samples/09_performance/04_sprites_as_classes/app/main.rb


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# Sprites represented as Classes using the queue ~args.outputs.sprites~.
# gives you full control of property declaration and method invocation.
# They are more performant than OpenEntities and StrictEntities, but more code upfront.
class Star
  attr_sprite

  def initialize grid
    @grid = grid
    @x = (rand @grid.w) * -1
    @y = (rand @grid.h) * -1
    @w    = 4
    @h    = 4
    @s    = 1 + (4.randomize :ratio)
    @path = 'sprites/tiny-star.png'
  end

  def move
    @x += @s
    @y += @s
    @x = (rand @grid.w) * -1 if @x > @grid.right
    @y = (rand @grid.h) * -1 if @y > @grid.top
  end
end

# calls methods needed for game to run properly
def tick args
  # sets console command when sample app initially opens
  if Kernel.global_tick_count == 0
    args.gtk.console.set_command "reset_with count: 100"
  end

  # init
  if args.state.tick_count == 0
    args.state.stars = args.state.star_count.map { |i| Star.new args.grid }
  end

  # update
  args.state.stars.each(&:move)

  # render
  args.outputs.sprites << args.state.stars
  args.outputs.background_color = [0, 0, 0]
  args.outputs.primitives << args.gtk.current_framerate_primitives
end

# resets game, and assigns star count given by user
def reset_with count: count
  $gtk.reset
  $gtk.args.state.star_count = count
end