1    /* 
2    A program to paint, centered on a canvas, a circle of randomly colored circles spaced from each other. 
3     */
4    
5    package npw;
6    
7    import painter.SPainter;
8    import shapes.SCircle;
9    import shapes.SSquare;
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 input information
20           int radius = getNumber("large circle radius");
21           int side = getNumber("small circles 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 hirst = new SCircle(side);
28   
29           //Paint the squares
30           paintCircleOfSquares(painter,circle,hirst);
31       }
32   
33       private void paintCircleOfSquares(SPainter painter, SCircle circle, SCircle hirst){
34           //Position the painter to begin drawing the rows
35           painter.mfd(circle.radius());
36           painter.tr();
37           //Paint the circle of squares
38           double moved=0;
39           while (moved < circle.diameter()) {
40               double chord = chordLength(circle.radius()-moved, circle);
41               int squares = squaresOnLineCount(chord, hirst.diameter());
42               paintRow(painter, hirst, squares);
43               nextRow(painter, hirst.diameter());
44               moved=moved+hirst.diameter();
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 hirst, int squaresToPaint){
60           //Move backward 1/2 of the length we're painting to get ready to paint the row
61           double centerOffset = (((squaresToPaint*hirst.diameter())/2)-hirst.diameter()/2);
62           painter.mbk(centerOffset);
63   
64           //Paint the row of squares
65           int painted=0;
66           while (painted < squaresToPaint) {
67               paintOneSquare(painter,hirst);
68               painter.mfd(hirst.diameter());
69               painted=painted+1;
70           }
71   
72           //make the method invariant with respect to painter position
73           painter.mbk(centerOffset+hirst.diameter());
74       }
75   
76       private void paintOneSquare(SPainter painter, SCircle hirst){
77           hirst.s2();
78           painter.setColor(randomColor());
79           painter.paint(hirst);
80           hirst.x2();
81       }
82   
83       private static int squaresOnLineCount(double lineLength, double sideLength){
84           int hirsts = ((int)Math.ceil((lineLength-sideLength)/sideLength)+1);
85           return hirsts;
86       }
87   
88       private double chordLength(double yOffset, SCircle circle){
89           double xLength=Math.sqrt(Math.pow(circle.radius(),2)-Math.pow(yOffset,2));
90           double chordLength=xLength*2;
91           return chordLength;
92       }
93   
94       private static int getNumber(String prompt) {
95           String nss = JOptionPane.showInputDialog(null,prompt+"?");
96           Scanner scanner = new Scanner(nss);
97           return scanner.nextInt();
98       }
99   
100      private static Color randomColor() {
101          Random rgen = new Random();
102          int r = rgen.nextInt(256);
103          int g = rgen.nextInt(256);
104          int b = rgen.nextInt(256);
105          return new Color(r,g,b);
106      }
107  
108      public HirstDots(){
109          paintTheImage();
110      }
111  
112      public static void main(String[] args) {
113          SwingUtilities.invokeLater(new Runnable() {
114              public void run() {
115                  new HirstDots();
116              }
117          });
118      }
119  }