| 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 HasEnpassant() { |
| 7 | return false; |
| 8 | } |
| 9 | |
| 10 | static get CanFlip() { |
| 11 | return false; |
| 12 | } |
| 13 | |
| 14 | setFlags(fenflags) { |
| 15 | this.pawnFlags = { |
| 16 | w: [...Array(8).fill(true)], //pawns can move 2 squares? |
| 17 | b: [...Array(8).fill(true)] |
| 18 | }; |
| 19 | for (let c of ["w", "b"]) { |
| 20 | for (let i = 0; i < 8; i++) |
| 21 | this.pawnFlags[c][i] = fenflags.charAt((c == "w" ? 0 : 8) + i) == "1"; |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | aggregateFlags() { |
| 26 | return this.pawnFlags; |
| 27 | } |
| 28 | |
| 29 | disaggregateFlags(flags) { |
| 30 | this.pawnFlags = flags; |
| 31 | } |
| 32 | |
| 33 | static GenRandInitFen() { |
| 34 | let pieces = { w: new Array(8), b: new Array(8) }; |
| 35 | // Shuffle pieces on first and fifth rank |
| 36 | for (let c of ["w", "b"]) { |
| 37 | let positions = ArrayFun.range(8); |
| 38 | |
| 39 | // Get random squares for bishops |
| 40 | let randIndex = 2 * randInt(4); |
| 41 | const bishop1Pos = positions[randIndex]; |
| 42 | // The second bishop must be on a square of different color |
| 43 | let randIndex_tmp = 2 * randInt(4) + 1; |
| 44 | const bishop2Pos = positions[randIndex_tmp]; |
| 45 | // Remove chosen squares |
| 46 | positions.splice(Math.max(randIndex, randIndex_tmp), 1); |
| 47 | positions.splice(Math.min(randIndex, randIndex_tmp), 1); |
| 48 | |
| 49 | // Get random squares for knights |
| 50 | randIndex = randInt(6); |
| 51 | const knight1Pos = positions[randIndex]; |
| 52 | positions.splice(randIndex, 1); |
| 53 | randIndex = randInt(5); |
| 54 | const knight2Pos = positions[randIndex]; |
| 55 | positions.splice(randIndex, 1); |
| 56 | |
| 57 | // Get random square for queen |
| 58 | randIndex = randInt(4); |
| 59 | const queenPos = positions[randIndex]; |
| 60 | positions.splice(randIndex, 1); |
| 61 | |
| 62 | // Rooks and king positions are now fixed, |
| 63 | // because of the ordering rook-king-rook |
| 64 | const rook1Pos = positions[0]; |
| 65 | const kingPos = positions[1]; |
| 66 | const rook2Pos = positions[2]; |
| 67 | |
| 68 | // Finally put the shuffled pieces in the board array |
| 69 | pieces[c][rook1Pos] = "r"; |
| 70 | pieces[c][knight1Pos] = "n"; |
| 71 | pieces[c][bishop1Pos] = "b"; |
| 72 | pieces[c][queenPos] = "q"; |
| 73 | pieces[c][kingPos] = "k"; |
| 74 | pieces[c][bishop2Pos] = "b"; |
| 75 | pieces[c][knight2Pos] = "n"; |
| 76 | pieces[c][rook2Pos] = "r"; |
| 77 | } |
| 78 | return ( |
| 79 | "8/8/pppppppp/" + |
| 80 | pieces["b"].join("") + |
| 81 | "/8/8/PPPPPPPP/" + |
| 82 | pieces["w"].join("").toUpperCase() + |
| 83 | // 16 flags: can pawns advance 2 squares? |
| 84 | " w 0 1111111111111111" |
| 85 | ); |
| 86 | } |
| 87 | |
| 88 | // Output basically x % 8 (circular board) |
| 89 | static ComputeX(x) { |
| 90 | let res = x % V.size.x; |
| 91 | if (res < 0) |
| 92 | res += V.size.x; |
| 93 | return res; |
| 94 | } |
| 95 | |
| 96 | getSlideNJumpMoves([x, y], steps, oneStep) { |
| 97 | let moves = []; |
| 98 | outerLoop: for (let step of steps) { |
| 99 | let i = V.ComputeX(x + step[0]); |
| 100 | let j = y + step[1]; |
| 101 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 102 | moves.push(this.getBasicMove([x, y], [i, j])); |
| 103 | if (oneStep !== undefined) continue outerLoop; |
| 104 | i = V.ComputeX(i + step[0]); |
| 105 | j += step[1]; |
| 106 | } |
| 107 | if (V.OnBoard(i, j) && this.canTake([x, y], [i, j])) |
| 108 | moves.push(this.getBasicMove([x, y], [i, j])); |
| 109 | } |
| 110 | return moves; |
| 111 | } |
| 112 | |
| 113 | getPotentialPawnMoves([x, y]) { |
| 114 | const color = this.turn; |
| 115 | let moves = []; |
| 116 | const [sizeX, sizeY] = [V.size.x, V.size.y]; |
| 117 | // All pawns go in the same direction! |
| 118 | const shiftX = -1; |
| 119 | const startRank = color == "w" ? sizeX - 2 : 2; |
| 120 | |
| 121 | // One square forward |
| 122 | const nextRow = V.ComputeX(x + shiftX); |
| 123 | if (this.board[nextRow][y] == V.EMPTY) { |
| 124 | moves.push(this.getBasicMove([x, y], [nextRow, y])); |
| 125 | if ( |
| 126 | x == startRank && |
| 127 | this.pawnFlags[color][y] && |
| 128 | this.board[x + 2 * shiftX][y] == V.EMPTY |
| 129 | ) { |
| 130 | // Two squares jump |
| 131 | moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y])); |
| 132 | } |
| 133 | } |
| 134 | // Captures |
| 135 | for (let shiftY of [-1, 1]) { |
| 136 | if ( |
| 137 | y + shiftY >= 0 && |
| 138 | y + shiftY < sizeY && |
| 139 | this.board[nextRow][y + shiftY] != V.EMPTY && |
| 140 | this.canTake([x, y], [nextRow, y + shiftY]) |
| 141 | ) { |
| 142 | moves.push(this.getBasicMove([x, y], [nextRow, y + shiftY])); |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | return moves; |
| 147 | } |
| 148 | |
| 149 | getPotentialKingMoves(sq) { |
| 150 | return this.getSlideNJumpMoves( |
| 151 | sq, |
| 152 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), |
| 153 | "oneStep" |
| 154 | ); |
| 155 | } |
| 156 | |
| 157 | filterValid(moves) { |
| 158 | const filteredMoves = super.filterValid(moves); |
| 159 | // If at least one full move made, everything is allowed: |
| 160 | if (this.movesCount >= 2) |
| 161 | return filteredMoves; |
| 162 | // Else, forbid check: |
| 163 | const oppCol = V.GetOppCol(this.turn); |
| 164 | return filteredMoves.filter(m => { |
| 165 | this.play(m); |
| 166 | const res = !this.underCheck(oppCol); |
| 167 | this.undo(m); |
| 168 | return res; |
| 169 | }); |
| 170 | } |
| 171 | |
| 172 | isAttackedByPawn([x, y], colors) { |
| 173 | const pawnShift = 1; |
| 174 | const attackerRow = V.ComputeX(x + pawnShift); |
| 175 | for (let c of colors) { |
| 176 | for (let i of [-1, 1]) { |
| 177 | if ( |
| 178 | y + i >= 0 && |
| 179 | y + i < V.size.y && |
| 180 | this.getPiece(attackerRow, y + i) == V.PAWN && |
| 181 | this.getColor(attackerRow, y + i) == c |
| 182 | ) { |
| 183 | return true; |
| 184 | } |
| 185 | } |
| 186 | } |
| 187 | return false; |
| 188 | } |
| 189 | |
| 190 | isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) { |
| 191 | for (let step of steps) { |
| 192 | let rx = V.ComputeX(x + step[0]), |
| 193 | ry = y + step[1]; |
| 194 | while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) { |
| 195 | rx = V.ComputeX(rx + step[0]); |
| 196 | ry += step[1]; |
| 197 | } |
| 198 | if ( |
| 199 | V.OnBoard(rx, ry) && |
| 200 | this.getPiece(rx, ry) === piece && |
| 201 | colors.includes(this.getColor(rx, ry)) |
| 202 | ) { |
| 203 | return true; |
| 204 | } |
| 205 | } |
| 206 | return false; |
| 207 | } |
| 208 | |
| 209 | getFlagsFen() { |
| 210 | // Return pawns flags |
| 211 | let flags = ""; |
| 212 | for (let c of ["w", "b"]) { |
| 213 | for (let i = 0; i < 8; i++) flags += this.pawnFlags[c][i] ? "1" : "0"; |
| 214 | } |
| 215 | return flags; |
| 216 | } |
| 217 | |
| 218 | updateVariables(move) { |
| 219 | const c = move.vanish[0].c; |
| 220 | const secondRank = {"w":6, "b":2}; |
| 221 | // Update king position + flags |
| 222 | if (move.vanish[0].p == V.KING && move.appear.length > 0) { |
| 223 | this.kingPos[c][0] = move.appear[0].x; |
| 224 | this.kingPos[c][1] = move.appear[0].y; |
| 225 | } |
| 226 | else if (move.vanish[0].p == V.PAWN && secondRank[c] == move.start.x) |
| 227 | // This move turns off a 2-squares pawn flag |
| 228 | this.pawnFlags[c][move.start.y] = false; |
| 229 | } |
| 230 | |
| 231 | static get VALUES() { |
| 232 | return { |
| 233 | p: 1, |
| 234 | r: 5, |
| 235 | n: 3, |
| 236 | b: 4, |
| 237 | q: 10, |
| 238 | k: 1000 |
| 239 | }; |
| 240 | } |
| 241 | }; |