Class: ConwayDeathmatch

Inherits:
Object
  • Object
show all
Defined in:
lib/conway_deathmatch.rb

Overview

Provides a 2d array for the grid Implements standard and deathmatch evaluation rules Boundaries are toroidal: they wrap in each direction

Defined Under Namespace

Modules: Shapes Classes: BoundsError

Constant Summary collapse

DEAD = 
'.'
ALIVE = 
'0'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(width, height, deathmatch = nil) ⇒ ConwayDeathmatch

Returns a new instance of ConwayDeathmatch.



25
26
27
28
29
30
31
 
# File 'lib/conway_deathmatch.rb', line 25

def initialize(width, height, deathmatch = nil)
  @width = width
  @height = height
  @grid = self.class.new_grid(width, height)
  @deathmatch = deathmatch
  #@lager = self.class.lager
end

Instance Attribute Details

#deathmatch ⇒ Object

nil for traditional, otherwise :aggressive, :defensive, or :friendly



23
24
25
 
# File 'lib/conway_deathmatch.rb', line 23

def deathmatch
  @deathmatch
end

Class Method Details

.new_grid(width, height) ⇒ Object 



16
17
18
19
20
 
# File 'lib/conway_deathmatch.rb', line 16

def self.new_grid(width, height)
  grid = []
  width.times { grid << Array.new(height, DEAD) }
  grid
end

Instance Method Details

#add_points(points, x_off = 0, y_off = 0, val = ALIVE) ⇒ Object

set several points (2d array)



128
129
130
131
 
# File 'lib/conway_deathmatch.rb', line 128

def add_points(points, x_off = 0, y_off = 0, val = ALIVE)
  points.each { |point| populate(point[0] + x_off, point[1] + y_off, val) }
  self
end

#neighbor_population(x, y) ⇒ Object

population of every neighboring entity, including DEAD



98
99
100
101
102
103
104
105
106
107
108
109
110
 
# File 'lib/conway_deathmatch.rb', line 98

def neighbor_population(x, y)
  x = x % @width
  y = y % @height
  neighbors = Hash.new(0)
  (x-1).upto(x+1) { |xn|
    (y-1).upto(y+1) { |yn|
      xn = xn % @width
      yn = yn % @height
      neighbors[@grid[xn][yn]] += 1 unless (xn == x and yn == y)
    }
  }
  neighbors
end

#neighbor_stats(x, y) ⇒ Object

total (alive) neighbor count and birthright



49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
 
# File 'lib/conway_deathmatch.rb', line 49

def neighbor_stats(x, y)
  x = x % @width
  y = y % @height
  npop = neighbor_population(x, y).tap { |h| h.delete(DEAD) }

  case @deathmatch
  when nil
    [npop.values.reduce(0, :+), ALIVE]

  when :aggressive, :defensive
    # dead: determine majority (always 3, no need to sample for tie)
    # alive: agg: determine majority (may tie at 2); def: cell_val
    determine_majority = (@grid[x][y] == DEAD or @deathmatch == :aggressive)
    total = 0
    largest = 0
    birthrights = []
    npop.each { |sym, cnt|
      total += cnt
      return [0, DEAD] if total > 3   # [optimization]
      if determine_majority
        if cnt > largest
          largest = cnt
          birthrights = [sym]
        elsif cnt == largest
          birthrights << sym
        end
      end
    }
    [total, determine_majority ? (birthrights.sample || DEAD) : @grid[x][y]]

  when :friendly
    # [optimization] with knowledge of conway rules
    # if DEAD, need 3 friendlies to qualify for birth sampling
    # if ALIVE, npop simply has the friendly count
    cell_val = if @grid[x][y] == DEAD
                 npop.reduce([]) { |memo, (sym,cnt)|
                   cnt == 3 ? memo + [sym] : memo
                 }.sample || DEAD
               else
                 @grid[x][y]
               end
    # return [0, DEAD] if no one qualifies
    [npop[cell_val] || 0, cell_val]
  else
    raise "unknown: #{@deathmatch.inspect}"
  end
end

#next_value(x, y) ⇒ Object

Conway’s Game of Life transition rules



34
35
36
37
38
39
40
41
42
 
# File 'lib/conway_deathmatch.rb', line 34

def next_value(x, y)
  # don't bother toroidaling, only called by #tick
  n, birthright = neighbor_stats(x, y)
  if @grid[x][y] != DEAD
    (n == 2 or n == 3) ? birthright : DEAD
  else
    (n == 3) ? birthright : DEAD
  end
end

#populate(x, y, val = ALIVE) ⇒ Object

set a single point



123
124
125
 
# File 'lib/conway_deathmatch.rb', line 123

def populate(x, y, val = ALIVE)
  @grid[x % @width][y % @height] = val
end

#population ⇒ Object

full grid scan



140
141
142
143
144
 
# File 'lib/conway_deathmatch.rb', line 140

def population
  population = Hash.new(0)
  @grid.each { |col| col.each { |val|  population[val] += 1  } }
  population
end

#render_text ⇒ Object Also known as: render

for line-based text output, iterate over y-values first (i.e. per row)



134
135
136
 
# File 'lib/conway_deathmatch.rb', line 134

def render_text
  @grid.transpose.map { |row| row.join }.join("\n")
end

#tick ⇒ Object

generate the next grid table



113
114
115
116
117
118
119
120
 
# File 'lib/conway_deathmatch.rb', line 113

def tick
  new_grid = self.class.new_grid(@width, @height)
  @width.times { |x|
    @height.times { |y| new_grid[x][y] = next_value(x, y) }
  }
  @grid = new_grid
  self
end

#value(x, y) ⇒ Object 



44
45
46
 
# File 'lib/conway_deathmatch.rb', line 44

def value(x, y)
  @grid[x % @width][y % @height]
end