| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | |
| 3 | export class WormholeRules extends ChessRules { |
| 4 | static get HasFlags() { |
| 5 | return false; |
| 6 | } |
| 7 | |
| 8 | static get HasEnpassant() { |
| 9 | return false; |
| 10 | } |
| 11 | |
| 12 | static get HOLE() { |
| 13 | return "xx"; |
| 14 | } |
| 15 | |
| 16 | static board2fen(b) { |
| 17 | if (b[0] == 'x') return 'x'; |
| 18 | return ChessRules.board2fen(b); |
| 19 | } |
| 20 | |
| 21 | static fen2board(f) { |
| 22 | if (f == 'x') return V.HOLE; |
| 23 | return ChessRules.fen2board(f); |
| 24 | } |
| 25 | |
| 26 | getPpath(b) { |
| 27 | if (b[0] == 'x') return "Wormhole/hole"; |
| 28 | return b; |
| 29 | } |
| 30 | |
| 31 | static IsGoodPosition(position) { |
| 32 | if (position.length == 0) return false; |
| 33 | const rows = position.split("/"); |
| 34 | if (rows.length != V.size.x) return false; |
| 35 | let kings = { "k": 0, "K": 0 }; |
| 36 | for (let row of rows) { |
| 37 | let sumElts = 0; |
| 38 | for (let i = 0; i < row.length; i++) { |
| 39 | if (['K','k'].includes(row[i])) kings[row[i]]++; |
| 40 | if (['x'].concat(V.PIECES).includes(row[i].toLowerCase())) sumElts++; |
| 41 | else { |
| 42 | const num = parseInt(row[i], 10); |
| 43 | if (isNaN(num)) return false; |
| 44 | sumElts += num; |
| 45 | } |
| 46 | } |
| 47 | if (sumElts != V.size.y) return false; |
| 48 | } |
| 49 | if (Object.values(kings).some(v => v != 1)) return false; |
| 50 | return true; |
| 51 | } |
| 52 | |
| 53 | getSquareAfter(square, movement) { |
| 54 | let shift1, shift2; |
| 55 | if (Array.isArray(movement[0])) { |
| 56 | // A knight |
| 57 | shift1 = movement[0]; |
| 58 | shift2 = movement[1]; |
| 59 | } else { |
| 60 | shift1 = movement; |
| 61 | shift2 = null; |
| 62 | } |
| 63 | const tryMove = (init, shift) => { |
| 64 | let step = [ |
| 65 | shift[0] / Math.abs(shift[0]) || 0, |
| 66 | shift[1] / Math.abs(shift[1]) || 0, |
| 67 | ]; |
| 68 | const nbSteps = Math.max(Math.abs(shift[0]), Math.abs(shift[1])); |
| 69 | let stepsAchieved = 0; |
| 70 | let sq = [init[0] + step[0], init[1] + step[1]]; |
| 71 | while (V.OnBoard(sq[0],sq[1])) { |
| 72 | if (this.board[sq[0]][sq[1]] != V.HOLE) |
| 73 | stepsAchieved++; |
| 74 | if (stepsAchieved < nbSteps) { |
| 75 | sq[0] += step[0]; |
| 76 | sq[1] += step[1]; |
| 77 | } |
| 78 | else break; |
| 79 | } |
| 80 | if (stepsAchieved < nbSteps) |
| 81 | // The move is impossible |
| 82 | return null; |
| 83 | return sq; |
| 84 | }; |
| 85 | // First, apply shift1 |
| 86 | let dest = tryMove(square, shift1); |
| 87 | if (dest && shift2) |
| 88 | // A knight: apply second shift |
| 89 | dest = tryMove(dest, shift2); |
| 90 | return dest; |
| 91 | } |
| 92 | |
| 93 | // NOTE (TODO?): some extra work done in some function because informations |
| 94 | // on one step should ease the computation for a step in the same direction. |
| 95 | static get steps() { |
| 96 | return { |
| 97 | r: [ |
| 98 | [-1, 0], |
| 99 | [1, 0], |
| 100 | [0, -1], |
| 101 | [0, 1], |
| 102 | [-2, 0], |
| 103 | [2, 0], |
| 104 | [0, -2], |
| 105 | [0, 2] |
| 106 | ], |
| 107 | // Decompose knight movements into one step orthogonal + one diagonal |
| 108 | n: [ |
| 109 | [[0, -1], [-1, -1]], |
| 110 | [[0, -1], [1, -1]], |
| 111 | [[-1, 0], [-1,-1]], |
| 112 | [[-1, 0], [-1, 1]], |
| 113 | [[0, 1], [-1, 1]], |
| 114 | [[0, 1], [1, 1]], |
| 115 | [[1, 0], [1, -1]], |
| 116 | [[1, 0], [1, 1]] |
| 117 | ], |
| 118 | b: [ |
| 119 | [-1, -1], |
| 120 | [-1, 1], |
| 121 | [1, -1], |
| 122 | [1, 1], |
| 123 | [-2, -2], |
| 124 | [-2, 2], |
| 125 | [2, -2], |
| 126 | [2, 2] |
| 127 | ], |
| 128 | k: [ |
| 129 | [-1, 0], |
| 130 | [1, 0], |
| 131 | [0, -1], |
| 132 | [0, 1], |
| 133 | [-1, -1], |
| 134 | [-1, 1], |
| 135 | [1, -1], |
| 136 | [1, 1] |
| 137 | ] |
| 138 | }; |
| 139 | } |
| 140 | |
| 141 | getJumpMoves([x, y], steps) { |
| 142 | let moves = []; |
| 143 | for (let step of steps) { |
| 144 | const sq = this.getSquareAfter([x,y], step); |
| 145 | if (sq && |
| 146 | ( |
| 147 | this.board[sq[0]][sq[1]] == V.EMPTY || |
| 148 | this.canTake([x, y], sq) |
| 149 | ) |
| 150 | ) { |
| 151 | moves.push(this.getBasicMove([x, y], sq)); |
| 152 | } |
| 153 | } |
| 154 | return moves; |
| 155 | } |
| 156 | |
| 157 | // What are the pawn moves from square x,y ? |
| 158 | getPotentialPawnMoves([x, y]) { |
| 159 | const color = this.turn; |
| 160 | let moves = []; |
| 161 | const [sizeX, sizeY] = [V.size.x, V.size.y]; |
| 162 | const shiftX = color == "w" ? -1 : 1; |
| 163 | const startRank = color == "w" ? sizeX - 2 : 1; |
| 164 | const lastRank = color == "w" ? 0 : sizeX - 1; |
| 165 | |
| 166 | const sq1 = this.getSquareAfter([x,y], [shiftX,0]); |
| 167 | if (sq1 && this.board[sq1[0]][y] == V.EMPTY) { |
| 168 | // One square forward (cannot be a promotion) |
| 169 | moves.push(this.getBasicMove([x, y], [sq1[0], y])); |
| 170 | if (x == startRank) { |
| 171 | // If two squares after is available, then move is possible |
| 172 | const sq2 = this.getSquareAfter([x,y], [2*shiftX,0]); |
| 173 | if (sq2 && this.board[sq2[0]][y] == V.EMPTY) |
| 174 | // Two squares jump |
| 175 | moves.push(this.getBasicMove([x, y], [sq2[0], y])); |
| 176 | } |
| 177 | } |
| 178 | // Captures |
| 179 | for (let shiftY of [-1, 1]) { |
| 180 | const sq = this.getSquareAfter([x,y], [shiftX,shiftY]); |
| 181 | if ( |
| 182 | !!sq && |
| 183 | this.board[sq[0]][sq[1]] != V.EMPTY && |
| 184 | this.canTake([x, y], [sq[0], sq[1]]) |
| 185 | ) { |
| 186 | const finalPieces = sq[0] == lastRank |
| 187 | ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN] |
| 188 | : [V.PAWN]; |
| 189 | for (let piece of finalPieces) { |
| 190 | moves.push( |
| 191 | this.getBasicMove([x, y], [sq[0], sq[1]], { |
| 192 | c: color, |
| 193 | p: piece |
| 194 | }) |
| 195 | ); |
| 196 | } |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | return moves; |
| 201 | } |
| 202 | |
| 203 | getPotentialRookMoves(sq) { |
| 204 | return this.getJumpMoves(sq, V.steps[V.ROOK]); |
| 205 | } |
| 206 | |
| 207 | getPotentialKnightMoves(sq) { |
| 208 | return this.getJumpMoves(sq, V.steps[V.KNIGHT]); |
| 209 | } |
| 210 | |
| 211 | getPotentialBishopMoves(sq) { |
| 212 | return this.getJumpMoves(sq, V.steps[V.BISHOP]); |
| 213 | } |
| 214 | |
| 215 | getPotentialQueenMoves(sq) { |
| 216 | return this.getJumpMoves( |
| 217 | sq, |
| 218 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]) |
| 219 | ); |
| 220 | } |
| 221 | |
| 222 | getPotentialKingMoves(sq) { |
| 223 | return this.getJumpMoves(sq, V.steps[V.KING]); |
| 224 | } |
| 225 | |
| 226 | isAttackedByJump([x, y], color, piece, steps) { |
| 227 | for (let step of steps) { |
| 228 | const sq = this.getSquareAfter([x,y], step); |
| 229 | if ( |
| 230 | sq && |
| 231 | this.getPiece(sq[0], sq[1]) == piece && |
| 232 | this.getColor(sq[0], sq[1]) == color |
| 233 | ) { |
| 234 | return true; |
| 235 | } |
| 236 | } |
| 237 | return false; |
| 238 | } |
| 239 | |
| 240 | isAttackedByPawn([x, y], color) { |
| 241 | const pawnShift = (color == "w" ? 1 : -1); |
| 242 | for (let i of [-1, 1]) { |
| 243 | const sq = this.getSquareAfter([x,y], [pawnShift,i]); |
| 244 | if ( |
| 245 | sq && |
| 246 | this.getPiece(sq[0], sq[1]) == V.PAWN && |
| 247 | this.getColor(sq[0], sq[1]) == color |
| 248 | ) { |
| 249 | return true; |
| 250 | } |
| 251 | } |
| 252 | return false; |
| 253 | } |
| 254 | |
| 255 | isAttackedByRook(sq, color) { |
| 256 | return this.isAttackedByJump(sq, color, V.ROOK, V.steps[V.ROOK]); |
| 257 | } |
| 258 | |
| 259 | isAttackedByKnight(sq, color) { |
| 260 | // NOTE: knight attack is not symmetric in this variant: |
| 261 | // steps order need to be reversed. |
| 262 | return this.isAttackedByJump( |
| 263 | sq, |
| 264 | color, |
| 265 | V.KNIGHT, |
| 266 | V.steps[V.KNIGHT].map(s => s.reverse()) |
| 267 | ); |
| 268 | } |
| 269 | |
| 270 | isAttackedByBishop(sq, color) { |
| 271 | return this.isAttackedByJump(sq, color, V.BISHOP, V.steps[V.BISHOP]); |
| 272 | } |
| 273 | |
| 274 | isAttackedByQueen(sq, color) { |
| 275 | return this.isAttackedByJump( |
| 276 | sq, |
| 277 | color, |
| 278 | V.QUEEN, |
| 279 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]) |
| 280 | ); |
| 281 | } |
| 282 | |
| 283 | isAttackedByKing(sq, color) { |
| 284 | return this.isAttackedByJump(sq, color, V.KING, V.steps[V.KING]); |
| 285 | } |
| 286 | |
| 287 | // NOTE: altering move in getBasicMove doesn't work and wouldn't be logical. |
| 288 | // This is a side-effect on board generated by the move. |
| 289 | static PlayOnBoard(board, move) { |
| 290 | board[move.vanish[0].x][move.vanish[0].y] = V.HOLE; |
| 291 | for (let psq of move.appear) board[psq.x][psq.y] = psq.c + psq.p; |
| 292 | } |
| 293 | |
| 294 | getCurrentScore() { |
| 295 | if (this.atLeastOneMove()) return "*"; |
| 296 | // No valid move: I lose |
| 297 | return this.turn == "w" ? "0-1" : "1-0"; |
| 298 | } |
| 299 | |
| 300 | static get SEARCH_DEPTH() { |
| 301 | return 2; |
| 302 | } |
| 303 | |
| 304 | evalPosition() { |
| 305 | let evaluation = 0; |
| 306 | for (let i = 0; i < V.size.x; i++) { |
| 307 | for (let j = 0; j < V.size.y; j++) { |
| 308 | if (![V.EMPTY,V.HOLE].includes(this.board[i][j])) { |
| 309 | const sign = this.getColor(i, j) == "w" ? 1 : -1; |
| 310 | evaluation += sign * V.VALUES[this.getPiece(i, j)]; |
| 311 | } |
| 312 | } |
| 313 | } |
| 314 | return evaluation; |
| 315 | } |
| 316 | |
| 317 | getNotation(move) { |
| 318 | const piece = this.getPiece(move.start.x, move.start.y); |
| 319 | // Indicate start square + dest square, because holes distort the board |
| 320 | let notation = |
| 321 | (piece != V.PAWN ? piece.toUpperCase() : "") + |
| 322 | V.CoordsToSquare(move.start) + |
| 323 | (move.vanish.length > move.appear.length ? "x" : "") + |
| 324 | V.CoordsToSquare(move.end); |
| 325 | if (piece == V.PAWN && move.appear[0].p != V.PAWN) |
| 326 | // Promotion |
| 327 | notation += "=" + move.appear[0].p.toUpperCase(); |
| 328 | return notation; |
| 329 | } |
| 330 | }; |