1 /* 2 * A program to paint, centered on the canvas, a circle of randomly colored, black-framed squares. 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 altRadius = getNumber("small circle radius"); 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 altCircle = new SCircle(altRadius); 26 27 // Paint the squares 28 paintHirstSquares(painter, circle, altCircle); 29 } 30 31 private void paintHirstSquares(SPainter painter, SCircle circle, SCircle altCircle){ 32 // Position the painter to begin drawing the rows 33 painter.mfd(circle.radius()); 34 painter.tr(); 35 // Paint the circle of squares 36 double moved = 0; 37 while (moved < circle.diameter()) { 38 double chord = chordLength(circle.radius() - moved, circle); 39 int circles = circlesOnLineCount(chord, altCircle.radius()); 40 paintRow(painter, altCircle, circles); 41 nextRow(painter, altCircle.radius()); 42 moved = moved + altCircle.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 altCircle, int circlesToPaint){ 58 // Move backward 1/2 of the length we're painting to get ready to paint the row. 59 double centerOffset = ( (circlesToPaint * altCircle.radius()) / 2) - altCircle.radius()/2; 60 painter.mbk(centerOffset); 61 62 // Paint the row of squares. 63 int painted = 0; 64 while (painted < circlesToPaint){ 65 paintOneSquare(painter, altCircle); 66 painter.mfd(altCircle.radius()); 67 painted = painted + 1; 68 } 69 70 // Make the method invariant with respect to painter position. 71 painter.mbk(centerOffset + altCircle.radius()); 72 } 73 74 private void paintOneSquare(SPainter painter, SCircle altCircle){ 75 painter.setColor(randomColor()); 76 altCircle.s3(); 77 painter.paint(altCircle); 78 altCircle.x3(); 79 } 80 81 private static int circlesOnLineCount(double lineLength, double sideLength){ 82 int circles = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1); 83 return circles; 84 } 85 86 private double chordLength(double yOffset, SCircle circle){ 87 double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2)); 88 double chordLength = xLength * 2; 89 return chordLength; 90 } 91 92 private static int getNumber(String prompt) { 93 String nss = JOptionPane.showInputDialog(null,prompt+"?"); 94 Scanner scanner = new Scanner(nss); 95 return scanner.nextInt(); 96 } 97 98 private static Color randomColor() { 99 Random rgen = new Random(); 100 int r = rgen.nextInt(256); 101 int g = rgen.nextInt(256); 102 int b = rgen.nextInt(256); 103 return new Color(r,g,b); 104 } 105 106 public HirstDots() { 107 paintTheImage(); 108 } 109 110 public static void main(String[] args) { 111 SwingUtilities.invokeLater(new Runnable() { 112 public void run() { 113 new HirstDots(); 114 } 115 }); 116 } 117 } 118 119