Class: RGame::Engine::Timer

Inherits:
Object
  • Object
show all
Defined in:
lib/rgame/engine/timer.rb

Overview

A repeating interval timer for periodic events that aren't driven by input — a spawner emitting an enemy every N seconds, a tower's fire rate, a wave clock.

It only accumulates time; the owner decides what each elapsed interval means. That split lets one primitive serve both styles: "act automatically" (consume every ready interval) and "stay loaded until conditions allow" (check ready?, but consume only when actually acting — so a tower with no target keeps its shot ready instead of wasting it). Pure and allocation-free, so it ticks on the per-frame path.

timer = Engine::Timer.new(0.8)
timer.update(dt)
if timer.ready?       # at least one whole interval has passed
timer.consume       # deduct it (remainder carries forward, so timing won't drift)
spawn_enemy
end

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(interval) ⇒ Timer

Returns a new instance of Timer.



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# File 'lib/rgame/engine/timer.rb', line 23

def initialize(interval)
  @interval = interval
  @elapsed = 0.0
end

Instance Attribute Details

#interval ⇒ Object

Returns the value of attribute interval.



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# File 'lib/rgame/engine/timer.rb', line 21

def interval
  @interval
end

Instance Method Details

#consume ⇒ Object

Deduct one interval after acting on a ready timer. Carries the remainder forward (rather than zeroing) so a long-running cadence doesn't drift. Returns self.



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# File 'lib/rgame/engine/timer.rb', line 39

def consume
  @elapsed -= @interval
  self
end

#ready? ⇒ Boolean

Has at least one whole interval accumulated since the last consume?

Returns:

  • (Boolean) 


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# File 'lib/rgame/engine/timer.rb', line 35

def ready? = @elapsed >= @interval

#reset ⇒ Object

Drop any accumulated time — e.g. after retuning the interval. Returns self.



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# File 'lib/rgame/engine/timer.rb', line 45

def reset
  @elapsed = 0.0
  self
end

#update(dt) ⇒ Object

Advance by one timestep. Returns self so callers can chain.



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# File 'lib/rgame/engine/timer.rb', line 29

def update(dt)
  @elapsed += dt
  self
end