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1 | class BerolinaRules extends ChessRules |
2 | { | |
3 | // En-passant after 2-sq jump | |
4 | getEpSquare(moveOrSquare) | |
5 | { | |
6 | if (!moveOrSquare) | |
7 | return undefined; | |
8 | if (typeof moveOrSquare === "string") | |
9 | { | |
10 | const square = moveOrSquare; | |
11 | if (square == "-") | |
12 | return undefined; | |
13 | return V.SquareToCoords(square); | |
14 | } | |
15 | // Argument is a move: | |
16 | const move = moveOrSquare; | |
17 | const [sx,ex,sy] = [move.start.x,move.end.x,move.start.y]; | |
18 | if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) == 2) | |
19 | { | |
20 | return { | |
f6dbe8e3 | 21 | x: (ex + sx)/2, |
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22 | y: (move.end.y + sy)/2 |
23 | }; | |
24 | } | |
25 | return undefined; //default | |
26 | } | |
27 | ||
f6dbe8e3 | 28 | // Special pawns movements |
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29 | getPotentialPawnMoves([x,y]) |
30 | { | |
31 | const color = this.turn; | |
32 | let moves = []; | |
33 | const [sizeX,sizeY] = [V.size.x,V.size.y]; | |
34 | const shiftX = (color == "w" ? -1 : 1); | |
35 | const firstRank = (color == 'w' ? sizeX-1 : 0); | |
36 | const startRank = (color == "w" ? sizeX-2 : 1); | |
37 | const lastRank = (color == "w" ? 0 : sizeX-1); | |
38 | ||
39 | if (x+shiftX >= 0 && x+shiftX < sizeX) //TODO: always true | |
40 | { | |
41 | const finalPieces = x + shiftX == lastRank | |
42 | ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN] | |
43 | : [V.PAWN] | |
44 | // One square diagonally | |
45 | for (let shiftY of [-1,1]) | |
46 | { | |
47 | if (this.board[x+shiftX][y+shiftY] == V.EMPTY) | |
48 | { | |
49 | for (let piece of finalPieces) | |
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50 | moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY], {c:color,p:piece})); |
51 | if (x == startRank && y+2*shiftY>=0 && y+2*shiftY<sizeY | |
52 | && this.board[x+2*shiftX][y+2*shiftY] == V.EMPTY) | |
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53 | { |
54 | // Two squares jump | |
f6dbe8e3 | 55 | moves.push(this.getBasicMove([x,y], [x+2*shiftX,y+2*shiftY])); |
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56 | } |
57 | } | |
58 | } | |
59 | // Capture | |
60 | if (this.board[x+shiftX][y] != V.EMPTY | |
61 | && this.canTake([x,y], [x+shiftX,y])) | |
62 | { | |
63 | for (let piece of finalPieces) | |
f6dbe8e3 | 64 | moves.push(this.getBasicMove([x,y], [x+shiftX,y], {c:color,p:piece})); |
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65 | } |
66 | } | |
67 | ||
68 | // En passant | |
69 | const Lep = this.epSquares.length; | |
70 | const epSquare = this.epSquares[Lep-1]; //always at least one element | |
71 | if (!!epSquare && epSquare.x == x+shiftX && epSquare.y == y) | |
72 | { | |
f6dbe8e3 | 73 | let enpassantMove = this.getBasicMove([x,y], [x+shiftX,y]); |
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74 | enpassantMove.vanish.push({ |
75 | x: epSquare.x, | |
f6dbe8e3 | 76 | y: epSquare.y, |
375ecdd1 | 77 | p: 'p', |
f6dbe8e3 | 78 | c: this.getColor(epSquare.x,epSquare.y) |
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79 | }); |
80 | moves.push(enpassantMove); | |
81 | } | |
82 | ||
83 | return moves; | |
84 | } | |
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85 | |
86 | isAttackedByPawn([x,y], colors) | |
87 | { | |
88 | for (let c of colors) | |
89 | { | |
90 | let pawnShift = (c=="w" ? 1 : -1); | |
91 | if (x+pawnShift>=0 && x+pawnShift<V.size.x) | |
92 | { | |
93 | if (this.getPiece(x+pawnShift,y)==V.PAWN && this.getColor(x+pawnShift,y)==c) | |
94 | return true; | |
95 | } | |
96 | } | |
97 | return false; | |
98 | } | |
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99 | } |
100 | ||
101 | const VariantRules = BerolinaRules; |