client/src/variants/Rifle.js

   1 import { ChessRules, PiPo, Move } from "@/base_rules";
   2
   3 export const VariantRules = class RifleRules extends ChessRules {
   4   getBasicMove([sx, sy], [ex, ey], tr) {
   5     let mv = new Move({
   6       appear: [],
   7       vanish: [],
   8       start: {x:sx, y:sy},
   9       end: {x:ex, y:ey}
  10     });
  11     if (this.board[ex][ey] != V.EMPTY) {
  12       // No movement: just vanishing enemy piece
  13       mv.vanish = [
  14         new PiPo({
  15           x: ex,
  16           y: ey,
  17           c: this.getColor(ex, ey),
  18           p: this.getPiece(ex, ey)
  19         })
  20       ];
  21     }
  22     else {
  23       // Normal move
  24       mv.appear = [
  25         new PiPo({
  26           x: ex,
  27           y: ey,
  28           c: tr ? tr.c : this.getColor(sx, sy),
  29           p: tr ? tr.p : this.getPiece(sx, sy)
  30         })
  31       ];
  32       mv.vanish = [
  33         new PiPo({
  34           x: sx,
  35           y: sy,
  36           c: this.getColor(sx, sy),
  37           p: this.getPiece(sx, sy)
  38         })
  39       ];
  40     }
  41
  42     return mv;
  43   }
  44
  45   getPotentialPawnMoves([x, y]) {
  46     const color = this.turn;
  47     let moves = [];
  48     const [sizeX, sizeY] = [V.size.x, V.size.y];
  49     const shiftX = color == "w" ? -1 : 1;
  50     const startRank = color == "w" ? sizeX - 2 : 1;
  51     const lastRank = color == "w" ? 0 : sizeX - 1;
  52
  53     const finalPieces =
  54       x + shiftX == lastRank
  55         ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
  56         : [V.PAWN];
  57     if (this.board[x + shiftX][y] == V.EMPTY) {
  58       for (let piece of finalPieces) {
  59         moves.push(
  60           this.getBasicMove([x, y], [x + shiftX, y], {
  61             c: color,
  62             p: piece
  63           })
  64         );
  65       }
  66       if (
  67         x == startRank &&
  68         this.board[x + 2 * shiftX][y] == V.EMPTY
  69       ) {
  70         moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
  71       }
  72     }
  73     // Captures
  74     for (let shiftY of [-1, 1]) {
  75       if (
  76         y + shiftY >= 0 &&
  77         y + shiftY < sizeY &&
  78         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
  79         this.canTake([x, y], [x + shiftX, y + shiftY])
  80       ) {
  81         for (let piece of finalPieces) {
  82           moves.push(
  83             this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
  84               c: color,
  85               p: piece
  86             })
  87           );
  88         }
  89       }
  90     }
  91
  92     // En passant
  93     const Lep = this.epSquares.length;
  94     const epSquare = this.epSquares[Lep - 1]; //always at least one element
  95     if (
  96       !!epSquare &&
  97       epSquare.x == x + shiftX &&
  98       Math.abs(epSquare.y - y) == 1
  99     ) {
 100       let enpassantMove = new Move({
 101         appear: [],
 102         vanish: [],
 103         start: {x:x, y:y},
 104         end: {x:x+shiftX, y:epSquare.y}
 105       });
 106       enpassantMove.vanish.push({
 107         x: x,
 108         y: epSquare.y,
 109         p: "p",
 110         c: this.getColor(x, epSquare.y)
 111       });
 112       moves.push(enpassantMove);
 113     }
 114
 115     return moves;
 116   }
 117 };