Class: MailChess::Piece::Bishop

Inherits:
Piece
  • Object
show all
Defined in:
lib/mail_chess/pieces/bishop.rb

Overview

Represents a bishop chess piece.

Instance Attribute Summary

Attributes inherited from Piece

#board, #color, #hits, #html, #id, #moves, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Piece

#can_hit?, #can_move?, create_tables, #delete!, load!, #move, need_to_create_tables?, #position, #save!

Constructor Details

#initialize(db, piece_id, board = nil) ⇒ Bishop

Calls the superclass.



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# File 'lib/mail_chess/pieces/bishop.rb', line 11

def initialize db, piece_id, board = nil
  super db, piece_id, board
  
  @html = @color == :white ? '♗' : '♝'
end

Class Method Details

.new!(db, board, position, color) ⇒ Object

Overwrite superclass method.



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# File 'lib/mail_chess/pieces/bishop.rb', line 18

def self.new! db, board, position, color
  super db, board, position, color

  id = db[:pieces].insert(:type => 'bishop', 
                          :color => color.to_s,
                          :position => position,
                          :board_id => board.id)

  return Bishop.new db, id, board
end

Instance Method Details

#generate_moves ⇒ Object

Generate the possible moves.



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# File 'lib/mail_chess/pieces/bishop.rb', line 30

def generate_moves
  super
  
  r, c = ROWS.index(position[1]), COLS.index(position[0])
  f = {:ul => false, :ur => false, :bl => false, :br => false}
  
  (1..7).each do |i|
    pos = []
    pos << [:ul, COLS[c - i] + ROWS[r - i]] if 
      c - i >= 0 and r - i >= 0 and !f[:ul]
    pos << [:ur, COLS[c - i] + ROWS[r + i]] if 
      c - i >= 0 and r + i <= 7 and !f[:ur]
    pos << [:bl, COLS[c + i] + ROWS[r - i]] if 
      c + i <= 7 and r - i >= 0 and !f[:bl]
    pos << [:br, COLS[c + i] + ROWS[r + i]] if 
      c + i <= 7 and r + i <= 7 and !f[:br]
    
    break if pos.empty?
    pos.each do |s, p|
      if @board.pieces[p]
        @hits << p if @board.pieces[p].color != @color
        f[s] = true
      else
        @moves << p
      end
    end
  end
end