YAPC::EU 2018 Glasgow Update!

Task/Fractal-tree/Ceylon/fractal-tree.ceylon

@@ -0,0 +1,45 @@
+import javax.swing {
+
+	JFrame { exitOnClose }
+}
+import java.awt {
+
+	Color { white, black },
+	Graphics
+}
+import ceylon.numeric.float {
+
+	cos,
+	toRadians,
+	sin
+}
+
+shared void run() {
+	
+    value fractalTree = object extends JFrame("fractal tree") {
+
+        background = black;
+        setBounds(100, 100, 800, 600);
+        resizable = false;
+        defaultCloseOperation = exitOnClose;
+
+        shared actual void paint(Graphics g) {
+
+            void drawTree(Integer x1, Integer y1, Float angle, Integer depth) {
+                if (depth <= 0) {
+                    return;
+                }
+                value x2 = x1 + (cos(toRadians(angle)) * depth * 10.0).integer;
+                value y2 = y1 + (sin(toRadians(angle)) * depth * 10.0).integer;
+                g.drawLine(x1, y1, x2, y2);
+                drawTree(x2, y2, angle - 20, depth - 1);
+                drawTree(x2, y2, angle + 20, depth - 1);
+            }
+
+            g.color = white;
+            drawTree(400, 500, -90.0, 9);
+        }
+    };
+
+    fractalTree.visible = true;
+}