| 1 | class MagneticRules extends ChessRules |
| 2 | { |
| 3 | static get HasEnpassant() { return false; } |
| 4 | |
| 5 | getPotentialMovesFrom([x,y]) |
| 6 | { |
| 7 | let standardMoves = super.getPotentialMovesFrom([x,y]); |
| 8 | let moves = []; |
| 9 | standardMoves.forEach(m => { |
| 10 | let newMove_s = this.applyMagneticLaws(m); |
| 11 | if (newMove_s.length == 1) |
| 12 | moves.push(newMove_s[0]); |
| 13 | else //promotion |
| 14 | moves = moves.concat(newMove_s); |
| 15 | }); |
| 16 | return moves; |
| 17 | } |
| 18 | |
| 19 | // Complete a move with magnetic actions |
| 20 | // TODO: job is done multiple times for (normal) promotions. |
| 21 | applyMagneticLaws(move) |
| 22 | { |
| 23 | if (move.appear[0].p == V.KING && move.appear.length==1) |
| 24 | return [move]; //kings are not charged |
| 25 | const aIdx = (move.appear[0].p != V.KING ? 0 : 1); //if castling, rook is charged |
| 26 | const [x,y] = [move.appear[aIdx].x, move.appear[aIdx].y]; |
| 27 | const color = this.turn; |
| 28 | const lastRank = (color=="w" ? 0 : 7); |
| 29 | const standardMove = JSON.parse(JSON.stringify(move)); |
| 30 | this.play(standardMove); |
| 31 | for (let step of [[-1,0],[1,0],[0,-1],[0,1]]) |
| 32 | { |
| 33 | let [i,j] = [x+step[0],y+step[1]]; |
| 34 | while (V.OnBoard(i,j)) |
| 35 | { |
| 36 | if (this.board[i][j] != V.EMPTY) |
| 37 | { |
| 38 | // Found something. Same color or not? |
| 39 | if (this.getColor(i,j) != color) |
| 40 | { |
| 41 | // Attraction |
| 42 | if ((Math.abs(i-x)>=2 || Math.abs(j-y)>=2) && this.getPiece(i,j) != V.KING) |
| 43 | { |
| 44 | move.vanish.push( |
| 45 | new PiPo({ |
| 46 | p:this.getPiece(i,j), |
| 47 | c:this.getColor(i,j), |
| 48 | x:i, |
| 49 | y:j |
| 50 | }) |
| 51 | ); |
| 52 | move.appear.push( |
| 53 | new PiPo({ |
| 54 | p:this.getPiece(i,j), |
| 55 | c:this.getColor(i,j), |
| 56 | x:x+step[0], |
| 57 | y:y+step[1] |
| 58 | }) |
| 59 | ); |
| 60 | } |
| 61 | } |
| 62 | else |
| 63 | { |
| 64 | // Repulsion |
| 65 | if (this.getPiece(i,j) != V.KING) |
| 66 | { |
| 67 | // Push it until we meet an obstacle or edge of the board |
| 68 | let [ii,jj] = [i+step[0],j+step[1]]; |
| 69 | while (V.OnBoard(ii,jj)) |
| 70 | { |
| 71 | if (this.board[ii][jj] != V.EMPTY) |
| 72 | break; |
| 73 | ii += step[0]; |
| 74 | jj += step[1]; |
| 75 | } |
| 76 | ii -= step[0]; |
| 77 | jj -= step[1]; |
| 78 | if (Math.abs(ii-i)>=1 || Math.abs(jj-j)>=1) |
| 79 | { |
| 80 | move.vanish.push( |
| 81 | new PiPo({ |
| 82 | p:this.getPiece(i,j), |
| 83 | c:this.getColor(i,j), |
| 84 | x:i, |
| 85 | y:j |
| 86 | }) |
| 87 | ); |
| 88 | move.appear.push( |
| 89 | new PiPo({ |
| 90 | p:this.getPiece(i,j), |
| 91 | c:this.getColor(i,j), |
| 92 | x:ii, |
| 93 | y:jj |
| 94 | }) |
| 95 | ); |
| 96 | } |
| 97 | } |
| 98 | } |
| 99 | break; |
| 100 | } |
| 101 | i += step[0]; |
| 102 | j += step[1]; |
| 103 | } |
| 104 | } |
| 105 | this.undo(standardMove); |
| 106 | let moves = []; |
| 107 | // Scan move for pawn (max 1) on 8th rank |
| 108 | for (let i=1; i<move.appear.length; i++) |
| 109 | { |
| 110 | if (move.appear[i].p==V.PAWN && move.appear[i].c==color |
| 111 | && move.appear[i].x==lastRank) |
| 112 | { |
| 113 | move.appear[i].p = V.ROOK; |
| 114 | moves.push(move); |
| 115 | for (let piece of [V.KNIGHT, V.BISHOP, V.QUEEN]) |
| 116 | { |
| 117 | let cmove = JSON.parse(JSON.stringify(move)); |
| 118 | cmove.appear[i].p = piece; |
| 119 | moves.push(cmove); |
| 120 | } |
| 121 | // Swap appear[i] and appear[0] for moves presentation (TODO: this is awkward) |
| 122 | moves.forEach(m => { |
| 123 | let tmp = m.appear[0]; |
| 124 | m.appear[0] = m.appear[i]; |
| 125 | m.appear[i] = tmp; |
| 126 | }); |
| 127 | break; |
| 128 | } |
| 129 | } |
| 130 | if (moves.length == 0) //no pawn on 8th rank |
| 131 | moves.push(move); |
| 132 | return moves; |
| 133 | } |
| 134 | |
| 135 | atLeastOneMove() |
| 136 | { |
| 137 | if (this.kingPos[this.turn][0] < 0) |
| 138 | return false; |
| 139 | return true; //TODO: is it right? |
| 140 | } |
| 141 | |
| 142 | underCheck(color) |
| 143 | { |
| 144 | return false; //there is no check |
| 145 | } |
| 146 | |
| 147 | getCheckSquares(move) |
| 148 | { |
| 149 | return []; |
| 150 | } |
| 151 | |
| 152 | updateVariables(move) |
| 153 | { |
| 154 | super.updateVariables(move); |
| 155 | const c = move.vanish[0].c; |
| 156 | if (move.vanish.length >= 2 && move.vanish[1].p == V.KING) |
| 157 | { |
| 158 | // We took opponent king ! |
| 159 | const oppCol = this.getOppCol(c); |
| 160 | this.kingPos[oppCol] = [-1,-1]; |
| 161 | this.castleFlags[oppCol] = [false,false]; |
| 162 | } |
| 163 | // Did we magnetically move our (init) rooks or opponents' ones ? |
| 164 | const firstRank = (c == "w" ? 7 : 0); |
| 165 | const oppFirstRank = 7 - firstRank; |
| 166 | const oppCol = this.getOppCol(c); |
| 167 | move.vanish.forEach(psq => { |
| 168 | if (psq.x == firstRank && this.INIT_COL_ROOK[c].includes(psq.y)) |
| 169 | this.castleFlags[c][psq.y==this.INIT_COL_ROOK[c][0] ? 0 : 1] = false; |
| 170 | else if (psq.x == oppFirstRank && this.INIT_COL_ROOK[oppCol].includes(psq.y)) |
| 171 | this.castleFlags[oppCol][psq.y==this.INIT_COL_ROOK[oppCol][0] ? 0 : 1] = false; |
| 172 | }); |
| 173 | } |
| 174 | |
| 175 | unupdateVariables(move) |
| 176 | { |
| 177 | super.unupdateVariables(move); |
| 178 | const c = move.vanish[0].c; |
| 179 | const oppCol = this.getOppCol(c); |
| 180 | if (this.kingPos[oppCol][0] < 0) |
| 181 | { |
| 182 | // Last move took opponent's king |
| 183 | for (let psq of move.vanish) |
| 184 | { |
| 185 | if (psq.p == 'k') |
| 186 | { |
| 187 | this.kingPos[oppCol] = [psq.x, psq.y]; |
| 188 | break; |
| 189 | } |
| 190 | } |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | checkGameEnd() |
| 195 | { |
| 196 | // No valid move: our king disappeared |
| 197 | return this.turn == "w" ? "0-1" : "1-0"; |
| 198 | } |
| 199 | |
| 200 | static get THRESHOLD_MATE() |
| 201 | { |
| 202 | return 500; //checkmates evals may be slightly below 1000 |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | const VariantRules = MagneticRules; |