gol.rb

#
# Conway's game of life in Gosu/Chingu
# http://toastymofo.blogspot.com/2010/06/conways-game-of-life-in-ruby-gosu.html
# 
# Developed by r.kachowski ( http://www.toastymofo.net/ )
# Additions by ippa ( http://ippa.se/gaming )
# Additions by Roberto Zanon ( https://github.com/robertoz-01 )
#
require 'rubygems' rescue nil
require 'chingu'

class Main < Chingu::Window
  def initialize
    super(640, 480, false)
    self.input={:esc => :exit}
    push_game_state(GameOfLife)
  end

  def draw
    fill_rect([0, 0, 640, 480], 0xffffffff, -2)
    super
  end
end

class GameOfLife < Chingu::GameState
  CELL_SIZE = 4
  @@tick =0

  def initialize
    super
    @grid = generate_grid

    self.input={:left_mouse_button => :start_painting,
                :released_left_mouse_button => :stop_painting,
                :right_mouse_button => :start_erasing,
                :released_right_mouse_button => :stop_erasing,
                :z => :reset,
                :n => :update_grid,
                :space => :toggle_running,
                [:mouse_wheel_up, :left_arrow] => :prev_pattern,
                [:mouse_wheel_down, :right_arrow] => :next_pattern,
                :up_arrow => :next_color,
                :down_arrow => :prev_color
    }

    @pattern = :pixel
    @pattern_nr = 0
    @painting = false
    @erasing = false
    @running = false
    @current_color_idx = 0

    @pattern_info = Chingu::Text.create(:x => 1, :y => 1, :size => 16, :color => Gosu::Color::BLACK)
    update_pattern_info
  end

  def update_pattern_info
    @pattern_info.text = "Current pattern: #{@pattern}. Current color: #{current_color_name}"
  end

  def prev_pattern
    @pattern_nr -= 1
    @pattern_nr = PATTERNS.keys.size-1 if @pattern_nr < 0
    @pattern = PATTERNS.keys[@pattern_nr]
    update_pattern_info
  end

  def next_pattern
    @pattern_nr += 1
    @pattern_nr = 0 if @pattern_nr >= PATTERNS.keys.size
    @pattern = PATTERNS.keys[@pattern_nr]
    update_pattern_info
  end

  def prev_color
    @current_color_idx += 1
    @current_color_idx %= colors.length
    update_pattern_info
  end

  def next_color
    @current_color_idx -= 1
    @current_color_idx %= colors.length
    update_pattern_info
  end

  def draw_pattern_at_mouse(pattern = :pixel, to_grid = false)
    start_x = ($window.mouse_x/CELL_SIZE).floor
    y = ($window.mouse_y/CELL_SIZE).floor - 1

    PATTERNS[pattern].each_line do |line|
      x = start_x
      line.each_char do |char|
        @grid[x][y] = current_color if char == 'o' && to_grid
        draw_cell(x, y) if char == 'o'
        x += 1
      end

      y += 1
    end
  end

  def update
    super

    update_grid if @running

    $window.caption = "Conway Generation #{@@tick}. Start/Stop with 'Space'. Run 1 generation with 'N'. Reset with 'Z'."
  end

  def draw
    super

    draw_grid

    if @painting
      draw_pattern_at_mouse(@pattern, true)
      @painting = false if  @running # Only put out pattern Once if game is running
    else
      draw_pattern_at_mouse(@pattern)
    end

  end

  private

  def generate_grid
    width = $window.width/CELL_SIZE
    height = $window.height/CELL_SIZE

    grid = Array.new(width)
    col = Array.new(height)
    col.map! { false }
    grid.map! { Array.new(col) }
    grid
  end

  def draw_grid
    @grid.each_with_index do |a, x|
      a.each_with_index do |c, y|
        if c != false
          $window.fill_rect([x*CELL_SIZE, y*CELL_SIZE, CELL_SIZE, CELL_SIZE], @grid[x][y], 0)
        end
      end
    end
  end

  def reset
    @grid = generate_grid
    @@tick = 0
    @running = false
  end

  def update_grid
    @new_grid = Marshal.load(Marshal.dump(@grid))

    @grid.each_with_index do |a, x|
      a.each_with_index do |c, y|
        minus_x =x-1
        minus_y = y-1
        plus_x = x+1
        plus_y = y+1
        minus_x = @grid.length-1 if minus_x <0
        minus_y = a.length-1 if minus_y <0
        plus_y = 0 if plus_y >= a.length
        plus_x = 0 if plus_x >= @grid.length

        live_neighbours = {}

        update_neighbours_count(live_neighbours, minus_x, y)
        update_neighbours_count(live_neighbours, plus_x, y)
        update_neighbours_count(live_neighbours, x, minus_y)
        update_neighbours_count(live_neighbours, x, plus_y)
        update_neighbours_count(live_neighbours, minus_x, plus_y)
        update_neighbours_count(live_neighbours, plus_x, minus_y)
        update_neighbours_count(live_neighbours, minus_x, minus_y)
        update_neighbours_count(live_neighbours, plus_x, plus_y)

        neighbours_count = live_neighbours.values.inject(0, :+)
        case neighbours_count
          when 0..1 then
            @new_grid[x][y] = false
          when 2 then
            @new_grid[x][y] = @grid[x][y] if @grid[x][y] != false
          when 3 then
            @new_grid[x][y] = neighbours_common_color(live_neighbours)
          when 4..8 then
            @new_grid[x][y] = false
        end
        @new_grid[x][y] = [*colors, false].sample if Random.rand < 0.00003
      end
    end

    @grid = @new_grid
    @@tick+=1
  end

  def update_neighbours_count(live_neighbours, x, y)
    if @grid[x][y] != false
      live_neighbours[@grid[x][y]] ||= 0
      live_neighbours[@grid[x][y]] +=1
    end
  end

  def neighbours_common_color(live_neighbours)
    live_neighbours.sort_by { |color_count1, color_count2| color_count1[1] <=> color_count2[1] }.first[0]
  end

  def current_color_name
    {0xffff0000 => 'RED',
     0xff00ff00 => 'GREEN',
     0xff0000ff => 'BLUE'}[current_color]
  end

  def current_color
    colors[@current_color_idx]
  end

  def colors
    [0xffff0000, 0xff00ff00, 0xff0000ff]
  end

  def toggle_running
    @running = !@running
  end

  def start_painting
    @painting = true
  end

  def stop_painting
    @painting = false
  end

  def start_erasing
    @erasing = true
  end

  def stop_erasing
    @erasing = false
  end

  def draw_cell(x, y)
    current_with_alpha = (current_color & 0x00ffffff) | 0xaa000000
    $window.fill_rect([x*CELL_SIZE, y*CELL_SIZE, CELL_SIZE, CELL_SIZE], current_with_alpha, 1)
  end

end


PATTERNS = Hash.new

PATTERNS[:pixel] = %q{
o
}

#
# Spaceships
#
PATTERNS[:glider] = %q{
---o
-o-o
--oo
}

PATTERNS[:lightweight_spaceship] = %q{
-oooo
o---o
----o
o--o-
}

#
# Oscillators
#
PATTERNS[:blinker] = %q{
ooo
}

PATTERNS[:beacon] = %q{
-ooo
ooo-
}

PATTERNS[:toad] = %q{
oo--
o---
---o
--oo
}

PATTERNS[:pulsar] = %q{
---ooo---ooo--
--------------
-o----o-o----o
-o----o-o----o
-o----o-o----o
---ooo---ooo--
--------------
---ooo---ooo--
-o----o-o----o
-o----o-o----o
-o----o-o----o
--------------
---ooo---ooo--
}

#
# Guns
#
PATTERNS[:gospel_glider_gun] = %q{
------------------------o-----------
----------------------o-o-----------
------------oo------oo------------oo
-----------o---o----oo------------oo
oo--------o-----o---oo--------------
oo--------o---o-oo----o-o-----------
----------o-----o-------o-----------
-----------o---o--------------------
------------oo----------------------
}

PATTERNS[:block_laying_switch_engine] = %q{
----------o-o--
oo-------o-----
oo--------o--o-
------------ooo
}


#
# Long lived patterns
#
PATTERNS[:rpentomino] = %q{
--oo
-oo
--o
}

PATTERNS[:diehard] = %q{
oo---o-o
oo----o-
------o-
}

PATTERNS[:acorn] = %q{
--o-----
----o---
-oo--ooo
}

Main.new.show