1    package npw;
2    
3    import painter.SPainter;
4    import shapes.SCircle;
5    import javax.swing.*;
6    import java.awt.*;
7    import java.util.Random;
8    import java.util.Scanner;
9    
10   public class HirstDots {
11       private void paintTheImage(){
12           //Get the input information
13           int radius = getNumber("Larger Circle radius");
14           int SecondRadius = getNumber("Smaller Circle radius");
15   
16           //establish the painter
17           SPainter painter = new SPainter ("Hirst Dots", radius*2+50, radius*2+50);
18           painter.setBrushWidth(3);
19           SCircle circle = new SCircle (radius);
20           SCircle SmallerCircle = new SCircle (SecondRadius);
21   
22           //paint the squares
23           paintCircleOfSquares(painter, circle, SmallerCircle);
24   
25       }
26       private void paintCircleOfSquares(SPainter painter, SCircle circle, SCircle SmallerCircle) {
27           //Position the painter to begin drawing the rows
28           painter.mfd(circle.radius());
29           painter.tr();
30           // Paint the circle of squares
31           double moved = 0;
32           while (moved < circle.diameter()) {
33               double chord = chordLength(circle.radius() - moved, circle);
34               int squares = circlesOnLineCount(chord, SmallerCircle.diameter());
35               paintRow(painter,SmallerCircle,squares);
36               nextRow(painter, SmallerCircle.diameter());
37               moved = moved + SmallerCircle.diameter();
38           }
39           //make the method invariant with respect to painter position
40           painter.tl();
41           painter.mfd(circle.radius());
42       }
43       // Move to the next row
44       private void nextRow(SPainter painter, double rowHeight){
45           painter.tr();
46           painter.mfd(rowHeight);
47           painter.tl();
48       }
49   
50       // Assumes the painter is at the center of the row to paint, facing right.
51       private void paintRow(SPainter painter, SCircle SmallerCircle, int circlesToPaint){
52           // Move backward 1/2 of the length we're painting to get ready to paint the row.
53           double centerOffset = ( (circlesToPaint * SmallerCircle.diameter()) / 2) - SmallerCircle.diameter()/2;
54           painter.mbk(centerOffset);
55   
56           // Paint the row of circles.
57           int painted = 0;
58           while (painted < circlesToPaint){
59               paintOneCircle(painter, SmallerCircle);
60               painter.mfd(SmallerCircle.diameter());
61               painted = painted + 1;
62           }
63   
64           // Make the method invariant with respect to painter position.
65           painter.mbk(centerOffset + SmallerCircle.diameter());
66       }
67   
68       private void paintOneCircle(SPainter painter, SCircle SmallerCircle){
69           SmallerCircle.s2();
70           painter.setColor(randomColor());
71           painter.paint(SmallerCircle);
72           painter.setColor(Color.BLACK);
73           SmallerCircle.x2();
74       }
75   
76       private static int circlesOnLineCount(double lineLength, double sideLength){
77           int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
78           return squares;
79       }
80   
81       private double chordLength(double yOffset, SCircle circle){
82           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
83           double chordLength = xLength * 2;
84           return chordLength;
85       }
86   
87       private static int getNumber(String prompt) {
88           String nss = JOptionPane.showInputDialog(null,prompt+"?");
89           Scanner scanner = new Scanner(nss);
90           return scanner.nextInt();
91       }
92   
93       private static Color randomColor() {
94           Random rgen = new Random();
95           int r = rgen.nextInt(256);
96           int g = rgen.nextInt(256);
97           int b = rgen.nextInt(256);
98           return new Color(r,g,b);
99       }
100  
101      public HirstDots() {
102          paintTheImage();
103      }
104  
105      public static void main(String[] args) {
106          SwingUtilities.invokeLater(new Runnable() {
107              public void run() {
108                  new HirstDots();
109              }
110          });
111      }
112  }