| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | |
| 3 | export const VariantRules = class ArenaRules extends ChessRules { |
| 4 | static get hasFlags() { |
| 5 | return false; |
| 6 | } |
| 7 | |
| 8 | static GenRandInitFen() { |
| 9 | return ChessRules.GenRandInitFen().replace("w 1111 -", "w -"); |
| 10 | } |
| 11 | |
| 12 | static InArena(x) { |
| 13 | return Math.abs(3.5 - x) <= 1.5; |
| 14 | } |
| 15 | |
| 16 | getPotentialMovesFrom([x, y]) { |
| 17 | const moves = super.getPotentialMovesFrom([x, y]); |
| 18 | // Eliminate moves which neither enter the arena or capture something |
| 19 | return moves.filter(m => { |
| 20 | const startInArena = V.InArena(m.start.x); |
| 21 | const endInArena = V.InArena(m.end.x); |
| 22 | return ( |
| 23 | (startInArena && endInArena && m.vanish.length == 2) || |
| 24 | (!startInArena && endInArena) |
| 25 | ); |
| 26 | }); |
| 27 | |
| 28 | return moves; |
| 29 | } |
| 30 | |
| 31 | getPotentialPawnMoves([x, y]) { |
| 32 | const color = this.turn; |
| 33 | let moves = []; |
| 34 | const [sizeX, sizeY] = [V.size.x, V.size.y]; |
| 35 | const shiftX = color == "w" ? -1 : 1; |
| 36 | const startRank = color == "w" ? sizeX - 2 : 1; |
| 37 | |
| 38 | if (this.board[x + shiftX][y] == V.EMPTY) { |
| 39 | // One square forward |
| 40 | moves.push(this.getBasicMove([x, y], [x + shiftX, y])); |
| 41 | // Next condition because pawns on 1st rank can generally jump |
| 42 | if ( |
| 43 | x == startRank && |
| 44 | this.board[x + 2 * shiftX][y] == V.EMPTY |
| 45 | ) { |
| 46 | // Two squares jump |
| 47 | moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y])); |
| 48 | } |
| 49 | } |
| 50 | // Captures |
| 51 | for (let shiftY of [-1, 1]) { |
| 52 | if ( |
| 53 | y + shiftY >= 0 && |
| 54 | y + shiftY < sizeY && |
| 55 | this.board[x + shiftX][y + shiftY] != V.EMPTY && |
| 56 | this.canTake([x, y], [x + shiftX, y + shiftY]) |
| 57 | ) { |
| 58 | moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY])); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | // En passant |
| 63 | const Lep = this.epSquares.length; |
| 64 | const epSquare = this.epSquares[Lep - 1]; //always at least one element |
| 65 | if ( |
| 66 | !!epSquare && |
| 67 | epSquare.x == x + shiftX && |
| 68 | Math.abs(epSquare.y - y) == 1 |
| 69 | ) { |
| 70 | let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]); |
| 71 | enpassantMove.vanish.push({ |
| 72 | x: x, |
| 73 | y: epSquare.y, |
| 74 | p: "p", |
| 75 | c: this.getColor(x, epSquare.y) |
| 76 | }); |
| 77 | moves.push(enpassantMove); |
| 78 | } |
| 79 | |
| 80 | return moves; |
| 81 | } |
| 82 | |
| 83 | getPotentialQueenMoves(sq) { |
| 84 | return this.getSlideNJumpMoves( |
| 85 | sq, |
| 86 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]) |
| 87 | ).filter(m => { |
| 88 | // Filter out moves longer than 3 squares |
| 89 | return Math.max( |
| 90 | Math.abs(m.end.x - m.start.x), |
| 91 | Math.abs(m.end.y - m.start.y)) <= 3; |
| 92 | }); |
| 93 | } |
| 94 | |
| 95 | getPotentialKingMoves(sq) { |
| 96 | return this.getSlideNJumpMoves( |
| 97 | sq, |
| 98 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]) |
| 99 | ).filter(m => { |
| 100 | // Filter out moves longer than 3 squares |
| 101 | return Math.max( |
| 102 | Math.abs(m.end.x - m.start.x), |
| 103 | Math.abs(m.end.y - m.start.y)) <= 3; |
| 104 | }); |
| 105 | } |
| 106 | |
| 107 | getCheckSquares() { |
| 108 | return []; |
| 109 | } |
| 110 | |
| 111 | filterValid(moves) { |
| 112 | // No check conditions |
| 113 | return moves; |
| 114 | } |
| 115 | |
| 116 | getCurrentScore() { |
| 117 | const color = this.turn; |
| 118 | if (!this.atLeastOneMove()) |
| 119 | // I cannot move anymore |
| 120 | return color == "w" ? "0-1" : "1-0"; |
| 121 | // Win if the opponent has no more pieces left (in the Arena), |
| 122 | // (and/)or if he lost both his dukes. |
| 123 | let someUnitRemain = false; |
| 124 | let atLeastOneDuke = false; |
| 125 | let somethingInArena = false; |
| 126 | outerLoop: for (let i=0; i<V.size.x; i++) { |
| 127 | for (let j=0; j<V.size.y; j++) { |
| 128 | if (this.getColor(i,j) == color) { |
| 129 | someUnitRemain = true; |
| 130 | if (this.movesCount >= 2 && V.InArena(i)) { |
| 131 | somethingInArena = true; |
| 132 | if (atLeastOneDuke) |
| 133 | break outerLoop; |
| 134 | } |
| 135 | if ([V.QUEEN,V.KING].includes(this.getPiece(i,j))) { |
| 136 | atLeastOneDuke = true; |
| 137 | if (this.movesCount < 2 || somethingInArena) |
| 138 | break outerLoop; |
| 139 | } |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | if ( |
| 144 | !someUnitRemain || |
| 145 | !atLeastOneDuke || |
| 146 | (this.movesCount >= 2 && !somethingInArena) |
| 147 | ) { |
| 148 | return color == "w" ? "0-1" : "1-0"; |
| 149 | } |
| 150 | return "*"; |
| 151 | } |
| 152 | }; |