R/square_to_bits.R

In eduardokapp/chessR: R Chess Engine

#' @title Generate a bitboard representation of a square
#' @description Given a Square, generate its bitboard integer.
#' @param square Any square from "a1" to "h8".
#' @returns A 64 binary vector.
#' @author Eduardo Kapp
square_to_bits <- function(square) {
    squares <- c(
        "h8", "g8", "f8", "e8", "d8", "c8", "b8", "a8",
        "h7", "g7", "f7", "e7", "d7", "c7", "b7", "a7",
        "h6", "g6", "f6", "e6", "d6", "c6", "b6", "a6",
        "h5", "g5", "f5", "e5", "d5", "c5", "b5", "a5",
        "h4", "g4", "f4", "e4", "d4", "c4", "b4", "a4",
        "h3", "g3", "f3", "e3", "d3", "c3", "b3", "a3",
        "h2", "g2", "f2", "e2", "d2", "c2", "b2", "a2",
        "h1", "g1", "f1", "e1", "d1", "c1", "b1", "a1"
    )
    if (!square %in% squares)
        stop("Square not valid.")

    # Match the square with the table and return the result
    return(as.numeric(square == squares))
}