| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | |
| 3 | export class ForwardRules extends ChessRules { |
| 4 | static get PawnSpecs() { |
| 5 | return Object.assign( |
| 6 | {}, |
| 7 | ChessRules.PawnSpecs, |
| 8 | { |
| 9 | bidirectional: true, |
| 10 | captureBackward: true, |
| 11 | promotions: [V.PAWN] |
| 12 | } |
| 13 | ); |
| 14 | } |
| 15 | |
| 16 | static get PROMOTED() { |
| 17 | return ['s', 'u', 'o', 'c', 't', 'l']; |
| 18 | } |
| 19 | |
| 20 | static get PIECES() { |
| 21 | return ChessRules.PIECES.concat(V.PROMOTED); |
| 22 | } |
| 23 | |
| 24 | getPpath(b) { |
| 25 | return (V.PROMOTED.includes(b[1]) ? "Forward/" : "") + b; |
| 26 | } |
| 27 | |
| 28 | scanKings(fen) { |
| 29 | this.INIT_COL_KING = { w: -1, b: -1 }; |
| 30 | // Squares of white and black king: |
| 31 | this.kingPos = { w: [-1, -1], b: [-1, -1] }; |
| 32 | const fenRows = V.ParseFen(fen).position.split("/"); |
| 33 | const startRow = { 'w': V.size.x - 1, 'b': 0 }; |
| 34 | for (let i = 0; i < fenRows.length; i++) { |
| 35 | let k = 0; //column index on board |
| 36 | for (let j = 0; j < fenRows[i].length; j++) { |
| 37 | switch (fenRows[i].charAt(j)) { |
| 38 | case "k": |
| 39 | case "l": |
| 40 | this.kingPos["b"] = [i, k]; |
| 41 | this.INIT_COL_KING["b"] = k; |
| 42 | break; |
| 43 | case "K": |
| 44 | case "L": |
| 45 | this.kingPos["w"] = [i, k]; |
| 46 | this.INIT_COL_KING["w"] = k; |
| 47 | break; |
| 48 | default: { |
| 49 | const num = parseInt(fenRows[i].charAt(j)); |
| 50 | if (!isNaN(num)) k += num - 1; |
| 51 | } |
| 52 | } |
| 53 | k++; |
| 54 | } |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | getPotentialMovesFrom(sq) { |
| 59 | const piece = this.getPiece(sq[0], sq[1]); |
| 60 | if (V.PROMOTED.includes(piece)) { |
| 61 | switch (piece) { |
| 62 | case 's': |
| 63 | return ( |
| 64 | super.getPotentialPawnMoves(sq) |
| 65 | // Promoted pawns back on initial rank don't jump 2 squares: |
| 66 | .filter(m => Math.abs(m.end.x - m.start.x) == 1) |
| 67 | ); |
| 68 | case 'u': return super.getPotentialRookMoves(sq); |
| 69 | case 'o': return super.getPotentialKnightMoves(sq); |
| 70 | case 'c': return super.getPotentialBishopMoves(sq); |
| 71 | case 't': return super.getPotentialQueenMoves(sq); |
| 72 | case 'l': return super.getPotentialKingMoves(sq); |
| 73 | } |
| 74 | } |
| 75 | // Unpromoted piece: only go forward |
| 76 | const color = this.turn; |
| 77 | let moves = |
| 78 | super.getPotentialMovesFrom(sq) |
| 79 | .filter(m => { |
| 80 | const delta = m.end.x - m.start.x; |
| 81 | return ((color == 'w' && delta <= 0) || (color == 'b' && delta >= 0)); |
| 82 | }); |
| 83 | // Apply promotions: |
| 84 | const lastRank = (color == 'w' ? 0 : 7); |
| 85 | moves.forEach(m => { |
| 86 | if (m.end.x == lastRank) { |
| 87 | const pIdx = ChessRules.PIECES.findIndex(p => p == m.appear[0].p); |
| 88 | m.appear[0].p = V.PROMOTED[pIdx]; |
| 89 | } |
| 90 | }); |
| 91 | return moves; |
| 92 | } |
| 93 | |
| 94 | isAttackedBySlideNJump([x, y], color, piece, steps, oneStep) { |
| 95 | const pIdx = ChessRules.PIECES.findIndex(p => p == piece); |
| 96 | const ppiece = V.PROMOTED[pIdx]; |
| 97 | const forward = (color == 'w' ? -1 : 1); |
| 98 | for (let step of steps) { |
| 99 | let rx = x + step[0], |
| 100 | ry = y + step[1]; |
| 101 | while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) { |
| 102 | rx += step[0]; |
| 103 | ry += step[1]; |
| 104 | } |
| 105 | if (V.OnBoard(rx, ry) && this.getColor(rx, ry) == color) { |
| 106 | const pieceR = this.getPiece(rx, ry); |
| 107 | if ( |
| 108 | pieceR == ppiece || |
| 109 | (pieceR == piece && (step[0] == 0 || -step[0] == forward)) |
| 110 | ) { |
| 111 | return true; |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | return false; |
| 116 | } |
| 117 | |
| 118 | postPlay(move) { |
| 119 | super.postPlay(move); |
| 120 | if (move.appear[0].p == "l") |
| 121 | this.kingPos[move.appear[0].c] = [move.appear[0].x, move.appear[0].y]; |
| 122 | } |
| 123 | |
| 124 | postUndo(move) { |
| 125 | super.postUndo(move); |
| 126 | if (move.appear[0].p == "l") |
| 127 | this.kingPos[this.turn] = [move.start.x, move.start.y]; |
| 128 | } |
| 129 | |
| 130 | static get VALUES() { |
| 131 | return Object.assign( |
| 132 | { |
| 133 | s: 2, |
| 134 | u: 8, |
| 135 | o: 5, |
| 136 | c: 5, |
| 137 | t: 15, |
| 138 | l: 1500 |
| 139 | }, |
| 140 | ChessRules.VALUES |
| 141 | ); |
| 142 | } |
| 143 | }; |