class Game

Class that simulates a Blackjack game

Public Class Methods

calculate_optimal_card_score(cards) click to toggle source

Calculates the optimal amount of points for blackjack for an array of cards @param [Card Array] cards the cards to be checked @return [int] the optimal blackjack value of the cards

# File src/game.rb, line 164
def self.calculate_optimal_card_score(cards)
  score = 0
  aces = 0
  cards.each { |card|
    unless card.is_flipped  # == if card is not flipped
      score += card.get_value
      if card.is_ace
        aces += 1
      end
    end
  }
  while score > 21 and aces > 0
    aces -= 1
    score -= 10
  end
  score
end

new() click to toggle source

Initializes the instance variables used to keep track of the game state @return [nil]

# File src/game.rb, line 25
def initialize
  @deck = generate_deck
  @used_cards = []
  @player_cards = []
  @dealer_cards = []
  @player_score = 0
  @dealer_score = 0
end

Public Instance Methods

cleanup() click to toggle source

Resets the game to enable starting a new game. @return [Card Array, Card Array] the user's cards and the dealer's cards

# File src/game.rb, line 146
def cleanup
  if @dealer_cards[1].is_flipped
    @dealer_cards[1].flip_over
  end
  @used_cards += @player_cards + @dealer_cards
  @player_score = 0
  @dealer_score = 0
  old_player_cards = @player_cards.clone
  old_dealer_cards = @dealer_cards.clone
  @player_cards = []
  @dealer_cards = []
  return old_player_cards, old_dealer_cards
end

draw_card() click to toggle source

Draws a new card It automatically stocks up the deck with previously used cards if the deck runs out of cards @return [Card] the newly drawn card

# File src/game.rb, line 53
def draw_card
  if @deck.length == 0
    @deck = @used_cards.shuffle
    @used_cards = []
  end
  @deck.pop
end

evaluate(player_standing = false) click to toggle source

Evaluates the current state of the game according to the standard blackjack rules @param [boolean] player_standing flag that is set to evaluate a game once the player has decided to stand @return [Card Array, Card Array, string] the player's cards,

the dealer's cards,
a string stating the current status of the match.
Possible Options:    'loss', if the user lost
                     'win', if the user won
                     'draw', if the game ended in a draw
                     'undecided', if the game is not finished

# File src/game.rb, line 120
def evaluate(player_standing = false)
  player_cards = @player_cards
  dealer_cards = @dealer_cards
  state = 'undecided'
  if @player_score > 21
    state = 'loss'
  elsif @dealer_score > 21
    state = 'win'
  elsif player_standing and @player_score > @dealer_score
    state = 'win'
  elsif player_standing and @player_score < @dealer_score
    state = 'loss'
  elsif player_standing and @player_score == @dealer_score
    state = 'draw'
  end

  if state != 'undecided'
    player_cards, dealer_cards = cleanup
  end

  return player_cards, dealer_cards, state
end

generate_deck() click to toggle source

Generates a new deck of cards The deck is shuffled directly after creation @return [Card Array] the generated deck

# File src/game.rb, line 38
def generate_deck
  deck = []
  suits = %w(spades hearts diamonds clubs)
  (2...15).each { |i|
    suits.each { |suit|
      deck.push(Card.new(suit, i))
    }
  }
  deck.shuffle
end

get_dealer_score() click to toggle source

@return [int] the dealer's current score

# File src/game.rb, line 190
def get_dealer_score
  @dealer_score
end

get_player_score() click to toggle source

@return [int] the player's current score

# File src/game.rb, line 184
def get_player_score
  @player_score
end

hit(dealer = false) click to toggle source

Draws a new card for a player and immediately evaluates the current state of the game @param [Object] dealer flag can be set to make the dealer instead of the player draw a card @return [Card Array, Card Array, string] the result of the drawing. Refer to evaluate() for details

# File src/game.rb, line 82
def hit(dealer = false)
  if dealer
    @dealer_cards.push(draw_card)
    @dealer_score = self.class.calculate_optimal_card_score(@dealer_cards)
  else
    @player_cards.push(draw_card)
    @player_score = self.class.calculate_optimal_card_score(@player_cards)
  end
  evaluate
end

stand() click to toggle source

Stops the user interaction. The cards of the user will no longer change, and now the dealer draws cards until he is above 16 points. Afterwards, the game state is evaluated @return [Card Array, Card Array, string] the result of the drawing. Refer to evaluate() for details

# File src/game.rb, line 97
def stand
  @dealer_cards[1].flip_over
  result = [@player_cards.clone, @dealer_cards.clone, 'undecided']
  while @dealer_score < 17 and result[2] == 'undecided'
    result = hit(true)
  end
  if result[2] == 'undecided'
    evaluate(true)
  else
    result
  end
end

start() click to toggle source

Starts a game of roulette. Each player will draw two cards, the dealer's second card will stay top down until the player stands @return [Card Array, Card Array, string] the result of the first few drawings. Refer to evaluate() for details

# File src/game.rb, line 65
def start
  # Let the player draw his cards
  hit
  hit

  # Let the dealer draw his cards
  hit(true)
  result = hit(true)
  @dealer_cards[1].flip_over  # Flip over the card

  result
end