chess-legal-moves/dist/createNewGameScan/moves/kingMoves.js

Analyses a given chess game position in Fen notation to return legal moves and provides the next game position after a given move

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.getKingAndColor = exports.kingMoves = void 0;
var BitBoard_1 = require("../BitBoard/BitBoard");
var positionsHashTable_1 = require("./../BitBoard/positionsHashTable");
function kingMoves(board, hasToPlay) {
    // @TODO document
    var opponent = hasToPlay === 'w' ? 'blacks' : 'whites';
    var allKingMovesTable = generateAllKingMovesBBTable();
    var kingList = board[getKingAndColor(hasToPlay)]
        .extractBits()
        .map(function (kingPositionCode) {
        var from = positionsHashTable_1.positionsTable[kingPositionCode];
        var quietMoves = allKingMovesTable[kingPositionCode]
            .and(board.quietDestinations)
            .extractBits()
            .map(function (knightDestination) { return positionsHashTable_1.positionsTable[knightDestination]; });
        var killMoves = allKingMovesTable[kingPositionCode]
            .and(board[opponent])
            .extractBits()
            .map(function (knightDestination) { return positionsHashTable_1.positionsTable[knightDestination]; });
        return {
            from: from,
            quietMoves: quietMoves,
            killMoves: killMoves,
        };
    });
    return kingList;
}
exports.kingMoves = kingMoves;
function generateAllKingMovesBBTable() {
    // King moves from a given position
    //
    //          noWe   no    noEa
    //            +7   +8   +9
    //              \  |  /
    //               \ | /
    //        we -1 -- 0 -- +1 ea
    //               / | \
    //              /  |  \
    //            -9  -8   -7
    //         soWe   so   soEa
    var AFile = [0, 8, 16, 24, 32, 40, 48, 56];
    var HFile = [7, 15, 23, 31, 39, 47, 55, 63];
    function no(position) {
        return position + 8;
    }
    function so(position) {
        return position - 8;
    }
    function noWe(position) {
        return !HFile.includes(position + 7) ? position + 7 : null;
    }
    function we(position) {
        return !HFile.includes(position - 1) ? position - 1 : null;
    }
    function soWe(position) {
        return !HFile.includes(position - 9) ? position - 9 : null;
    }
    function noEa(position) {
        return !AFile.includes(position + 9) ? position + 9 : null;
    }
    function ea(position) {
        return !AFile.includes(position + 1) ? position + 1 : null;
    }
    function soEa(position) {
        return !AFile.includes(position - 7) ? position - 7 : null;
    }
    var allKingMoves = [];
    for (var position = 0; position < 64; position++) {
        var movesFromThisPosition = [];
        // if position is not out of the board, add it to the list
        if (no(position))
            movesFromThisPosition.push(no(position));
        if (noEa(position))
            movesFromThisPosition.push(noEa(position));
        if (noWe(position))
            movesFromThisPosition.push(noWe(position));
        if (so(position))
            movesFromThisPosition.push(so(position));
        if (soEa(position))
            movesFromThisPosition.push(soEa(position));
        if (soWe(position))
            movesFromThisPosition.push(soWe(position));
        if (we(position))
            movesFromThisPosition.push(we(position));
        if (ea(position))
            movesFromThisPosition.push(ea(position));
        allKingMoves.push(BitBoard_1.default.fromPositions(movesFromThisPosition));
    }
    return allKingMoves;
}
function getKingAndColor(hasToPlay) {
    if (hasToPlay === 'w')
        return 'whiteKing';
    if (hasToPlay === 'b')
        return 'blackKing';
}
exports.getKingAndColor = getKingAndColor;