| 1 | class LosersRules extends ChessRules |
| 2 | { |
| 3 | static get HasFlags() { return false; } |
| 4 | |
| 5 | getPotentialPawnMoves([x,y]) |
| 6 | { |
| 7 | let moves = super.getPotentialPawnMoves([x,y]); |
| 8 | |
| 9 | // Complete with promotion(s) into king, if possible |
| 10 | const color = this.turn; |
| 11 | const shift = (color == "w" ? -1 : 1); |
| 12 | const lastRank = (color == "w" ? 0 : V.size.x-1); |
| 13 | if (x+shift == lastRank) |
| 14 | { |
| 15 | // Normal move |
| 16 | if (this.board[x+shift][y] == V.EMPTY) |
| 17 | moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:V.KING})); |
| 18 | // Captures |
| 19 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) |
| 20 | && this.board[x+shift][y-1] != V.EMPTY) |
| 21 | { |
| 22 | moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:V.KING})); |
| 23 | } |
| 24 | if (y<V.size.y-1 && this.canTake([x,y], [x+shift,y+1]) |
| 25 | && this.board[x+shift][y+1] != V.EMPTY) |
| 26 | { |
| 27 | moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:V.KING})); |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | return moves; |
| 32 | } |
| 33 | |
| 34 | getPotentialKingMoves(sq) |
| 35 | { |
| 36 | // No castle: |
| 37 | return this.getSlideNJumpMoves(sq, |
| 38 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); |
| 39 | } |
| 40 | |
| 41 | // Stop at the first capture found (if any) |
| 42 | atLeastOneCapture() |
| 43 | { |
| 44 | const color = this.turn; |
| 45 | const oppCol = V.GetOppCol(color); |
| 46 | for (let i=0; i<V.size.x; i++) |
| 47 | { |
| 48 | for (let j=0; j<V.size.y; j++) |
| 49 | { |
| 50 | if (this.board[i][j] != V.EMPTY && this.getColor(i,j) != oppCol) |
| 51 | { |
| 52 | const moves = this.getPotentialMovesFrom([i,j]); |
| 53 | if (moves.length > 0) |
| 54 | { |
| 55 | for (let k=0; k<moves.length; k++) |
| 56 | { |
| 57 | if (moves[k].vanish.length==2 && this.filterValid([moves[k]]).length > 0) |
| 58 | return true; |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | return false; |
| 65 | } |
| 66 | |
| 67 | // Trim all non-capturing moves |
| 68 | static KeepCaptures(moves) |
| 69 | { |
| 70 | return moves.filter(m => { return m.vanish.length == 2; }); |
| 71 | } |
| 72 | |
| 73 | getPossibleMovesFrom(sq) |
| 74 | { |
| 75 | let moves = this.filterValid( this.getPotentialMovesFrom(sq) ); |
| 76 | // This is called from interface: we need to know if a capture is possible |
| 77 | if (this.atLeastOneCapture()) |
| 78 | moves = V.KeepCaptures(moves); |
| 79 | return moves; |
| 80 | } |
| 81 | |
| 82 | getAllValidMoves() |
| 83 | { |
| 84 | let moves = super.getAllValidMoves(); |
| 85 | if (moves.some(m => { return m.vanish.length == 2; })) |
| 86 | moves = V.KeepCaptures(moves); |
| 87 | return moves; |
| 88 | } |
| 89 | |
| 90 | underCheck(color) |
| 91 | { |
| 92 | return false; //No notion of check |
| 93 | } |
| 94 | |
| 95 | getCheckSquares(move) |
| 96 | { |
| 97 | return []; |
| 98 | } |
| 99 | |
| 100 | // No variables update because no royal king + no castling |
| 101 | updateVariables(move) { } |
| 102 | unupdateVariables(move) { } |
| 103 | |
| 104 | checkGameEnd() |
| 105 | { |
| 106 | // No valid move: you win! |
| 107 | return this.turn == "w" ? "1-0" : "0-1"; |
| 108 | } |
| 109 | |
| 110 | static get VALUES() |
| 111 | { |
| 112 | // Experimental... |
| 113 | return { |
| 114 | 'p': 1, |
| 115 | 'r': 7, |
| 116 | 'n': 3, |
| 117 | 'b': 3, |
| 118 | 'q': 5, |
| 119 | 'k': 5 |
| 120 | }; |
| 121 | } |
| 122 | |
| 123 | static get SEARCH_DEPTH() { return 4; } |
| 124 | |
| 125 | evalPosition() |
| 126 | { |
| 127 | return - super.evalPosition(); //better with less material |
| 128 | } |
| 129 | |
| 130 | static GenRandInitFen() |
| 131 | { |
| 132 | let pieces = { "w": new Array(8), "b": new Array(8) }; |
| 133 | // Shuffle pieces on first and last rank |
| 134 | for (let c of ["w","b"]) |
| 135 | { |
| 136 | let positions = range(8); |
| 137 | |
| 138 | // Get random squares for bishops |
| 139 | let randIndex = 2 * randInt(4); |
| 140 | let bishop1Pos = positions[randIndex]; |
| 141 | // The second bishop must be on a square of different color |
| 142 | let randIndex_tmp = 2 * randInt(4) + 1; |
| 143 | let bishop2Pos = positions[randIndex_tmp]; |
| 144 | // Remove chosen squares |
| 145 | positions.splice(Math.max(randIndex,randIndex_tmp), 1); |
| 146 | positions.splice(Math.min(randIndex,randIndex_tmp), 1); |
| 147 | |
| 148 | // Get random squares for knights |
| 149 | randIndex = randInt(6); |
| 150 | let knight1Pos = positions[randIndex]; |
| 151 | positions.splice(randIndex, 1); |
| 152 | randIndex = randInt(5); |
| 153 | let knight2Pos = positions[randIndex]; |
| 154 | positions.splice(randIndex, 1); |
| 155 | |
| 156 | // Get random square for queen |
| 157 | randIndex = randInt(4); |
| 158 | let queenPos = positions[randIndex]; |
| 159 | positions.splice(randIndex, 1); |
| 160 | |
| 161 | // Random square for king (no castle) |
| 162 | randIndex = randInt(3); |
| 163 | let kingPos = positions[randIndex]; |
| 164 | positions.splice(randIndex, 1); |
| 165 | |
| 166 | // Rooks positions are now fixed |
| 167 | let rook1Pos = positions[0]; |
| 168 | let rook2Pos = positions[1]; |
| 169 | |
| 170 | // Finally put the shuffled pieces in the board array |
| 171 | pieces[c][rook1Pos] = 'r'; |
| 172 | pieces[c][knight1Pos] = 'n'; |
| 173 | pieces[c][bishop1Pos] = 'b'; |
| 174 | pieces[c][queenPos] = 'q'; |
| 175 | pieces[c][kingPos] = 'k'; |
| 176 | pieces[c][bishop2Pos] = 'b'; |
| 177 | pieces[c][knight2Pos] = 'n'; |
| 178 | pieces[c][rook2Pos] = 'r'; |
| 179 | } |
| 180 | return pieces["b"].join("") + |
| 181 | "/pppppppp/8/8/8/8/PPPPPPPP/" + |
| 182 | pieces["w"].join("").toUpperCase() + |
| 183 | " w -"; //no en-passant |
| 184 | } |
| 185 | } |