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