Refactoring The Prototype - Developing Games With Ruby - page 87

8 end
9 else
10 if @driving && @driving . playing?
11 @driving . pause
12 end
13 end
14 end
15
16 def collide
17 crash_sound . play( 1 , 0.25 , false )
18 end
19
20

private

21
22 def driving_sound
23 @@driving_sound ||= Gosu :: Sample . new(

$window , Utils . media_path( 'tank_driving.mp3' ))

24

25 end
26
27 def crash_sound
28 @@crash_sound ||= Gosu :: Sample . new(

$window , Utils . media_path( 'crash.ogg' ))

29

30 end
31 end

Unlike Explosion and Bullet , Tank sounds are stateful. We have to keep track of
tank_driving.mp3 , which is no longer Gosu::Song , but Gosu::Sample , like it
should have been.

When Gosu::Sample#play is invoked, Gosu::SampleInstance is returned, and
we have full control over it. Now we are ready to play sounds for more than one tank at
once.
05-refactor/entities/components/player_input.rb

1 class PlayerInput < Component
2 def initialize (camera)
3 super ( nil )
4 @camera = camera
5 end
6
7 def control (obj)
8 self . object = obj
9 end
10