class Bchess::Board

Attributes

castles[RW]
en_passant[RW]
fen[RW]
halfmove_clock[RW]
move_number[RW]
pieces[RW]
to_move[RW]

Public Class Methods

new(fen = Bchess::START_FEN, to_move = Bchess::WHITE) click to toggle source
# File lib/bchess/board.rb, line 11
def initialize(fen = Bchess::START_FEN, to_move = Bchess::WHITE)
  @fen = fen
  @to_move = to_move
  @move_number = 0
  @halfmove_clock = 0
  @pieces = []
  @en_passant = '-'
  @castles = '-'
end

Public Instance Methods

at(column, row) click to toggle source
# File lib/bchess/board.rb, line 73
def at(column, row)
  pieces.select { |p| p.row == row && p.column == column }.first
end
change_to_move() click to toggle source
# File lib/bchess/board.rb, line 98
def change_to_move
  @to_move = to_move == Bchess::WHITE ? Bchess::BLACK : Bchess::WHITE
end
execute_promotion(piece, column, row, promoted_piece) click to toggle source
# File lib/bchess/board.rb, line 60
def execute_promotion(piece, column, row, promoted_piece)
  raise 'Promotion Not Specified' if promoted_piece.nil? || !(promoted_piece < Bchess::Piece)

  pieces.delete(piece)
  promoted = promoted_piece.new(piece.color, column, row)
  promoted.moved = true if promoted_piece == Bchess::Rook
  pieces << promoted
end
get_possible_pieces(info) click to toggle source
# File lib/bchess/board.rb, line 48
def get_possible_pieces(info)
  @pieces.select { |p| p.can_make_move?(info, self) }
end
king(color) click to toggle source
# File lib/bchess/board.rb, line 94
def king(color)
  @pieces.select { |p| p.class == Bchess::King && p.color == color }.first
end
move(piece, column, row, promoted_piece = nil) click to toggle source
# File lib/bchess/board.rb, line 21
def move(piece, column, row, promoted_piece = nil)
  return false if invalid_data?(piece, column, row)

  @en_passant = '-' unless en_passant_detected?(piece, column, row)

  if castle_detected?(piece, column)
    castle(piece, column, row)
  elsif promotion_detected?(piece, row)
    execute_promotion(piece, column, row, promoted_piece)
  elsif en_passant_detected?(piece, column, row)
    validate_en_passant(piece, column, row) && execute_en_passant(piece, column, row)
  elsif pawn_long_move_detected?(piece, row)
    long_pawn_move(piece, column, row)
  elsif piece.can_move_to_field?(column, row)
    piece.move(column, row)
  elsif piece.can_take_on_field?(column, row)
    piece.move(column, row)
  else
    return false
  end

  update_info(piece, column, row)
  validate_move
rescue RuntimeError
  false
end
print() click to toggle source
read_fen() click to toggle source
# File lib/bchess/board.rb, line 77
def read_fen
  fen_pieces, fen_colors, fen_castles, fen_en_passant, fen_halfmove_clock, fen_move_number = fen.strip.split(' ')
  set_pieces(fen_pieces)
  set_to_move(fen_colors)
  set_castles(fen_castles)
  set_en_passant(fen_en_passant)
  set_halfmove_clock(fen_halfmove_clock)
  set_move_number(fen_move_number)
end
transform_field(field) click to toggle source
# File lib/bchess/board.rb, line 69
def transform_field(field)
  [field.chars.first.ord - 97, field.chars.last.to_i - 1]
end
update_info(piece, column, row) click to toggle source
# File lib/bchess/board.rb, line 52
def update_info(piece, column, row)
  update_castles_after_move(piece) if piece.moved
  change_halfmove_clock(piece)
  change_to_move
  change_move_number if piece.color == Bchess::BLACK
  remove_old_piece(column, row, piece.color) if !!at(column, row)
end

Private Instance Methods

_other_pieces(color) click to toggle source
# File lib/bchess/board.rb, line 129
def _other_pieces(color)
  @pieces.reject { |p| p.color == color }
end
_pieces(color) click to toggle source
# File lib/bchess/board.rb, line 125
def _pieces(color)
  @pieces.select { |p| p.color == color }
end
attacks?(piece, king) click to toggle source
# File lib/bchess/board.rb, line 120
def attacks?(piece, king)
  piece.can_take_on_field?(king.column, king.row) &&
    piece.fields_between(king.column, king.row).none? { |f| at(*f) }
end
just_moved() click to toggle source
# File lib/bchess/board.rb, line 109
def just_moved
  to_move == Bchess::WHITE ? Bchess::BLACK : Bchess::WHITE
end
king_attacked(color) click to toggle source
# File lib/bchess/board.rb, line 113
def king_attacked(color)
  _king = king(color)
  _pieces = _other_pieces(color)

  _pieces.any? { |p| attacks?(p, _king) }
end
remove_old_piece(column, row, color) click to toggle source
# File lib/bchess/board.rb, line 104
def remove_old_piece(column, row, color)
  taken_piece = _other_pieces(color).select { |p| p.row == row && p.column == column }.first
  pieces.delete(taken_piece)
end