Data commit

Task/Brownian-tree/Scala/brownian-tree.scala

@@ -0,0 +1,50 @@
+import java.awt.Graphics
+import java.awt.image.BufferedImage
+
+import javax.swing.JFrame
+
+import scala.collection.mutable.ListBuffer
+
+object BrownianTree extends App {
+  val rand = scala.util.Random
+
+  class BrownianTree extends JFrame("Brownian Tree") with Runnable {
+    setBounds(100, 100, 400, 300)
+    val img = new BufferedImage(getWidth, getHeight, BufferedImage.TYPE_INT_RGB)
+
+    override def paint(g: Graphics): Unit = g.drawImage(img, 0, 0, this)
+
+    override def run(): Unit = {
+      class Particle(var x: Int = rand.nextInt(img.getWidth),
+                     var y: Int = rand.nextInt(img.getHeight)) {
+
+        /* returns false if either out of bounds or collided with tree */
+        def move: Boolean = {
+          val (dx, dy) = (rand.nextInt(3) - 1, rand.nextInt(3) - 1)
+          if ((x + dx < 0) || (y + dy < 0) ||
+            (y + dy >= img.getHeight) || (x + dx >= img.getWidth)) false
+          else {
+            x += dx
+            y += dy
+            if ((img.getRGB(x, y) & 0xff00) == 0xff00) {
+              img.setRGB(x - dx, y - dy, 0xff00)
+               false
+            } else true
+          }
+        }
+      }
+
+      var particles = ListBuffer.fill(20000)(new Particle)
+      while (particles.nonEmpty) {
+        particles = particles.filter(_.move)
+        repaint()
+      }
+    }
+
+    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE)
+    img.setRGB(img.getWidth / 2, img.getHeight / 2, 0xff00)
+    setVisible(true)
+  }
+
+  new Thread(new BrownianTree).start()
+}