anchor.diff:  open Grid
   open Simulator
   
  -type Game() =
  +type Splashy() =
     inherit GameWindow(800, 600, GraphicsMode.Default, "Splashy")
   
     do base.VSync <- VSyncMode.On
  
positive.code:     if base.Keyboard.[Key.Escape] then base.Close()
      if base.Keyboard.[Key.Right] then
        Simulator.advance ()
        refresh_drawables ()
  
    override o.OnRenderFrame(e) =
      GL.Clear(ClearBufferMask.ColorBufferBit ||| ClearBufferMask.DepthBufferBit)
  
negative.code:     let mutable lookat = rot * Matrix4.LookAt(eye, Vector3.Zero, Vector3.UnitY)
      GL.UniformMatrix4(modelViewLocation, false, &lookat)
  
      refresh_drawables ()
      for drawable in drawables do
        drawable.render vertexLocation
  
  