| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | |
| 3 | export const VariantRules = class KnightrelayRules extends ChessRules { |
| 4 | getPotentialMovesFrom([x, y]) { |
| 5 | let moves = super.getPotentialMovesFrom([x, y]); |
| 6 | |
| 7 | // Expand possible moves if guarded by a knight: |
| 8 | if (this.getPiece(x,y) != V.KNIGHT) { |
| 9 | const color = this.turn; |
| 10 | let guardedByKnight = false; |
| 11 | for (const step of V.steps[V.KNIGHT]) { |
| 12 | if ( |
| 13 | V.OnBoard(x+step[0],y+step[1]) && |
| 14 | this.getPiece(x+step[0],y+step[1]) == V.KNIGHT && |
| 15 | this.getColor(x+step[0],y+step[1]) == color |
| 16 | ) { |
| 17 | guardedByKnight = true; |
| 18 | break; |
| 19 | } |
| 20 | } |
| 21 | if (guardedByKnight) { |
| 22 | for (const step of V.steps[V.KNIGHT]) { |
| 23 | if ( |
| 24 | V.OnBoard(x+step[0],y+step[1]) && |
| 25 | this.getColor(x+step[0],y+step[1]) != color |
| 26 | ) { |
| 27 | moves.push(this.getBasicMove([x,y], [x+step[0],y+step[1]])); |
| 28 | } |
| 29 | } |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | return moves; |
| 34 | } |
| 35 | |
| 36 | isAttacked(sq, colors) { |
| 37 | if (super.isAttacked(sq, colors)) |
| 38 | return true; |
| 39 | |
| 40 | // Check if a (non-knight) piece at knight distance |
| 41 | // is guarded by a knight (and thus attacking) |
| 42 | const x = sq[0], |
| 43 | y = sq[1]; |
| 44 | for (const step of V.steps[V.KNIGHT]) { |
| 45 | if ( |
| 46 | V.OnBoard(x+step[0],y+step[1]) && |
| 47 | colors.includes(this.getColor(x+step[0],y+step[1])) && |
| 48 | this.getPiece(x+step[0],y+step[1]) != V.KNIGHT |
| 49 | ) { |
| 50 | for (const step2 of V.steps[V.KNIGHT]) { |
| 51 | const xx = x+step[0]+step2[0], |
| 52 | yy = y+step[1]+step2[1]; |
| 53 | if ( |
| 54 | V.OnBoard(xx,yy) && |
| 55 | colors.includes(this.getColor(xx,yy)) && |
| 56 | this.getPiece(xx,yy) == V.KNIGHT |
| 57 | ) { |
| 58 | return true; |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | return false; |
| 65 | } |
| 66 | |
| 67 | getNotation(move) { |
| 68 | if (move.appear.length == 2 && move.appear[0].p == V.KING) |
| 69 | // Castle |
| 70 | return move.end.y < move.start.y ? "0-0-0" : "0-0"; |
| 71 | |
| 72 | // Translate final and initial square |
| 73 | const initSquare = V.CoordsToSquare(move.start); |
| 74 | const finalSquare = V.CoordsToSquare(move.end); |
| 75 | const piece = this.getPiece(move.start.x, move.start.y); |
| 76 | |
| 77 | // Since pieces and pawns could move like knight, indicate start and end squares |
| 78 | let notation = |
| 79 | piece.toUpperCase() + |
| 80 | initSquare + |
| 81 | (move.vanish.length > move.appear.length ? "x" : "") + |
| 82 | finalSquare |
| 83 | |
| 84 | if ( |
| 85 | piece == V.PAWN && |
| 86 | move.appear.length > 0 && |
| 87 | move.appear[0].p != V.PAWN |
| 88 | ) { |
| 89 | // Promotion |
| 90 | notation += "=" + move.appear[0].p.toUpperCase(); |
| 91 | } |
| 92 | |
| 93 | return notation; |
| 94 | } |
| 95 | }; |