| 1 | import { ChessRules, PiPo, Move } from "@/base_rules"; |
| 2 | |
| 3 | export const VariantRules = class BenedictRules extends ChessRules { |
| 4 | static get HasEnpassant() { |
| 5 | return false; |
| 6 | } |
| 7 | |
| 8 | // TODO(?): some duplicated code in 2 next functions |
| 9 | getSlideNJumpMoves([x, y], steps, oneStep) { |
| 10 | let moves = []; |
| 11 | outerLoop: for (let loop = 0; loop < steps.length; loop++) { |
| 12 | const step = steps[loop]; |
| 13 | let i = x + step[0]; |
| 14 | let j = y + step[1]; |
| 15 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 16 | moves.push(this.getBasicMove([x, y], [i, j])); |
| 17 | if (oneStep) continue outerLoop; |
| 18 | i += step[0]; |
| 19 | j += step[1]; |
| 20 | } |
| 21 | // No capture check: handled elsewhere (next method) |
| 22 | } |
| 23 | return moves; |
| 24 | } |
| 25 | |
| 26 | // Find possible captures from a square |
| 27 | // follow steps from x,y until something is met. |
| 28 | findCaptures([x, y]) { |
| 29 | const color = this.getColor(x, y); |
| 30 | const piece = this.getPiece(x, y); |
| 31 | let squares = []; |
| 32 | const steps = |
| 33 | piece != V.PAWN |
| 34 | ? [V.QUEEN,V.KING].includes(piece) |
| 35 | ? V.steps[V.ROOK].concat(V.steps[V.BISHOP]) |
| 36 | : V.steps[piece] |
| 37 | : color == "w" |
| 38 | ? [ |
| 39 | [-1, -1], |
| 40 | [-1, 1] |
| 41 | ] |
| 42 | : [ |
| 43 | [1, -1], |
| 44 | [1, 1] |
| 45 | ]; |
| 46 | const oneStep = [V.KNIGHT,V.PAWN,V.KING].includes(piece); |
| 47 | outerLoop: for (let loop = 0; loop < steps.length; loop++) { |
| 48 | const step = steps[loop]; |
| 49 | let i = x + step[0]; |
| 50 | let j = y + step[1]; |
| 51 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
| 52 | if (oneStep) continue outerLoop; |
| 53 | i += step[0]; |
| 54 | j += step[1]; |
| 55 | } |
| 56 | if ( |
| 57 | V.OnBoard(i, j) && |
| 58 | this.getColor(i, j) == V.GetOppCol(color) |
| 59 | ) { |
| 60 | // eat! |
| 61 | squares.push([i, j]); |
| 62 | } |
| 63 | } |
| 64 | return squares; |
| 65 | } |
| 66 | |
| 67 | getPotentialPawnMoves([x, y]) { |
| 68 | const color = this.getColor(x, y); |
| 69 | let moves = []; |
| 70 | const sizeY = V.size.y; |
| 71 | const shift = color == "w" ? -1 : 1; |
| 72 | const startRank = color == "w" ? sizeY - 2 : 1; |
| 73 | const firstRank = color == "w" ? sizeY - 1 : 0; |
| 74 | const lastRank = color == "w" ? 0 : sizeY - 1; |
| 75 | |
| 76 | if (x + shift != lastRank) { |
| 77 | // Normal moves |
| 78 | if (this.board[x + shift][y] == V.EMPTY) { |
| 79 | moves.push(this.getBasicMove([x, y], [x + shift, y])); |
| 80 | if ( |
| 81 | [startRank, firstRank].includes(x) && |
| 82 | this.board[x + 2 * shift][y] == V.EMPTY |
| 83 | ) { |
| 84 | // Two squares jump |
| 85 | moves.push(this.getBasicMove([x, y], [x + 2 * shift, y])); |
| 86 | } |
| 87 | } |
| 88 | } |
| 89 | else { |
| 90 | // Promotion |
| 91 | let promotionPieces = [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]; |
| 92 | promotionPieces.forEach(p => { |
| 93 | // Normal move |
| 94 | if (this.board[x + shift][y] == V.EMPTY) |
| 95 | moves.push( |
| 96 | this.getBasicMove([x, y], [x + shift, y], { c: color, p: p }) |
| 97 | ); |
| 98 | }); |
| 99 | } |
| 100 | |
| 101 | // No en passant here |
| 102 | |
| 103 | return moves; |
| 104 | } |
| 105 | |
| 106 | // No "under check" verifications: |
| 107 | getCastleMoves([x, y]) { |
| 108 | const c = this.getColor(x, y); |
| 109 | if (x != (c == "w" ? V.size.x - 1 : 0) || y != this.INIT_COL_KING[c]) |
| 110 | return []; //x isn't first rank, or king has moved (shortcut) |
| 111 | |
| 112 | // Castling ? |
| 113 | const oppCol = V.GetOppCol(c); |
| 114 | let moves = []; |
| 115 | let i = 0; |
| 116 | // King, then rook: |
| 117 | const finalSquares = [ |
| 118 | [2, 3], |
| 119 | [V.size.y - 2, V.size.y - 3] |
| 120 | ]; |
| 121 | castlingCheck: for ( |
| 122 | let castleSide = 0; |
| 123 | castleSide < 2; |
| 124 | castleSide++ //large, then small |
| 125 | ) { |
| 126 | if (this.castleFlags[c][castleSide] >= 8) continue; |
| 127 | // If this code is reached, rooks and king are on initial position |
| 128 | |
| 129 | const rookPos = this.castleFlags[c][castleSide]; |
| 130 | if (this.getColor(x, rookPos) != c) |
| 131 | // Rook is here but changed color |
| 132 | continue; |
| 133 | |
| 134 | // Nothing on the path of the king ? |
| 135 | const finDist = finalSquares[castleSide][0] - y; |
| 136 | let step = finDist / Math.max(1, Math.abs(finDist)); |
| 137 | for (let i = y; i != finalSquares[castleSide][0]; i += step) { |
| 138 | if ( |
| 139 | this.board[x][i] != V.EMPTY && |
| 140 | // NOTE: next check is enough, because of chessboard constraints |
| 141 | (this.getColor(x, i) != c || |
| 142 | ![V.KING, V.ROOK].includes(this.getPiece(x, i))) |
| 143 | ) { |
| 144 | continue castlingCheck; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | // Nothing on the path to the rook? |
| 149 | step = castleSide == 0 ? -1 : 1; |
| 150 | for (i = y + step; i != rookPos; i += step) { |
| 151 | if (this.board[x][i] != V.EMPTY) continue castlingCheck; |
| 152 | } |
| 153 | |
| 154 | // Nothing on final squares, except maybe king and castling rook? |
| 155 | for (i = 0; i < 2; i++) { |
| 156 | if ( |
| 157 | this.board[x][finalSquares[castleSide][i]] != V.EMPTY && |
| 158 | this.getPiece(x, finalSquares[castleSide][i]) != V.KING && |
| 159 | finalSquares[castleSide][i] != rookPos |
| 160 | ) { |
| 161 | continue castlingCheck; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | // If this code is reached, castle is valid |
| 166 | moves.push( |
| 167 | new Move({ |
| 168 | appear: [ |
| 169 | new PiPo({ x: x, y: finalSquares[castleSide][0], p: V.KING, c: c }), |
| 170 | new PiPo({ x: x, y: finalSquares[castleSide][1], p: V.ROOK, c: c }) |
| 171 | ], |
| 172 | vanish: [ |
| 173 | new PiPo({ x: x, y: y, p: V.KING, c: c }), |
| 174 | new PiPo({ x: x, y: rookPos, p: V.ROOK, c: c }) |
| 175 | ], |
| 176 | end: |
| 177 | Math.abs(y - rookPos) <= 2 |
| 178 | ? { x: x, y: rookPos } |
| 179 | : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) } |
| 180 | }) |
| 181 | ); |
| 182 | } |
| 183 | |
| 184 | return moves; |
| 185 | } |
| 186 | |
| 187 | // TODO: appear/vanish description of a move is too verbose for Benedict. |
| 188 | // => Would need a new "flipped" array, to be passed in Game.vue... |
| 189 | getPotentialMovesFrom([x, y]) { |
| 190 | const color = this.turn; |
| 191 | const oppCol = V.GetOppCol(color); |
| 192 | // Get all moves from x,y without captures: |
| 193 | let moves = super.getPotentialMovesFrom([x, y]); |
| 194 | // Add flips: |
| 195 | moves.forEach(m => { |
| 196 | let newAppear = []; |
| 197 | let newVanish = []; |
| 198 | V.PlayOnBoard(this.board, m); |
| 199 | // If castling, m.appear has 2 elements. |
| 200 | // In this case, consider the attacks of moving units only. |
| 201 | // (Sometimes the king or rook doesn't move). |
| 202 | for (let i = 0; i < m.appear.length; i++) { |
| 203 | const a = m.appear[i]; |
| 204 | if (m.vanish[i].x != a.x || m.vanish[i].y != a.y) { |
| 205 | const flipped = this.findCaptures([a.x, a.y]); |
| 206 | flipped.forEach(sq => { |
| 207 | const piece = this.getPiece(sq[0],sq[1]); |
| 208 | const pipoA = new PiPo({ |
| 209 | x:sq[0], |
| 210 | y:sq[1], |
| 211 | c:color, |
| 212 | p:piece |
| 213 | }); |
| 214 | const pipoV = new PiPo({ |
| 215 | x:sq[0], |
| 216 | y:sq[1], |
| 217 | c:oppCol, |
| 218 | p:piece |
| 219 | }); |
| 220 | newAppear.push(pipoA); |
| 221 | newVanish.push(pipoV); |
| 222 | }); |
| 223 | } |
| 224 | } |
| 225 | Array.prototype.push.apply(m.appear, newAppear); |
| 226 | Array.prototype.push.apply(m.vanish, newVanish); |
| 227 | V.UndoOnBoard(this.board, m); |
| 228 | }); |
| 229 | return moves; |
| 230 | } |
| 231 | |
| 232 | // Moves cannot flip our king's color, so all are valid |
| 233 | filterValid(moves) { |
| 234 | return moves; |
| 235 | } |
| 236 | |
| 237 | // No notion of check here: |
| 238 | getCheckSquares() { |
| 239 | return []; |
| 240 | } |
| 241 | |
| 242 | // Stop at the first move found |
| 243 | atLeastOneMove() { |
| 244 | const color = this.turn; |
| 245 | const oppCol = V.GetOppCol(color); |
| 246 | for (let i = 0; i < V.size.x; i++) { |
| 247 | for (let j = 0; j < V.size.y; j++) { |
| 248 | if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) { |
| 249 | const moves = this.getPotentialMovesFrom([i, j]); |
| 250 | if (moves.length > 0) |
| 251 | return true; |
| 252 | } |
| 253 | } |
| 254 | } |
| 255 | return false; |
| 256 | } |
| 257 | |
| 258 | getCurrentScore() { |
| 259 | const color = this.turn; |
| 260 | // Did a king change color? |
| 261 | const kp = this.kingPos[color]; |
| 262 | if (this.getColor(kp[0], kp[1]) != color) |
| 263 | return color == "w" ? "0-1" : "1-0"; |
| 264 | if (this.atLeastOneMove()) |
| 265 | return "*"; |
| 266 | // Stalemate: |
| 267 | return "1/2"; |
| 268 | } |
| 269 | |
| 270 | getNotation(move) { |
| 271 | // Just remove flips: |
| 272 | const basicMove = { |
| 273 | appear: [move.appear[0]], |
| 274 | vanish: [move.vanish[0]], |
| 275 | start: move.start, |
| 276 | end: move.end |
| 277 | }; |
| 278 | return super.getNotation(basicMove); |
| 279 | } |
| 280 | }; |