1    /* 
2     * A program to paint, centered on the canvas, a circle of randomly colored, black-framed squares. 
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   
20           // Get the input information
21           int rad = getNumber("circle radius");
22           int side = (getNumber("small circle radius")) * 2;
23   
24           // Establish the painter
25           SPainter painter = new SPainter("Hirst Dots", rad*2+50, rad*2+50);
26           painter.setBrushWidth(3);
27           SCircle circle = new SCircle(rad);
28           SSquare square = new SSquare(side);
29   
30           // Paint the squares
31           paintCircleOfSquares(painter, circle, square);
32       }
33   
34       private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square){
35   
36           // Position the painter to begin drawing the rows
37           painter.mfd(circle.radius());
38           painter.tr();
39           // Paint the circle of squares
40           double moved = 0;
41           while (moved < circle.diameter()) {
42               double chord = chordLength(circle.radius() - moved, circle);
43               int squares = squaresOnLineCount(chord, square.side());
44               paintRow(painter, square, squares);
45               nextRow(painter, square.side());
46               moved = moved + square.side();
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, SSquare square, int squaresToPaint){
63   
64           // Move backward 1/2 of the length we're painting to get ready to paint the row.
65           double centerOffset = ( (squaresToPaint * square.side()) / 2) - square.side()/2;
66           painter.mbk(centerOffset);
67   
68           // Paint the row of squares.
69           int paint = 0;
70           while (paint < squaresToPaint){
71               paintOneSquare(painter, square);
72               painter.mfd(square.side());
73               paint = paint + 1;
74           }
75   
76           // Make the method invariant with respect to painter position.
77           painter.mbk(centerOffset + square.side());
78       }
79   
80       private void paintOneSquare(SPainter painter, SSquare square){
81           square.s2();
82           painter.setColor(randomColor());
83           painter.paint(square.inscribingCircle());
84           square.x2();
85       }
86   
87       private static int squaresOnLineCount(double lineLength, double sideLength){
88           int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
89           return squares;
90       }
91   
92       private double chordLength(double yOffset, SCircle circle){
93           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
94           double chordLength = xLength * 2;
95           return chordLength;
96       }
97   
98       private static int getNumber(String prompt) {
99           String nss = JOptionPane.showInputDialog(null,prompt+"?");
100          Scanner scanner = new Scanner(nss);
101          return scanner.nextInt();
102      }
103  
104      private static Color randomColor() {
105          Random rgen = new Random();
106          int r = rgen.nextInt(256);
107          int g = rgen.nextInt(256);
108          int b = rgen.nextInt(256);
109          return new Color(r,g,b);
110      }
111  
112      public HirstDots() {
113          paintTheImage();
114      }
115  
116      public static void main(String[] args) {
117          SwingUtilities.invokeLater(new Runnable() {
118              public void run() {
119                  new HirstDots();
120              }
121          });
122      }
123  }