ScalaFiddle gist

SierpinskiTriangle.scala

case class Pt(x: Double, y: Double)

object ScalaFiddle extends js.JSApp{
  println("Hello!!")
  
  val corners = Seq(
    Pt(Page.canvas.width/2, 0),
    Pt(0, Page.canvas.height),
    Pt(Page.canvas.width, Page.canvas.height)
  )
  var p = corners(0)
  val (w, h) = (Page.canvas.height.toDouble, Page.canvas.height.toDouble)
  
  def main() = {
    dom.window.setInterval(() => for(_ <- 0 until 10){
      val c = corners(util.Random.nextInt(3))
      p = Pt((p.x + c.x) / 2, (p.y + c.y) / 2)
      val m = (p.y / h)
      val r = 255 - (p.x / w * m * 255).toInt
      val g = 255 - ((w-p.x) / w * m * 255).toInt
      val b = 255 - ((h - p.y) / h * 255).toInt
      Page.renderer.fillStyle = s"rgb($r, $g, $b)"
      Page.renderer.fillRect(p.x, p.y, 1, 1)
    }, 10)
  }
}