bitboard-demo.js

// Run this code at: https://algorithm-pad.now.sh/

const matrix = (n) => [
    [ (n >> 8) & 1, (n >> 7) & 1, (n >> 6) & 1 ],
    [ (n >> 5) & 1, (n >> 4) & 1, (n >> 3) & 1 ],
    [ (n >> 2) & 1, (n >> 1) & 1, (n >> 0) & 1 ]
];

let board = 0b000100010;
const pawn = 0b000100000;
const knight = 0b000000010;

debug({ board: matrix(board), pawn: matrix(pawn), knight: matrix(knight) });

log("Knight move to C3");

let new_board = 0b001100000;
let move = new_board ^ board;

debug({ move: matrix(move) });

const isKnightMove = move => (knight ^ (move & knight)) === 0;
const isPawnMove = move => (pawn ^ (move & pawn)) === 0;

debug({ isKnightMove: isKnightMove(move), isPawnMove: isPawnMove(move) });

let start = move & knight;
let end = move ^ knight;

debug({ start: matrix(start), end: matrix(end) });

log("Pawn move to A1");

new_board = 0b000000110;
move = new_board ^ board;

debug({ move: matrix(move) });

debug({ isKnightMove: isKnightMove(move), isPawnMove: isPawnMove(move) });

start = move & pawn;
end = move ^ pawn;

debug({ start: matrix(start), end: matrix(end) });