mini interactive visualization made in ruby + gosu

hyperspace.rb

require 'gosu'

class Window < Gosu::Window
  attr_accessor :hyperspace

  def initialize(width, height)
    super(width, height, false)
    @hyperspace = HyperSpace.new
  end

  def update
    hyperspace.update
  end

  def draw
    hyperspace.draw
  end

  def button_down(id)
    hyperspace.button_down(id)
  end

  def button_up(id)
    hyperspace.button_up(id)
  end

  def needs_cursor?
    true
  end
end

class HyperSpace
  attr_reader :dots, :moving, :count

  def initialize
    @dots = []
    @moving = false
    @count = 0
  end

  def update
    dots.each(&:update)
    dots.select!(&:visible?)
    update_caption
  end

  def draw
    dots.each(&:draw)
    create_dots(25) if moving
  end

  def create_dots(n)
    n.times { dots << Dot.new(x: $win.mouse_x, y: $win.mouse_y, speed: 5, dir: rand(360).to_i) }
  end

  def button_down(id)
    $win.close if id == Gosu::KbEscape
    if id == Gosu::MsLeft
      @moving = true
      create_dots(25)
    end
  end

  def button_up(id)
    if id == Gosu::MsLeft
      @moving = false
    end
  end

  def update_caption
    now = Gosu.milliseconds
    if now - (@caption_updated_at || 0) > 200
      $win.caption = "[FPS: #{Gosu.fps}. " << "item count: #{dots.count}]"
      @caption_updated_at = now
    end
  end
end

class Dot
  RAD = 0.0174533.freeze

  attr_reader :speed, :x, :y, :dx, :dy, :dir, :scale, :color, :size, :layer
  def initialize(args = {})
    @speed = args.fetch(:speed, 4)
    @x = args.fetch(:x)
    @y = args.fetch(:y)
    @dir = args.fetch(:dir)
    @scale = 0.1
    @size = 10
    @color = 0
    @layer = 0
  end

  def update
    cos = Math.cos(dir * RAD)
    sin = Math.sin(dir * RAD)

    @x += cos * (speed ** scale)
    @y += sin * (speed ** scale)
    @dx = x + cos * size ** scale
    @dy = y + sin * size ** scale

    @scale += 0.002 * speed
    @color += 1 if @color <= 253
    @layer += 1
  end

  def draw
    c = Gosu::Color.new(color, color, color)
    Gosu.draw_line(x, y, c,   dx, dy, c,   layer)
  end

  def visible?
    x >= 0 - size &&
    x <= $win.width + size &&
    y >= 0 - size &&
    y <= $win.height + size
  end
end

$win = Window.new(1280, 768)
$win.show