| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | import { ArrayFun } from "@/utils/array"; |
| 3 | import { randInt, shuffle } from "@/utils/alea"; |
| 4 | |
| 5 | export const VariantRules = class RoyalraceRules extends ChessRules { |
| 6 | static get HasFlags() { |
| 7 | return false; |
| 8 | } |
| 9 | |
| 10 | static get HasEnpassant() { |
| 11 | return false; |
| 12 | } |
| 13 | |
| 14 | static get CanFlip() { |
| 15 | return false; |
| 16 | } |
| 17 | |
| 18 | static get size() { |
| 19 | return { x: 11, y: 11 }; |
| 20 | } |
| 21 | |
| 22 | static GenRandInitFen() { |
| 23 | let pieces = { w: new Array(10), b: new Array(10) }; |
| 24 | // Shuffle pieces on first and second rank |
| 25 | for (let c of ["w", "b"]) { |
| 26 | // Reserve 4 and 5 which are pawns positions |
| 27 | let positions = ArrayFun.range(10).filter(i => i != 4 && i != 5); |
| 28 | |
| 29 | // Get random squares for bishops |
| 30 | let randIndex = 2 * randInt(4); |
| 31 | const bishop1Pos = positions[randIndex]; |
| 32 | // The second bishop must be on a square of different color |
| 33 | let randIndex_tmp = 2 * randInt(4) + 1; |
| 34 | const bishop2Pos = positions[randIndex_tmp]; |
| 35 | // Remove chosen squares |
| 36 | positions.splice(Math.max(randIndex, randIndex_tmp), 1); |
| 37 | positions.splice(Math.min(randIndex, randIndex_tmp), 1); |
| 38 | |
| 39 | // Place the king at random on (remaining squares of) first row |
| 40 | let maxIndex = 4; |
| 41 | if (positions[maxIndex-1] >= 4) |
| 42 | maxIndex--; |
| 43 | if (positions[maxIndex-1] >= 4) |
| 44 | maxIndex--; |
| 45 | randIndex = randInt(maxIndex); |
| 46 | const kingPos = positions[randIndex]; |
| 47 | positions.splice(randIndex, 1); |
| 48 | |
| 49 | // Get random squares for knights |
| 50 | randIndex = randInt(5); |
| 51 | const knight1Pos = positions[randIndex]; |
| 52 | positions.splice(randIndex, 1); |
| 53 | randIndex = randInt(4); |
| 54 | const knight2Pos = positions[randIndex]; |
| 55 | positions.splice(randIndex, 1); |
| 56 | |
| 57 | // Get random squares for rooks |
| 58 | randIndex = randInt(3); |
| 59 | const rook1Pos = positions[randIndex]; |
| 60 | positions.splice(randIndex, 1); |
| 61 | randIndex = randInt(2); |
| 62 | const rook2Pos = positions[randIndex]; |
| 63 | positions.splice(randIndex, 1); |
| 64 | |
| 65 | // Queen position is now determined, |
| 66 | // because pawns are not placed at random |
| 67 | const queenPos = positions[0]; |
| 68 | |
| 69 | // Finally put the shuffled pieces in the board array |
| 70 | pieces[c][rook1Pos] = "r"; |
| 71 | pieces[c][knight1Pos] = "n"; |
| 72 | pieces[c][bishop1Pos] = "b"; |
| 73 | pieces[c][queenPos] = "q"; |
| 74 | pieces[c][kingPos] = "k"; |
| 75 | pieces[c][bishop2Pos] = "b"; |
| 76 | pieces[c][knight2Pos] = "n"; |
| 77 | pieces[c][rook2Pos] = "r"; |
| 78 | pieces[c][4] = "p"; |
| 79 | pieces[c][5] = "p"; |
| 80 | } |
| 81 | const whiteFen = pieces["w"].join("").toUpperCase(); |
| 82 | const blackFen = pieces["b"].join(""); |
| 83 | return ( |
| 84 | "11/11/11/11/11/11/11/11/11/" + |
| 85 | whiteFen.substr(5).split("").reverse().join("") + |
| 86 | "1" + |
| 87 | blackFen.substr(5).split("").reverse().join("") + |
| 88 | "/" + |
| 89 | whiteFen.substr(0,5) + "1" + blackFen.substr(0,5) + |
| 90 | " w 0" |
| 91 | ); |
| 92 | } |
| 93 | |
| 94 | getPotentialPawnMoves([x, y]) { |
| 95 | // Normal moves (as a rook) |
| 96 | let moves = |
| 97 | this.getSlideNJumpMoves([x, y], V.steps[V.ROOK]).filter(m => { |
| 98 | // Remove captures. Alt: redefine canTake |
| 99 | return m.vanish.length == 1; |
| 100 | }); |
| 101 | |
| 102 | // Captures |
| 103 | const shiftX = -1; |
| 104 | for (let shiftY of [-1, 1]) { |
| 105 | if ( |
| 106 | V.OnBoard(x + shiftX, y + shiftY) && |
| 107 | this.board[x + shiftX][y + shiftY] != V.EMPTY && |
| 108 | this.canTake([x, y], [x + shiftX, y + shiftY]) |
| 109 | ) { |
| 110 | moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY])); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | return moves; |
| 115 | } |
| 116 | |
| 117 | getPotentialKnightMoves(sq) { |
| 118 | // Knight becomes knightrider: |
| 119 | return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT]); |
| 120 | } |
| 121 | |
| 122 | // What are the king moves from square x,y ? |
| 123 | getPotentialKingMoves(sq) { |
| 124 | return this.getSlideNJumpMoves( |
| 125 | sq, |
| 126 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), |
| 127 | "oneStep" |
| 128 | ); |
| 129 | } |
| 130 | |
| 131 | filterValid(moves) { |
| 132 | if (moves.length == 0) return []; |
| 133 | const color = this.turn; |
| 134 | const oppCol = V.GetOppCol(color); |
| 135 | return moves.filter(m => { |
| 136 | this.play(m); |
| 137 | // Giving check is forbidden as well: |
| 138 | const res = !this.underCheck(color) && !this.underCheck(oppCol); |
| 139 | this.undo(m); |
| 140 | return res; |
| 141 | }); |
| 142 | } |
| 143 | |
| 144 | isAttackedByPawn([x, y], colors) { |
| 145 | const pawnShift = 1; |
| 146 | if (x + pawnShift < V.size.x) { |
| 147 | for (let c of colors) { |
| 148 | for (let i of [-1, 1]) { |
| 149 | if ( |
| 150 | y + i >= 0 && |
| 151 | y + i < V.size.y && |
| 152 | this.getPiece(x + pawnShift, y + i) == V.PAWN && |
| 153 | this.getColor(x + pawnShift, y + i) == c |
| 154 | ) { |
| 155 | return true; |
| 156 | } |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | return false; |
| 161 | } |
| 162 | |
| 163 | isAttackedByKnight(sq, colors) { |
| 164 | return this.isAttackedBySlideNJump( |
| 165 | sq, |
| 166 | colors, |
| 167 | V.KNIGHT, |
| 168 | V.steps[V.KNIGHT] |
| 169 | ); |
| 170 | } |
| 171 | |
| 172 | getCurrentScore() { |
| 173 | // Turn has changed: |
| 174 | const color = V.GetOppCol(this.turn); |
| 175 | if (this.kingPos[color][0] == 0) |
| 176 | // The opposing edge is reached! |
| 177 | return color == "w" ? "1-0" : "0-1"; |
| 178 | return "*"; |
| 179 | } |
| 180 | |
| 181 | static get SEARCH_DEPTH() { |
| 182 | return 2; |
| 183 | } |
| 184 | |
| 185 | static get VALUES() { |
| 186 | return { |
| 187 | p: 2, |
| 188 | r: 5, |
| 189 | n: 3, |
| 190 | b: 3, |
| 191 | q: 9, |
| 192 | k: 1000 |
| 193 | }; |
| 194 | } |
| 195 | |
| 196 | evalPosition() { |
| 197 | // Count material: |
| 198 | let evaluation = super.evalPosition(); |
| 199 | // Ponder with king position: |
| 200 | return evaluation/5 + this.kingPos["b"][0] - this.kingPos["w"][0]; |
| 201 | } |
| 202 | |
| 203 | getNotation(move) { |
| 204 | // Since pawns are much more mobile, treat them as other pieces: |
| 205 | return ( |
| 206 | move.vanish[0].p.toUpperCase() + |
| 207 | (move.vanish.length > move.appear.length ? "x" : "") + |
| 208 | V.CoordsToSquare(move.end) |
| 209 | ); |
| 210 | } |
| 211 | }; |