| 1 | import { ChessRules, PiPo, Move } from "@/base_rules"; |
| 2 | import { ArrayFun } from "@/utils/array"; |
| 3 | import { randInt, shuffle } from "@/utils/alea"; |
| 4 | |
| 5 | export const VariantRules = class CircularRules extends ChessRules { |
| 6 | static get HasFlags() { |
| 7 | return false; |
| 8 | } |
| 9 | |
| 10 | static get HasEnpassant() { |
| 11 | return false; |
| 12 | } |
| 13 | |
| 14 | // TODO: CanFlip --> also for racing kings (answer is false) |
| 15 | |
| 16 | // TODO: shuffle on 1st and 5th ranks |
| 17 | static GenRandInitFen() { |
| 18 | let pieces = { w: new Array(8), b: new Array(8) }; |
| 19 | // Shuffle pieces on first and last rank |
| 20 | for (let c of ["w", "b"]) { |
| 21 | let positions = ArrayFun.range(8); |
| 22 | |
| 23 | // Get random squares for bishops |
| 24 | let randIndex = 2 * randInt(4); |
| 25 | const bishop1Pos = positions[randIndex]; |
| 26 | // The second bishop must be on a square of different color |
| 27 | let randIndex_tmp = 2 * randInt(4) + 1; |
| 28 | const bishop2Pos = positions[randIndex_tmp]; |
| 29 | // Remove chosen squares |
| 30 | positions.splice(Math.max(randIndex, randIndex_tmp), 1); |
| 31 | positions.splice(Math.min(randIndex, randIndex_tmp), 1); |
| 32 | |
| 33 | // Get random squares for knights |
| 34 | randIndex = randInt(6); |
| 35 | const knight1Pos = positions[randIndex]; |
| 36 | positions.splice(randIndex, 1); |
| 37 | randIndex = randInt(5); |
| 38 | const knight2Pos = positions[randIndex]; |
| 39 | positions.splice(randIndex, 1); |
| 40 | |
| 41 | // Get random square for queen |
| 42 | randIndex = randInt(4); |
| 43 | const queenPos = positions[randIndex]; |
| 44 | positions.splice(randIndex, 1); |
| 45 | |
| 46 | // Rooks and king positions are now fixed, |
| 47 | // because of the ordering rook-king-rook |
| 48 | const rook1Pos = positions[0]; |
| 49 | const kingPos = positions[1]; |
| 50 | const rook2Pos = positions[2]; |
| 51 | |
| 52 | // Finally put the shuffled pieces in the board array |
| 53 | pieces[c][rook1Pos] = "r"; |
| 54 | pieces[c][knight1Pos] = "n"; |
| 55 | pieces[c][bishop1Pos] = "b"; |
| 56 | pieces[c][queenPos] = "q"; |
| 57 | pieces[c][kingPos] = "k"; |
| 58 | pieces[c][bishop2Pos] = "b"; |
| 59 | pieces[c][knight2Pos] = "n"; |
| 60 | pieces[c][rook2Pos] = "r"; |
| 61 | } |
| 62 | return ( |
| 63 | pieces["b"].join("") + |
| 64 | "/pppppppp/8/8/8/8/PPPPPPPP/" + |
| 65 | pieces["w"].join("").toUpperCase() + |
| 66 | " w 0" |
| 67 | ); |
| 68 | } |
| 69 | |
| 70 | // TODO: adapt this for a circular board |
| 71 | getSlideNJumpMoves([x, y], steps, oneStep) { |
| 72 | let moves = []; |
| 73 | outerLoop: for (let step of steps) { |
| 74 | let i = x + step[0]; |
| 75 | let j = y + step[1]; |
| 76 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 77 | moves.push(this.getBasicMove([x, y], [i, j])); |
| 78 | if (oneStep !== undefined) continue outerLoop; |
| 79 | i += step[0]; |
| 80 | j += step[1]; |
| 81 | } |
| 82 | if (V.OnBoard(i, j) && this.canTake([x, y], [i, j])) |
| 83 | moves.push(this.getBasicMove([x, y], [i, j])); |
| 84 | } |
| 85 | return moves; |
| 86 | } |
| 87 | |
| 88 | // TODO: adapt: all pawns go in thz same direction! |
| 89 | getPotentialPawnMoves([x, y]) { |
| 90 | const color = this.turn; |
| 91 | let moves = []; |
| 92 | const [sizeX, sizeY] = [V.size.x, V.size.y]; |
| 93 | const shiftX = color == "w" ? -1 : 1; |
| 94 | const firstRank = color == "w" ? sizeX - 1 : 0; |
| 95 | const startRank = color == "w" ? sizeX - 2 : 1; |
| 96 | const lastRank = color == "w" ? 0 : sizeX - 1; |
| 97 | const pawnColor = this.getColor(x, y); //can be different for checkered |
| 98 | |
| 99 | // NOTE: next condition is generally true (no pawn on last rank) |
| 100 | if (x + shiftX >= 0 && x + shiftX < sizeX) { |
| 101 | const finalPieces = |
| 102 | x + shiftX == lastRank |
| 103 | ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN] |
| 104 | : [V.PAWN]; |
| 105 | // One square forward |
| 106 | if (this.board[x + shiftX][y] == V.EMPTY) { |
| 107 | for (let piece of finalPieces) { |
| 108 | moves.push( |
| 109 | this.getBasicMove([x, y], [x + shiftX, y], { |
| 110 | c: pawnColor, |
| 111 | p: piece |
| 112 | }) |
| 113 | ); |
| 114 | } |
| 115 | // Next condition because pawns on 1st rank can generally jump |
| 116 | if ( |
| 117 | [startRank, firstRank].includes(x) && |
| 118 | this.board[x + 2 * shiftX][y] == V.EMPTY |
| 119 | ) { |
| 120 | // Two squares jump |
| 121 | moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y])); |
| 122 | } |
| 123 | } |
| 124 | // Captures |
| 125 | for (let shiftY of [-1, 1]) { |
| 126 | if ( |
| 127 | y + shiftY >= 0 && |
| 128 | y + shiftY < sizeY && |
| 129 | this.board[x + shiftX][y + shiftY] != V.EMPTY && |
| 130 | this.canTake([x, y], [x + shiftX, y + shiftY]) |
| 131 | ) { |
| 132 | for (let piece of finalPieces) { |
| 133 | moves.push( |
| 134 | this.getBasicMove([x, y], [x + shiftX, y + shiftY], { |
| 135 | c: pawnColor, |
| 136 | p: piece |
| 137 | }) |
| 138 | ); |
| 139 | } |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | return moves; |
| 145 | } |
| 146 | |
| 147 | // What are the king moves from square x,y ? |
| 148 | getPotentialKingMoves(sq) { |
| 149 | return this.getSlideNJumpMoves( |
| 150 | sq, |
| 151 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), |
| 152 | "oneStep" |
| 153 | ); |
| 154 | } |
| 155 | |
| 156 | // TODO: check boundaries here as well |
| 157 | isAttackedByPawn([x, y], colors) { |
| 158 | for (let c of colors) { |
| 159 | let pawnShift = c == "w" ? 1 : -1; |
| 160 | if (x + pawnShift >= 0 && x + pawnShift < V.size.x) { |
| 161 | for (let i of [-1, 1]) { |
| 162 | if ( |
| 163 | y + i >= 0 && |
| 164 | y + i < V.size.y && |
| 165 | this.getPiece(x + pawnShift, y + i) == V.PAWN && |
| 166 | this.getColor(x + pawnShift, y + i) == c |
| 167 | ) { |
| 168 | return true; |
| 169 | } |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | return false; |
| 174 | } |
| 175 | |
| 176 | // TODO: adapt this function |
| 177 | isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) { |
| 178 | for (let step of steps) { |
| 179 | let rx = x + step[0], |
| 180 | ry = y + step[1]; |
| 181 | while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) { |
| 182 | rx += step[0]; |
| 183 | ry += step[1]; |
| 184 | } |
| 185 | if ( |
| 186 | V.OnBoard(rx, ry) && |
| 187 | this.getPiece(rx, ry) === piece && |
| 188 | colors.includes(this.getColor(rx, ry)) |
| 189 | ) { |
| 190 | return true; |
| 191 | } |
| 192 | } |
| 193 | return false; |
| 194 | } |
| 195 | }; |