Class: Board

Inherits:
Object
  • Object
show all
Defined in:
lib/board.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(setup = true) ⇒ Board

Returns a new instance of Board.



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# File 'lib/board.rb', line 11

def initialize(setup = true)
  @grid = Array.new(8) { Array.new(8) }
  @cursor = [0,0]

  populate_board if setup
end

Instance Attribute Details

#cursor ⇒ Object (readonly)

Returns the value of attribute cursor.



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# File 'lib/board.rb', line 9

def cursor
  @cursor
end

#grid ⇒ Object (readonly)

Returns the value of attribute grid.



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# File 'lib/board.rb', line 9

def grid
  @grid
end

Instance Method Details

#[](pos) ⇒ Object 



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# File 'lib/board.rb', line 53

def [](pos)
  @grid[pos.first][pos.last]
end

#[]=(pos, piece) ⇒ Object 



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# File 'lib/board.rb', line 57

def []=(pos, piece)
  @grid[pos.first][pos.last] = piece
end

#checkmate?(color) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 82

def checkmate?(color)
  pieces(color).all? { |piece| piece.valid_moves.empty? } &&
  in_check?(color)
end

#deep_dup ⇒ Object 



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# File 'lib/board.rb', line 95

def deep_dup
  dup_board = Board.new(false)

  [:white, :black].each do |color|
    pieces(color).each do |piece|
      duped_piece = piece.dup(dup_board)
      dup_board[duped_piece.pos] = duped_piece
    end
  end

  dup_board
end

#in_check?(color) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 87

def in_check?(color)
  opponent_color = color == :white ? :black : :white
  king_pos = king(color).pos
  pieces(opponent_color).any? do |piece|
    piece.moves.include?(king_pos)
  end
end

#king(color) ⇒ Object 



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# File 'lib/board.rb', line 143

def king(color)
  pieces(color).find { |piece| piece.is_a?(King)}
end

#move(start_pos, end_pos, color) ⇒ Object

Raises:



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# File 'lib/board.rb', line 18

def move(start_pos, end_pos, color)
  raise OffBoardError unless on_board?(start_pos) && on_board?(end_pos)
  raise NoPieceError unless piece_at(start_pos)
  raise WrongColorError unless piece_at(start_pos).color == color

  current_piece = piece_at(start_pos)
  if current_piece.valid_moves.include?(end_pos)
    move!(start_pos, end_pos)
  else
    raise InvalidMoveError
  end
end

#move!(start_pos, end_pos) ⇒ Object 



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# File 'lib/board.rb', line 31

def move!(start_pos, end_pos)
  current_piece = piece_at(start_pos)
  self[start_pos] = nil
  self[end_pos] = current_piece
  current_piece.pos = end_pos
  current_piece.moved = true
end

#move_cursor ⇒ Object 



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# File 'lib/board.rb', line 39

def move_cursor
  input = ""
  until input == "\r"
    render(@cursor)
    input = STDIN.getch
    @cursor[0] += 1 if input == 'k' && @cursor[0] + 1 < 8
    @cursor[0] -= 1 if input == 'i' && @cursor[0] - 1 >= 0
    @cursor[1] -= 1 if input == 'j' && @cursor[1] - 1 >= 0
    @cursor[1] += 1 if input == 'l' && @cursor[1] + 1 < 8

  end
  @cursor.dup
end

#occupied?(pos) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 65

def occupied?(pos)
  return false unless on_board?(pos)
  !!self[pos]
end

#on_board?(pos) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 61

def on_board?(pos)
  (pos[0]).between?(0, 7) && (pos[1]).between?(0, 7)
end

#piece_at(pos) ⇒ Object 



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# File 'lib/board.rb', line 78

def piece_at(pos)
  self[pos]
end

#pieces(color) ⇒ Object 



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# File 'lib/board.rb', line 147

def pieces(color)
  pieces = @grid.flatten.compact
  pieces.select { |piece| piece.color == color}
end

#populate_board ⇒ Object 



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# File 'lib/board.rb', line 152

def populate_board
  [[1,:white], [6, :black]].each do |row|
    @grid[row.first].map!.with_index do |space, i|
      Pawn.new(self, row.last, [row.first, i])
    end
  end

  [[0, :white], [7, :black]].each do |row|
    @grid[row.first].map!.with_index do |space, i|
      case i
      when 0
        Rook.new(self, row.last, [row.first, i])
      when 1
        Knight.new(self, row.last, [row.first, i])
      when 2
        Bishop.new(self, row.last, [row.first, i])
      when 3
        King.new(self, row.last, [row.first, i])
      when 4
        Queen.new(self, row.last, [row.first, i])
      when 5
        Bishop.new(self, row.last, [row.first, i])
      when 6
        Knight.new(self, row.last, [row.first, i])
      when 7
        Rook.new(self, row.last, [row.first, i])
      end
    end
  end
end

#render(cursor = nil) ⇒ Object 



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# File 'lib/board.rb', line 108

def render(cursor = nil)
  system('clear')
  print ("   " + ('a'..'h').to_a.join(" ") + "\n")
  self.grid.each_with_index do |row, i|
    print "#{i + 1} "
    row.each_with_index do |space, j|
      if cursor.nil?
        if (i + j).odd?
          background = :light_black
        else
          background = :light_blue
        end
      else
        if @cursor == [i,j]
          background = :yellow
        elsif (i + j).odd?
          background = :light_black
        else
          background = :light_blue
        end
      end
      if space.nil?
        print '  '.colorize(:background => background)
      else
        print "#{space.symbol} ".colorize(:color => space.color,
          :background => background)
      end
    end
    print " #{i + 1}"
    puts
  end
  print ("  " + ('a'..'h').to_a.join(" ") + "\n")
end

#stalemate?(color) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 74

def stalemate?(color)
  pieces(color).all? { |piece| piece.valid_moves.empty? } && !in_check?(color)
end

#won? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/board.rb', line 70

def won?
  checkmate?(:white) || checkmate?(:black)
end