chess displayer in ruby, powered by gosu

README.md

Please run gem install gosu before running. Run as ruby chess.rb <fileName>, and make sure the board is formatted as above. Press the Escape key or simply press the x button to exit.

board.txt

14... Qe8
  +---+---+---+---+---+---+---+---+
8 |bR |bN.|bB |  .|bQ |bR.|bK |  .|
  +---+---+---+---+---+---+---+---+
7 |  .|   |  .|   |  .|   | b.| b |
  +---+---+---+---+---+---+---+---+
6 |   |  .|   |  .| b |  .|   |  .|
  +---+---+---+---+---+---+---+---+
5 | b.|wQ |wB.|   |  .| b |  .|   |
  +---+---+---+---+---+---+---+---+
4 |   |  .|   |  .|   |  .|   |  .|
  +---+---+---+---+---+---+---+---+
3 |  .|   | w.|   |  .|wN |  .|   |
  +---+---+---+---+---+---+---+---|
2 | w | w.|   |  .|   | w.| w | w.|
  +---+---+---+---+---+---+---+---|
1 |  .|   |wK.|wR |  .|   |  .|wR |
  +---+---+---+---+---+---+---+---+
    A   B   C   D   E   F   G   H

chess.rb

require 'gosu'

board = File.read ARGV[0]
$cells = board.scan(/(?<=\|)(.)(.)(.)(?=\|)/)

turn_num, color = board.scan(/^(\d+)(\.+)/).pop
next_col = color == "." ? "black" : "white"
next_turn = turn_num.to_i + (color == "." ? 0 : 1)

$caption = "Waiting for #{next_col} to play turn #{next_turn}..."

# team = 0, 1 (0 for white, 1 for black)
def get_chess(chr, team)
    ind = "KQRBNP".index chr
    return " " if ind < 0
    [0x2654 + ind + 6 * team].pack("U")
end

class Cell
    def initialize(arr)
        color, piece, tileColor = arr
        # print arr
        @tileColor = tileColor == "." ? 0 : 1
        if color == " "
            unless piece == " "
                color = piece
                piece = "P"
            else
                @color = 0
                @piece = " "
            end
        end
        @color = @color || color == "b" ? 1 : 0
        @piece = @piece || get_chess(piece, @color)
        # print [@color, @piece]
    end
    
    attr_accessor :piece, :tileColor, :color
end

$cell_width = 64
$height     = 8 * $cell_width
$width      = $height

class DisplayWindow < Gosu::Window
    def initialize
        super $width, $height
        self.caption = $caption
        @tiles = []
        $cells.each { |cell| @tiles.push Cell.new cell }
        @font = Gosu::Font.new $cell_width
    end
    
    def update
        if Gosu::button_down? Gosu::KbEscape
            close
        end
    end
    
    def draw
        row = column = 0
        @tiles.each do |tile|
            if tile.tileColor == 1
                # white
                tile_color = Gosu::Color.new 255, 221, 198, 166
            else
                # black
                tile_color = Gosu::Color.new 255, 174, 139,  85
            end
            
            if tile.color == 1
                # black
                font_color = Gosu::Color.new 255,   0,   0,   0
            else
                # white
                font_color = Gosu::Color.new 255, 255, 255, 255
            end
            
            y = row * $cell_width
            x = column * $cell_width
            
            Gosu.draw_rect(
                x,
                y,
                $cell_width,
                $cell_width,
                tile_color
            )
            
            column += 1
            if column == 8
                row += 1
                column = 0
            end
            @font.draw(tile.piece, x + 7, y, 3, 1, 1, font_color)
        end
    end
end

window = DisplayWindow.new
window.show