shogi-board.rb

class Board
  def initialize
    @board = [
      0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
      0x40, 0x22, 0x23, 0x24, 0x25, 0x28, 0x25, 0x24, 0x23, 0x22, 0x40,
      0x40, 0x00, 0x27, 0x00, 0x00, 0x00, 0x00, 0x00, 0x26, 0x00, 0x40,
      0x40, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x40,
      0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40,
      0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40,
      0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40,
      0x40, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x40,
      0x40, 0x00, 0x16, 0x00, 0x00, 0x00, 0x00, 0x00, 0x17, 0x00, 0x40,
      0x40, 0x12, 0x13, 0x14, 0x15, 0x18, 0x15, 0x14, 0x13, 0x12, 0x40,
      0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
    ]
  end

  def point(x, y)
    @board[point_to_index(x, y)]
  end

  def move(x1, y1, x2, y2)
    from = @board[point_to_index(x1, y1)]
    raise if from == 0x00
    raise if from == 0x40
    tmp = @board[point_to_index(x2, y2)]
    @board[point_to_index(x2, y2)] = @board[point_to_index(x1, y1)]
    @board[point_to_index(x1, y1)] = tmp
  end

  def to_csa
    csa = ""
    1.upto(9) do |y|
      csa << "P#{y}"
      9.downto(1) do |x|
        cell = point(x, y)
        hand = cell & 0xf0
        case hand
        when 0x10
          csa << "+"
        when 0x20
          csa << "-"
        end
        type = cell & 0x0f
        case type
        when 0x00
          csa << " * "
        when 0x01
          csa << "FU"
        when 0x02
          csa << "KY"
        when 0x03
          csa << "KE"
        when 0x04
          csa << "GI"
        when 0x05
          csa << "KI"
        when 0x06
          csa << "KA"
        when 0x07
          csa << "HI"
        when 0x08
          csa << "OU"
        end
      end
      csa << "\n"
    end
    csa
  end

  private
  def point_to_index(x, y)
    y * 11 + (10 - x)
  end
end

board = Board.new
board.move(5, 9, 5, 8)
puts board.to_csa