chessgroundxx/dist/premove.js

lichess.org chess ui

import * as util from "./util.js";
const bPalace = [
    [4, 10],
    [5, 10],
    [6, 10],
    [4, 9],
    [5, 9],
    [6, 9],
    [4, 8],
    [5, 8],
    [6, 8],
];
const wPalace = [
    [4, 3],
    [5, 3],
    [6, 3],
    [4, 2],
    [5, 2],
    [6, 2],
    [4, 1],
    [5, 1],
    [6, 1],
];
function diff(a, b) {
    return Math.abs(a - b);
}
function pawn(color) {
    return (x1, y1, x2, y2) => (x2 === x1 && (color === "white" ? y2 === y1 + 1 : y2 === y1 - 1)) ||
        (y2 === y1 &&
            (x2 === x1 + 1 || x2 === x1 - 1) &&
            (color === "white" ? y1 > 5 : y1 < 6));
}
export const knight = (x1, y1, x2, y2) => {
    const xd = diff(x1, x2);
    const yd = diff(y1, y2);
    return (xd === 1 && yd === 2) || (xd === 2 && yd === 1);
};
function bishop(color) {
    return (x1, y1, x2, y2) => diff(x1, x2) === diff(y1, y2) &&
        diff(x1, x2) === 2 &&
        (color === "white" ? y2 < 6 : y2 > 5);
}
const rook = (x1, y1, x2, y2) => {
    return x1 === x2 || y1 === y2;
};
export function advisor(color) {
    const palace = color == "white" ? wPalace : bPalace;
    return (x1, y1, x2, y2) => diff(x1, x2) === diff(y1, y2) &&
        diff(x1, x2) === 1 &&
        palace.some((point) => point[0] === x2 && point[1] === y2);
}
function king(color) {
    const palace = color == "white" ? wPalace : bPalace;
    return (x1, y1, x2, y2) => ((x1 === x2 && diff(y1, y2) === 1) || (y1 === y2 && diff(x1, x2) === 1)) &&
        palace.some((point) => point[0] === x2 && point[1] === y2);
}
// function rookFilesOf(pieces: cg.Pieces, color: cg.Color) {
//   const backrank = color === 'white' ? '1' : '8';
//   const files = [];
//   for (const [key, piece] of pieces) {
//     if (key[1] === backrank && piece.color === color && piece.role === 'rook') {
//       files.push(util.key2pos(key)[0]);
//     }
//   }
//   return files;
// }
export function premove(pieces, key) {
    const piece = pieces.get(key);
    if (!piece)
        return [];
    const pos = util.key2pos(key), r = piece.role, mobility = r === "pawn"
        ? pawn(piece.color)
        : r === "knight"
            ? knight
            : r === "bishop"
                ? bishop(piece.color)
                : r === "rook"
                    ? rook
                    : r === "cannon"
                        ? rook
                        : r === "advisor"
                            ? advisor(piece.color)
                            : king(piece.color);
    return util.allPos
        .filter((pos2) => (pos[0] !== pos2[0] || pos[1] !== pos2[1]) &&
        mobility(pos[0], pos[1], pos2[0], pos2[1]))
        .map(util.pos2key);
}
//# sourceMappingURL=premove.js.map