open Graphics2D

let highlight =
  Fill.radial
    (vec2 0.4 0.5) (vec2 0.6 0.7) (vec2 0.1 0.8) Fill.white Fill.clear

let geo =
  [Contour.Closed, [curve_to (-0.8) 0. (-0.8) 0. (-1.) 1.; line_to 1. 1.;
		    curve_to 0.8 0. 0.8 0. 1. (-1.); line_to (-1.) (-1.)]] |>
      ContourGeometry.make 

let styles =
  [ Fill.flat Fill.red, Style.Interior `Odd;
    highlight, Style.Interior `Odd;
    Fill.Flat Fill.blue, Style.stroke ~joins:`Round 0.2 ]

let portal =
  {view = Some(vec2 (-1.6) (-1.6), vec2 1.6 1.6); scene = Group [||]}

let paint() = portal.scene <- Transform(rot(time()), Shape(styles, geo))

let () =
  let on_paint = Event.create() in
  Event.add paint on_paint;
  GUI.spawn ~on_paint portal