anchor.diff:              viewportSize.Value <- newViewport.Size
           )
       ) |> ignore
  +
  +
  +
  +
   //
   //    w.Mouse.Events.Values.Subscribe(fun e ->
   //        match e with
  
positive.code: 
      //let sg = Sg.group' [sg]
  
      // compile the rendertask and pass it to the window
      w.RenderTask <- app.Runtime.CompileRender(ExecutionEngine.Native ||| ExecutionEngine.Optimized, sg.RenderJobs())
  
      // a very sketch controller for changing the viewport
      let lastPos = ref V2d.Zero
  
negative.code: open System.Web
  open System.Globalization
  open Aardvark.SceneGraph.Semantics
  open Aardvark.Base.Rendering
  
  let app = new OpenGlApplication()
  let source = KnownTileSources.Create(KnownTileSource.BingHybrid)
  