1    package npw;
2    
3    import painter.SPainter;
4    import shapes.SCircle;
5    
6    import javax.swing.*;
7    import java.awt.*;
8    import java.util.Random;
9    import java.util.Scanner;
10   
11   public class HirstDots {private void paintTheImage(){
12       // Get the input information
13       int radius = getNumber("circle radius");
14       int dotRadius = getNumber("radius of dot");
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 dot = new SCircle(dotRadius);
21   
22       // Paint the squares
23       paintCircleOfSquares(painter, circle, dot);
24   }
25   
26       private void paintCircleOfSquares(SPainter painter, SCircle circle, SCircle dot){
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 dots = circlesOnLineCount(chord, dot.diameter());
35               paintRow(painter, dot , dots);
36               nextRow(painter, dot.radius());
37               moved = moved + dot.radius();
38           }
39           // Make the method invariant with respect to painter position
40           painter.tl();
41           painter.mfd(circle.radius());
42       }
43   
44       // Move to the next row
45       private void nextRow(SPainter painter, double rowHeight){
46           painter.tr();
47           painter.mfd(rowHeight);
48           painter.tl();
49       }
50   
51       // Assumes the painter is at the center of the row to paint, facing right.
52       private void paintRow(SPainter painter, SCircle dot, int CirclesToPaint){
53           // Move backward 1/2 of the length we're painting to get ready to paint the row.
54           double centerOffset = ( (CirclesToPaint * dot.diameter()) / 2) - dot.diameter()/2;
55           painter.mbk(centerOffset);
56   
57           // Paint the row of squares.
58           int painted = 0;
59           while (painted < CirclesToPaint){
60               paintOneSquare(painter, dot);
61               painter.mfd(dot.diameter());
62               painted = painted + 1;
63           }
64   
65           // Make the method invariant with respect to painter position.
66           painter.mbk(centerOffset + dot.diameter());
67       }
68   
69       private void paintOneSquare(SPainter painter, SCircle dot){
70           painter.setColor(randomColor());
71           dot.s3();
72           painter.paint(dot);
73           dot.x3();
74   
75   
76       }
77   
78       private static int circlesOnLineCount(double lineLength, double sideLength){
79           int circles = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
80           return circles;
81       }
82   
83       private double chordLength(double yOffset, SCircle circle){
84           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
85           double chordLength = xLength * 2;
86           return chordLength;
87       }
88   
89       private static int getNumber(String prompt) {
90           String nss = JOptionPane.showInputDialog(null,prompt+"?");
91           Scanner scanner = new Scanner(nss);
92           return scanner.nextInt();
93       }
94   
95       private static Color randomColor() {
96           Random rgen = new Random();
97           int r = rgen.nextInt(256);
98           int g = rgen.nextInt(256);
99           int b = rgen.nextInt(256);
100          return new Color(r,g,b);
101      }
102  
103      public HirstDots() {
104          paintTheImage();
105      }
106  
107      public static void main(String[] args) {
108          SwingUtilities.invokeLater(new Runnable() {
109              public void run() {
110                  new HirstDots();
111              }
112          });
113      }
114  }
115