在某些位板国际象棋引擎中，棋子位板初始化如下：
white_pawns = 0x000000000000ff00
black_pawns = 0x00ff000000000000
white_knights = 0x000000000000042
black_knights = 0x4200000000000000
white_bishops =0x000000000000024
black_bishops = 0x2400000000000000
white_rooks = 0x000000000000081
black_rooks = 0x8100000000000000
white_queens = 0x0000000000000008
black_queens = 0x0800000000000000
white_king = 0x0000000000000010
black_king = 0x1000000000000000
有人可以解释一下这些片段如何获得各自的十六进制值吗？