module Graphics

  @@super_sprite = Sprite.new
  @@super_sprite.z = (2 ** (0.size * 8 - 2) - 1)

  class << self

    def freeze(*args, &block)
      @@super_sprite.bitmap = snap_to_bitmap
    end

    def transition(time = 10, filename = nil, vague = nil)
      if filename
        @@super_sprite.bitmap = Bitmap.new(filename)
      end
      @@super_sprite.opacity = 255
      incs = 255.0 / time
      time.times do |i|
        @@super_sprite.opacity = 255.0 - incs * i
        Graphics.wait(1)
      end
      @@super_sprite.bitmap.dispose
      reform_sprite_bitmap
      Graphics.brightness = 255
    end

    def reform_sprite_bitmap
      @@super_sprite.bitmap = Bitmap.new(Graphics.width, Graphics.height)
      @@super_sprite.bitmap.fill_rect(@@super_sprite.bitmap.rect, Color.new(0, 0, 0, 255))
    end

    def fadeout(frames)
      incs = 255.0 / frames
      frames.times do |i|
        i += 1
        Graphics.brightness = 255 - incs * i
        Graphics.wait(1)
      end
    end

    def fadein(frames)
      incs = 255.0 / frames
      frames.times do |i|
        Graphics.brightness = incs * i
        Graphics.wait(1)
      end
    end

    def brightness=(i)
      @@super_sprite.opacity = 255.0 - i
    end

    def brightness
      255 - @@super_sprite.opacity
    end

    def ensure_sprite
      if @@super_sprite.disposed?
        @@super_sprite = Sprite.new
        @@super_sprite.z = (2 ** (0.size * 8 - 2) - 1)
        reform_sprite_bitmap
      end
    end
  end
end

class << SceneManager

  alias resolution_run run
  def run(*args, &block)
    Graphics.ensure_sprite
    resolution_run(*args, &block)
  end
end