Implementing Health And Damage - Developing Games With Ruby - page 105

21 else
22 text = @health . to_s
23 font_size = 18
24 end
25 @image = Gosu :: Image . from_text(
26 $window , text,
27 Gosu . default_font_name, font_size)
28 @health_updated = false
29 end
30 end
31
32 def dead?
33 @health < 1
34 end
35
36 def inflict_damage (amount)
37 if @health > 0
38 @health_updated = true
39 @health = [ @health - amount . to_i, 0]. max
40 if @health < 1
41 Explosion . new( @object_pool , x, y)
42 end
43 end
44 end
45
46 def draw (viewport)
47

@image . draw(

x - @image . width / 2 , 48

y - object . graphics . height / 2 - 49

@image . height, 100 )

50

51 end
52 end

It hooks itself into the game right away, after we initialize it in Tank class:

class Tank < GameObject
attr_accessor :health
# ...
def initialize (object_pool, input)
# ...
@health = TankHealth . new( self , object_pool)
# ..
end
# ..
end