1    /* 
2     * A program to paint, centered on the canvas, a circle of randomly colored, unframed dots; a simple variant of the HirstSquares program. 
3     */
4    package npw;
5    
6    import painter.SPainter;
7    import shapes.SCircle;
8    
9    import javax.swing.*;
10   import java.awt.*;
11   import java.util.Random;
12   import java.util.Scanner;
13   
14   public class HirstDots {
15   
16       private void paintTheImage() {
17           // Get the input information
18           int radius = getNumber("circle radius");
19           int radius2 = getNumber("circle radius2");
20   
21           // Establish the painter
22           SPainter painter = new SPainter("Hirst Dots", radius * 2 + 50, radius * 2 + 50);
23           painter.setBrushWidth(3);
24           SCircle circle = new SCircle(radius);
25           SCircle dot = new SCircle(radius2);
26   
27           // Paint the dots
28           paintHirstDots(painter, circle, dot);
29       }
30   
31       private void paintHirstDots(SPainter painter, SCircle circle, SCircle dot) {
32           // Position the painter to begin drawing the rows
33           painter.mfd(circle.radius());
34           painter.tr();
35           // Paint the circle of dots- Hirst
36           double moved = 0;
37           while (moved < circle.diameter()) {
38               double chord = chordLength(circle.radius() - moved, circle);
39               int dots = dotsOnLineCount(chord, dot.radius());
40               paintRow(painter, dot, dots);
41               nextRow(painter, dot.radius());
42               moved = moved + dot.radius();
43           }
44           // Make the method invariant with respect to painter position
45           painter.tl();
46           painter.mfd(circle.radius());
47       }
48   
49       // Move to the next row
50       private void nextRow(SPainter painter, double rowHeight) {
51           painter.tr();
52           painter.mfd(rowHeight);
53           painter.tl();
54       }
55   
56       // Assumes the painter is at the center of the row to paint, facing right.
57       private void paintRow(SPainter painter, SCircle dot, int dotsToPaint) {
58           // Move backward 1/2 of the length we're painting to get ready to paint the row.
59           double centerOffset = ((dotsToPaint * dot.radius()) / 2) - dot.radius() / 2;
60           painter.mbk(centerOffset);
61   
62           // Paint the row of dots.
63           int painted = 0;
64           while (painted < dotsToPaint) {
65               paintOneDot(painter, dot);
66               painter.mfd(dot.radius());
67               painted = painted + 1;
68           }
69   
70           // Make the method invariant with respect to painter position.
71           painter.mbk(centerOffset + dot.radius());
72       }
73   
74       private void paintOneDot(SPainter painter, SCircle dot) {
75           painter.setColor(randomColor());
76           dot.s3();
77           painter.paint(dot);
78           //painter.draw(dot);
79           dot.x3();
80       }
81   
82       private static int dotsOnLineCount(double lineLength, double sideLength) {
83           int dots = ((int) Math.ceil((lineLength - sideLength) / sideLength) + 1);
84           return dots;
85       }
86   
87       private double chordLength(double yOffset, SCircle circle) {
88           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
89           double chordLength = xLength * 2;
90           return chordLength;
91       }
92   
93       private static int getNumber(String prompt) {
94           String nss = JOptionPane.showInputDialog(null, prompt + "?");
95           Scanner scanner = new Scanner(nss);
96           return scanner.nextInt();
97       }
98   
99       private static Color randomColor() {
100          Random rgen = new Random();
101          int r = rgen.nextInt(256);
102          int g = rgen.nextInt(256);
103          int b = rgen.nextInt(256);
104          return new Color(r, g, b);
105      }
106  
107      public HirstDots() {
108          paintTheImage();
109      }
110  
111      public static void main(String[] args) {
112          SwingUtilities.invokeLater(new Runnable() {
113              public void run() {
114                  new HirstDots();
115              }
116          });
117      }
118  }