1    /* 
2     * A program to paint, centered on the canvas, a circle of randomly colored, black-framed squares 
3     * with a gap in between each square. 
4     */
5    
6    package npw;
7    
8    import painter.SPainter;
9    import shapes.SCircle;
10   import javax.swing.*;
11   import java.awt.*;
12   import java.util.Random;
13   import java.util.Scanner;
14   
15   public class HirstDots {
16   
17       private void paintTheImage() {
18   
19           // Get the input information
20           int radius = getNumber("circle radius");
21           int radii = getNumber("circle radii");
22   
23           // Establish the painter
24           SPainter painter = new SPainter("Circle of Circles", radius*2+50, radius*2+50);
25           painter.setBrushWidth(3);
26           SCircle circle = new SCircle(radius);
27           SCircle circles = new SCircle(radii);
28   
29           // Paint the circles
30           paintHirstDots(painter, circle, circles);
31       }
32   
33       private void paintHirstDots(SPainter painter, SCircle circle, SCircle circles) {
34   
35           // Position the painter to begin drawing the rows
36           painter.mfd(circle.radius());
37           painter.tr();
38   
39           // Paint the circle of circles
40           double moved = 0;
41           while (moved < circle.diameter()) {
42               double chord = chordLength(circle.radius() - moved, circle);
43               int circNum = circlesOnLineCount(chord, circles.diameter());
44               paintRow(painter, circles, circNum);
45               nextRow(painter, circles.diameter());
46               moved = moved + circles.diameter();
47           }
48   
49           // Make the method invariant with respect to painter position
50           painter.tl();
51           painter.mfd(circle.radius());
52       }
53   
54       // Move to the next row
55       private void nextRow(SPainter painter, double rowHeight) {
56           painter.tr();
57           painter.mfd(rowHeight);
58           painter.tl();
59       }
60   
61       // Assumes the painter is at the center of the row to paint, facing right
62       private void paintRow(SPainter painter, SCircle circles, int circlesToPaint) {
63   
64           // Move backward 1/2 of the length we're painting to get ready to paint the row.
65           double centerOffset = ( (circlesToPaint * circles.diameter()) / 2) - circles.diameter() / 2;
66           painter.mbk(centerOffset);
67   
68           // Paint the row of circles
69           int painted = 0;
70           while (painted < circlesToPaint) {
71               paintOneSquare(painter, circles);
72               painter.mfd(circles.diameter());
73               painted = painted + 1;
74           }
75   
76           // Make the method invariant with respect to painter position
77           painter.mbk(centerOffset + circles.diameter());
78       }
79   
80       private void paintOneSquare(SPainter painter, SCircle circles) {
81   
82           circles.s2();
83           painter.setColor(randomColor());
84           painter.paint(circles);
85           circles.x2();
86       }
87   
88       private static int circlesOnLineCount(double lineLength, double sideLength) {
89   
90           int circNum = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
91           return circNum;
92       }
93       private double chordLength(double yOffset, SCircle circle) {
94   
95           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
96           double chordLength = xLength * 2;
97           return chordLength;
98       }
99   
100      private static int getNumber(String prompt) {
101  
102          String nss = JOptionPane.showInputDialog(null, prompt+"?");
103          Scanner scanner = new Scanner(nss);
104          return scanner.nextInt();
105      }
106  
107      private static Color randomColor() {
108  
109          Random rgen = new Random();
110          int r = rgen.nextInt(256);
111          int g = rgen.nextInt(256);
112          int b = rgen.nextInt(256);
113          return new Color(r,g,b);
114      }
115  
116      public HirstDots() {
117  
118          paintTheImage();
119      }
120  
121      public static void main(String[] args) {
122          SwingUtilities.invokeLater(new Runnable() {
123              public void run() {
124                  new HirstDots();
125              }
126          });
127      }
128  }