RECURSION - Introduction to Java Programming: Comprehensive Version - page 723

(a) Order 0 (b) Order 1

(c) Order 2 (d) Order 3

F IGURE 18.9

A Sierpinski triangle is a pattern of recursive triangles.

drawing a Sierpinski triangle of order n can be reduced to drawing three Sierpinski triangles
of order n - 1 .
Listing 18.9 gives a program that displays a Sierpinski triangle of any order, as shown in
Figure 18.9. You can enter an order in a text field to display a Sierpinski triangle of the speci-
fied order.

L ISTING 18.9

SierpinskiTriangle.java
1 import javafx.application.Application;
2 import javafx.geometry.Point2D;
3 import javafx.geometry.Pos;
4 import javafx.scene.Scene;
5 import javafx.scene.control.Label;
6 import javafx.scene.control.TextField;
7 import javafx.scene.layout.BorderPane;
8 import javafx.scene.layout.HBox;
9 import javafx.scene.layout.Pane;
10 import javafx.scene.paint.Color;
11 import javafx.scene.shape.Polygon;
12 import javafx.stage.Stage;
13
14 public class SierpinskiTriangle extends Application {
15 @Override // Override the start method in the Application class
16 public void start(Stage primaryStage) {
17 SierpinskiTrianglePane trianglePane = new SierpinskiTrianglePane();
18 TextField tfOrder = new TextField();
19

recursive triangle pane

tfOrder.setOnAction(