Позволяет рисовать такие штуки:
http://i.imgur.com/UHl9nyB.gif
http://i.imgur.com/q3mysMs.png
Язык программирования Scala

                        
import scala.swing.Swing._

import scala.swing._

import scala.swing.event._

import java.awt.{Color, Graphics2D, geom}

 

object PaintApp {

  def main(args: Array[String]) = PaintAppSwing.main(args)

 

  object PaintAppSwing extends SimpleSwingApplication with Runnable {

    val SIZE = 500

 

    val path = new geom.GeneralPath

    val at = new geom.AffineTransform

    at.rotate(Math.toRadians(10), SIZE / 2d, SIZE / 2d)

    var rotate = true

    var sleep = 40

 

    lazy val ui = new Panel {

      background = Color.WHITE

      preferredSize = (SIZE, SIZE)

 

      focusable = true

      listenTo(mouse.clicks, mouse.moves, mouse.wheel, keys)

      reactions += {

        case e: MousePressed => path.moveTo(e.point.x, e.point.y)

        case e: MouseDragged => path.lineTo(e.point.x, e.point.y)

        case e: MouseWheelMoved =>

          sleep += e.rotation

          if (sleep < 1) sleep = 1

          else if (sleep > 300) sleep = 300

        case KeyTyped(_,'r',_,_) => rotate = !rotate

        case KeyTyped(_,'c',_,_) => path.reset

      }

 

      override def paintComponent(g: Graphics2D) = {

        super.paintComponent(g)

        g.drawString(s"Wheel - Change speed [$sleep], C - Clear, R - Rotate [$rotate]", 10, size.height-10)

        g.setColor(Color.BLACK)

        g.draw(path)

      }

    }

 

    def top = new MainFrame {

      title = "Rotate Paint"

      contents = ui

    }

 

    def run() {

      while (true) {

        if (rotate) path.transform(at)

        ui.repaint

        Thread.sleep(sleep)

      }

    }

    new Thread(this).start

  }

}