variants/Arena/class.js

   1 import ChessRules from "/base_rules.js";
   2
   3 export default class ArenaRules extends ChessRules {
   4
   5   static get Options() {
   6     return {}; //TODO
   7   }
   8
   9   get hasFlags() {
  10     return false;
  11   }
  12
  13   getSvgChessboard() {
  14     let board = super.getSvgChessboard().slice(0, -6);
  15     // Add lines to delimitate the central area
  16     board += `
  17       <line x1="0" y1="20" x2="80" y2="20" stroke="black" stroke-width="0.15"/>
  18       <line x1="0" y1="60" x2="80" y2="60" stroke="black" stroke-width="0.15"/>
  19       </svg>`;
  20     return board;
  21   }
  22
  23   pieces(color, x, y) {
  24     let allSpecs = super.pieces(color, x, y);
  25     let pawnSpec = allSpecs['p'],
  26         queenSpec = allSpecs['q'],
  27         kingSpec = allSpecs['k'];
  28     const pawnShift = (color == "w" ? -1 : 1);
  29     Array.prototype.push.apply(pawnSpec.attack[0].steps,
  30                                [[-pawnShift, 1], [-pawnShift, -1]]);
  31     queenSpec.both[0].range = 3;
  32     kingSpec.both[0].range = 3;
  33     return Object.assign({},
  34       allSpecs,
  35       {
  36         'p': pawnSpec,
  37         'q': queenSpec,
  38         'k': kingSpec
  39       }
  40     );
  41   }
  42
  43   static InArena(x) {
  44     return Math.abs(3.5 - x) <= 1.5;
  45   }
  46
  47   getPotentialMovesFrom([x, y]) {
  48     const moves = super.getPotentialMovesFrom([x, y]);
  49     // Eliminate moves which neither enter the arena or capture something
  50     return moves.filter(m => {
  51       const startInArena = V.InArena(m.start.x);
  52       const endInArena = V.InArena(m.end.x);
  53       return (
  54         (startInArena && endInArena && m.vanish.length == 2) ||
  55         (!startInArena && endInArena)
  56       );
  57     });
  58   }
  59
  60   filterValid(moves) {
  61     // No check conditions
  62     return moves;
  63   }
  64
  65   getCurrentScore() {
  66     const color = this.turn;
  67     if (!this.atLeastOneMove(color))
  68       // I cannot move anymore
  69       return color == 'w' ? "0-1" : "1-0";
  70     // Win if the opponent has no more pieces left (in the Arena),
  71     // (and/)or if he lost both his dukes.
  72     let someUnitRemain = false,
  73         atLeastOneDuke = false,
  74         somethingInArena = false;
  75     outerLoop: for (let i=0; i<this.size.x; i++) {
  76       for (let j=0; j<this.size.y; j++) {
  77         if (this.getColor(i,j) == color) {
  78           someUnitRemain = true;
  79           if (this.movesCount >= 2 && V.InArena(i)) {
  80             somethingInArena = true;
  81             if (atLeastOneDuke)
  82               break outerLoop;
  83           }
  84           if (['q', 'k'].includes(this.getPiece(i, j))) {
  85             atLeastOneDuke = true;
  86             if (this.movesCount < 2 || somethingInArena)
  87               break outerLoop;
  88           }
  89         }
  90       }
  91     }
  92     if (
  93       !someUnitRemain ||
  94       !atLeastOneDuke ||
  95       (this.movesCount >= 2 && !somethingInArena)
  96     ) {
  97       return color == 'w' ? "0-1" : "1-0";
  98     }
  99     return "*";
 100   }
 101
 102 };