| 1 | class UpsidedownRules extends ChessRules |
| 2 | { |
| 3 | static get HasFlags() { return false; } |
| 4 | |
| 5 | static get HasEnpassant() { return false; } |
| 6 | |
| 7 | getPotentialKingMoves(sq) |
| 8 | { |
| 9 | // No castle |
| 10 | return this.getSlideNJumpMoves(sq, |
| 11 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); |
| 12 | } |
| 13 | |
| 14 | static GenRandInitFen() |
| 15 | { |
| 16 | let pieces = { "w": new Array(8), "b": new Array(8) }; |
| 17 | for (let c of ["w","b"]) |
| 18 | { |
| 19 | let positions = range(8); |
| 20 | |
| 21 | let randIndex = randInt(8); |
| 22 | const kingPos = positions[randIndex]; |
| 23 | positions.splice(randIndex, 1); |
| 24 | |
| 25 | // At least a knight must be next to the king: |
| 26 | let knight1Pos = undefined; |
| 27 | if (kingPos == 0) |
| 28 | knight1Pos = 1; |
| 29 | else if (kingPos == V.size.y-1) |
| 30 | knight1Pos = V.size.y-2; |
| 31 | else |
| 32 | knight1Pos = kingPos + (Math.randInt() < 0.5 ? 1 : -1); |
| 33 | // Search for knight1Pos index in positions and remove it |
| 34 | const knight1Index = positions.indexOf(knight1Pos); |
| 35 | positions.splice(knight1Index, 1); |
| 36 | |
| 37 | // King+knight1 are on two consecutive squares: one light, one dark |
| 38 | randIndex = 2 * randInt(3); |
| 39 | const bishop1Pos = positions[randIndex]; |
| 40 | let randIndex_tmp = 2 * randInt(3) + 1; |
| 41 | const bishop2Pos = positions[randIndex_tmp]; |
| 42 | positions.splice(Math.max(randIndex,randIndex_tmp), 1); |
| 43 | positions.splice(Math.min(randIndex,randIndex_tmp), 1); |
| 44 | |
| 45 | randIndex = randInt(4); |
| 46 | const knight2Pos = positions[randIndex]; |
| 47 | positions.splice(randIndex, 1); |
| 48 | |
| 49 | randIndex = randInt(3); |
| 50 | const queenPos = positions[randIndex]; |
| 51 | positions.splice(randIndex, 1); |
| 52 | |
| 53 | const rook1Pos = positions[0]; |
| 54 | const rook2Pos = positions[1]; |
| 55 | |
| 56 | pieces[c][rook1Pos] = 'r'; |
| 57 | pieces[c][knight1Pos] = 'n'; |
| 58 | pieces[c][bishop1Pos] = 'b'; |
| 59 | pieces[c][queenPos] = 'q'; |
| 60 | pieces[c][kingPos] = 'k'; |
| 61 | pieces[c][bishop2Pos] = 'b'; |
| 62 | pieces[c][knight2Pos] = 'n'; |
| 63 | pieces[c][rook2Pos] = 'r'; |
| 64 | } |
| 65 | return pieces["w"].join("").toUpperCase() + |
| 66 | "/PPPPPPPP/8/8/8/8/pppppppp/" + |
| 67 | pieces["b"].join("") + |
| 68 | " w"; //no castle, no en-passant |
| 69 | } |
| 70 | } |