Class: SnakeGame::Snake

Inherits:
Object
  • Object
show all
Includes:
Constants
Defined in:
lib/snake.rb

Overview

Class representing the whole snake

Constant Summary

Constants included from Constants

Constants::EVASION, Constants::FPS, Constants::HEIGHT, Constants::NEXTLEVEL, Constants::STEP, Constants::WIDTH

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Snake

Returns a new instance of Snake.



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# File 'lib/snake.rb', line 12

def initialize
  @images = ImageDatabase.new
  @snake_parts = []
  initialize_snake 5, WIDTH / 2, HEIGHT / 2
  @score = 0
  @speed = 8.0
  @last_direction = :up
  @direction_to_go = :up
  @gameover = false
end

Instance Attribute Details

#direction_to_go ⇒ Object

Returns the value of attribute direction_to_go.



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# File 'lib/snake.rb', line 10

def direction_to_go
  @direction_to_go
end

#gameover ⇒ Object

Returns the value of attribute gameover.



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# File 'lib/snake.rb', line 10

def gameover
  @gameover
end

#head ⇒ Object

Returns the value of attribute head.



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# File 'lib/snake.rb', line 10

def head
  @head
end

#last_direction ⇒ Object

Returns the value of attribute last_direction.



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# File 'lib/snake.rb', line 10

def last_direction
  @last_direction
end

#score ⇒ Object

Returns the value of attribute score.



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# File 'lib/snake.rb', line 10

def score
  @score
end

#snake_parts ⇒ Object

Returns the value of attribute snake_parts.



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# File 'lib/snake.rb', line 10

def snake_parts
  @snake_parts
end

#speed ⇒ Object

Returns the value of attribute speed.



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# File 'lib/snake.rb', line 10

def speed
  @speed
end

Instance Method Details

#add_part(position) ⇒ Object 



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# File 'lib/snake.rb', line 98

def add_part(position)
  @head.image = @images.tail
  @head = SnakePart.new position, @images.head
  @snake_parts << @head
end

#cut_tail ⇒ Object 



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# File 'lib/snake.rb', line 104

def cut_tail
  @snake_parts.shift
end

#draw ⇒ Object 



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# File 'lib/snake.rb', line 112

def draw
  @snake_parts.each(&:draw)
  return unless @gameover
  Gosu::Font.new(60).draw_rel(
    'GAME OVER', WIDTH / 2, HEIGHT / 2,
    0, 0.5, 0.5, 1.0, 1.0, Gosu::Color::RED
  )
end

#eating?(bait_manager) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/snake.rb', line 62

def eating?(bait_manager)
  eating = false
  bait_manager.baits.each do |bait|
    next unless bait.position == @head.position
    # puts 'I AM EATING'
    @score += bait.size
    eating = true
    bait_manager.baits.delete bait
    @speed *= 1.1 if (@score % NEXTLEVEL).zero?
  end
  eating
end

#gameover! ⇒ Object 



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

def gameover!
  @gameover = true
end

#go(direction) ⇒ Object 



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# File 'lib/snake.rb', line 75

def go(direction)
  position = nil
  case direction
  when :left
    @head.position.x += WIDTH if @head.position.x <= 0
    position = Position.new @head.position.x - STEP,
                            @head.position.y
  when :right
    position = Position.new (@head.position.x + STEP) % WIDTH,
                            @head.position.y
  when :up
    @head.position.y += HEIGHT if @head.position.y <= 0
    position = Position.new @head.position.x,
                            @head.position.y - STEP
  when :down
    position = Position.new @head.position.x,
                            (@head.position.y + STEP) % HEIGHT
  else
    position = go @last_direction
  end
  position
end

#initialize_snake(count, center_x, center_y) ⇒ Object 



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# File 'lib/snake.rb', line 23

def initialize_snake(count, center_x, center_y)
  count.times do |i|
    part = SnakePart.new (Position.new center_x,
                                       center_y + (count - i) * STEP),
                         @images.tail
    @snake_parts << part
  end
  @head = SnakePart.new (Position.new center_x,
                                      center_y),
                        @images.head
  @snake_parts << @head
end

#process_input ⇒ Object 



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# File 'lib/snake.rb', line 36

def process_input
  if (Gosu.button_down? Gosu::KB_LEFT) && (@last_direction != :right)
    @direction_to_go = :left
  elsif (Gosu.button_down? Gosu::KB_RIGHT) && (@last_direction != :left)
    @direction_to_go = :right
  elsif (Gosu.button_down? Gosu::KB_UP) && (@last_direction != :down)
    @direction_to_go = :up
  elsif (Gosu.button_down? Gosu::KB_DOWN) && (@last_direction != :up)
    @direction_to_go = :down
  end
end

#update(bait_manager) ⇒ Object 



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# File 'lib/snake.rb', line 48

def update(bait_manager)
  next_position = go @direction_to_go

  @snake_parts.each do |part|
    if part.position == next_position
      # puts 'GAME OVER!'
      gameover!
    end
  end
  add_part next_position
  cut_tail unless eating? bait_manager
  @last_direction = @direction_to_go
end