Refactoring The Prototype - Developing Games With Ruby - page 77

PlayState would

then iterate through @object_pool.objects and invoke

update and draw methods.

Now, let's begin by implementing base class for GameObject :
05-refactor/entities/game_object.rb

1 class GameObject
2 def initialize (object_pool)
3 @components = []
4 @object_pool = object_pool
5 @object_pool . objects << self
6 end
7
8 def components
9 @components
10 end
11
12 def update
13 @components . map( & :update )
14 end
15
16 def draw (viewport)
17 @components . each { | c | c . draw(viewport) }
18 end
19
20 def removable?
21 @removable
22 end
23
24 def mark_for_removal
25 @removable = true
26 end
27
28 protected

29
30 def object_pool
31 @object_pool
32 end
33 end

When GameObject is initialized, it registers itself with ObjectPool and prepares
empty @components array. Concrete GameObject classes should initialize

Components so that array would not be empty.