A glowing line with JavaFX

GlowingLine.scala

class GlowingLine extends javafx.application.Application {
 
  val canvasWidth = 1024
  val canvasHeight = 768
 
  override def start(primaryStage: Stage): Unit = {
    primaryStage.setTitle("Level0")
    val root = new BorderPane()
    val drawingBoard = new Group()
    val background = {
      val b = new Rectangle(0, 0, canvasWidth, canvasHeight)
      b.setFill(Color.BLACK)
      b
    }
    val refline = new Line(canvasWidth / 10, canvasHeight / 2, canvasWidth * 9 / 10, canvasHeight / 2)
    refline.setStroke(Color.WHITESMOKE)
    val line = new Line(canvasWidth / 10, canvasHeight / 2, canvasWidth * 9 / 10, canvasHeight / 2)
    line.setStroke(Color.WHITE)
    line.setStrokeWidth(4)
    val bloom = new Bloom(1.0)
    val blur = new GaussianBlur()
    blur.setInput(bloom)
    line.setEffect(blur)
    drawingBoard.getChildren().addAll(background, refline, line)
    root.setCenter(drawingBoard)
    primaryStage.setScene(new Scene(root, canvasWidth, canvasHeight))
    primaryStage.show()
  }
 
}