lib/games/shogi/state.rb

   1 require 'games/state_base'
   2 require 'point'
   3
   4 module Shogi
   5   class State < StateBase
   6     def initialize(board, pool_factory, move_factory, piece_factory)
   7       super(board, move_factory, piece_factory)
   8       @pools = to_enum(:each_color).inject({}) do |res, c|
   9         res[c] = pool_factory.new
  10         res
  11       end
  12       @turn = :black
  13     end
  14
  15     def initialize_copy(other)
  16       super
  17       @pools = to_enum(:each_color).inject({}) do |res, c|
  18         res[c] = other.pool(c).dup
  19         res
  20       end
  21     end
  22
  23     def pool(color)
  24       @pools[color]
  25     end
  26
  27     def setup
  28       each_color do |color|
  29         (0...@board.size.x).each do |i|
  30           @board[Point.new(i, row(2, color))] = piece_factory.new(color, :pawn)
  31         end
  32
  33         r = row(0, color)
  34         set_piece = lambda do |x, type|
  35           @board[Point.new(x, r)] = piece_factory.new(color, type)
  36         end
  37         set_piece[0, :lance]
  38         set_piece[1, :horse]
  39         set_piece[2, :silver]
  40         set_piece[3, :gold]
  41         set_piece[4, :king]
  42         set_piece[5, :gold]
  43         set_piece[6, :silver]
  44         set_piece[7, :horse]
  45         set_piece[8, :lance]
  46
  47         r = row(1, color)
  48         @board[Point.new(r, r)] = piece_factory.new(color, :rook)
  49         @board[Point.new(@board.size.x - r - 1, r)] = piece_factory.new(color, :bishop)
  50       end
  51     end
  52
  53     def each_color(&blk)
  54       yield :black
  55       yield :white
  56     end
  57
  58     def row(i, color)
  59       color == :black ? @board.size.y - 1 - i : i
  60     end
  61
  62     def opposite_color(color)
  63       color == :black ? :white : :black
  64     end
  65
  66     def direction(color)
  67       Point.new(0, color == :black ? -1 : 1)
  68     end
  69
  70     def perform!(move)
  71       if move.dropped
  72         pool(turn).remove(move.dropped)
  73         board[move.dst] = move.dropped
  74       else
  75         captured = basic_move(move)
  76         if move.promote?
  77           board[move.dst] = promoted(board[move.dst])
  78         end
  79         if captured
  80           piece = piece_factory.new(turn, captured.type)
  81           pool(turn).add(demoted(piece))
  82         end
  83         switch_turn!
  84       end
  85     end
  86
  87     def switch_turn!
  88       @turn = opposite_color(@turn)
  89     end
  90
  91     def in_promotion_zone?(p, color)
  92       (row(6, color) <=> p.y) != (color == :black ? -1 : 1)
  93     end
  94
  95     def promoted(piece)
  96       piece_factory.new(
  97         piece.color,
  98         ('promoted_' + piece.type.to_s).to_sym)
  99     end
 100
 101     def demoted(piece)
 102       piece_factory.new(
 103         piece.color,
 104         piece.type.to_s.gsub(/^promoted_/, '').to_sym)
 105     end
 106
 107     def promoted_type?(type)
 108       type.to_s =~ /^promoted_/
 109     end
 110
 111     def promoted?(piece)
 112       promoted_type? piece.type
 113     end
 114   end
 115 end