1 /* 2 * File: OctagonTest2.java 3 * 4 * Draw a quadrilateral inside a regular octagon (an exercise) 5 * 6 * Copyright: Northeast Parallel Architectures Center 7 * 8 */ 9 10 import java.applet.Applet; 11 import java.awt.Graphics; 12 import java.awt.Color; 13 import java.awt.Point; 14 15 public class OctagonTest2 extends Applet { 16 17 // create a reference to an octagon: 18 private Octagon octagon; 19 20 // create a reference to a quadrilateral: 21 private Quadrilateral quad; 22 23 // create references to eight points: 24 private Point p1, p2, p3, p4, p5, p6, p7, p8; 25 26 public void init() { 27 28 // instantiate eight points (the vertices of a regular octagon): 29 p1 = new Point( 69, 25 ); 30 p2 = new Point( 131, 25 ); 31 p3 = new Point( 175, 69 ); 32 p4 = new Point( 175, 131 ); 33 p5 = new Point( 131, 175 ); 34 p6 = new Point( 69, 175 ); 35 p7 = new Point( 25, 131 ); 36 p8 = new Point( 25, 69 ); 37 38 // instantiate a regular octagon: 39 octagon = new Octagon( p1, p2, p3, p4, p5, p6, p7, p8 ); 40 41 // instantiate a quadrilateral inside the octagon: 42 quad = new Quadrilateral( p1.x, p1.y, p3.x, p3.y, 43 p5.x, p5.y, p7.x, p7.y ); 44 45 } 46 47 public void paint( Graphics g ) { 48 49 // fill the octagon: 50 g.setColor( Color.red ); 51 octagon.fill( g ); 52 53 // draw the quadrilateral: 54 g.setColor( Color.yellow ); 55 quad.draw( g ); 56 57 } 58 59 }