1    /* 
2     * A program to paint, centered on the canvas, a circle of randomly colored circles, spaced evenly 
3     * from each other. 
4     */
5    package npw;
6    
7    import painter.SPainter;
8    import shapes.SCircle;
9    
10   
11   import javax.swing.*;
12   import java.awt.*;
13   import java.util.Random;
14   import java.util.Scanner;
15   
16   public class HirstDots {
17   
18       private void paintTheImage(){
19           // Get the input information
20           int radius = getNumber("circle radius");
21           int radius2 = getNumber("individual circle radius");
22   
23           // Establish the painter
24           SPainter painter = new SPainter("Hirst Dots", radius*2+50, radius*2+50);
25           painter.setBrushWidth(3);
26           SCircle circle = new SCircle(radius);
27           SCircle circle2 = new SCircle(radius2);
28   
29           // Paint the circles
30           paintCircleOfCircles(painter, circle, circle2);
31       }
32   
33       private void paintCircleOfCircles(SPainter painter, SCircle circle, SCircle circle2){
34           // Position the painter to begin drawing the rows
35           painter.mfd(circle.radius());
36           painter.tr();
37           // Paint the circle of circles
38           double moved = 0;
39           while (moved < circle.diameter()) {
40               double chord = chordLength(circle.radius() - moved, circle);
41               int circles = circlesOnLineCount(chord, circle2.radius());
42               paintRow(painter, circle2, circles);
43               nextRow(painter, circle2.radius());
44               moved = moved + circle2.radius();
45           }
46           // Make the method invariant with respect to painter position
47           painter.tl();
48           painter.mfd(circle.radius());
49       }
50   
51       // Move to the next row
52       private void nextRow(SPainter painter, double rowHeight){
53           painter.tr();
54           painter.mfd(rowHeight);
55           painter.tl();
56       }
57   
58       // Assumes the painter is at the center of the row to paint, facing right.
59       private void paintRow(SPainter painter, SCircle circle2, int circlesToPaint){
60           // Move backward 1/2 of the length we're painting to get ready to paint the row.
61           double centerOffset = ( (circlesToPaint * circle2.radius()) / 2) - circle2.radius()/2;
62           painter.mbk(centerOffset);
63   
64           // Paint the row of circles.
65           int painted = 0;
66           while (painted < circlesToPaint){
67               paintOneCircle(painter, circle2);
68               painter.mfd(circle2.radius());
69               painted = painted + 1;
70           }
71   
72           // Make the method invariant with respect to painter position.
73           painter.mbk(centerOffset + circle2.radius());
74       }
75   
76       private void paintOneCircle(SPainter painter, SCircle circle2) {
77           painter.setColor(randomColor());
78           circle2.s5();
79           painter.paint(circle2);
80           circle2.x5();
81   
82   
83   
84   
85   
86   
87   
88   
89   
90   
91   
92   
93   
94   
95       }
96   
97       private static int circlesOnLineCount(double lineLength, double sideLength){
98           int circles = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
99           return circles;
100      }
101  
102      private double chordLength(double yOffset, SCircle circle){
103          double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
104          double chordLength = xLength * 2;
105          return chordLength;
106      }
107  
108      private static int getNumber(String prompt) {
109          String nss = JOptionPane.showInputDialog(null,prompt+"?");
110          Scanner scanner = new Scanner(nss);
111          return scanner.nextInt();
112      }
113  
114      private static Color randomColor() {
115          Random rgen = new Random();
116          int r = rgen.nextInt(256);
117          int g = rgen.nextInt(256);
118          int b = rgen.nextInt(256);
119          return new Color(r,g,b);
120      }
121  
122      public HirstDots() {
123          paintTheImage();
124      }
125  
126      public static void main(String[] args) {
127          SwingUtilities.invokeLater(new Runnable() {
128              public void run() {
129                  new HirstDots();
130              }
131          });
132      }
133  }