class TungstenEngine::Core::Game

Represents the base class for a real game

Attributes

fixed_time_step[RW]

Public Class Methods

new(fixed_time_step = true, target_frame_rate = 60) click to toggle source
# File lib/core/game.rb, line 11
def initialize(fixed_time_step = true, target_frame_rate = 60)
  @components = []
  @fixed_time_step = fixed_time_step
  self.target_frame_rate = target_frame_rate
end

Public Instance Methods

exit() click to toggle source
# File lib/core/game.rb, line 68
def exit
  @running = false
end
register_component(component) click to toggle source
# File lib/core/game.rb, line 21
def register_component(component)
  raise("Cannot register objects that ain't GameComponent instances") \
    unless component.is_a? GameComponent
end
render(game_time) click to toggle source
# File lib/core/game.rb, line 62
def render(game_time)
  @components.each do |component|
    component.render(game_time)
  end
end
run() click to toggle source
# File lib/core/game.rb, line 26
def run
  started = Time.now
  last_loop = Time.now
  @running = true

  game_loop = Thread.new do
    while @running
      now = Time.now
      total = TimeSpan.diff(started, now)
      elapsed = TimeSpan.diff(last_loop, now)
      spare = @target_frame_microseconds - elapsed.microseconds
      slow = spare < 0
      if @fixed_time_step && !slow
        sleep(spare / 1_000_000)
        now = Time.now
        total = TimeSpan.diff(started, now)
        elapsed = TimeSpan.diff(last_loop, now)
        # do not re-calculate 'slow' here, since we want to know if we
        # have been to slow when the loop was entered again, not if we maybe
        # are too slow after waiting
      end
      game_time = GameTime.new(total, elapsed, slow)
      update(game_time)
      render(game_time)
      last_loop = now
    end
  end
  game_loop.join
end
target_frame_rate=(frame_rate) click to toggle source
# File lib/core/game.rb, line 17
def target_frame_rate=(frame_rate)
  @target_frame_microseconds = 1_000_000.0 / frame_rate
end
update(game_time) click to toggle source
# File lib/core/game.rb, line 56
def update(game_time)
  @components.each do |component|
    component.update(game_time)
  end
end