YAPC::EU 2018 Glasgow Update!

Task/Brownian-tree/Perl/brownian-tree.pl

@@ -101,13 +101,11 @@ my $count;
 PARTICLE: while (1) {
         my $a = rand(2 * PI);
         my $p = [ $r_start * cos($a), $r_start * sin($a) ];
-        while ($_ = move($p)) {
-                given ($_) {
-                        when (1) { next }
-                        when (2) { $count++; last; }
-                        when (3) { last PARTICLE }
-                        default  { last }
-                }
+        while (my $m = move($p)) {
+                if    ($m == 1) { next }
+                elsif ($m == 2) { $count++; last; }
+                elsif ($m == 3) { last PARTICLE }
+                else            { last }
         }
         print STDERR "$count $max_dist/@{[int($r_start)]}/@{[STOP_RADIUS]}\r" unless $count% 7;
 }

Task/Brownian-tree/Ring/brownian-tree.ring

@@ -1,8 +1,4 @@
 # Project : Brownian tree
-# Date    : 2018/02/16
-# Author : Gal Zsolt (~ CalmoSoft ~)
-# Email   : <calmosoft@gmail.com>
-
 
 load "stdlib.ring"
 load "guilib.ring"

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()
+}