <= 1.5;
  22   }
  23
  24   getPotentialMovesFrom([x, y]) {
  25     const moves = super.getPotentialMovesFrom([x, y]);
  26     // Eliminate moves which neither enter the arena or capture something
  27     return moves.filter(m => {
  28       const startInArena = V.InArena(m.start.x);
  29       const endInArena = V.InArena(m.end.x);
  30       return (
  31         (startInArena && endInArena && m.vanish.length == 2) ||
  32         (!startInArena && endInArena)
  33       );
  34     });
  35
  36     return moves;
  37   }
  38
  39   getPotentialQueenMoves(sq) {
  40     return this.getSlideNJumpMoves(
  41       sq,
  42       V.steps[V.ROOK].concat(V.steps[V.BISHOP])
  43     ).filter(m => {
  44       // Filter out moves longer than 3 squares
  45       return Math.max(
  46         Math.abs(m.end.x - m.start.x),
  47         Math.abs(m.end.y - m.start.y)) <= 3;
  48     });
  49   }
  50
  51   getPotentialKingMoves(sq) {
  52     return this.getSlideNJumpMoves(
  53       sq,
  54       V.steps[V.ROOK].concat(V.steps[V.BISHOP])
  55     ).filter(m => {
  56       // Filter out moves longer than 3 squares
  57       return Math.max(
  58         Math.abs(m.end.x - m.start.x),
  59         Math.abs(m.end.y - m.start.y)) <= 3;
  60     });
  61   }
  62
  63   getCheckSquares() {
  64     return [];
  65   }
  66
  67   filterValid(moves) {
  68     // No check conditions
  69     return moves;
  70   }
  71
  72   getCurrentScore() {
  73     const color = this.turn;
  74     if (!this.atLeastOneMove())
  75       // I cannot move anymore
  76       return color == "w" ? "0-1" : "1-0";
  77     // Win if the opponent has no more pieces left (in the Arena),
  78     // (and/)or if he lost both his dukes.
  79     let someUnitRemain = false;
  80     let atLeastOneDuke = false;
  81     let somethingInArena = false;
  82     outerLoop: for (let i=0; i<V.size.x; i++) {
  83       for (let j=0; j<V.size.y; j++) {
  84         if (this.getColor(i,j) == color) {
  85           someUnitRemain = true;
  86           if (this.movesCount >= 2 && V.InArena(i)) {
  87             somethingInArena = true;
  88             if (atLeastOneDuke)
  89               break outerLoop;
  90           }
  91           if ([V.QUEEN,V.KING].includes(this.getPiece(i,j))) {
  92             atLeastOneDuke = true;
  93             if (this.movesCount < 2 || somethingInArena)
  94               break outerLoop;
  95           }
  96         }
  97       }
  98     }
  99     if (
 100       !someUnitRemain ||
 101       !atLeastOneDuke ||
 102       (this.movesCount >= 2 && !somethingInArena)
 103     ) {
 104       return color == "w" ? "0-1" : "1-0";
 105     }
 106     return "*";
 107   }
 108
 109   static get SEARCH_DEPTH() {
 110     return 4;
 111   }
 112 };